Platinum Group Metals (PGMs)

Platinum Group Metals (PGMs)

Overview

The platinum group metals consist of six elements that are characterized by similarity, namely platinum, iridium, osmium, rhodium, ruthenium and palladium. Based on their densities, the first three are categorized as heavy, while the last three are regarded as light. PGMs are superb catalysts in addition to other characteristics like corrosion resistance, high melting points and chemical stability. It is precisely these characteristics that make PGMs highly desirable in many applications. Currently, the single largest market for the three most important PGMs (i.e. platinum palladium and rhodium) is the automotive sector, specifically the catalytic converter industry. PGM resources are rare and 80% of the world’s platinum reserves are located in South Africa (Adapted from Department of Research and Information, 2013).

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Figure 1: Two Rivers Mine In South Africa

Applications

The leading demand for PGMs continued to be catalytic converters to decrease harmful emissions from automobiles. PGMs are also used in the glass industry; in jewelry; in the chemical industry for catalysts in nitric acid and other bulk-chemical production, for refining petroleum, and for fabricating laboratory equipment; and in the electronics industry in computer hard disks to increase storage capacity, in multilayer ceramic capacitors, and in hybridized integrated circuits. Platinum and palladium, along with gold-silver-copper-zinc alloys, are used as dental restorative materials. Platinum, palladium, and rhodium are used as investment in the form of exchange-traded products, as well as physical bars and coins (Adapted from US Geological Survey, 2015). According to Department of Research and Information (2013), PGMs demand are distributed as following: autocatalysts (39%) and industrial applications (22%), Jewelry 31% and investment demand (8%), particularly through exchange traded funds (ETFs).

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Figure 2: Downstream applications of PGM

Geology and Key Producing Regions

There are broadly considered to be four main types of economic PGM mineral deposits (Adapted from Mudd and Glaister, 2009 and Vermaak, 1995):

  • Norite intrusions: Where meteoritic impact has been instrumental in PGM emplacement; eg. Sudbury Irruptive Complex in Ontario, Canada (~10-1000 Mt, 1-3 g/t, ~2-3% Ni+Cu);
  • Stratiform deposits: Where PGMs occur in large Pre-Cambrian mafic to ultramafic layered intrusions, such as the Merensky and Upper Group 2 Chromitite (UG2) Reefs of the Bushveld Complex in South Africa, Great Dyke in Zimbabwe and the Stillwater complex in Montana, United States (usually ~10-1000 Mt, grade 3-10 g/t PGMs, ~0.2-1% Ni+Cu);
  • Ni-Cu bearing sills: Related to rift structures and concordant intrusive sheets, eg. Noril’sk-Talnakh District, Russia, and Jinchuan deposits, China (~10-1000 Mt, 5-10 g/t, ~3-5% Ni+Cu);
  • Placer deposits: Alluvial deposits containing coarse PGMs (mainly Pt) were mined with alluvial gold for ~2,000 years prior to the 20th century . Columbia produced 1.4 t alluvial Pt in 2007;

However, most of the primary PGM’s come from low-sulfide platinum ores (South Africa and the U.S.A) and from sulfide copper-nickel ores (Russian and Canadian deposits).

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Figure 3: Sperrylite (Silver-colored) in platinum-copper ore

World resources of PGMs are estimated to total more than 100 million kilograms. The largest reserves are in the Bushveld Complex in South Africa. South Africa has over 80% of global PGM reserves, with Zimbabwe holding a further 7% and Russia 8%, with the three countries claiming 95% of global reserves.

World mine production of PGMs was 393,000 kg in 2014 (decreasing by about 14% from 455,000 kg in 2013). South Africa accounted for 48% of total PGM mine production in 2014; Russia, 30%; Canada, 7%; Zimbabwe, 7%; the United States, 4%; and other countries, 3%. In 2014, world platinum mine production decreased by 21%. In South Africa, which accounted for 64% of world platinum production, production totaled 94,000 kg of platinum, a 28% decrease from that in 2013, accounting for most of the decrease in global production. Global mine production of palladium in 2014 decreased by 5% to 193,000 kg, with Russia and South Africa accounting for 43% and 30%, respectively, of production; Canada and the United States accounting for 10% and 6%, respectively; and Zimbabwe accounting for 5%. World mine production of other PGM s (iridium, osmium, rhodium, and ruthenium) decreased by 21% in 2014 compared with that of 2013. South Africa, which accounted for 71% of global production, accounted for most of the decrease of other PGMs. Estimated production in Russia, the second leading producer, remained unchanged (Adapted from US Geological Survey, 2016).

Mining and Processing

The mining of PGM ores is through conventional underground or open cut mines. The next stage is grinding and gravity-based (or dense media) separation, followed by flotation to produce a PGM-rich concentrate. The concentrate is then smelted to produce a PGM-rich Ni-Cu matte, with the PGMs extracted and purified at a precious metals refinery. The processing is therefore more analogous to base metals rather than Au-Ag mills which use cyanide-based hydrometallurgy. Smelting of Ni-Cu concentrates can also be a modest source of PGMs (eg. Russia, Canada). (Adapted from Mudd and Glaister, 2009).

Most of the PGM mines in South Africa operate at a depth below 500 meters and up to 2 kilometers. Their orebodies are tabular and narrow, varying in width between 0.9 meters and 2.1 meters and requiring labor-intensive mining techniques. PGM ore is drilled and broken with explosives before being removed through mechanical transportation methods to the surface; electricity consumption is high, not only for ore haulage but also to drive compressed air to the miners’ hand-held pneumatic drills and, because the hard rock in platinum mines has a high thermal gradient, to refrigerate the working areas. On the surface the ore is crushed and milled into fine particles. Wet chemical treatment known as froth flotation produces a concentrate which is dried and smelted in an electric furnace at temperatures over 1,500°C. A matte containing the valuable metals is transferred to converters to remove iron and sulfur. PGMs are then separated from the base metals nickel, copper and cobalt, and refined to a high level of purity using a combination of solvent extraction, distillation and ion-exchange techniques (Adapted from IPA, 2013).

Process

Figure 4: Generic flow chart for PGM production in South Africa

 

Key Issues (Adapted from Vronsky, 1997)

The annual supply of platinum is only about 130 tons – which is equivalent to only 6% (by weight) of the total Western World’s annual mine production of gold. All the platinum ever mined throughout history would fill a basement of less than 25 cubic feet.

Approximately, 10 tons of ore must be mined – sometimes almost a mile underground at temperatures greater than 120 degrees Fahrenheit – to produce one pure ounce of the “so-called white gold.” Furthermore, the total extraction process takes six long months. Also, production is concentrated in very few sites around the world.

Unlike gold, there are no large inventories of above-ground platinum. Therefore, any breakdown in the two major supply sources would catapult the price of platinum into orbit.

