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By R. H. Colquhoun

"INTRODUCTION The Holt-McDermott Mine is wholly-owned gold mining operation of American Barrick Resources Corp. that begun operations in June 1988.The property is located 0.5 km. south of Highway 101 East in the Harker-Holloway Townships of Northeastern Ontario, 7 miles south of Lake Abitibi and 15 miles west of the Quebec-Ontario border.Employees of the operation travel daily from various communities in the area, predominantly from Kirkland Lake, Ont., which is located 65 km. to the southwest.The significance of the operation is that it is the first full scale operation associated to the Oestor-Porcupine Fault to go into full production in recent history as well as the first Carbon-in-Leach (CIL) operation in the province owing to the natural occurring carbonaceous ores that are associated to the ore body and the geological fault systems.GEOLOGYThe Holt-McDermott deposit is located in the Abitibi Greenstone Belt, a short distance west of the Ontario-Quebec border. Ore grade material follows the footwall contact of a fault zone known locally as the McKenna Fault, which is thought to be a splay off of the Oestor-Porcupine Fault, itself a major feature in the Abitibi belt.The McKenna Fault strikes approximately east-west (as does the Oestor-Porcupine) and dips to the south at sixty-five to seventy degrees. The fault lies within a package of mafic volcanic rocks (basalts). These rocks have been strongly altered and mineralized adjacent to the McKenna Fault, and the resulting lens-like ore bodies constitute the mining targets."

Jan 1, 1989

By John D. Smith

This paper describes how a knowledge of inherent rock characteristics can aid the mining engineer in his design of a mining method for a massive domelike structure. The paper shows how the pertinent rock characteristics were measured and analyzed and how the data obtained was used for design purposes. This analysis was conducted in 1964 in a producing salt dome, since that time, mine management has tried certain of the recommendations for mine design changes. The results of such changes are presented.

Jan 1, 1968

By Andrew Barnes

The adsorption capacity of peat collected from a proposed mine development in northern Sweden has been determined using laboratory column experiments in which peat was irrigated with a simulated (acidic) waste rock dump leachate. The simulated leachate was made using a hydrogen peroxide leach of composite waste rock from the proposed mine development. The waste rock samples were composited in proportion to their predicted extractable tonnage for the mine development in order to generate a more representative leachate solution for the waste rock facility. As expected the test revealed that the peat material shows a very high affinity for attenuation with greater than 70% of Co, 90% of Ni and 95% of Cu removed from influent solutions through the majority of the tests demonstrating the potential benefits in mine water treatment. In contrast, it was found that Fe is initially released from the peat at concentrations up to 100 mg/L and can mean potential problems for the water released depending on the receiving environment. The exact mechanisms for Fe release is uncertain, though it is suspected that ion exchange / competitive desorption is responsible. Inspection of the laboratory results and drainage data from the natural peat wetland receiving drainage during overburden prestriping and mine development at the mine site are comparable, confirm the validity of the experiments, and further emphasize the potential for future use of pre-stripped peat material in managing water quality.

Aug 1, 2013

By R. J. Pine, J. S. Coggan

Distinct-element modelling has been used to study the mechanisms associated with observed deformation of the western face of the quarry. A complex failure mechanism involving distinct planar surfaces that was proposed for a slope failure in 1967 has been modelled and shown to be plausible. In addition, deep-seated flexural toppling may contribute to the slope instability. Modelling has confirmed the detrimental influence of a raised water-table on the stability of the slope and also indicates that the observed cyclic opening and closing of tension cracks may be attributed to seasonal rise and fall of the groundwater level

Apr 1, 1996

By Sidney Katell

This Bureau of Mines study estimates capital investment, operating costs, and selling prices for three underground bituminous mines producing coal with annual production ranging from 1.03 to 3.09 million tons. It is assumed that the mines have a 20-year life. Wages and union welfare payments are considered as of November 12, 1973, under the Bituminous Wage Agreement of 1971, and costs for material and equipment are based on 1973 indexes. Initial capital investment ranges from $12,938,200 for the 1.03-million-ton-per-year (MJ.Vl tpy) mine to $31,435,500 for the 3.09 MM tpy mine. Total capital investment ranges from $21,607,200 to $51,982,000 for the same mines. Corresponding selling prices for the coal range from $9.11 to $8.06 per ton, assuming a 12-percent discounted cash flow rate of return after Federal income taxes.

