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By William J. Orlandi

The intent and scope of this paper is to present to you, as concisely as possible, the problems and requirements -- and what we consider advantages -- of all-belt haulage in a modern underground coal mine. Mine No, 10, at Pawnee, Illinois, was opened in 1951; consequently, all the planning and consideration given to haulage selection was based on information then available and on Peabody Coal Company? s experience to that date,

Jan 1, 1961

During a period of six months in FY2018, a series of trials were conducted to compare drilling accuracy using two different methodologies and the subsequent impact this had on ore dilution. Testing was conducted at Cracow underground gold mine in Queensland, Australia. The drill rig’s existing alignment process was compared to a new technology system with the following observations: - Using the existing alignment process only 20% of holes surveyed recorded toe points within the +/-300mm (11.8in) tolerance blast-hole deviation. - The new technology was proven to limit rig alignment error, reducing average blast-hole deviation and increasing the number of holes drilled within tolerance by 160%. The increased accuracy reduced stope dilution by reducing over-break of subgrade ore: - Stopes drilled using the new technology recorded 62.6% less average dilution. - This contributed to an overall reduction in dilution for the full year (FY18) of 5 percentage points compared to FY17 - from 22% to 17% (a net decrease of 22.7%). A cost-benefit analysis extrapolated from the trials stipulates that if the new technology were in use for a full 12 months, when applied to FY17 full year data, a 10 percentage point reduction in dilution would represent a net 45.4% decrease, and would result in AUD8.2M (USD5.9) additional ore recovered, with AUD4.5M (USD3.2M) less spent on wasted cost of haulage and processing of diluted ore. As a result, return per tonne would increase 22%, from AUD87 (USD63) to AUD106 (USD77.1). INTRODUCTION Dilution – planned and unplanned – remains a significant cost impairment in the mining process. A series of trials were held over a six-month period in FY18 which established the cost-benefit of new technology as it applies to the alignment accuracy of production drilling rigs in underground mining, thus confirming its ability to limit drilling as one of the causes of dilution. The trials identified three underlying factors affecting drilling accuracy, measurable by blast-hole deviation surveys of planned vs actual toe data. These were; rig alignment error, collar location change/error, and in-hole deviation. The trials involved a comparison of existing rig setup processes and technology, with the new technology (Minnovare’s Production Optimiser system). The trials were undertaken in the same environment; an operating underground gold mine - Cracow Gold Mine. The comparison first revealed the extent to which rig alignment impacts blast-hole deviation. Secondly, the new technology was proven to limit rig alignment error, thereby reducing average blast-hole deviation and increasing the number of holes drilled within tolerance by 160%.

Jan 1, 2019

By E. Nickel

"Bi- and multilateral banks as well as export credit agencies in the OECD countries, but also numerous commercial banks, last year committed themselves to compliance with the World Bank’s standards. These environmental and social guidelines, also known as the Safeguard Policies, are the strictest international standards in the area of financing of major investment projects. The Safeguard Policies are procedural and quality guidelines by means of which socially and environmentally relevant impacts can be taken into account in the planning and implementation phase of a project. Objectives of the Bank Safeguard Policies are to ensure that environmental and social issues are evaluated in decision-making, to reduce and manage risk of projects and programs, and to provide a mechanism for consultation and disclosure of information. They are often referred to as the "10+1 Safeguard Policies," since ten of the guidelines address environmentally and socially relevant issues, while one guideline is exclusively concerned with public participation ("Public Disclosure"). In the presentation, the transparency of risk management measures and emergency response plans in pipeline projects will be discussed as an indicator of sustainability. The discussion is to be carried out on the basis of the results of an evaluation of several major pipeline projects, which have been financed at least in part by multilateral banks over the past few years. The controversies surrounding some of these projects due environmentally and socially relevant impairments connected with the investments have also been addressed by the Extractive Industry Report of the World Bank. Pipeline construction was the investment type chosen for the examination to be presented here, since pipelines frequently start in remote, unspoiled regions, and their routes often cross various natural zones and areas with various social structures. The question of safety during construction and operation of the line is always central to these projects; not only for the responsible authorities but also for other societal groups involved, such as environmental associations."