Market

The performance of the automobile industry will have the greatest impact on future consumption of these PGM s. Global automobile production is expected to increase, particularly in emerging markets, such as China and India, as well as in developed markets in the United States and Europe. In the electronics industry, palladium demand is expected to increase owing to increased demand for electronic items, such as tablets and other mobile devices, as well as a continued demand for laptop and desktop computers. The demand for platinum in the jewelry industry is expected to increase, especially in China, owing to lower prices (U.S. Geological Survey, 2016).

According to The World Platinum Investment Council (Platinum Quarterly), Global platinum demand is projected to increase to 8,255 koz during the full year 2016 – up from 8,220 koz in 2015. Growth is being powered by strong investment demand, forecast to rise to 350 koz in 2016; assisted by booming demand in Japan. Jewellery consumption is expected to increase by 1% during the full year, with growth in India, the US and Europe offsetting weaker demand elsewhere. Automotive demand is forecast to remain largely similar to 2015, down only 1% from the previous year. On the supply side the estimate of the amount of total mining supply and recycling for the full year has been reduced by 230 koz. Total supply is forecast to decrease by 1% to 7,800 koz this year, lower than the pre-strike level of 2013, as lower refined production from South Africa and Russia outweighs increases in other regions and from recycling. Refined supply is forecast to be 5,895 koz in 2016, with total mining supply at 5,995 koz with some sales from producer inventory expected. Platinum recovered via recycling is estimated to increase by 95 koz (+6%) to 1,805 koz, with secondary supply from autocatalysts growing to 1,305 koz (+10%), rebounding as volumes recover alongside the improvement in metal prices.

This month (July, 2016) palladium is up 16 per cent to $697.92 a troy ounce, while platinum has risen 11 per cent to $1,138 a troy ounce (Sanderson, 2016).

Have you been inside a deep underground platinum mine? See the video below for some insights.

Underground Platinum Mine

Kind regards,

Ronaldo

Follow me on twitter @rcrdossantos

References:

Department of Research and Information “Industry analysis: Opportunities for downstream value addition in the platinum group metals value chain: Fuel cells”, Industrial Development Corporation of South Africa Limited. (February 2013). Last accessed on 07/31/2016 at http://idc.co.za/images/2015/PGMsMetalsValueChain.pdf

C.F. Vermaak, “The Platinum-Group Metals – A Global Perspective”, Mintek, Randburg, South Africa, 247p, 1995.

Mudd, G M and Glaister, B J, “The Environmental Costs of Platinum-PGM Mining: An Excellent Case Study In Sustainable Mining. Proc.“ 48th Annual Conference of Metallurgists”, Canadian Metallurgical Society, Sudbury, Ontario, Canada, August 2009.

U.S. Geological Survey, “2014 Mineral Commodity Summaries”. U.S. Department of the Interior. (January, 2015). Last accessed on 07/31/2016 at http://minerals.usgs.gov/minerals/pubs/commodity/platinum/mcs-2015-plati.pdf

U.S. Geological Survey “2014 Minerals Yearbook”. U.S. Department of the Interior. (January, 2016). Last accessed on 07/31/2016 at http://minerals.usgs.gov/minerals/pubs/commodity/platinum/myb1-2014-plati.pdf

International Platinum Group Metals Association (IPA) “The Primary Production of Platinum Group Metals (PGMs)”. International Platinum Group Metals Association, Munich – Germany. (2013). Last accessed on 07/31/2016 at http://ipa-news.com/assets/sustainability/Primary%20Production%20Fact%20Sheet_LR.pdf

Vronsky, I. M, “Platinum: The Rich Man’s Gold”, Gold-Eagle Website, May 1, 1997. Last accessed on 07/31/2016 at http://www.gold-eagle.com/article/platinum-rich-mans-gold

Sanderson, H, “Platinum, palladium chase down gold’s stellar showing”, Financial Times, Commodities, Website, July 2016, 2016. Last accessed on 07/31/2016 at http://www.ft.com/cms/s/0/79c5652a-54b8-11e6-befd-2fc0c26b3c60.html#axzz4G0WwDatq

Photos Credit:

Feature: An assortment of nuggets of native platinum. Author: Aram Dulyan

Figure 1: Two Rivers mine in South Africa. Author: Ryanj93

Figure 2: Downstream applications of PGMs. Author: Platinum Beneficiation Committee

Figure 3: Sperrylite (silver-colored) in platinum-copper ore. Author: James St. John.

Figure 4: Generic flow chart for PGM production in South Africa. Author: Lonmin

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Iron Ore

Iron Ore

Overview

Iron (Fe) is one of the most abundant rock-forming elements, constituting about 5% of the Earth’s crust. It is the fourth most abundant element after oxygen, silicon and aluminum and, after aluminum, the most abundant and widely distributed metal. Iron is indispensable to modern civilization and people have been skilled in its use for more than 3,000 years. However, its use only became widespread in the 14th century, when smelting furnaces (the forerunner of blast furnaces) began to replace forges. Iron ores are rocks from which metallic iron can be economically extracted. These rocks are usually found in the form of hematite (Fe2O3) or magnetite (Fe3O4). About 98% of world iron ore production is used to make iron in the form of steel (Adapted from Geoscience Australia, 2011).

Mining iron ore is a high volume and low margin business since the value of iron is significantly lower than other base metals. It is highly capital intensive, and requires investments in mining facilities as well as in infrastructure such as railways and harbor to facilitate the transport of iron ore (Adapted from Ou, 2012).

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Figure 1: Massif Hematita – Iron Ore

Applications

Although iron in cast form has many specific uses (e.g. pipes, fittings, engine blocks) its main use is to make steel. Steel is the most useful metal known being used 20 times more than all other metals put together. Steel is strong, durable and extremely versatile. The many different kinds of steel consist almost entirely of iron with the addition of small amounts of carbon (usually less than 1%) and of other metals to form different alloys (e.g. stainless steel). Pure iron is quite soft, but adding a small amount of carbon makes it significantly harder and stronger. Most of the additional elements in steel are added deliberately in the steelmaking process (e.g. chromium, manganese, nickel, molybdenum). By changing the proportions of these additional elements, it is possible to make steels suitable for a great variety of uses (Adapted from Geoscience Australia, 2011).

Steel’s desirable properties and its relatively low cost make it the main structural metal in engineering and building projects, accounting for about 90% of all metal used each year. About 60% of iron and steel products are used in transportation and construction, 20% in machinery manufacture, and most of the remainder in cans and containers, in the oil and gas industries, and in various appliances and other equipment (Adapted from Geoscience Australia, 2011).