Jan 1, 1974

By J. L. O’Brien, M. Suenaga, K. M. Ralls, V. F. Zackay

The effecls of aging a1 400°C on tile resistive transition at 4.2°K of a superconducling 70Zr-30Nb alloy are reporled. Microstrclural changes were studied by critical temperature, resistiue critical field, residual resistiuily, and microhardness measurements and by X-ray diffraction, optical microscoby, ad replication electron microscopy. The result of the aging treat- A defect-free Type 11 superconductor in a magnetic field above Hc1 cannot sustain a transport current runt is a fine array of w-phase pavticles with a mean center to center interparticle spacing of about 800A. At an aging time of 300 hr the maximum onset critical current density is rcached. The particle size at the maximum current density if about 4202. At times longer than 300 hr effective particle impingement leads to lower onset critical current densities. perpendicular to the applied field without power loss in the sample.'-3 This power loss is due to flux line motion caused by the Lorentz force and is manifested by a longitudinal voltage.4-6 When defects are present in the material, flux lines are pinned until the Lorentz force exceeds the "pinning force". That is, it is thought that flux lines reside in free-energy wells existing at the defects, and the critical Lorentz force is that which when integrated over distance will supply the free-energy difference necessary to move the flux

Jan 1, 1968

Edward Keller, Baltimore, Md. (communication to the Secretary*) :—The authors of this paper are to be commended for their industry and congratulated upon the many interesting results which were the fruit of their researches. While thoroughness has marked their work in general, yet on a few points in particular they have touched but lightly, for which reason, it would appear to me, they have hit wide of the mark in their respective conclusions. The work alluded to pertains chiefly to the occurrence of magnetic iron oxide (ferroseferric oxide) in copper-mattes. Because the authors find that the magnetic residue, left by the dissolved sulphides, varies largely in quantity according to the strength of nitric acid used (with potassium chlorate) in dissolving the mattes, they conclude :— "It appears, therefore, that the ferroso-ferric oxide is the result of precipitation by the oxidizing agent, rather than an original constituent of the matte." In this part of their investigation, Messrs. Gibb and Philp have ignored some well-established data,. In the first place, they have overlooked the fact that there are mattes which are strongly magnetic and others which scarcely show any magnetic property. There is nothing in their work tending to explain this variation. They Seem to have tested none of their products for magnetism. Secondly, they have overlooked the fact that magnetic iron oxide probably exists in all ore-charges in the copper-matting furnaces, and, under the given conditions, that this oxide is very difficult to reduce and to combine with silica to form slag. Thirdly, they pay no attention to the varying specific gravity of the several grades of copper-matte, which may exceed, equal, or fall below that of the magnetic oxide. These are .essential points which, I believe, clearly in-

Jan 1, 1906

By J. L. Rodda, M. L. Fuller

In connection with an investigation in this laboratory on the high-zinc side of the copper-zinc system, it was observed that well developed segregate structures of the Widmansttten type were formed when a secondary phase precipitated from the solid solution of copper in zinc. This paper presents an analysis of the crystallographic relationship between the segregate and the solid solution matrix. The data to be presented are an interesting addition to the literature on segregate structures in that the plane of segregation is one of the less densely populated planes. In agreement with the generalization of C. H. Mathewson and D. W. Smith' the plane of segregation in the matrix contains the direction of closest atomic packing of the lattice. Furthermore, the matrix and the segregate are both hexagonal close-packed, which has not been reported hitherto in the 1iternture.l The increasing commercial importance of zinc alloys containing copper makes this fundamental study of value to the metallography of zinc alloys. Zinoeich Copper-zinc Alloys Copper enters into solid solution with zinc to at least 1.8 per cent at 400" C., according to W. M. Peirce.3 The solubility is less at lower temperatures. Thus a solid solution of copper in zinc, saturated at an elevated temperature, will precipitate the excess copper in a separate phase at a lower temperature, conditions of concentration, time, and temperature being suitable. The nature of these two phases has been established by the X-ray method of crystal analysis. Westgren and Phmgmén4 and also Owen and Preston5 have shown that the solid solution eta (7) is of the substitu-tional type with copper atoms replacing zinc atoms on the hexagonal

