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At the Prospectors and Developers Annual Convention (PDAC) in Toronto, Canada mining and exploration companies of all sizes were on hand to discuss the year that was and those that will be. The following is a look at some of the companies with Canadian operations that were on hand for PDAC 2009. Iamgold Corporation is a leading mid-tier gold mining company producing approximately 31 t (1 million oz) of gold from seven mines on three continents. With record revenues of $870 million ? up 28 percent when compared to 2007 ? the company is focused on growth with a target to reach 56 t (1.8 million oz) gold production by 2012. During 2008, the company acquired the Essakane project in West Africa. The project is fully permitted, under construction and will contribute more than 9.3 t (300,000 oz) of lower cost production by late 2008. Iamgold increased its reserves by 55 percent, to 385 t (12.4 million oz) and its resources in-creased by 16 percent to 821 t (26.4 million oz) in 2008. Going forward, Iamgold has three areas of focus ? West Africa, Guyana Shield and Quebec ? with seven gold operations, five advanced projects and the Niobec niobium mine included. The Rosebel Mine in Suriname is Iamgold?s fl agship property. With measured and indicated resources of 300 t (9.6 million oz), it accounts for 30 percent of Iamgold?s production. Production there was up 20 percent compared with 2007 and further production increases are expected in 2009 and 2010. Mill expansion and optimization increased throughput from 8.9 Mt/a (9.8 million st) to 10 Mt/a (11 million stpy). In West Africa, Iamgold has joint ventures at Sadiola in Mali; Tarkwa in Ghana; Yatela in Mali and Daman in Ghana. Iamgold also has 100 percent ownership of the Mupane gold mine in Botswana and the Doyon gold mine in Quebec, Canada. Also in Quebec, Iamgold has 100 per-cent ownership of the Niobec niobium mine in Quebec. Niobium is used in high strength specialty steels.

Jan 1, 2009

By C. L. Emery

The geology and early history of the discovery of potash in Saskatchewan as described by Heber Cole (1) and R. V. Thompkins (2) has dealt with the distribution of the salt beds and their potash content. From the many bore holes through the Prairie Evaporites the outlines and contours of the series have been well established. The thickest section of the salt beds lies to the north of the "barren" area and forms a belt running easterly to a point west of Yorkton. The "barren" area is a region where the salt has been redissolved and the strata have slumped down, to fill the voids. This area is of interest from the standpoint of rock mechanics. The potash-rich beds extend both east and west of the region. mentioned and the top of the Prairie Evaporite is at a depth below 3200 feet from the surface near Saskatoon and dips southerly at an average rate of about five feet to ten feet per mile.

Jan 1, 1966

By T. M. Biddle

If an accident occurs at a mine, the mining company, its parent and affiliates, and its supervisory employees may face substantial -- and sometimes unexpected -- liabilities and costs. This presentation surveys the likely sources for post-accident exposure, including wrongful death and personal injury claims, mine closure/operational disruptions, and government civil and criminal actions against the company and its employees.

Jan 1, 1986

By D. J. Crawford

The Lucerne Valley Operations of the Minerals, Pigments and Metals Division of Chas. Pfizer & Co., Inca, are located about 5 miles south of the town of Lucerne Valley, California. These operations consist of several limestone quarries, a whiting plant which produces finely pulverized limestone products, a-kiln which produces granular quicklime and lime products, and maintenance shops, warehousing, shipping, and office facilities. Construction of the Lucerne Valley plant began in 1961 as the result of a decision to utilize large undeveloped reserves of limestone in that area. Quarry development was started in the following year; and by 1965, Lucerne Valley had become the principle limestone and lime facility of the Western Operations of the Minerals, Pigments and Metals Division.