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Figure 2: Stockpile of coal and iron ore, Detroit Michigan

Geology and Key Producing Regions

Although iron is present in most common rock types, it is generally uneconomic, or in forms that are not readily processed. Iron-ore deposits generally have >25 wt % Fe, usually in the form of hematite (Fe2O3), magnetite (Fe3O4), goethite (FeO(OH)), limonite (FeO(OH)•nH2O) or siderite (FeCO3). Iron-ore deposits are found in a wide range of igneous, sedimentary and metamorphic rocks. Examples of igneous iron ores include magnetite accumulations in mafic intrusions, as well as large deposits of probable magmatic–hydrothermal affinity, such as Kiruna in Sweden. However, most (>90%) of global iron-ore production comes from iron-rich cherty sedimentary rocks and their metamorphic or supergene derivatives, grouped under the general term ‘iron formations’. Iron formations are stratigraphic units of bedded or laminated sedimentary rocks or layered metasedimentary rocks with >15% Fe. They can be subdivided into two main types, based on their tectonic settings, associated rocks, and depositional environment. Algoma-type iron formations are associated with submarine-emplaced volcanic rocks, especially in greenstone belts. Lake Superior type iron formations formed on continental-margins, without direct relationships with volcanic rocks, and are typically much larger than Algoma-type iron formations. Lake Superior-type iron formations are most common in Precambrian sedimentary successions, with peaks in iron sedimentation between ~2.65 and 2.32 billion years ago (Ga) and again from ~1.90 to 1.85 Ga (Adapted from Conliffe, Kerr and Hanchar, 2012).

Iron ore is mined in about 50 countries. China was the leading global producer of iron ore, accounting for 47% of iron ore production by gross weight (29% by metal content), followed by Australia, Brazil, and India.  Australia and Brazil together dominate the world’s iron ore exports, each having about one-third of total exports (U.S. Geological Survey, 2016).

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Figure 3: Mount Whaleback Mine, Australia

Mining and Processing (Adapted from U.S. EPA, 1994).

Iron ore is almost exclusively mined by surface operations. The most predominant surface mining methods used for mining of iron ores are open pit mining methods and open cut mining methods. Overburden and stripping ratios are important in determining whether a deposit will be mined. The stripping ratio describes the unit of overburden that must be removed for each unit of crude ore mined. These ratios may be as high as 7:1 (for high-grade wash ores) or as low as 0.5:1 (for low-grade taconite ores).

However a few underground iron ore mines are also in operation around the globe (e.g. caving and s Stripping ratios increase with the quality of the ore being mined and cost factors related to beneficiation and transportation.

Most beneficiation operations will result in the production of three materials: a concentrate; a middling or very low-grade concentrate, which is either reprocessed (in modern plants) or stockpiled; and a tailing (waste), which is discarded.

Primary Milling operations are designed to produce uniform size particles by crushing, grinding, and wet or dry classification. Secondary milling (comminution) further reduces particle size and prepares the ore for beneficiation processes that require finely ground ore feed.

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Figure 4: Carajas Mine, Brazil

Beneficiation processes includes:

  • Magnetic separation is most commonly used to separate natural magnetic iron ore (magnetite) from a variety of less-magnetic or nonmagnetic material;
  • Flotation is a technique where particles of one mineral or group of minerals are made to adhere preferentially to air bubbles in the presence of a chemical reagent. This is achieved by using chemical reagents that preferentially react with the desired mineral;
  • Gravity concentration is used to suspend and transport lighter gangue (nonmetallic or non-valuable rock) away from the heavier valuable mineral. This separation process is based primarily on differences in the specific gravities of the materials and the size of the particles being separated;
  • Agglomeration is used to combine the resulting fine particles into durable clusters. The iron concentrate is balled in drums and heated to create hardened agglomerate. Agglomerates may be in the form of pellets, sinter, briquettes, or nodules;

Large scale iron ore smelting are used for producing pig iron. In this process ore is put into a blast furnace along with limestone and coke and subjected to hot air blasting and heat which converts the ore to molten iron. This is tapped from the bottom of the furnace into molds known as pigs.

Key Issues

Waste materials generated as a result of open pit mining include overburden, waste rock, and mine water containing suspended solids and dissolved materials. Other waste materials may include small quantities of oil and grease spilled during extraction. Mine water contains dissolved or suspended constituents similar to those found in the ore body itself. These may include traces of aluminum, antimony, arsenic, beryllium, cadmium, chromium, copper manganese, nickel, selenium, silver, sulfur, titanium and zinc etc. (Adapted from Satyendra, 2014).

The beneficiation of iron ore typically occurs in a liquid medium. In addition, many pollution abatement devices use water to control dust emissions. At a given facility, these techniques may require between 600 and 7,000 gallons of water per ton of iron concentrate produced, depending on the specific beneficiation methods used (Adapted from U.S. EPA, 1994).

The need for the disposal of iron ore tailings in an environmentally friendly manner is of great concern (Adapted from Ghose and Sen, 2005).

Market

As a basic ingredient in the production of steel, iron ore is generally viewed as a cyclical commodity, sensitive to changes in global economic conditions. As a global commodity, the prices of iron ore typically fluctuate with changes in worldwide industrial demand. Globally, price reductions continued for seaborne iron ore in 2015 as steel production in China decreased and projects to increase iron ore production capacity continued, primarily in Australia and Brazil. Production, by gross weight, in Australia and Brazil increased by 112 million tons in 2013 and by 116 million tons in 2014, and was estimated to increase by 67 million tons in 2015. Global steel demand was forecast to decrease by 1.7% in 2015, following an increase of 0.7% in 2014. The monthly mean price of iron ore fines at 62% iron content at Tianjin Port, cost and freight, fell from the 5-year high of $187.18 in February 2011 to $56.43 in September 2015, the most recent date for which prices were available. As a result of lower prices, an estimated 200 million tons of iron ore capacity was idled between 2014 and 2015, most notably in Australia, Brazil, Canada, China, Sweden, the United States, and western Africa. Additional capacity was expected to be brought online during the next 5 years, with the largest capacity increases among the top four miners to reach 40 million tons in 2016 and 60 million tons in 2017 (U.S. Geological Survey, 2016).

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Figure 5: Iron ore train in Pilbara region, Australia

Recently, “Goldman has lifted its three-month target to $US 50 a tonne from $US 45 a tonne previously, saying port stockpiles remain at historically low levels. The bank also lifted its six-month target to $US 40, from $US 35”. Have we reached the bottom of the cycle?

Kind regards,

Ronaldo

Follow me on twitter @rcrdossantos

References:

Geoscience Australia “Australian Atlas of Minerals Resources, Mines and Processing Centres”, Australian Government, Commonwealth of Australia (2011). Last accessed on 07/29/2016 at http://www.australianminesatlas.gov.au/education/fact_sheets/iron.html

Ou, L. “China’s Influence on the World’s Iron Ore Market  – A Supply-Side Perspective”. Undergraduate Honors Thesis, Department of Economics, University of California, Berkeley (2012).

U.S. Geological Survey, 2016. “Mineral Commodity Summaries”. U.S. Department of the Interior. (January, 2016). Last accessed on 07/29/2016 at http://minerals.usgs.gov/minerals/pubs/commodity/iron_ore/mcs-2016-feore.pdf

Satyendra “Mining of Iron Ores”, ISPAT Website, (March, 2014).  Last accessed on 07/29/2016 at http://ispatguru.com/mining-of-iron-ores/

U.S. EPA “Extraction and Beneficiantion of Ores and Minerals – Volume 3 – Iron”, Technical Resource Document, United States Environmental Protection Agency. Washington, DC, USA (1994).