Jan 1, 1933

Removal of Dilute Toxic Anions in Wastewater Using Aluminum Hydroxides Co-Precipitation Method

Sep 13, 2010

By J Herbertson

æZero waste steel making productionÆ has already been the subject of several studies and also the successful result of some companies. Regarding waste and by-products, slags are the largest in terms of weight, although among the least hazardous. All steelmakers around the world are presently looking into profitable solutions, according to their local conditions: environment constraints, available markets, and mode of operation. Today the major technical methods of slag value capture include different levels of magnetic separation and screening to remove entrained steel, for production of aggregate in civil works. A survey of different retrieval processes shows that pyrometallurgical processing of steelmaking slags will increase the recovery ratio of iron and other metals. In the process, the remaining part of the material, a mixture of metallic oxides, can be easily transformed into hydraulic binder such as cement. Can steelmakers consider the slag as a co-product, and not only a waste or by-product? The ability of pyrometallurgical processes to treat other wastes and by-products generated in the steelplant is an opportunity for the steelmakers to reach the æzero waste productionÆ status. A technical survey of the experiences and possible solutions of pyrometallurgical processing is presented as well as technical descriptions of technological, economical and profitability analysis in relation with foreseeable markets.

Jan 1, 2002

By Jürgen Antrekowitsch, Gerardo R. F. Alvear Flores, Mehmet Ayhan, Christoph Zschiesche

Synergies between copper and lead extractive metallurgical processes enable the processing of a broad range of polymetallic materials. However, this complexity also brings some challenges expressed in terms of complex intermediates and final products. For instance, based on the limited solubility of Cu and Ni in crude lead bullion additional phases will appear during the crystallization of the melt. Beyond the need for continuous optimization of metallurgy the control of phase solidification is a further important pillar to achieve a more efficient process by minimizing the amount and cycles of reverts. This paper describes the microscopy study of one of the most relevant intermediate in the Cu and Pb metallurgy, the Cu based alloy and highlights the importance of applying a well-controlled cooling sequence to improve the overall process efficiency. INTRODUCTION One of the key aspects in Aurubis’s 2025 vision is to move towards the implementation of a multi metal recovery strategy. The implementation of this new multi metal vision is supported by the long tradition of the company, founded in 1866 as Norddeutsche Affinerie, and further developed by adopting modern copper smelting and lead smelting technologies for the processing of primary and secondary materials. The combination of these assets have already build the basis for processing of complex materials in the copper and lead circuits implemented in Aurubis’s facilities. The addition of a new smelting facility, will enhance these capabilities. Aurubis current flowsheet combines Cu, Pb and Zn metallurgy. This includes primary smelting of copper concentrate, processing of secondaries (residues, slimes, slags) and recycling materials (scrap, shredder material, e-scrap). These broad range of materials contain not only the mentioned base metals but also a number of minor metals that requires to be properly managed to ensure efficient recoveries and quality of the targeted metals.

