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By C. E. Rodgers

WHEN the writer was engaged early last year by Canadian Comstock and its subsidiary, the Metropolitan Electric Company, to act as Consulting Mining Engineer in connection with the layout and equipment of the new ore-dressing laboratories at Laval University, Quebec, the metallurgical laboratory section of the School of Mines building was completely erected, including plastered walls, partitions, etc., and finished concrete floors. At that time, however, no equipment had been ordered, except three Dominion ball-mills and two Bell screening machines. ADVANCED OR CONTINUOUS LABORATORIES The continuous laboratory section of the Department occupies the basement and three floors of the building, with an approximate floor area of 9,000 square feet. Because of limitations imposed by the design of the building (height and arrangement of rooms, strength and design of floors, etc.), modifications of layout from what otherwise seemed most desirable were, of necessity, made. These included: (a) Omission of automatic sampling of the dry ore. (b) Complete elimination of inclined belt-conveyors through floors. (c) Exclusion of bucket elevators for either dry or wet ore transfer. (d) As a substitute for grill-covered drains and floor sumps, drainage from sections or from individual pieces of equipment was piped to a disposal system in the basement. (e) Substitution in several instances of fabricated steel in place of the usual concrete foundations for machinery. (f) Reducing floor cutting and area of such opening to a minimum. Ore storage and chute capacity above the basement level was also minimized to reduce total weight.

Jan 1, 1941

In the last 30 years, human appropriation of global renewable resources has accelerated to the point where 35 per cent of the earthÆs land surface is now in managed agro-ecosystems, consumptive water use consumes between 50 per cent and 85 per cent of freshwater supply and 60 per cent of ecosystem services are utilised in an unsustainable manner. There are virtually no landscapes in which renewable resources are not already fully allocated among different economic and environmental uses. Furthermore, it is increasingly recognised that water availability issues do not exist in isolation but are linked with the related environmental issues of biodiversity preservation, the carbon cycle, soil degradation, and energy use and supply. It is against this background that the sustainable management of water in mining is increasingly developing a strategic viewpoint where water is viewed as a resource within an interconnected landscape, having economic, environmental and social value and providing a range of environmental services in the provision of public and private goods. This paper explores the issues associated with sustainable management of water in mining from a strategic viewpoint. The cumulative impacts of multiple water users, both within and outside the mining sector, is increasingly threatening the security of supply for all users. To quantitatively assess the ætrueÆ value of water it is necessary to: Better understand the science of ecosystem functioning and how human actions impact on environmental processes. Develop appropriate policy, finance and governance structures to support innovative programs that preserve ecosystem function and services (including market based instruments). Apply knowledge as interventions across landscapes in ways that maximise benefits and minimise unintended consequences taking into account differences in the value of water among sectors. A strategic viewpoint of water management relies on knowledge to guide decision making that has been acquired at a range of scales from mine site to mining region. This knowledge must be based on rigorous science, sound data and syntheses of different types of information. Strategic management of water resources will better position the industry in terms of understanding the risks posed by complex, interlinked environmental issues that are increasingly impacting on future access to land and renewable resources, including water, thereby ensuring miningÆs future social licence to operate.

Jan 1, 2009

The principal dirnensions of the chimney were fixed as follows: Height from formation to coping, 328 ft. 8 in.; inside diameter concrete shell, 13 ft. Gin.; inside diameter of the 4~-in. brick lining. 11 ft. (j in. ; shell thickness above flue inlet at a point 39 ft. above formation, 1 ft. 8in.; shell thickness at coping, 6 in. That is, the inside of chimney is cylindrical, wldst the outside is gradually stepped inwards with of 1 in. and less until the shell is 6 in. thick only at the top. With these dimensions in mind, it will be seen that some close thought was necessary to ensure a satisfactory of fonn which could be kept rigid and plumb to a height and at the same time provide safe working conditions for the labourers employed.FOUNDATIONSThe spread base of the chimney is 45 ft. in diameter, and foundations were carried down to a depth of 8 ft. 6 in. below natural surface into good hard clay which was known to be the best foundation obtainable in the vicinity being capable of withstanding, when dry, a load of 3 tons to 4 tons per square foot, whereas dead load is 1A tons per square foot and the maximum load expeeted under the most severe wind condition is 2 tons per square foot to ensure the foundation being kept dry and unaffected by ground water, the site was surrounded by a ring drain at a distance of six feet from edge of concrete foundation and at a minimum depth of one foot below bottom of concrete. Open-jointed pipes were laid in the bottom ofthe drain and graded to a pipe drain with outfall clear of the site.