Jan 1, 2005

By R. E. Brewer

Pilot scale flotation tests were conducted with a 1-ft-diam column at the Barrick Resources (USA) Mercur mine, Tooele County, UT, to scavenge unleached (0.01 to 0.018 oz/st) gold values from the tailings of a carbon-in-leach (CIL) circuit. The optimal recovery was 35 pct of the unamenable-to-leaching gold, at a grade of 0.353 ounces of gold per short ton, using a mixture of dithiophosphate, xanthate, and diesel fuel as a collector. This was achieved by floating approximately 1.6 wt pct of the CIL tailings. The gold values are believed to be contained in arsenic-bearing minerals, attrited carbon, and carbonaceous material in the ore. Redox potentials were measured with a gold electrode during the conditioning stage prior to flotation. The correlation between flotation recovery and redox potential values could be used to control reagent additions. Treatment of a previously leached and weathered tailings material, averaging about 0.055 ounces of gold per short ton, was also investigated using the column. The tailings were first water leached at approximately 600 C, and the water-leached tailings, which contained approximately 0.03 ounces of gold per short ton, were then fed to the column flotation unit. The effects of pH and sodium sulfide addition on gold flotation recovery and redox potentials were examined. maximum gold recovery, 36 pct, was achieved at pH 8.5 with a sodium sulfide addition of 0.18 lb/st.

Jan 1, 1989

By D. R. Nagaraj

The practice of nonsulfide minerals flotation can be best characterized as an evolutionary blend of scientific theory and art. Although extensive fundamental studies have been carried out in the past several decades, and significant theoretical aspects have been developed, plant practice has developed the art form, often ahead of the theory, which is somewhat in contrast to sulfide minerals flotation. Several excellent review articles have been published in the past highlighting both the theoretical aspects and plant practice. An overview of nonsulfide flotation is presented here. Major differences in sulfide and nonsulfide flotation are highlighted. An assessment of the state of nonsulfide flotation, recent advances made in flotation processing, and industry needs are also given.

Jan 1, 1999

By J. Eldridge, A. J. Carter, D. N. Leavell

Minpro International has developed an innovative, flexible¬shaft impact crusher that produces glass aggregate from mixed¬color, post-consumer glass. The crusher operates with low power and generates a subangular aggregate, with minimal fines. Output is screened to yield sized aggregate, which can be used directly as surfacing material in Owens Corning's shingle process. Metal, plastic and paper waste is preferentially removed by the Minpro system. Duval County and the City of Jacksonville collect more than 12,000 tons of glass bottle waste per year. It is anticipated that a successful end-use application by Owens Corning, will allow increased collection and cost-effective glass recycling in north Florida.

Jan 1, 2002

By J. Drzymala

Particle beneficiation tests are often conducted to determine how the recovery of a key component of a particle mixture varies with overall product yield, i.e., the separation curve. The results can be misleading when an attempt is made to determine the effect of feed grade by comparing separation curves representing different feed grades or key component concentrations. This is a shortcoming of the conventional recovery versus yield diagram, which may not appear to be affected by feed concentration. To overcome this shortcoming, a method is presented for transforming and normalizing the recovery and yield coordinates so that the separation curves representing dif-ferent feed concentrations are directly comparable.

Jan 1, 2007

By Niles E. Grosvenor

Several methods have been proposed for determining the tensile strength of rock. These have been tried out over the past several years, but the results have been erratic and of doubtful value. The tensile strength of rock is its weakest property, and this property apparently enters into all failure phenomena whether underground or on the slope of an open pit. Therefore, it is essential that detailed quantitative information is known about the tensile strength of rock if the design engineer is going to select the proper pit' slope, pit orientation, or orientation of underground workings so as to give the most economical and safest mining condition. This quantitative information may be used to orient the pit in such a manner as to allow steep slopes along two sides. This information may possibly be used to orient the direction of either underground workings or open pits so as to decrease powder consumption and to increase blasting efficiency. Hence it is of prime importance that a method of determining accurately the tensile strength of rocks be developed.