Jan 1, 2019

By Luciana Angelita Machado

Os rejeitos gerados na mineração de carvão, sob condições atmosféricas e a possível presença de bactérias acidofílicas proporcionam a oxidação primária do sulfeto de ferro, formando sulfatos e ácido sulfúrico. Com a redução do pH da água, ocorre a mobilização de metais contidos no material, gerando a drenagem ácida de mina (DAM). A DAM causa um impacto nocivo na qualidade da água superficial ou subterrânea. Uma das tecnologias de prevenção da geração da DAM consiste no método de aditivos alcalinos. Assim, o objetivo do presente trabalho foi avaliar o controle da DAM pela mistura de rejeito de carvão com escória de aciaria elétrica do forno panela. A metodologia utilizada baseou-se nos ensaios estáticos e ensaios cinéticos. Os resultados demonstram que o rejeito de carvão gera DAM. Contudo os problemas ambientais podem ser em grande parte resolvidos pela mistura do rejeito com a escória na proporção acima de 10:10. Os ensaios cinéticos demonstram que, nessa condição, ocorre aumento do pH e redução do potencial redox e sulfatos na água lixiviada. Desta forma, a disposição conjunta de escória de aciaria elétrica do forno panela com rejeito de carvão é uma alternativa viável para o controle da geração de DAM em minerações de carvão.

Jul 30, 2018

By A. Mukherjee

This paper presents an analytical technique for prediction of the damaged rock zone (DRZ) around a circular drift subjected to an anisotropic stress field (analytical solution exists only for the case of hydrostatic stress field). The method can readily be adapted to micro or personal computers. Stress concentrations around the drift are calculated at the centers of small rock elements, using the analytical solutions for a hole in an infinite plate. Potential failure of a rock element is assumed to be governed by the Coulomb failure criterion. When the failure condition is exceeded for an element, the excess shear stress is transferred to the neighboring elements. Progressive failure is allowed to occur until convergence is obtained. The final configuration of the damaged rock zone so obtained can be used to assess rock support requirements, as well as modified modulus and permeability of the DRZ.

Jan 1, 1988

By Gary Brendel

India produces about 70 Mt/a (77million stpy) of coal ash (fly ash and bottom ash) from burning about 200 Mt/a (220 million stpy) of coal for electric power generation. The average ash content is 35%. In contrast, the United States produces about 70 Mt/a (77 million stpy) of coal ash from burning 800 Mt/a (880million stpy) of coal for power generation. Its average ash content is less than 10%. In 1998, GAI Consultants Inc.(GAI) embarked on a federally funded, multiyear project to assist the government of India in solving its growing coal-ash management problem.

Jan 1, 1999

By Barnabus Bryan

THE normal statistics of supply and demand of petroleum and its products have little more than local influence on the market movements of oil securities. The two major reasons for this condition might be called the technique of production and the technique of refining. The speed of improvement in each and the complete lack of control of their, inter-relation have resulted in overproduction of both crude oil and gasoline in the face of immense in-crease in demand. The trouble with oil securities has been that of the mushroom radio companies, where too frequent changes have killed the possibility of profits. It is a case of too much efficiency. During the past ten years there has been continual talk of wasting reserves of crude oil. This has been based on "present methods of production." Yet the methods of ten years ago in the oil industry are as antiquated today as the kerosene lamp.. The fear of famine has transformed the industry. The refiner, through the cracking process, has doubled the gaso-line output from a barrel of crude oil, thus doubling reserves and changing a current undersupply into oversupply. When the automobile driver desires he can again double reserves and transform want into abundance by demanding an automobile which will deliver twice as many miles per gallon of gasoline. Entirely apart from refining and in complete dis-regard for its needs, the oil producer has forged ahead at a pace too rapid for his own good. The science of geology has developed with experience and' lavish expenditure into a constant danger to profits in the production of oil. Two and one-half per ;cent of the producing wells in the United States are yielding one-half of the oil, while their flush production is used as an excuse to force down the price of crude oil until 200,000 wells must be abandoned or produce at a loss. The fabulous yield of the new high-pres-sure fields enables the fortunate owners to make a profit regardless of the price of oil. Such a condi-tion is unhealthy from the standpoint of oil itself and as a national policy. It is manifestly absurd to suppose that such a condition can endure for a gen-eration. There will come a day when the sequence of discovery will be temporarily broken, and at that time the consumer will be forced to pay heavy interest on the foolhardy policy of today.