Jan 1, 1967

By W. A. Vine

Next year, in 1964, Butte will celebrate its Centennial. It was in May, 1864, that the first recorded mining activity took place. During that summer, several rich placers were found on Silver Bow Creek and its tributaries, and a gold rush followed. As placer mining proceeded in the creek beds, the quartz lodes on the hillsides were located and the veins were prospected. Mining in Butte entered its second phase when the rich silver mines, the Alice, Moulton, and Lexington, were opened. The silver boom lasted until the decline in the price of silver in the early 1890's forced the closure of many of the mines. An indication of the beginning of the copper mining era in Butte was in 1866 when it was noticed that green copper carbonate discolored some of the, lode material. It was not until ten years later, however, that the Anaconda and St. Lawrence claims were located by Michael and Ed Hickey. The claims were sold in 1880 to Marcus Daly and in 1881, Daly obtained financing and organized the Anaconda Silver Mining Company to exploit the vein The silver venture was a failure because of the predominance of copper which diluted the bullion to only 400 fine.

Jan 1, 1963

By E. Ben-Awuah, H. Askari-Nasab, N. Al Habib

Open pit mines are getting deeper with time and transportation expenses are increasing because of the increasing haulage distance. In-pit crushing and conveying (IPCC) is getting popular in deeper open pit mines as a suitable alternative to truck haulage because it offers a lower operating cost due to shorter haulage distance and less truck requirement. Semi-mobile in-pit crusher, currently the most popular IPCC system, is relocated every two to five years and the short-term plan needs to be updated accordingly. Short-term planning with IPCC is an area of research that has not been explored extensively yet and hardly any model can generate short-term extraction sequence considering an IPCC in place. This research work proposes a mixed integer programming model to generate short-term production plan within a time horizon of 12 months. The objective of the model is to optimally allocate shovels to minimize cost of material handling and maximize revenue subject to meeting plant requirement, maximum allowable tonnage variation and IPCC location constraints to achieve production and NPV targets set by strategic plan. The proposed model has been implemented in a hypothetical case study for verification. The comparison of results between scenarios with and without IPCC is expected to justify the use of IPCC in large open pit mines from a short to medium term perspective. A semi-mobile IPCC system with one relocation is considered in the case study.

Feb 1, 2023

By C. Copeland, S. Kawatra

Airborne particulates can be generated by combustion processes, comminution, or materials handling, and regulation of these particulates by EPA are becoming progressively more stringent. Regulations will soon include “nanoparticulates,” particles finer than 100 nanometers, which are believed to have significant health effects due to their high surface area and reactivity. Although it was argued that nanoparticulate concerns were only important for combustion, studies here have shown that material handling and comminution release significant quantities of nanoparticles into the air. Laboratory studies have shown that sodium metasilicate reduced airborne particles finer than 10 micrometers (PM10) by 86% and particles finer than 2.5 micrometers (PM2.5) by 80% for iron ore. Additional studies were conducted which revealed that nanoparticulate emissions were present in the types of operations conducted at pyrometallurgical facilities.

Jan 1, 2007

By S. Bhagwat

Coals capable of emitting 2 lbs SO2/106 Btu heat input must be defined as high sulfur coals. This is because electric utility plants built after 1971 may not emit more than 1.2 lbs SO2, and those built before 1971, and regulated under the State Implementation Plans (SIP), may exceed the 2 lbs S0 limit only under closely defined restrictions concerning ambient air quality and prevention of air quality deterioration. Coals produced in Kentucky, Illinois, West Virginia, Ohio, Pennsylvania, and Indiana account for 77% of SO2 pollution potential and are, therefore, the subject of this investigation. These coals have suffered market share losses in the 10 years from 1974 through 1984. This is due to their sulfur content as well as their lack of price competitiveness with low sulfur western and imported coals. Kentucky and West Virginia have been able to increase their compliance quality coal production substantially, but other states have largely been unable to do so because of nonavailability of low sulfur coal deposits. Assuming that the current relative productivity and cost competitiveness of coal producing states will not change significantly by 1994, this paper makes two projections of coal production in the selected states. In scenario I, the current clean air regulations are assumed to apply until 1994, and coal production in the selected states is projected to in¬crease by about 6% in 1994 compared to 1984. In scenario II, it is assumed that acid rain legislation will be implemented, which will adversely affect the markets for high sulfur coals. Coal production in the selected states under this scenario is projected to decline about 10% between 1984 and 1994, jeopardizing up to 13,000 mining jobs. The author concludes that better coal quality and greater cost competitiveness are both essential to stem the market losses and to regain strength.