Conliffe, J., Kerr A. and Hanchar, D. “Mineral Commodities of Newfoundland and Labrador – Iron Ore” Geological Survey Mineral Commodities Series, Number 7, Newfoundland Labrador Natural Resources, Canada. (2012).

Ghose M. and Sen, P. K. “Environmentally safe design of tailing dams for the management of iron ore tailing in Indian context”.  Journal of Environment Science and Eng. 2005 October; 47(4):296-303.

Photos Credit:

Feature: Mining Iron – Transport Conveyor Iron. Author: Sarangib

Figure 1: Massif hematite (5×7 cm). Iron ore. Author: Eurico Zimbres FGEL/UERJ

Figure 2: Hanna furnaces of the Great Lakes Steel Corporation, stock pile of coal and iron ore, Detroit, Mich. Author: Arthur S. Siegel, 1913-1978, photographer.

Figure 3: Mount Whaleback Mine Author: Graeme Churchard from Bristol, UK

Figure 4: Carajas Mine, Brazil. Author: NASA Earth Observatory

Figure 5: Iron ore train in Pilbara region, Western Australia. Author: Geez-oz

Mining and the Environment

Mining and the Environment

Mining in the early days took place at a time when environmental impacts were not as well understood and most importantly, not a matter of significant concern. During these times, primarily before the 1970s, the mining cycle did not necessarily include closure activities specifically designed to mitigate environmental or social impacts. As a result, historical mine sites may still have un-reclaimed areas, remnants of facilities, and untreated water. This inherited legacy of environmental damage from mining is not indicative of the mining cycle today. Now, mine closure and a number of activities to mitigate the social and environmental impacts of mining are an integral part of mine planning and mineral development from the discovery phase through to closure (Adapted from Hudson et. al, 1999).

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Figure 1: Dedicated camera for environmental monitoring. Author: Jim Barton

Environmental Impacts of Mining (Adapted from Aswathanaryana, 2003; Carr and Herz, 1989; and Nilsson and Randhem, 2008):

  • Lithosphere: Depending on the type of mining conducted and the site of mining there are several types of impacts on the lithosphere. The results range from formation of ridges, depressions, pits and subsidence on the surface as well as underground cavities affecting the stability of the ground. Furthermore, both the area for mining and the area used for waste dumps, occupy and degrade land that could be used for farming, agriculture or other economic activity.
  • Hydrosphere: Impacts on the hydrosphere resulting from mining include lowering of the groundwater table, mine water discharge into rivers, seas and lakes, leakage from settling tanks and evaporators that have a negative effect on the groundwater quality and pumping of water into the ground for the extraction of a mineral. Significantly lowered groundwater levels can result in significant surface depressions and drained rivers and lakes with serious impacts on surrounding agriculture for example. Furthermore, depending on the chemical composition of the rock, the drained water usually becomes highly acidic with the resulting capability of taking into solution a variety of toxic and heavy metals.
  • Atmosphere: Atmospheric emissions during mining occur not only from internal combustion engines in mining machinery but dust and gases are also released from blasts and rocks and mineral masses. One tonne of explosives produces about 40-50 m3 nitrogen oxides and huge amounts of dust. Also, smelters are commonly used for mineral purification and emissions from these processes include particulate matter and gases such as sulfur dioxide, carbon monoxide and carbon dioxide. Although some installations use different kinds of flue gas purifications, these are never completely effective.
  • Biosphere: The biosphere is adversely affected by mining mainly by pollution and by degradation of land and vegetation resulting in loss in biodiversity. Mining can also have impact on local microclimate.
  • Public Safety: Old mining sites are inherently interesting to people, but potentially dangerous as well. They may have surface pits, exposed or hidden entrances to underground workings, or old intriguing buildings. Another safety consideration at some mine sites is ground sinking or “subsidence.”

 

Key Mining Related Environmental Issues (Adapted from Environmental Law Alliance Worldwide, 2010):

  • Greenhouse Gases: Reduction in greenhouse gas emission as an initiative for minimizing the heat retention caused by the accumulation of greenhouse gases around the earth.
  • Acid Rock Drainage (ARD): When the sulfides in the rock are excavated and exposed to water and air during mining, they form sulfuric acid. This acidic water can dissolve other harmful metals in the surrounding rock. If uncontrolled, the acid mine drainage may runoff into streams or rivers or leach into groundwater.
  • Toxicity: Humans and the surrounding ecosystem can be impacted by not only the physical effects of mining, but also the toxicological impacts of minerals mined, chemicals used, and byproducts of the overall refining process.
  • Biodiversity: Biodiversity is the variation of organisms within a given species, ecosystem, and/or biome. The number of species and the variety of genetic material available within a population determines the diversity within an ecological system. Biodiversity promotes species adaptation and evolution.
  • Erosion and Sedimentation: Though erosion and sedimentation are naturally occurring processes, mining and mine-related activities amplify their effect, and may negatively affect the surrounding environment. In the absence of adequate prevention and control strategies, erosion can carry excessive amounts of sediment into streams, rivers, and other surface waters and aeolian movement can affect broader terrestrial ecosystems.
  • Water and Groundwater Supply: Large volumes of groundwater are either discharged, or are used by the mining and associated supporting operations. Also, drawing down the water table and diverting runoff to other watersheds may reduce the volume of water available for other uses (e.g., fisheries).
  • Tailings Management: Tailings are the rejected materials after the process of separating the valuable fraction from the uneconomic fraction of an ore. Tailings management is an important aspect in the design and operation of mining projects and needs to balance a variety of considerations, including potential environmental, social, economic, public health and safety impacts.
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Figure 2: Iron hydroxide precipitate from surface coal mining

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Figure 3: Bento Rodrigues dam disaster

Although mining can have significant impact on environment, as scientific and technological advances increase the understanding of the physical and chemical processes that cause undesired environmental consequences, mines and related beneficiation or smelting facilities apply this understanding to improve prevention and solve environmental problems (Adapted from Langer et. al., 2004).

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Figure 4: Snapping turtle near the St. Lawrence River

Society’s requirement for mineral resources establishes a strong link between our standard of living, the Earth, and science. By understanding key concepts of the process of mining, citizens should be prepared for the necessary discussions and decisions concerning society’s increasing need for mineral resources and the related environmental tradeoffs. Decisions about the development and use of Earth’s mineral resources affect the economic, social, and environmental fabric of societies worldwide (Adapted from Hudson et al., 1999).

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Figure 5: Reclamation process at the Seneca Yoast coal mine

What is the most important mining related environmental issue? Are there the good practices for addressing this concern?

Kind regards,

Ronaldo

Follow me on twitter @rcrdossantos

References:

Hudson, T. L., Fox, F. D. and Plumlee, G. S. “Metal Mining and The Environment”. American Geological Institute, Alexandria, Virginia (1999).