Jan 6, 1927

By Harold D. Palmer

The marine geologist and coastal engineer have at their disposal a wide variety of geophysical tools with which to investi¬gate sea floor topography and structure. Such devices include towed magnetometers, shipboard gravimeters and a variety of acoustical systems for recording the relief of the sea floor and buried structural features. The versatility of this latter group of systems lends itself to a variety of applications essential to those projects where excava¬tion of the sea floor is required. This paper describes the use of several acoustic devices and their Limitations and presents a case history in which a rapid survey from a small vessel provided detailed information critical to the planning stage of a specific coastal project. In this discussion, shallow water is defined as depths less than 150 feet. At present, this limit includes the maximum depth of economic dredging and most other offshore activities. To be sure, the maximum depth at which routine useful work can be accomplished is rapidly increasing, but the majority of current marine activities are located in water depths here defined as shallow.

Jan 1, 1968

By J. L. Holman

The Federal Bureau of Mines has conducted research to delineate factors affecting relative fabricability of electrowon and electrorefined copper. The Bureau's Rolla Metallurgy Research Center coordinated and participated in a statistical round-robin chemical analysis and performed impact tests on lead-doped copper specimens. In a series of round-robin analyses, cathode, bar, or rod from a domestic lot of electrorefined copper and electrowon copper from a domestic and a Peruvian source were analyzed for Pb, Fe, Bi, Se, Ag, O, S, Sb, and seven other elements. The electrowon cathode from both sources surpassed requirements for electrolytic cathode, although lead in the Peruvian lot exceeded specification for oxygen-free electronic grade. The least interlaboratory agreement was for oxygen analysis, Copper specimens, doped with up to ~300 ppm Pb and consisting of as-cast material (fine-grained or coarse-grained) and hot-rolled material, were impact-tested at temperatures to 871° C (1,600° F). Impact energy of fine-grained material dropped 26 pct with increased Pb up to 20 ppm and more gradually thereafter. Coarse-grained specimens fractured at lower energy with little dependence on lead. Hot rolling raised impact energy substantially. Grain structure is evidently as significant as lead in influencing workability. Some discussion is given of possible effects of oxygen, sulfur, and porosity.

Jan 1, 1978

By David G. Dixon

A mathematical model is derived in dimensionless form which simulates the effluent concentration response of reagents from spent heaps under both fresh and recycled water rinsing. The model is based on dispersion from isochoric pathways distributed in length and cross-section, oriented normal to convection channels in ideal plug flow. The effects of heap height, rinsate flow, and initial reagent concentration are examined. It is shown that the rinsing cycle undergoes a distinct shift between fast and slow rinsing at a certain time depending on the amount of stagnant solution in the heap, and the distribution of dispersion pathways. Results of preliminary column rinsing tests on both agglomerated and unagglomerated ores are presented which partially validate the model.

Jan 1, 1994

By Duniam P

Sequencing of large underground firings is a critical aspect of blast performance. Using theory developed in open cut operations, where blast results are easier to quantify, a new technique for sequencing underground mass blasts has been developed. The basis for the technique is to identify timing regimes to control fragmentation and relief then apply non-electrics to fit these criteria. The use of computer software to graphically interpret delay statistics enables the evaluation of designs in a realistic manner.

Jan 1, 1995

By Forest J. Sur

"This report describes an exploratory project conducted by the Bureau of Mines on a fluorite deposit near Vado, N. Mex. Results of trenching are given. Together with analyses made upon samples of the ore. The Federal Geological Survey3/ completed a preliminary geologic study and mapped the deposit during the summer of 1944. A Bureau engineer examined the deposit in August 1944. As a result of these investigations, it was concluded that the deposit contained substantial inferred ore reserves. Exploratory work was recommended to obtain information that might possibly lead to production from the property. Assistance was given the Bureau by the Geological Survey.A gasoline-powered air compressor, other equipment, and supplies were delivered to the property from January 20 to 25, 1943. Trenching began under the direction of a Bureau of Mines engineer on January 25, 1947, and ended on March 15, 1945. The results of trenching and sampling form he basis of this report.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. IT is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, R.G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervisions of Dr. R. S. Dean, assistant director."

Sep 1, 1946