Jan 1, 1924

By J. Gholamnejad

The aim of short-term production scheduling is to decide which blocks of ore and waste to mine in which time period (shift, days, weeks or months) so that several operational and geometrical constraints can be satisfied simultaneously. Since 1960s several mathematical programming approaches were developed for solving production scheduling problems that are based on a combination of various operational research approaches such as linear programming (LP), integer programming (IP), dynamic programming (DP), etc. A number of models have been developed in the past three decades but some models have limited application especially to geometrical mining constraints. One of the geometrical constraints is block accessibility. All blocks must be accessible to mining equipments on the same bench. In this paper a binary integer programming model is developed in order to incorporate block accessibility constraints in an efficient manner. This mathematical model insures that each block has been open and can be loaded and transported easily by shovels and trucks.

Jan 1, 2008

By J. D. Morgan

Introduction In 1986, the US economy passed the $4 trillion mark. However, the value of domestically processed materials of mineral origin fell slightly to $240 billion. The value of metals produced from US ores was unchanged at $5.6 billion, as was recycled scrap at $4 billion, while the value of industrial minerals rose slightly to $17.9 billion. Consumer demand strongly affects mining and the US economy is relatively saturated with longlived products. Moreover, in recent years there has been a steady increase in consumer, mortgage, and federal debt, inhibiting new purchases of goods. Motor vehicles and housing are major traditional markets for mineral materials. However, the 242 million US citizens already possess 170 million licensed motor vehicles and 92 million dwelling units. In 1986, domestic motor vehicle production fell 3%, to 11.3 million units, while new housing starts rose slightly to 1.8 million units. Nearly all mineral commodities move relatively freely in world trade. As detailed in Figs. 1 and 2, in the last three decades world production of major mineral materials has greatly increased. At present, substantial excess productive capacity exists not only in the US but also in many other countries. Consequently, the US mineral industry is encountering increasing competition from other sources, along with increasing competition from newer, engineered materials. For example, US production of plas¬tics has risen from 900 kt (1 million st) in 1950 to 22.7 Mt (25 million st) in 1986 - on a volume basis significantly greater than steel. Plastics, too, are mineral-based materials, some 7% of petrochemicals going to their manufacture. 1986 saw increased calls for protection. But President Reagan, in his 1987 State of the Union Message and Economic Report to the Congress, reaffirmed adherence to a policy of free and fair trade. However, he stressed the need for increased efforts to open foreign markets to US exports and to increase competitiveness of US industry US imports of mineral-based minerals in 1986 were valued at $40 billion and exports at $24 billion. Strategic minerals As detailed in Fig. 3, imports supplied a significant proportion of total US consumption of several important materials, including many classified as "strategic and critical." There were no changes in stockpile policy during the year. Congress debated the President's 1985 proposals to reduce stocks of World War II-type materials and to focus more on high technology materials needed for the cutting edge of future military material. But no final action resulted. However, Congressional concern about apartheid in South Africa did result in increasing pressure to limit imports of South African minerals. Meanwhile, the National Critical Materials Council in the Executive Office of the President intensified its efforts to be better able to advise the President. The Defense Production Act provides authority for priorities and allocations, supply expansions, voluntary agreements, and

Jan 5, 1987

By J. Y. Hascoet, M. Marya, S. Marya

Additive manufacturing (AM) brings disruptive changes over the ways parts and products are designed, tested, qualified, assembled, inspected and marketed. With these changes come real technical challenges, therefore, concerns that mainly stem from the maturity and diversity of today’s AM processes, the feedstock materials, and the interactions between the numerous process parameters. Additive manufacturing is somewhat similar to laser and electron-beam conduction-mode welding and involves a multitude of dynamic physical events between projected feedstock and moving heat source that influence process robustness, thus deposit properties. For this paper, a simple air vent, selected for its size, thin-wall, hollow geometry and materials (specifically 316L) was made using a laser-based powder blown technology (Construction Laser Additive Direct or CLAD) and systematically inspected by optical microscopy, microhardness indentations, and electron-back-scattering diffraction (EBSD). This exemplary part is first analyzed to broadly discuss metallurgical phenomena in additive manufacturing, particularly solidification and texture development. The paper then expands to other alloys and continues correlating metallurgical observations to process parameters and part properties, also borrowing from past experience with the same 3D printing CLAD system.

