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By N. Melnyk

IN the past, the Cadomin Coal Company has opened four mines, all in the same coal seam or its folds. Three of these were opened from river level by horizontal entries or rock tunnels, and the fourth, the present working mine, by vertical shafts. This paper deals largely with some operating phases of this fourth mine, with which the writer has been associated. The seam worked here is a thick, steep, bituminous seam, and the writer feels there is a paucity of published data on the mining of such seams. Possible reasons for this are that such seams do not !end themselves to intensive development or mining, there is little chance to mechanize because of the extreme pitch, and operations are fraught with many problems. In addition, the present operations in this particular seam are being carried on at a level below the former workings, introducing new problems, not en-countered on the upper level. Coal will, without question, long continue to be an important factor in the national economy, and some of the best coal is to be found in thick, steep seams. But with the exhaustion of the easily-mined coal near the outcrops, future coal will have to come more and more from lower levels. At Cadomin there is still considerable coal on the second level, below the old river-workings, and there is a possibility that, in the future, still lower levels will be worked. It is the purpose of this paper to indicate some phases of such lower-level operations and to invite discussion.

Jan 1, 1942

By C. Poon

For slope stability, knowledge of major and minor discontinuity sets that form the rock mass fabric is paramount for pit slope designs. Due to the increased awareness of health and safety in mining projects, efforts have been made to limit structural mapping in order to minimize the risk to personnel associated with approaching potentially unstable areas. Recognizing the importance of such safety precautions, Golder Associates Ltd. is applying a combination of techniques including 3D photogrammetry, conventional mapping and drilling with core orientation to enhance structural data collection. Photogrammetry uses digital photographs to produce a virtual model of a rock mass surface. The application of these techniques will be exemplified through an expansion design of an existing open pit. A comparison of stereonets obtained using these techniques showed some agreements, but also highlighted limitations of each method. The application of photogrammetry was found to be very useful in complementing the other existing techniques.

May 1, 2009

By R. A. L. Drew, F. Edelmann

Brazing is a low-cost process used extensively in the manufacturing and repair of aircraft gas turbine engines. Components within the compressor stage of the engine experience relatively low temperatures (600-700°C), therefore joints of stainless steels are typically employed. In such joints, a Pd-Ni-Cr-Si-B (PalNiCroTM) brazing alloy is used as a sealant, however brazing procedures are not well understood. The wetting behavior of PalNiCroTM on AISI 347 was evaluated with respect to contact angle. A microstructural evaluation was carried out with variable joint clearances. Microhardness profiles were performed to investigate the presence of hard secondary phases, which were later confirmed by electron microscopy. The results indicated an equilibrium contact angle of 10° within 100 seconds. The average microhardness of the braze layer and base metal were approximately 550 and 205 VHN, respectively. At the interface, a diffusion zone was present containing carbides and borides.

Jan 1, 2004

By K. Sawada

Along with the expanding demand of copper concentrate in Asian countries, custom-smelters have confronted with difficulties of low TC/RC. Now, Japanese Copper Industry have 2 options; investment in mine development and/or recycling of copper scraps. The strategy of global mining companies is analyzed, and implications for Japanese Copper Industry will be discussed from the viewpoint of sustainability of smelters in Japan.

Jan 1, 2014

By Bian Xue, Wu Wenyuan

High quality, mono-dispersed, hollow CeO2 microspheres with high surface area were produced by a spray pyrolysis method at 700oC. CeCl3 was used as the raw material of the process rather than Ce(NO3)3 because the latter is relatively difficult to obtain in industrial quantities. X-ray diffraction and electron microscopy results confirm the high quality synthesis of hollow CeO2 microspheres with narrow size distribution, good mono-disperse, and good reproducibility. The process of the formation of mono-dispersive CeO2 microspheres was investigated by chemical dynamics and a possible mechanism is proposed. This simple method for synthesis of CeO2 microspheres is easily scaled up to fabricate other metal oxide nanostructured materials at industrial scale.