Jan 1, 1960

By A. D. Walters

Computer simulation models of preparation plant operations and cost analysis have been used to determine the profitability of individual coals. The model's input consists of raw coal size and washability analysis, operating cost data, and raw coal and clean costs. The model's output predicts yields, qualities, costs and profitability for an individual coal.

Jan 1, 1987

By G. S. S. Raman, M. S. Klima

Coal refuse slurries stored in tailings impoundments can potentially lead to environmental concerns such as effluent seepage, property devaluation, and in extreme cases, dam failures. Pressure filtration offers an opportunity to reduce the impoundment requirements by providing significantly drier solids. A full-factorial design was used to study the effects of temperature and pH on dewatering a refuse slurry obtained from a coal preparation facility in Pennsylvania, USA. The experimental results indicated a strong effect of temperature on cake moisture as the cake moisture after about 2800 s was 22% at 43 °C and only 36% at 10 °C for tests conducted at pH 3. ANOVA results confirmed the statistical significance of pH, temperature, and their interaction effect. Also, the results showed no significant differences between the tests conducted near neutral and alkaline pH values at low and ambient temperatures. On the other hand, Tukey’s test indicated higher reductions in cake moisture at higher temperatures for lower pH values. This study affirms the need to monitor and control the pressure filtration process as throughput could significantly vary with changes in temperature and slurry conditions.

By Jozef S. Stachulak, Bruce R. Conard

INTRODUCTION The concern of occupational exposure to diesel exhaust pollutants is an important workplace issue for the mining industry. During the last three decades of diesel operations at Inco, a significant amount of research and improvement has been made in the area of work environment, and effective diesel operation. This paper will review the experience gained by Inco's Ontario Division from the implementation and the use of modern engines, improved fuel quality, and the exhaust control technology, coupled with adherence to proper maintenance and ventilation design and practices. Past monitoring practices and the current occupational monitoring program at lnco are outlined. A major new research initiative involving multi-stake holders in diesel performance is described. MINING IN THE SUDBURY AREA The discovery of nickel-copper ore in the Sudbury area dates back to the year 1856. The existence of this orebody was noticed when a strong compass deflection was observed by a provincial surveyor. This discovery, even though documented in official re- ports, failed to arouse any public attention at that time. In 1884, a rock-cut was blasted through a small hill near the village of Sudbury to permit laying track for the Canadian Pacific Railway (Boldt 1967). The rock-cut uncovered a body of massive sulfides with a copper content of over nine percent. The mineralization is concentrated along the outer margin of the Sudbury Basin, an oval-shaped structure having a dimension of 55 x 95 kilometres. The ore extends down-dip to to at least 3000 metres below the surface. The mining methods at lnco can be divided into two categories: "filled-stope" and 'bulk" mining. This division, in the broad sense, may also reflect the environmental conditions of the mine. In the past, the selection of a mining method was based on the size, shape, grade and the strength of the ore and its surroundings. The recent development of improved technology and mining equipment permitted wider application of low cost bulk mining methods. UNDERGROUND DIESEL EQUIPMENT The first diesel-powered machine, a 145-horsepower scooptram, was put into operation in March 1966, in a cut-and-fill stoping complex at Frood Mine. The number of diesel machines underground in the Inco, Ontario Division, mines was increased to 360 units by 1971,550 in 1977 (Rutherford 1978), and over 830 diesel-powered units in 1995. The following list indicates current mobile diesel equipment. LHD 194 Loaders 81 Trucks 28 Jumbo Drills 78 Personnel Carrier 101 Service Equipment 155 Locomotives 50 Bolters 30 Scissor Lift 113 About 20 percent of the LHD and truck units are equipped with electronic fuel controlled engines. COMPOSITION OF DIESEL EXHAUST Diesel exhaust contains hundreds of pollutants (Watts 19921, including components of unburned fuel and lubricating oil and products of incomplete combustion of the fuel and oil. These pollutants are emitted either as gases or as particles. Gaseous pollutants include carbon monoxide, nitrogen oxides, and sulfur ox- ides, as well as a variety of organic compounds, such as hydro- carbons, aldehydes, and polynuclear aromatic hydrocarbons. The particle phase, also known as diesel particulate matter (DPM), is the filterable portion of diesel exhaust. Figure 1 depicts the trimodal particle size distribution that arises from different mechanisms of aerosol generation (Cantrell and Rubow 1992). Primary combustion aerosols, including diesel exhaust aerosol, are formed as very small particles (in the 0.001 to 0.08 micrometre range), but physical mechanisms such as condensation and coagulation quickly transfer the aerosol mass from the nuclei mode to the accumulation mode. These processes result in a mass median diameter of approximately 0.2 micrometres for diesel particulate matter, and 90% of the particles are less than 1.0 micrometre in size. These particles have a high surface area, permitting the adsorption of different substances produced during combustion. Mechanically generated aerosols, on the other hand, typically contain particles greater than 1 micrometre in diameter. The particle phases of diesel exhaust contain three components (Bagley, et al, 1996) shown by Figure 2, namely: a carbon- aceous fraction composed mainly of solid-carbon particles, a sulfate fraction containing small hydrated sulfate particles, and a soluble fraction that contains compounds that are soluble in organic solvents and are adsorbed or condensed onto carbon core particles. These compounds consist primarily of higher molecular weight hydrocarbons and PAH's and may contribute 15% to 45% of the weight of the total particulate matter (Schuetzle, 1983). The control of these pollutants is necessary to ensure a healthy work environment. Proper engine maintenance, engine design modifications, improved fuel quality, and use of exhaust control technology, coupled with good ventilation practices, all