Jan 1, 2014

By S. H. Jason Choi

The Systems Conveyance and Operations Program (SCOP) is being implemented to convey tertiary-treated effluent to Lake Mead near Las Vegas, Nevada. The Reach 3 Tunnel Project is part of SCOP. The tunnel?s planned location along and across the Las Vegas Wash creates challenging tunneling conditions. A number of feasible excavation and initial support methods are being considered during the final design stage. This paper describes how the tunnel construction options were refined based on anticipated tunneling conditions and compatibility between tunnel excavation and initial support methods. A brief description of the most significant characteristics of the anticipated ground conditions is included for the purpose of discussion.

By M. Moseki

Paper written on project work carried out in partial fulfilment of B.Sc. (Eng.) (Metallurgy of Materials) degree This paper presents the research into melting of scrap for job creation purposes in rural areas. The research was done on behalf of Mine Recycling Services (MRS), the company that will implement the project. The project involves the research into available cost effective and easy to operate technology. The paper covers the experimental and theoretical work that was conducted. The results were used to determine the best equipment and method for melting and casting brass scrap.

Jan 1, 2002

By W. C. Lacy

Stratabound copper ore bodies in thick Proterozoic metamorphosed sedimentary and volcanic rocks at the Tong Kuang Yu Mine in southern Shanxi Province of China were considered as possibly being amenable to block cave mining. Initial evaluation of caving characteristics was based upon old calyx drilling records, limited underground mining experience and geological mapping, a few diamond drill holes and measurements in surface subsidence features. Classification and mapping distribution of rock quality types aided in mine design, prediction of fragment sizing and explosive requirements, cave assist and ground support requirements. Comparison is made between early feasibility predictions and actual mine experience.

Jan 1, 1989

By B. Lueger, D. Shen, M. Sedighy, R. Rand, R. Saleh, J. Cheung, M. Rifai, I. Khan, W. Sauri, D. Setianto

The world’s first active power demand stabilization system for a 3-electrode electric arc smelting furnace was commissioned at PT Vale Indonesia in December 2012 on Furnace No. 2 using an SPLC (Smart Predictive Line Controller). The SPLC technology in combination with the Furnace No. 2 rebuild and other upgrades has enabled PT Vale to increase the electrical input to the furnace by up to 20% on a stable and sustainable basis by eliminating peak powers that overload and trip out the electrical equipment, and by reducing power unbalances. The SPLC technology maintains smooth arc power using a continuously variable thyristor controlled series reactor. The SPLC compensates variations in the furnace arc with predictive changes in the circuit reactance at a speed of up to 60 times a second. The system started up quickly and has been shown to be easy to operate and maintain by PT Vale. PT Vale’s Operations Team has been testing the new system at set points of up to 90 MW on the newly re-built Furnace No. 2. Over the last 12 months, the throughput of Line 2 has increased by approximately 10% on an annual average; however, debottlenecking in other design areas of the operation is required in order to achieve 90MW operation on a sustainable basis. This outstanding success results from a combination of the furnace and other upgrades, the SPLC active power stabilization, and the skill of PT Vale in quickly adopting new technologies and maximizing the combined benefits of each technology in their operation.

Jan 1, 2014

By C. Özgen Karacan

The methane emission rate into an underground mine environment from overburden strata during longwall mining is impacted by reservoir and geomechanical characteristics of the coal measure rocks in the overlying strata, as well as the presence of any coal seam. The reservoir characteristics and how they change during mining potentially affect the performance of gob gas ventholes, which consequently impacts the efficiency of methane control in the mining environment. This study presents reservoir and elastic properties of coal measure rocks in the Lower Monongahela Group in Greene County, southwestern Pennsylvania, of the Northern Appalachian Basin. Since the source of methane in this region from underground mining is located between the Sewickley coal and the Pittsburgh coal, a specific emphasis was given to this interval. Core analyses were performed in the laboratory to determine rock porosity and permeability. Geophysical logging data (gamma, density, sonic) obtained from two exploration boreholes were used for evaluating formation boundaries, shale contents, log porosities, and geomechanical properties of formations. Permeability was also calculated using density-log data and empirical equations and compared with laboratory measurements and slug tests performed in isolated intervals of boreholes. The results presented in this study can be used as data sources for reservoir studies related to the production and control of methane.