Jan 1, 2014

By G. W. Poling, J. R. Hoffert

"A common practice in preventing gravity-fed tailing pipeline from plugging due to sanding is to add lime at relatively high dosage rates. The lime affects the rheology of the slurry ""vehicle"" which transports the coarser particles in a heterogeneous flow-regime. This paper describes a study of the effect of lime on the critical deposition velocities and friction head losses of Highmont Mining Company's mill tailing. Testwork using an extrusion viscometer was related to the surface chemistry changes brought about by the high lime additions. Lime additions which typically increased the tailing pH from 8.4 to 11.5 reduced the critical deposition velocities from approximately 3.2 to 1.7 m/sec.IntroductionCommon practice, at least in base metal concentrators in British Columbia, is to use high lime additions in tailing slurries when the pipeline becomes partially plugged with sands. Some concentrators, such as the Highmont Mining Co. Ltd. plant, add lime on a continuous basis during low tonnage periods and during startup/shutdown transition s. Although such high lime additions often solve temporary plugging problems, the effect of lime on slurry rheology has not been well understood.Slurry pipelines are designed to transport solids in suspension with a minimum of wear and without particle deposition. These two objectives are in opposition because the velocities required to maintain solid suspension can sometimes cause high head losses in the pipeline, as well as wear problems. Thus, the optimum velocity for a long distance slurry pipeline is in the range that provides just enough turbulence to keep coarse particles in suspension."

Jan 1, 1985

By J. O. Marsden

Over the past eight years, Phelps Dodge (a division of Freeport-McMoRan Copper and Gold, Inc.) has developed a suite of proprietary hydrometallurgical processes for the treatment of copper concentrates as an alternative to conventional smelting and refining technology. The technical viability of two processes has been commercially demonstrated in a large scale plant at Bagdad, Arizona, designed to process approximately 52,500 metric tons per year of concentrate containing 30.5% copper. The first process utilizes high temperature (225°C) pressure leaching, followed by countercurrent solid-liquid separation, and then blending of the copper-bearing solution with low grade stockpile leach solution for subsequent treatment by SXlEW for copper recovery. The second process uses super-fine grinding, medium temperature (l60°C) pressure leaching, followed by solid-liquid separation, and treatment of high grade copper-bearing solution by direct electrowinning to recover the bulk of the copper values. The latter process will be utilized at Morenci in a commercial facility designed to treat mixed chalcopyrite-chalcocite-covellite concentrates. This facility is scheduled to start up in 2007. Other flowsheet options have been developed by Phelps Dodge for application to a variety of concentrate materials in specific situations. Examples of various flow sheet options are presented in this paper, and the advantages and disadvantages associated with each are discussed in detail.

Jan 1, 2007

By R. S. Douglas

Introduction The mine at Copper Mountain of the Granby Consolidated Mining, Smelting and Power Company was one of the pioneers in the use of blast-hole diamond drilling for ore breakage. This method of mining has now been brought to a high degree of perfection. The system in use has?been described in a previously published paper which has become an important part of the literature o the blast-hole drilling method. At the time of the establishment of the system at Copper Mountain, standardized loading and drilling procedures were set up. These procedures were based partly on the results of experiment and partly upon the judgment of men experienced in breaking rock in the mine. The success of the method has been proof of their adequacy. With the progress of scoping in the mine, the diamond drill method of breaking was applied to other ore blocks where different conditions obtained. It was found necessary to make adjustments in the standard procedures to get the best results under the new conditions. The following paper attempts to express, in terms of mathematics, the relations of the variable factors. Until recently, estimations of drilling required were based upon the tonnage to be broken and the proposed rate of explosive loading. A revised method of estimating is outlined below which is direct and which involves no unrelated variable factors.