Jan 1, 1988

By Alejandro Prieto

Traditionally, Mexico has been a mining country. This industry has played a very important role in our country's development, creating jobs, integrating geographical regions - generally very remote from urban communities - and, an essential factor in our present day economy, generating an influx of foreign currency. The Fluorspar mining industry's development started in the 1920?s, but it was not until World War II that its exploitation became consistent and started growing. During the last few years, Mexico has become the world's leading producer, with an annual output of more than one million tons, which directly generates over 3,000 jobs. The actual proven reserves can guarantee fifty years of production at this same annual rate, and it is due to this fact that the producers have not increased their reserves. However, there is concrete information of the existence of several deposits, extending from the northern border to the gulf of Mexico, forming the "Fluorspar Belt? in Mexico.

Jan 1, 1986

By C. L. Schneider

The calculation of the liberation spectrum in the product from continuous milling operations is a problem of considerable importance and is difficult to solve because the population balance equation must be integrated in two-dimensional space. Complete solutions require the estimation of a large number of parameters unless a structural model of the ore texture can be used. A very simplified textural model based on the use of the modified Andrews-Mika diagram and the PARGEN simulation of multi-phase particles has been formulated and is used to simulate the behavior of a continuously operating laboratory ball mill. A sensitivity analysis for this mill has been done to show the likely effect of model approximations on the predicted liberation spectrum which will be measured.

Jan 1, 1992

By J. Schenck

Goldcorp Inc. has mining operations and exploration projects throughout Canada, the United States, Mexico, Guatemala and Honduras; as well as partnerships in Argentina and the Dominican Republic. In rural areas of developing countries it is very common to have mining operations surrounded by diverse communities consisting of people with limited, or no formal education. This is fertile ground for anti-mining NGOs to cultivate. The limited educational backgrounds of the people, coupled with a company desire to maintain a low profile can lead to a problematic lack of trust between the local communities and the mining company. As part of its commitment to environmental stewardship and sustainable development, Goldcorp has implemented various programs to build trust at these operations, as well as incorporating this policy into any new projects prior to commencement of operations. This paper is intended to describe two initiatives that have shown positive results for both the communities and the Marlin Mine.

Jan 1, 2009

By Alejandro Gutiérrez, David Ahues, Paola Merino, Felipe González

A Discrete Elements Method (DEM) study of load movement within a SAG mill 12,192 × 7620 (40′ × 25′) in normal operating conditions is performed. The purpose is to determine how the geometry of the lifters affects the kinetics of the load inside the mill. Specifically, the changes produced by the incorporation of inclined lifters and spiral or helicoidal pulp lifters to the kinetics are evaluated. Four study cases are identified: first, the base case corresponds to a conventional geometry; the second case corresponds to inclined lifters incorporation; third case corresponds to a mill with helicoidal discharge; and the fourth case corresponds to a mill with inclined lifters and helicoidal pulp lifters. To save computational resources, the water that enters the mill has been modeled by varying the coefficient of restitution. The results of a series of experiments are presented to determine how this coefficient varies when having impacts on surfaces with different liquid levels. A comparative analysis is made of the following variables: mean transport speed and material flow, for normal operating conditions. Taking as reference the mill with straight lifters and radial pulp lifters (case 1), the case with the inclined lifters and radial pulp lifters increases the material discharge flow less to 76 mm of size by 5.1%, and this value increases even more when the helicoidal pulp lifters are incorporated reaching a 58.6%. The most significant change is seen in the flow through the grates and the pulp lifters discharge, which can increase substantially improving the operation.