Jan 1, 2009

By G. I. McPhail

The authors have conducted several investigations into the prediction of the beach profile of high-density tailings and have found that there are a number of important considerations that need to be taken into account over and above the reliability of the beach profile prediction methodology. These considerations relate to the chemistry of the slurry and specifically the influence of pH and flocculation, both of which have a significant influence on the rheology of the slurry at the discharge point. A number of examples are discussed and a potential testing protocol that will assist in assessing the influence of chemistry ahead of the beach profile predictions is presented. A methodology for assimilating the results of the testing into the likely field situation is discussed, and suggestions are made on application of the results in beach profile prediction. The suspected influence of residual flocculation on the stratification

Jan 1, 2012

By J. Willan

This paper addresses the problem of designing a destress blasting procedure to reduce the incidence of rockbursting in hard rock mines. A review is made of the developed theory and practice of destress blasting in rockburst-prone ground. Specific reference is made to a recent survey of past and current practice with particular reference to Ontario mining operations. The need is identified for a more scientific basis for destress blast design and monitoring. Reference to developments in blasting technology as well as rock mechanics are then made to support a proposed, integrated design procedure and research strategy.

Jan 1, 1984

By F. A. Rutledge

The Millet copper deposit is on the north shore of Iliamna Lake in southwestern Alaska. Copper mineralization occurs in a zone of altered limestone .adjacent to and intruded by a diorite porphyry with some diabase facies. During 1949 and 1950, the Bureau of Mines investigated this prospect as a part of the U. S. Department of the Interior program in Alaska for the development of critical and strategic minerals. Field work was begun August 8, 1949; it was recessed November 28, 1949, because of inclement weather. The work was resumed Nay 28, 1950, and completed July 3, 1950. The program of investigation by the Bureau of Nines included topographic surveying, machine and hand trenching, diamond drilling, and sampling the zones of mineralization. This report outlines the general geology of the area, gives a description of the deposit, and contains the factual data resulting from work by the Bureau of Mines.

Jan 1, 1952

By Sivan Iswaran, Will McLean

This paper details a 2MLD ion exchange water treatment plant which selectively removes arsenic, antimony, iron, hardness, and sulphate from mining water; designed to meet environmental quality indicators such as sulphates. The client, Fosterville Gold Mine Pty Ltd, is owned by Kirkland Lake Gold and is one of the world’s highest grade gold mines. The site located near Melbourne, Australia had identified a risk of reduced mine water storage capacity due to surface run-off and increased sulphate rich dewatering of the underground mine at depth. Clean TeQ Water carried out the project management, process design, procurement, and commissioning for the plant, which was handed over in August 2020.

Sep 30, 2022

A rotating disc geometry was used to provide a uniformly accessible surface for a kinetic study of the cementation of cadmium, lead, and silver from dilute aqueous solutions. This work is an extension of studies carried out on the Cu-Zn and Cu-Fe systems for which the reaction rate was found to be completely solution phase mass transfer controlled.When the amount of material deposited was greater than 0·2 to 0·4 mg/cm2 there was an apparent enhancement in rate which is attributed to the formation of a roughened deposit. This same phenomenon was observed in the Cu-Zn and Cu-Fe systems. Again, the rate of reaction of each system investigated was found to be solution-phase mass transfer controlled.

Jan 1, 1971

By D. Fray

Electrochemical processing using molten electrolytes is undergoing a considerable renaissance due to several innovative ideas being explored both in the laboratory and also at the pilot scale. Several of these new ideas are related to developments in energy generation and storage and involve solid electrolytes. Sodium has been prepared by the electrolysis of sodium carbonate or sodium hydroxide with the transfer of sodium ions through a sodium beta" alumina membrane and magnesium oxide dissociated by the removal of the oxygen through a stabilized zirconiaelectrolyte incorporating a fuel cell electrode. By using halides with highly electropositive cations, such as molten calcium chloride, it has been found that the favoured cathodic reaction, when oxygen is present, is the ionization of oxygen and not the deposition of calcium. This approach has been applied to the reduction of many metal oxides including titanium, zirconium, niobium and rare earth oxides and, by using a mixture of oxides as the cathode, homogeneous alloys are produced. This concept can also be applied to deoxidation of solid and liquid metals. Refining of metals is possible using intercalation compounds and, in a completely different application, it has-been found that, by intercalating alkali metals by electrolysis of alkali halides into graphite, it is possible to produce carbon nanotubes and nanoparticles. The technological opportunities of these various concepts will be discussed.