Langer, W. H., Drew, L. J. and Sachs, J. S. “Aggregate and The Environment”. American Geological Institute, Alexandria, Virginia (2004).

Hatch Ltd “Environmental Analysis of the Mining Industry in Canada”, Canadian Mining Innovation Council, Canada (2013). Last accessed on 07/27/2016 at http://www.cmic-ccim.org/wp-content/uploads/2013/07/HatchScopingReport.pdf

Nilsson, J. A. and Randhem, J. “Environmental Impacts and Health Aspects in the Mining Industry, A Comparative Study of the Mining and Extraction of Uranium, Copper and Gold”, Master of Science Thesis in the Master Degree Programme Industrial Ecology, Department of Energy and Environment, Chalmers University of Technology, Sweden (2008).

Aswathanarayana, U. “Mineral resources management and the environment”, A.A. Balkema. Tokyo, Japan. ISBN 978-90-5809-545-9. (2003).

Carr, D. D. and Herz, N. “Concise Encyclopedia of Mineral Resources”. Oxford: Pergamon Press. (1989).

Hartman, H. L. and Mutmansky, J. M. “Introductory Mining Engineering”, Published by Wiley, Hoboken, NJ, USA, (August, 2002).

Environmental Law Alliance Worldwide “Guidebook for Evaluating Mining Project EIAs”, Environmental Law Alliance Worldwide. Eugene, OR 97403 U.S.A. (July, 2010) Last accessed on 07/27/2016 at https://www.earthworksaction.org/files/pubs-others/Evaluating-Mining-EIAs-ELAW.pdf

Photos Credit:

Feature: USGS hydrologist Greg Clark measures streamflow on Government Gulch Creek, a tributarty to the Coeur d’Alene River in northern Idaho. Author: U.S. Geological Survey

Figure 1: Dedicated camera for environmental monitoring. Author: Jim Barton

Figure 2: Iron hydroxide precipitate (orange) in a Missouri stream receiving acid drainage from surface coal mining. Author: D. Hardesty, USGS Columbia Environmental Research Center

Figure 3: Bento Rodrigues dam disaster Author: Brazilian Senate

Figure 4: Head-on view of a snapping turtle (Chelydra serpentina) hidden near the St. Lawrence River in northern New York state. Author: User:Moondigger

Figure 5: Land reclamation – restored land at the Seneca Yoast coal mine. Author: Peabody Energy, Inc.

Traditional Surface Mining Methods

Traditional Surface Mining Methods

Surface mining is the predominant exploitation procedure worldwide. Approximately, more than 90% of all non-metallic minerals and metallic minerals and more than 60% of coal are mined by surface methods. Over 30 billion tonnes of ore and waste materials that are mined each year and surface mining accounts for nearly 25 billion tonnes. The subsurface of the earth is the only source for fossil energy and mineral products, and mining is the only way to get at them (Adapted from Ramani, 2012).

Extraction of mineral or energy resources by operations exclusively involving personnel working on the surface without provision of manned underground operations is referred to as surface mining. While an opening may sometimes be constructed below the surface and limited underground development may occasionally be required, this type of mining is essentially surface-based. Traditional surface mining can be classified into two groups on the basis of the method of extraction: Mechanical extraction or aqueous extraction. The primary differences between these mining methods are the location of the ore body and the mode of mechanical extraction. (Adapted from Yamatomi and Okubo, 2009; Hartman, 2002 and Sharma, 2011).

Mechanical surface mining methods Includes:

  • Open-pit mining: Open-pit mining is employed to remove hard rock ore (mostly metallic ore) that is disseminated and/or located in deep seams and is typically limited to extraction by shovel and truck equipment. Many metals are mined by the open pit technique: gold, silver and copper, to name a few.
  • Quarrying: It is a term used to describe a specialized open-pit mining technique wherein solid rock with a high degree of consolidation and density is extracted from localized deposits. Quarried materials are either crushed and broken to produce aggregate or building stone, such as dolomite and limestone, or combined with other chemicals to produce cement and lime. Construction materials are produced from quarries located in close proximity to the site of material in order to reduce transportation costs. Dimension stone such as flagstone, granite, limestone, marble, sandstone and slate represent a second class of quarried materials. Dimension stone quarries are found in areas having the desired mineral characteristics which may or may not be geographically remote and require transportation to user markets.
  • Strip mining: “Open-cast mining” techniques relate to the extraction of ore bodies that are near the surface and relatively flat or tabular in nature and mineral seams. It uses a variety of different types of equipment including shovels, trucks, drag lines, bucket wheel excavators and scrapers. Most strip mines process non-hard rock deposits. Coal is the most common commodity that is strip mined from surface seams.
  • Auger mining: It is a surface mining technique used to recover additional coal from a seam located behind a highwall produced either by stripping or open-pit mining. Auger mining is especially employed when contour strip mining has been exhausted and the removal of overburden to access additional coal no longer becomes economically feasible.
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Figure 1: Surface coal mine in Gillette, Wyoming, USA

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Figure2: Large Limestone Quarry, Ontario, Canada

Aqueous surface mining methods can be subdivided in Placer and Solution and Includes:

  • Placer: concentrations of metals such as gold, titanium, silver, tin and tungsten are washed from within an alluvial deposit.
  • Hydraulic mining: “Hydraulicking” applies high pressure water spray to excavate loosely consolidated or unconsolidated material into a slurry for processing. Hydraulic methods are applied primarily to metal and aggregate stone deposits, although coal, sandstone and metal mill tailings are also amenable to this method. Water supply and pressure, ground slope gradient for runoff, distance from the mine face to the processing facilities, degree of consolidation of the mineable material and the availability of waste disposal areas are all primary considerations in the development of a hydraulic mining operation.
  • Dredging: When hydraulic mining occurs underwater it is referred to as dredging. In this method a floating processing station extracts loose deposits such as clay, silt, sand, gravel and any associated minerals using a bucket line, dragline and/or submerged water jets. The mined material is transported hydraulically or mechanically to a washing station which may be part of the dredging rig or physically separate with subsequent processing steps to segregate and complete processing. While dredging is used to extract commercial minerals and aggregate stone, it is best known as a technique used to clear and deepen water channels and floodplains.
  • Solution: It is applied to the process of removing a soluble mineral by dissolving it and leaching it out.
  • Surface Techniques and In-situ Leaching: Both are applicable to deposit of minerals that can be recovered usually by dissolution, but also by melting, leaching, or slurrying. The two methods are similar and are differentiated primarily through the location and the type of minerals recovered. Surface leaching generally employs heap (or dump) leaching of mineral values; copper, gold, silver, and uranium are common examples. In-situ mining specifically uses barren solution, introduced down by a set of wells. The loaded solution then returns to the surface through concentric or other set of wells. Chemicals and/or bacteriological reagents usually are mixed with water in order to selectively dissolve the valuable minerals.
  • Evaporite (or salt) Mining: In solution mining, fresh water is injected through a pipe into deep shafts that end in the salt beds, and salty water (brine) is drawn upward and dried, to recrystallize the salt. Or, salty brine found in shallow wells can simply be pumped to the surface and dried there, to make salt.
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Figure 3: Dredge no. 3, Klondike River, Canada

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Figure 4: Cyanide leaching Heap, Nevada, USA

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Figure 5: Hydraulic Mining

Mining conditions are likely to be more difficult in the future. While finding a world class mineral deposit cannot be ruled out, if history is a guide, future discoveries will be deeper, thinner, lower grade and have severe conditions, all increasing the difficulty of mining and processing. Therefore, operators should continuously re-evaluate traditional surface mining methods, incorporating new technologies and practices. Hybrid and new methods will be required for delivering economic results and efficiency when approaching these new mineral deposits (Adapted from Ramani, 2012).