Jan 1, 1947

By Gabriel Zarate

"Los Bronces had two ROM dump leach operations designated Leach I and Leach II. Leach I was commissioned in 1998 and stopped in 2014 due to the mine requirements. Leach II plant, commissioned in early 2002, was built to treat around 700 million tons of marginal ROM ore averaging 0.45 % total copper. The mineralogy of this material was estimated to be 70% chalcopyrite, 20% chalcocite/covellite and the balance oxides.The original electrowinning plant design capacity for copper production was nominal 19,500 tonnes per year at a current density of 276 A/m2 and a current efficiency of 92%. Presently, Los Bronces San Francisco plant typically operates at current densities between 390 and 440 A/m2, much higher than the average in the industry, with current efficiencies around 93% and a maximum copper cathodes production of 37,200 tonnes per year.In order to accomplish these achievements, a number of modifications in the process conditions, in the cell hardware and in the operational procedures have been implemented. In the first case, the specific flowrate, copper concentration and temperature of the electrolyte were modified to accommodate the operational requirements facilitating the increased current density. Associated with the cell hardware, a six cells expansion was added, upgraded equipotential inner cell busbars were installed and the cross section of the cathode hanger bars was enlarged for increased current carrying capacity. Documented operational procedures like short circuit detection and cathode weight control were improved.The modifications implemented and the results obtained are discussed in this paper.INTRODUCTIONLos Bronces Division of Anglo American Chile is located up in the Andes Mountains, northeast of Santiago. It had two cathode plants, Los Bronces at an altitude of 3500 meters above sea level (m.a.s.l.) commissioned in 1998 and closed in 2014 and San Francisco at an altitude of 2800 m.a.s.l. and in operation since 2002.The process is leaching run off mine (ROM) low grade copper sulphide ore in dumps. The mineralogy of this material was estimated to be 70% chalcopyrite, 20% chalcocite/covellite and the balance oxides. The average grade is 0.45% total copper (Cut).At Los Bronces dump, Leach I plant, the pregnant leach solution (PLS) was collected and stored in an underground reservoir. From there, it was fed to a solvent extraction plant with a series-parallel configuration in two extraction stages and one stripping stage. The electrolyte produced was fed to the electrowinning plant having 30 cells and 60 cathodes per cell. Maximum capacity of this plant was 12,000 tonnes per year (tpy)."

Jan 1, 2016

By Paul Graham

Presentation Focus ? What is LTUG / What do we do? ? History of LTUG ? Examples of Benefits from LTUG Participation ? Encourage Participation What is LTUG? ? An informal gathering of surface mining companies to discuss and work issues of common interest and to share information and best practices around large tires.

May 1, 2008

By Robert G. Boutilier

Mining companies in communities without other large employers often encounter dependent or defiant stakeholder attitudes, sometimes simultaneously. Less often they also see some slip into social dissipation or advance towards sustainable development. This paper presents a four-quadrant framework that shows how patterns of social capital foster these four reactions. The two dimensions defining the quadrants are the social capital levels (a) between the company and each stakeholder, and (b) among stakeholders themselves. Examples from the Antamina mine in Peru illustrate a social capital measurement system that can predict these reactions and help the community chart its path towards sustainable development.

May 1, 2006

By Donald J. Farrish

"Mr. Chairman and fellow CMP members, most of these remarks will be made with particular reference to copper concentrate but the basics apply generally to other metal concentrates as well.For very good reasons, using copper as an example, smelting capacity usually is located either close to mine production or close to areas of high copper consumption. The mine producer can add on smelting capacity to insure that the copper in his concentrate can be processed into a marketable form under more or less controlled conditions including costs. On the other hand, the consumer wishing to assure a better supply of copper likewise can build smelting capacity and offer treatment charges attractive enough to discourage mines from investing in their own facilities. In this regard, freight is an important factor. Bulk shipments from the heart of Africa with a large overland component are uneconomic whereas concentrate movements from Australia or South America compare favourably with smaller metal shipments.A mine project which incorporates smelting capacity, will often, through the presence of this capacity, encourage active exploration and development of additional concentrate production in the vicinity. The usual result is that new mines within reasonable distance of the smelter will be able to avoid the capital required to build their own smelting and refining facilities and that the existing facilities will expand to appreciate economies of scale."

Jan 1, 1978

By Andrea Lisjak

The mechanical behaviour of Opalinus Clay, an indurated over-consolidated argillaceous rock, is heavily influenced by the presence of preferably oriented bedding planes. The objective of this study is to illustrate a new modeling approach aimed at capturing the bedding-induced anisotropy of Opalinus Clay as observed in the laboratory and in situ. The combined finite-discrete element method (FEM/DEM) is employed as the main simulation tool. FEM/DEM is a numerical method that models material damage processes by explicitly considering fracture nucleation and propagation. A transversely isotropic elastic constitutive law is used to account for different elastic property values in the direction parallel and perpendicular to the layering, while strength anisotropy is captured using a directional cohesive fracture model. Quantitative calibration and validation of the model is based on laboratory results of indirect tensile tests and uniaxial compression tests. Emergent strength and deformation properties, together with the simulated damage mechanisms, are shown to be in good agreement with experimental observations. Preliminary results relative to the analysis of a circular tunnel show that the approach is able to reproduce the main Excavation Damaged Zone (EDZ) formation mechanisms as observed in the field.