Jan 1, 2004

By George A. Morgan

Output of mineral products was estimated to be unchanged in 1983 from that of 1982 with the exception of petroleum. The country began production of crude oil from the Seme Oilfield, and all output was exported. Wd and charcoal constituted 72% of Benin's total energy consumption, and imported petroleum products and electric power accounted for the remainder. Cement was produced from imported clinker. The gross domestic product (GDP) was $1,061 million in 1982, the latest year for which information was available.2 COMMODITY REVIEW Gold.-Exploration was underway at Perma by the U.S.S.R. as part of the United Nations development program. Gold had been produced previously at Perma, where a grade of 0.289 troy ounce of gold per ton was reported, An exploitation program for the deposit was to employ about 100 people, and output was targeted to reach 1,600 troy ounces per year. Recoverable reserves were put at 96,000 troy ounces.

Jan 1, 1985

By E N. Sajin

The final arsenic bearing waste products at the majority of metallurgical and chemical enterprises are cakes in which arsenic is present in the form of calcium arsenate. Burial of cakes demands construction of special burial sites and does not guarantee reliable protection from arsenic penetration into the ground and surface waters. Under laboratory conditions we developed technology for processing calcium arsenate cakes with obtaining low toxic products suitable for long-term storage, meeting environmental requirements. The investigations have shown that thermal processing of briquetted mixtures of cakes containing 15 - 20 per cent weight of pyrite under the temperature of 873 - 923¦K during 45 - 60 minutes gives briquettes sufficiently hard for transportation and long-term storage. Arsenic, under high sulphidisation temperature is bonded into low solubility non-volatile iron sulphide bearing compounds having chemical properties similar to the natural arsenic compounds. Solubility of the obtained products in neutral, acid and alkaline media was investigated during long period of time (three to 12 months). It was determined that arsenic content in the solutions did not exceed the norms for cultural and welfare basins and fish-ponds.

Jan 1, 2002

By N. Hiroyoshi, R. D. Corpuz, M. Ito, Hokkaido University, C. B. Tabelin, S. Veerawattananun

"Acid mine drainage (AMD), the very acidic and heavy metal-contaminated leachate generated when pyrite-bearing rocks are exposed to surface oxidizing conditions, is a serious environmental problem encountered after the closure of mines and mineral processing operations. In this study, we investigated the effects of soluble phases and metallic oxides, which are commonly found in strongly weathered pyritic wastes, on pyrite oxidation. Strongly weathered pyrite containing melanterite (FeSO4·7H2O) as the main soluble phase was obtained from Furikusa mine, Japan. The sample was washed using two methods to vary the relative amounts of melanterite in the sample. The effect of metallic oxides on pyrite oxidation was evaluated using ultrapure hematite suspensions. Our results showed that under acidic conditions, the effect of soluble salts on the oxidation of pyrite was stronger than hematite. More thorough washing of the sample resulted in the formation of an arsenic-bearing iron-oxyhydroxysulfate coating that minimized pyrite dissolution. This oxidized layer became relatively thicker and mechanically stronger when hematite was introduced after the more thorough removal of soluble salts. Characterization of this “coating” coupled with geochemical modeling suggest that it is most probably composed of two materials: schwertmannite and scorodite. Based on these results, a new approach to suppress pyrite oxidation by directly using iron-oxyhydroxysulfate as coating material is introduced.INTRODUCTION Acid mine drainage (AMD), the very acidic and heavy metals-contaminated leachate produced in closed/abandoned mine sites (Evangelou, 1995), mineral processing and coal cleaning tailings (Evangelou, 1995), and tunnel construction waste rocks (Tabelin and Igarashi, 2009, Tabelin et al., 2012), is one of the oldest and probably the most serious environmental problem of anthropogenic origin. When released to the environment, it rapidly pollutes river, soil and groundwater systems leading to the destruction of affected ecosystems. AMD is produced when pyrite (FeS2), one of the primary gangue minerals in sulfide ores and coals, is exposed to oxidizing conditions as illustrated by the following reactions:"

Jan 1, 2016