How can autonomous equipment and vehicles be applied to mining? Are there opportunities to enhance this application by the use of telemetry and artificial intelligence?

Mining Automation

Kind regards,

Ronaldo

Follow me on twitter @rcrdossantos

References:

Ramani, R. V.” Surface Mining Technology: Progress and Prospects”, 1st International Symposium on Innovation and Technology in the Phosphate Industry, Published by Elsevier Ltd. (September, 2012).

Darling, P.,“ SME Mining Engineering Handbook”, Society for Mining, Metallurgy, and Exploration, Inc, Third Edition. (2011).

Hartman, H. L. and Mutmansky, J. M. “Introductory Mining Engineering”, Published by Wiley, Hoboken, NJ, USA, (August, 2002).

Okubo S. and Yamatomi, “Underground Mining Methods and Equipment, Civil Engineering- Vol. II, Encyclopedia of Life Support System (EOLSS), EOLSS Publishers/UNESCO (2009).

Sharma, P. D., “Coal and Metal (Surface and Underground) Mining –  An Overview”, Weblog of Partha Das Sharma. (2011). Last accessed on 07/23/2016 at https://miningandblasting.files.wordpress.com/2009/09/coal_and_metal_surface_and_underground_mining_an_overview.pdf

Dunbar, W. S., “Basics of Mining and Mineral Processing”, Americas School of Mines, University of British Columbia, PWC. (2012). Last accessed on 07/23/2016 at https://www.pwc.com/gx/en/mining/school-of-mines/2012/pwc-basics-of-mining-2-som-mining-methods.pdf

RitchieWiki Team, “Underground Mining”, Ritchie Bros. Auctioneers (2012). Last accessed on 07/23/2016 at https://www.pwc.com/gx/en/mining/school-of-mines/2012/pwc-basics-of-mining-2-som-mining-methods.pdf

Photos Credit:

Feature: Bingham Canyon copper mine, UT, USA: Rio Tinto, Kennecott Utah Copper Corp. Author: Spencer Musick.

Figure 1: A surface coal mine in Gillette, Wyoming. Author: Greg Goebel

Figure 2: Limestone Quarry. Author: Mike Pierce

Figure 3: Dredge no. 3, working in the Klondike River, May the 31st, 1915. Author: Frank and Frances Carpenter collection

Figure 4: Cyanide leaching “heap” at a gold mining operation near Elko, Nevada. Author: U.S. Fish and Wildlife Service

Figure 5: Hydromonitor – Hydraulic mining. Author: Paesslergung

 

Mine Closure and Rehabilitation (Reclamation)

Mine Closure and Rehabilitation (Reclamation)

Mineral resources are finite ore bodies, and as a result all mine facilities will eventually close and the reputation of the mining industry dependent on the legacy in which it leaves (Sassoon, 1996).

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Figure 1: former underground salt mine

Closure is the general term used to describe all the activities involved in decommissioning a mining operation and/or processing facility including reclamation, re-vegetation, removing equipment and structures, removal of chemicals and reagents, removal of hazardous wastes, remediation of any releases of hazardous substances to the environment, and post closure monitoring. Closure refers to decommissioning an operation in accordance with its reclamation plan (Adapted from Lowrie, 2002).

In planning for closure, there are four key objectives that must be considered (Adapted from Ontario Mining Act, August 2005):

  1. Protect public health and safety;
  2. Alleviate or eliminate environmental damage;
  3. Achieve a productive use of the land, or a return to its original condition or achieve the highest practicable level in the rehabilitation hierarchy;
  4. To the extent achievable, provide for sustainability of social and economic benefits resulting from mine development and operations;

Mining operators should identify post-mining land uses that are acceptable to the community, local government and any other relevant stakeholders.

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Figure 2: Mine water treatment plant

Main potential impacts associated with mining operations can be categorized in four groupings (Adapted from Ontario Mining Act, August 2005):

  1. Physical stability – buildings, structures, workings, pit slopes, underground openings etc. must be stable and not move so as to eliminate any hazard to the public health and safety or material erosion to the terrestrial or aquatic receiving environment at concentrations that are harmful. Engineered structures must not deteriorate and fail.
  2. Geochemical stability – minerals, metals and ‘other’ contaminants must be stable, that is, must not leach and/or migrate into the receiving environment at concentrations that are harmful. Weathering oxidation and leaching processes must not transport contaminants, in excessive concentrations, into the environment. Surface waters and groundwater must be protected against adverse environmental impacts resulting from mining and processing activities.
  3. Land use – the closed mine site should be rehabilitated to pre-mining conditions or conditions that are compatible with the surrounding lands or achieves an agreed alternative productive land use. Generally the former requires the land to be aesthetically similar to the surroundings and capable of supporting a self-sustaining ecosystem typical of the area.
  4. Sustainable development – elements of mine development that contribute to (impact) the sustainability of social and economic benefit, post mining, should be maintained and transferred to succeeding custodians. Mine closure may bring severe reduction in income and taxes and additional cost in terms of social and environmental mitigation initiatives.

Mine closure is an increasingly complex process, and given the concerns of all stakeholders regarding environmental, social, and economic impacts, best practice has long gone beyond technical solutions. Trilateral process of consultation and problem solving, involving mining companies, governments, and communities, is required for a mine to be closed successfully. In fact, to be fully effective, the process of planning for mine closure should start at the mine design stage (Adapted from Bond, 2002).

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Figure 3: Erosion control and regrading of steep slopes

The cost of physical mine closure tends to be significantly lower if the mine operator is in charge of the closure and clean-up process, rather than government or environmental funds. This is primarily due to the operator’s familiarity with the mine site and the lower incremental cost of using on-site equipment and staff. Initial cost estimates should be prepared early in the mine’s life and should be updated systematically on a regular basis (Adapted from The World Bank Group, 2002).

Closure plans should be re-evaluated as the mine site development progresses since the initial plans are based on projected conditions which are expected to change in response to additional ore discoveries, changing conditions of product and mining economics, advances in technology and new regulatory requirements. Once the initial plan has been developed and is accepted, periodic, iterative re-assessments and revisions should be completed to ensure that the plan remains current, relevant and optimized. Reclamation commonly is planned before mining begins, allowing the mine to be developed in a manner that facilitates final reclamation. Additionally, reclamation plans must be integrated into the mine planning process (Adapted from Robertson and Shaw, 1998 and 1999).