Jan 1, 1997

By J. A. Matar

Mineralization features at the Bajo La Alumbrera porphyry copper-gold deposit are discussed as they affect gold leaching and copper flotation behavior. Alteration-mineralization geological blocks are assigned in the zoned body, and each required its own geostatistical model. They extend horizontally outward from potassic to the phyllic-propylitic boundary, vertically from surface down to 300 meters, and include oxide, secondary enriched, and hypogene mineralization. Copper and gold values are calculated geostatistically from assays and all available geologic-mineralogic information. Reserves are classified for each geologic block and for each open-pit bench into leach or float ore according to metal grades, geologic characteristics, and supergene-hypogene relations. Finally ore extraction behaviour is briefly described, grouping gold and copper reserves into metallurgical families.

Jan 1, 1986

By Ernest L. Bradley

A positive pressure ventilation system, augmented by a dewatering well curtain and underground longhole drilling, provides effective ventilation and radon control at EXXON Minerals Company's Highland Underground Mine in the Southern Powder River Basin of Wyoming. Testing different types of bulkheads, sealants, and bleeder systems has led to improvements in the basic ventilation system. Continued testing of new or different materials and equipment is expected to lead to further improvement in the ventilation program. Effective training of both miners and supervisors is essential to maintaining and improving ventilation techniques. This paper addresses the ongoing ventilation program and experience to date at the Highland Uranium Mine.

Jan 1, 1979

By Timothy M. Dyhr, Marie Garrett

The Cannon Mine gold project has been perceived as unique for being developed in an area characterized by orchards and suburban residences. The Cannon Mine was permitted and developed successfully in this setting. However, the ability of companies to permit, develop and operate mines in mated areas is becoming more difficult as a result of opposition by residents and increasingly stringent regulation. The challenge to the mining operator in the future on otherwise economically attractive mineral deposits will be the ability to explore and develop these types of projects successfully and cost- effectively

Jan 1, 1987

By B. J. Arnold, F. F. Aplan, S. Chander

There is a broad range of chemical reagents of potential use to the coal preparation industry: flotation frothers, flotation collectors (for coal, ash minerals or pyrite) and collector-assisting (conditioning) agents, flotation depressants (for coal, ash minerals or pyrite), pH regulating agents, acid mine drainage treatment chemicals, flocculants, filtration aids, dispersants, dust suppressants (wetting agents and car-top or pile binders), freeze conditioning agents, water treatment chemicals (corrosion and scale inhibitors) and suspension stabilizing reagents (dispersants, stabilizers, biocides). The application of each of these types is discussed with particular attention paid to those of greatest importance: flotation frothers and collectors, pH regulators and acid mine drainage treatment chemicals, flocculants and freeze conditioning agents.