Jun 1, 2012

By Michael Nicol

A quantitative description of hydrometallurgical operations depends primarily on an understanding of the kinetics of the chemical and physical processes that take place in such operations. This paper will review the current status of kinetics in hydrometallurgy in terms primarily of the author’s experience in diverse unit operations. A distinction will be made between the popular use of models based on limited kinetic data and mechanisms which reflect the actual elementary chemical or physical steps involved in an overall process. Several examples will be used to illustrate this distinction. The proliferation of published papers of declining quality has resulted in the bequest to later researchers of outdated and often incorrect conclusions by a process that is often difficult to reverse. Some examples of these mysterious concepts will be examined and hopefully reversed. Finally, several examples will be given that identify significant gaps in our understanding of the kinetics of important processes that remain unresolved.

Jan 1, 2014

By C. Sartain

In recent years market pressures have been building on companies to develop the next era of mining projects to follow the previous boom in copper projects of the mid 90's. However the response from the industry has been slow in coming, and somewhat muted. It is clear that there simply have not been the obvious quality projects waiting to be rapidly developed. Many of the known undeveloped copper projects have particular characteristics that have previously prevented their development, including mineralogical complexity in the ore bodies, environmental challenges or particularly difficult geographic locations. This paper describes how the Copper Division of an international mining company, Xstrata plc, is preparing to progressively develop an impressive pipeline of projects, armed with an array of proprietary technologies and with a strong approach towards sustainable development and community engagement. The approach being taken is enabling Xstrata to complement its acquisitive corporate philosophy with a management emphasis on project development and operational optimization and enhancement.

Jan 1, 2007

By Dr. Rory Cameron, Dr. Terry Cheng, Dr. Nadia Mykytczuk, Ian Bedard, Kristie Tarr, Ruth Joseph

Pyrrhotite-rich tailings from Sudbury, Ontario mining activities are known to contain significant amounts of EV metals, such as nickel and cobalt.  CanmetMINING has developed a novel bioleaching process for recovering the nickel and cobalt (both critical for vehicle electrification) from tailings that incorporates partial neutralization and iron removal in the bioleaching circuit; bench- and pilot-scale tests have resulted in excellent nickel and cobalt recovery over a range of temperatures.  However, this process generates a new bioleach residue, which is heavier and more voluminous than the original tailings due to pyrrhotite oxidation and jarosite formation during the bioleaching process. This residue can be problematic for long-term disposal. A possible solution being studied for this issue is using mine backfill as a disposal mechanism.  Underground backfilling allows for effective re-purposing of mine waste, however the backfill must also be able to withstand a certain load, since in most cases it is used as an underground construction material, such as in cut-and-fill mining methods.  Therefore, the composition of the mill tailings must be such that when combined with a binding agent and pumped underground, the slurry or paste is then able to withstand a certain load within a certain period of time.  Unfortunately, high-pyrrhotite content tailings, commonly found on mine sites in Ontario and Quebec, are reactive and can easily oxidize and produce acidity and/or metal-laden drainage under some disposal conditions. This means that the pyrrhotite in the tailings can lead to acid mine drainage if stored on surface, however, it can also cause strength degradation if re-purposed in too high a concentration in underground mine backfill.  The research being done at CanmetMINING related to the bioleaching process is aimed not only at recovering nickel and cobalt from mine tailings, it is also being used in an attempt to neutralize the tailings to reduce acid mine drainage and backfill strength degradation. This paper reports on research designed to evaluate different options for transforming the bioleaching process residue into iron oxide phases, for better environmental footprints if stored on surface, as well as increased disposal possible, if re-purposed as underground mine backfill material.  

May 4, 2025

By J. E. Rowland

NIOCALITE is a new mineral species which has been identified in rock from the Oka district, Quebec. It occurs as prismatic crystals up to l 0 mm. in length and I mm. in width, in coarse, white, crystalline calcite with associated apatite, diopside, biotite, pyrochlore, and niobian perovskite. The crystals of niocalite are light yellow in col-our and have a vitreous lustre. The optical properties of niocalite (I) are as follows: Biaxial negative -2V = 56° a = 1.700, [ ] = 1.730 Birefringence y -a = 0.030 Optic orientation: X = b, Z/\c 12°, Y , /\a = 32° The specific gravity is 3.32 and the hardness is approximately 6 (Mohs scale). A detailed analysis performed on 2.4 gm. of hand-picked material reveals that niocalite is essentially a calcium niobium silicate. Table I gives the result of the analysis. Crystals of niocalite, apparently suitable for X-ray diffraction work, were selected, and single crystal photographs were obtained using both Weissenberg and Precession cameras. Initial difficulties were encountered in interpreting these films, and in correlating the crystal data with the optical data. The in-consistencies were explained by the fact that every grain examined was twinned to some extent.