Good mine closure planning should begin at the feasibility stage and contain at least the following six elements:

  1. Clarity about time lines and costs;
  2. Specifics about the expected final landform and surface rehabilitation, including removal of plant and equipment and stabilization and detoxification of dumps and impoundments;
  3. Risk assessment to help set priorities for preparatory work;
  4. Cost-benefit analysis of different options as the plan is being prepared, reviewed, and updated;
  5. A management plan for how closure will be implemented;
  6. Proposals for post-closure monitoring arrangements (who monitors, for how long, who pays, who enforces compliance with environmental requirements);

An initial mine closure plan can influence key technology and waste disposal choices before mining commences and thereby enable rehabilitation to be built into operational activities at a lower cost over the overall mine life. Also, considering closure early can result in a plan that places decisions regarding the size and location of townships and other social infrastructure in a time frame that goes beyond the life of the mine (Adapted from The World Bank Group, 2002).

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Figure 4: Undeground mine museum

Consistent deployment of sustainable practices and the use of progressive rehabilitation are critical elements for successful mine closure and rehabilitation.

Do you know any interesting post-mining land uses? Are there any potential synergies with other industries within your community?

Kind regards,

Ronaldo

Follow me on twitter @rcrdossantos

References:

Sassoon, M., “Closure or Abandonment”, Mining Magazine, (August, 1996).

Ontario Mining Act Fact Sheet. August 2005. Last accessed on 07/10/2016 at http://www.canaryinstitute.ca/publications/Ontario_Closure_Brochure.pdf

Robertson, A. and Shaw, S., “Mine Closure”, InfoMine E-book, (2002). Last accessed on 07/10/2016 at http://www.infomine.com/library/publications/docs/e-book%2002%20mine%20closure.pdf

Lawrie, R. L.., “Mining Reference Handbook”, Society for Mining, Metallurgy, and Exploration, Inc, Denver, CO – US (2002).

The World Bank Group’s Mining Department, “It’s Not Over When It’s Over: Mine Closure Around the World”, The Energy and Mining Sector Board, World Bank and the International Finance Corporation. (2002). Last accessed on 07/10/2016 at http://siteresources.worldbank.org/INTOGMC/Resources/notoverwhenover.pdf

Bond, J., “Foreword at It’s Not Over When It’s Over: Mine Closure Around the World”, Mining Department, World Bank Group, Washington D.C. (June, 2002).

 

 

Mine Planning: Overview and Key Concepts.

Mine Planning: Overview and Key Concepts.

Although mine planning is essentially the same as planning conducted by other businesses, it has certain unique characteristics that result from its dependence on a mineral resource. After a mining operation begins, the knowledge of the deposit is gradually enriched as more information is revealed by the ongoing activities associated with the mining cycle. The final product of the mine planning process is a business plan for exploiting the deposit. The business plan includes a mine plan, which is the production schedule that indicates the origin and destination of different materials and respective qualities to be extracted from the deposit (Adapted from Camus, 2002).

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Figure 1: Block model – mining cell 1

Mine Planning can be defined as the process of optimizing the exploitation of mineral reserves for maximum added value aligned with the strategic goals and objectives of the business enterprise. The complex set of activities associated with this process aim to identify the best possible mine design and production scheduling considering, among others, capital investments, operational cost, revenue forecasting, and management of cash flows of a mining operation. It is a critical component to the financial aspects of mining ventures (Adapted from Dimitrakopoulos et al., 2002).

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Figure 2: Large scale mining operations

Mine design and sequencing are based on an orebody model in which the deposit is discretized into a grid of blocks, each of which consists of a volume of material and the corresponding mineral properties; the value of each block, which is determined by comparing market prices for ore with extraction and processing costs; and a geometric model of the deposit. Blocks are used as spatial reference points. Geometrical and geotechnical constraints ensure that the extraction will be carried out in a way that is physically possible (Adapted from Newman et al., 2010).

Typically, two different approaches – cutoff grade approach and operations research approach – are used for determining the best possible mine design of open pit mines (Adapted from Epstein et al., 2012).

  • The basic premise of the cutoff grade approach is that one can use cutoff grades to maximize NPV subject to capacity constraints, with higher cutoffs in the initial years leading to higher overall profits. The approach has important operational advantages, and it is embedded in the background of most mining practitioners. However, the assumption of a fixed cutoff grade—which depends on an aggregated delineation between ore and waste—generates suboptimal solutions because it ignores that the value of a block is not inherent to the block but rather depends on the interaction with the rest of the mine and the capacity of the downstream processes.
  • The operations research approach started with the classic “moving cone” heuristic. This approach takes a block as a reference point and expands the pit upward according to pit slope rules. This solution can be suboptimal, but it is intuitively appealing. Among the algorithms that are guaranteed to reach the optimum, historically the most important are Lerchs and Grossmann (1965) and Picard (1976). The first one is based on graph theory, but its structure is very similar to the dual simplex method. The algorithm by Picard reduces the ultimate pit problem to finding a maximum closure in a graph, so it can be solved as a maximum flow.

The literature on underground mining is limited, partially due to the complicated nature of its operations. In fact, there is no equivalent to the Lerchs-Grossman or Picard algorithms commonly used for open pit. Basically, the literature indicates few applications considering genetic algorithms, floating stope method and mixed integer programming.

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Figure 3: Mine planning objectives (Frimpong, 2011)

In general terms, operations research approach is also applied for solving the problem associated with the best possible production scheduling. The techniques utilized include mixed integer linear programming, Lagrangian relaxation, dynamic programming, branch and cut, heuristic methods and combined approaches.

Traditionally, the mine planning process is divided in stages according to either the level of detail of the analysis or the time scope to which the planning decision apply. However, a more practical classification is based on the distinction between strategic mine planning and tactical mine planning. In operating mines, the scope of strategic mine planning is related to the continuous revisions of long and medium term plans, which is essential for maintaining an up-to date basis that defines the future of the operation. Tactical mine planning, on the other hand, encompasses the routine planning activities required for commissioning the operation and ramping it up.  In operating mines, the scope includes the continuous reworking of short term production plans with the aim of incorporating the new information gathered from the operation into the actual plan. Tactical mine planning also deals with the preparation of budgets; equipment deployment and production scheduling, on a monthly, weekly, and daily basis; grade and quality control; and various other routines activities (Adapted from Camus, 2002).

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Figure 4: Geological cross-sections

As mine planning progresses, initial planning assumptions are refined. This may trigger a review and potential revision of earlier analysis. Improvements in the quality and quantity of available data may help to reduce the uncertainty associated with the mine plan, but do not completely eliminate it. At all stages of the process, from early conceptual and pre-feasibility work through feasibility and detailed long and short range planning, the evaluation of multiple planning scenarios and the sensitivity analysis of input parameters is critical to successful mine planning. The end product should be a plan that is robust enough to remain economically attractive under a range of variations from initial planning assumptions (Adapted from Thorley, 2012).