By Matthew Spedding

The complex nature of the carboniferous measures prevailing in the U.K. has dictated the types of mining required to exploit the coal seams. Most mines in Britain are referred to as deep mines in the sense that they operate at depths of 1800 - 3000 feet. The main system of coal transport to the surface is by vertical shafts which intersect the workable seams which at times number between 4 and 5. As mining has been practiced in most of the major coalfields in the U.K. for well over 100 years, with the initial extraction of the shallower and more profitable seams, the present management have been left a legacy of indiscriminate extraction which severely hampers their efforts to maximise the mine layouts. There is no single standard design of mining layout capable of meeting the wide variety of conditions which exist in the British coalfields. Mining layouts are subject to fixed and variable parameters. In discussing multi-seam working, the main parameter must be the effect of old workings above and below the seam to be extracted. There is a distinct lack of reliable information which would enable layouts to be designed to completely avoid or control these destructive forces. The guidelines are, therefore, mostly empirical.

Jan 1, 1977

By Palmer C. Sweet

Kyanite. andalusite, and sillimanite are anhydrous aluminum silicate minerals, and they have the same chemical formula, Al2SiO3. Dumortierite and topaz are also classified as aluminum silicates although they contain boron and fluorine respectively. Mullite (a rare mineral named for its discovery site, the Scottish island of Mull) is produced when kyanite, andalusite, or sillimanite are heated. Synthetic mullite, also classified as an aluminum silicate, is formed by melting alumina and silica, bauxite, and kaolin or alumina, kaolin, and kyanite, depending on the type of synthetic mullite desired. These materials are either sintered in rotary, periodic, or tunnel kilns, or fused in an electric arc furnace. The world's largest producer of kyanite is the United States. Domestic kyanite is presently produced from one company at two sites in Virginia; Kyanite Mining Corporation mines kyanite from Willis Mountain and adjacent East Ridge in Buckingham County in the central Piedmont province of Virginia. Internationally, kymite is produced in Australia, Brazil, India, Kenya, Sweden, and Zimbabwe; the former USSR also produces kyanite (Fig. 1). Andalusite is produced by Piedmont Minerals Company, Inc. in the Piedmont province near Hillsborough, NC. Andalusite is also produced in France, India, the Republic of South Africa, and Spain (Fig. 1). Sillimanite is produced in Australia, Brazil, India, Spain, and the Republic of South Africa; the former USSR is also thought to be a major producer (Fig. 1). Some of the countries produce only for domestic use. Synthetic mullite, made by sintering and by electric arc fusion, is produced by Mulcoa (Mullite Company of America) in Andersonville, GA, and by Washington Mills Electro Minerals Corporation in Niagara Falls, NY. Annual world production of kyanite, andalusite, sillimanite, and synthetic mullite is approximately 672 727 tons (Potter, 1988). GEOLOGY Mineralogy Kyanite is a blue to light-green, triclinic mineral that occurs in long, thin-bladed crystals and crystalline aggregates in gneiss, schist, and pegmatites. The mineral has a hardness of 5 parallel to the long axis of the crystal and a hardness of 7 across the crystal. Andalusite is a yellow, brown, green, or red orthorhombic mineral that occurs in thick, almost square prisms in schist, gneiss, and hornfels. Gem quality andalusite exhibits a strong pleochroism; brownish-green in one direction and brownish-red perpendicular to it. Andalusite also occurs in placer concentrations where it has weathered out of rock. Sillimanite is a brown, pale-green, gray, or white orthorhombic mineral that occurs in long, slender, needlelike crystals in schist and gneiss. Chemical and Physical Properties Chemical and physical properties of kyanite, andalusite, and sillimanite are noted in Table 1. Kyanite is the only mineral that irreversibly expands when heated (calcined to produce mullite) and may offset the shrinkage of most ceramic or refractory ingredients when heated.

Jan 1, 1994

By Susan P. Taite, Alain R. Charest, Peter D. Lewis

The El Sauzal deposit is a classic, high sulfidation, epithermal gold system located in the southwestern Chihuahua state of Mexico (Fig. 1). A Francisco Gold geologist discovered the prospect in1995. El Sauzal was encountered as a result of an extensive grassroots exploration program in the rugged, dissected volcanic terrains of the Sierra Madre Occidental, around the historical Batopilas silver camp. At El Sauzal, high grade gold is hosted within a series of more permeable, low-dipping, lithic and fine-grained dacitic rocks of early Tertiaryage. The mineralization appears tobe structurally and lithologically controlled. The alteration characteristics are typical of a high sulfidation system, including kaolinite, illite, alunite, dickite and pyrophyllite.