Jan 1, 1957

By Steve R. McCutcheon, Cees R. Van Staal, John P. Langton, Leslie R. Fyffe

The volcanic-dominated Tetagouche Group in northern New Brunswick contains numerous massive-sulfide deposits and intimately associated metalliferous sediments. The massive sulfides are generally hosted by Llanvirnian-Llandeilian volcaniclastic sedimentary rocks of the Nepisiguit Falls, Patrick Brook, and Boucher Brook formations. These formations are intercalated or closely associated with rhyolitic-dacitic flows and/or domes, and minor continental tholeiites of the Flat Landing Brook Formation. Pyroclastic rocks are relatively scarce in the silicic volcanic complex. Tuffites and epiclastic sandstones, of the Nepisiguit Falls and Patrick Brook formations, respectively, generally occur along the fringes of the silicic volcanic complex. The flows and tuffites are intruded by quartz- and feldspar-phyric rhyolite (porphyry) dykes, sills, and domes. Although the volume of the silicic volcanic complex is large, evidence for a previously proposed collapsed-caldera model is lacking. On the basis of host-rock type and stratigraphic position, the sediment-hosted massive sulfides have been divided into three groups: the Brunswick-, Caribou- and Halfmile Lake-type deposits. Syngenetic feeder pipes and asociated alteration zones are generally not present beneath the Caribou- and the Halfmile Lake-type deposits and, if present at all, are poorly developed underneath the Brunswick-type.

Jan 1, 1992

By Ros Taplin

Realizing the potential of cutting greenhouse gases (GHGs) associated with mining, a variety of approaches has been proposed for their mitigation. The Clean Development Mechanism (CDM) under the Kyoto Protocol to the UN Framework Convention on Climate Change (UNFCCC) has been a key mechanism to assist in implementation of mitigation measures. The objectives of CDM are not only to assist Annex I countries in meeting their GHG emissions reduction targets with cost-effective reduction but also to achieve sustainable development in non-Annex I countries. However, apart from China, India, Brazil and Mexico, many developing countries are still in the stages of formulation or realizing CDM strategies. Projects associated with methane capture and flaring are the fourth most prevalent type of CDM project internationally. This research primarily has addressed emissions abatement and sustainable development aims and effectiveness of registered CDM projects associated with coal mining in China. The paper reviews 30 currently registered CDM projects in China on the UNFCCC database and six other non- Chinese projects. Systematic evaluation involving content analysis of documentary evidence regarding coal mining CDM projects is presented in relation to firstly, quantitative reduction of GHG emissions and secondly, sustainable development outcomes. The projects have been assessed via a set sustainability criteria. Overall it was found that sustainable development goals are only briefly referred to in Project Design Documents, Letter of Approvals and validation documents. Varying types of sustainability initiatives have been implemented with weak to strong indications of effectiveness. This has implications for the future effectiveness of CDM projects in the mining sector, the proposed new market mechanism under UNFCCC, and for assessment of projects under mechanisms established outside the UNFCCC.

Aug 1, 2013

By W. Dan Hausel

"Hundreds of diamonds have been found in the United States. The majority of the discoveries occurred during the 19th century as a by-product of placer gold mining. Most of these early diamond finds have no known source, and in many cases are situated in areas unfavorable for diamond exploration based on current models that require kimberlite or lamproite to be emplaced in a stable Archean craton or Proterozoic craton margin.Diamonds have also been recovered in situ from lamproite at Murfreesburo, Arkansas, from kimberlite in the Lake Ellen region of Michigan, and in several kimberlites in the Colorado–Wyoming State Line district. Unverifed reports also suggest that diamonds may have been recovered from other related intrusions at a number of localities in the United States.IntroductionTo date, diamonds have been recovered in situ from kimberlite in the Colorado–Wyoming State Line district and from a kimberlite in Michigan. Additionally, diamonds have been recovered from lamproites in Arkansas. Diamonds have also been reported from kimberlite in Kansas, and from peridotite in New York and Maryland. However, these latter reports have not been verified."

Jan 1, 1995