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Figure 5: Mine site – 3D view with geological formations

Although a well-crafted mine plan is paramount for efficient mining operations, its implementation is what truly adds value for the mining enterprise. I would argue that management must have extra care in communicating effectively the mine plan and continuously evaluating its adherence. Moreover, by applying the concept of PDCA (plan–do–check–adjust) to mine planning, mining enterprises should capture enhanced added value associated with continuous improvement of processes and products.

How is mining safety incorporated into the mine plan?

Kind regards,

Ronaldo

Follow me on twitter @rcrdossantos

References:

Thorley, U. “Open Pit Mine Planning: Analysis and System Modeling of Conventional and Oil Sands Applications”, A thesis submitted to The Robert M. Buchan Department of Mining In conformity with the requirements for the degree of Doctor of Philosophy Queen’s University Kingston, Ontario, Canada (September, 2012).

Camus, J., “Management of Mineral Resources: Creating Value in the Mining Business”. Englewood, CO. Society for Mining, Metallurgy, and Exploration, Inc. (SME). (2002)

Newman, A. M. et al. “A Review of Operations Research in Mine Planning” Interfaces, Vol. 40, No 3, May-June 2010, pp. 222-245 ISSN 0092-2102 (June, 2010).

Epstein, R. et al. “Optimizing Long-Term Production Plans in Underground and Open-Pit Copper Mines” Operations Research vo. 60, No 1, January-February 2012, pp 4-17 ISSN 00330-364X (Print) ISSN 1526-5463 (online) (February, 2012).

Dimitrakopoulos, R., Farrelly, C. T. and Godoy, M. “Moving forward from traditional optimization: grade uncertainty and risk effects in open-pit design”, Trans Inst Min Metall (Section A) 111:A82-88. (2002).

Frimpong, S., “Notes on Mine Planning and Design (Mi Eng 393)”, Missouri University of Science and Technology, Rolla, MO, USA. (July, 2011).

Early Phase of Mineral Exploration: Developing a solid foundation

Early Phase of Mineral Exploration: Developing a solid foundation

Generating potential targets for geological evaluation is the critical first stage in the mineral exploration process. Initially, review of existing geological data and other relevant source is performed, including information from depleted mines and previous exploration work. This process will provide important guidance for a more cost effective exploratory program.

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Figure 1: Usage of GIS mapping as  tool for prospecting

Prospecting is the systematic process of searching for a mineral deposit by narrowing down areas of promising enhanced mineral potential. In other words, prospecting involves searching a district for mineral deposits with the view to mine it at a profit (Adapted from Hartman, 2002 and Fernberg, 2010).

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Figure 2: Reviewing geological data

During the stages of prospecting and exploration of a mining project, there is usually great potential for value creation. A mining project may change hands during these stages, with exploration and junior mining companies often owning projects in the initial exploration stages, and with medium and larger mining companies acquiring projects and developing them further into the post feasibility stages. Typically, exploration and junior mining companies do not generate any cash flow or earnings. These companies often consist of a management team, one to several properties and some cash. They raise risk capital by selling shares for exploring potential mineral deposits (Adapted from Hohn, 2009 and Smit, 2008).

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Figure 3: Mineral exploration in remote locations

Traditionally, prospecting was the search for simple visual surface indications of mineralization. Nowadays the range of surface indications expanded significantly by the use of sophisticated geophysical and geo-chemical techniques. However, the skills and abilities involved in successful prospecting are common to all techniques. They involve hands on approach, communication skills, knowledge, insight, opportunism, persistence, lateral thinking and luck (Adapted from Marjoribanks, 1997).

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Figure 4: Usage of electrical resistivity as prospecting tool

Once a prospect has been identified, and the right to explore it acquired, assessing it involves advancing through a progressive series of definable exploration stages. Positive results in any stage will lead to advance to the next stage and an escalation of the exploration effort. Negative results mean that the prospect will be discarded, sold or joint ventured to another party, or simply put on hold until the acquisition of new data, concepts and/or technology lead to a positive re-evaluation and subsequent reactivation (Adapted from Marjoribanks, 1997).

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Figure 5: Prospecting for gold: old tricks of the trade

Early and sustained engagement and partnerships among governments, industry, and communities are critical at each stage of the mineral development sequence. Sustained engagement and partnership help to alleviate some of the issues and concerns that act as barriers to advancing resource projects. Relationships developed through collaboration and dialogue among multiple stakeholders, communities, and governments offer the opportunity to gain a better reciprocal understanding, establish trust, develop respect, and identify mutually beneficial goals in a transparent manner (Adapted from Advisory committee Energy and Mines Ministers’ Conference, 2014).

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Figure 6: Usage of open house and/or follow up meetings for engaging local community

As identified by The National Stone, Sand and Gravel Association (NSSGA), sustainable business practices integrate environmental stewardship, social responsibility and economic prosperity to ensure the long-term supply of aggregate materials to society.  The long-term viability of the industry is dependent on obtaining and maintaining a social license to operate.

Are you aware of any mining project in your area (e.g. aggregates operations) ? Do you have any suggestion regarding sustainable initiatives?

References:

Marjoribanks, R. W.,” Geological Methods in Mineral Exploration and Mining”, Springer-Verlag Berlin 1997).

Hartman et al, “Introductory to Mining engineering”, SME Mining Engineering Handbook, Society for Mining, Metallurgy and Exploration (2002).

Hohn, M.,” Investing in Community: Canadian Junior Mining Companies, Corporate Social Responsibility, and the Communication Gap”, thesis submitted in partial fulfillment of the requirements for the degree of Master of Arts in Professional communication, Royal Roads University (June, 2009).

Smith, L. D.,” Discounted Cash Flow Analysis, Methodology & Discount Rates”, CIM-PDAC Mining Millennium 2000, (March, 2000).

Advisory committee, “Good Practices in Community Engagement and Readiness: Compendium of Case Studies from Canada’s”, Minerals and Metals Sector”, 2014 Energy and Mines Ministers’ Conference, Sudbury, Ontario (August, 2014). Last accessed on 06/11/2016 https://www.nrcan.gc.ca/sites/www.nrcan.gc.ca/files/www/pdf/publications/emmc/Good_practice_Compendium_e.pdf

The National Stone, Sand and Gravel Association (NSSGA), ” H.R. 1633, the Farm Dust Regulation Prevention Act of 2011”, Hearing Before the Subcommittee on Energy and Power of the Committee on Energy and Commerce, House of Representatives, One Hundred Twelfth Congress, First Session, (October 25, 2011).

Fernberg, H. “Prospecting and exploration for minerals” Atlas Copco, Talking Technically Series, (July, 2010). Last accessed on 06/11/2016 http://www.atlascopcoexploration.com/1.0.1.0/354/TS3.pdf