Jan 1, 2005

By Alizeibek Saleimen Nader

The intensive use of computers for mineral application at Serrana's phosphate mine in Jacupiranga, State of Sao Paulo, Brazil, began in the late seventies. The early hardware and software available are described in sufficient detail to allow comparisons between that solution and the new one, based on a personal computer and a new software package - PC MINE SYSTEM from GEMCOM SERVICES INC - that provides full color graphics capabilities plus mine design and planning tools. The process needed for adaptation to the new technology' and its impact on SERRANA S.A. DE MINERACAO are described. Finally, future enhancements to the System and mine control and planning are focused.

Jan 1, 1989

By Jacek Kolacz, Knut Lyng Sandvik

Fine grinding in an air swept and a grate discharge ball mill working in closed circuit with a forced vortex air classifier has been investigated in continuous laboratory scale. Minerals with different physical properties were ground down to 40, 20, and 10 micron top size. The shape of the product particle size distribution curve was investigated and specific surface (BET) was measured. During production of material with top size of 40 microns in an air swept mill, the capacity was up to 25% higher when compared to a grate discharge mill. This difference dropped to 180A during production of 10 micron top size material. A corresponding decrease in power consumption was observed. An important finding is that by regulation of the air flow rate through the mill, it is possible to achieve products with different specific surfaces and particle size distribution curve steepness. During production of the 10 pm material, the specific surface could be varied in the range 3 to 4.5 m2/g. Such powders could hardly be produced in a grate discharge mill because fine particles coated the grinding media and the lining. On the other hand the internal classification in the air swept mill kept the size distribution of the mill content relatively free of fines. This prevented a similar slowing-down of the air swept grinding process.

Jan 1, 1995

Newmont has been producing gold from the Carlin Trend for over 45 years. Naturally the focus, scale and complexity of the operations have changed considerably over this time. Newmont discovered and developed the Carlin Main ore body which is located about 32 km (20 miles) north of Carlin Nevada. The property was developed as a one mine one gold mill treatment plant operation which produced about 6,200 kg (200,000 Troy ounces) of dorè gold bars per year. The initial mine, mill and gold refining facilities were relatively small in comparison to today?s standards. The milling circuit used the Merrill-Crowe zinc precipitation process to recover dissolved gold and prepare a concentrated precious metal ?precipitate? to be melted into a dorè bar for sale.

Jan 1, 2012

By Robert C. Freas

Dravo Lime Company has opened a new 290m (940 ft.) deep lime-stone mine near Maysville, Kentucky. As the mine was opened there were many unknowns as to the stress relationships within the rock, and their influence, if any, on the selected mining method. Therefore, a system of overlay geologic and structural maps, borehold extenso-meter measurements, and oriented photography was developed for the purposes of monitoring the internal structural relationships of the rock mass. This paper presents a description of the methods used, the observations made, and the conclusions and recommendations made as a result of the initial monitoring program.

Jan 1, 1977

By Vincent C. Grimshaw

High pressure fluid energy grinding, or jet milling, is a versatile method of continuously fracturing solids into fine particles to gain substantial increases in exposed surface area. Applications in the minerals industries include calcium carbonate, talc, barytes, mica, diatamaceous earth, bauxite, rutile, coal, kaolin, sepiolite, diamonds, etc. The basic principles can be extended to provide continuous drying and delivery of discrete particles from a wet process slurry. The main design and operational features of jet mills and dryers are described, relating energy consumption for both air and steam milling and hot air drying techniques. Mean particle sizes in the order of 1 micron are achieveable from pre-milled feeds, or maintained from similar slurries in the drying mode. Aspects of feed preparation and multi-stage processing are discussed.

Jan 1, 1983