Jan 1, 1986

By C. Sun

With complex component, higher salt content, low biodegradability, DSD acid oxidation wastewater could not be efficiently dealt with traditional methods. It is pointed that the coal water slurry could be made with DSD acid oxidation wastewater of different concentration and the density of coal water slurry could be up to 70%, while its viscosity is only 850~930 mPa?s. The coal water slurry could be perfectly jetted and burnt under different conditions. The higher density the DSD acid oxidation wastewater has, the better properties the coal water slurry have. The pollution components and characteristic group of DSD acid oxidation wastewater are similar to the additives of coal water slurry, so it could be used as a kind of usable additive of water coal slurry. It is so reasonable and feasible to make coal water slurry with DSD acid oxidation wastewater that the pollution of DSD acid oxidation wastewater can be solved completely.

Feb 23, 2014

By Brian E. Davies, Bobby G. Wixson

INTRODUCTION The impact of modern mining and ore processing on the environment is readily minimised. Our improving knowledge of how pollutants are released to and move through the environment has been accompanied by better expertise in controlling these emissions. For example, when the new mines and smelters were developed in the Viburnum Trend of Missouri a sulfur dioxide pollution problem was quickly recognized and soon controlled. (Wixson 1974) But older operations were not efficiently organized and, despite their smaller scale, they often caused major pollution problems. The British mining fields are among the world's oldest and during the heyday of their operation (approximately 1750-1900) they were worked with- out regard to their environmental impact. The Rivers Pollution Commissioners in the mid-nineteenth century were led to remark that ore dressing was carried on in a slovenly and wasteful manner and the complaints by farmers, that river borne mine wastes were poisoning both their crops and stock, were justified. (Frankland and Mortan, 1984). The Comissioners report led to the 1876 River Pollution Act of Parliament, the first modern environment protection legislation. The development of mining since the last century is characterized by improved regulation of the pollution potential of ore dressing, smelting and refining. The collective memory is unfortunately long and pessimistic. A serious problem arises when old mines are reopened especially if the mine has not been worked for several years since local action groups may soon blame the new owners for causing problems which, in reality, are longstanding and were caused by the use of earlier state of the art technology. It is therefore essential that during the early development stages prior to reopening that comprehensive studies be carried out to identify and quantify local contamination problems. These baseline studies should include surveys on the nature and composition of old tailings disposal areas and other wastes on the mine properties. The composition of air and water should be monitored. Soils are long term sinks for all heavy metals and particular attention should be paid to soils within any city areas near the mine since there are sources of heavy metals in urban areas which are not connected with mining and ore processing. This paper describes some of the results of such a study around a prospective cobalt mine in Southeastern Missouri. It is restricted to the soil survey of forest and agricultural land which took place in and around Fredericktown, Missouri. The city is located at approximately 37° 30' North and 90° 20' West and lies 143 kilometers south of St. Louis. There are several metal mines near Fredericktown, including Mine La Motte, which is the oldest and was first opened in 1720. [Figure 1] is a location map of the area. The survey described here was in connection to the reopening of the Madison Cobalt Mine which was first worked in 1947.

Jan 1, 1985

By Zbigniew Hladysz

INTRODUCTION In the Polish coal mining industry, the Upper Silesian coal basin has an important position. It contributes over 98% of the total coal production of Poland which reached 193 mt in the year 1979. In view of the significant urbanized area in this region as well as the industrial potential, it is important to protect the surface by stowing the mined out underground workings. Approximately 18% of the total production is mined from longwall faces with stowing. However, caved longwall faces are most popular. In the upper Silesian coalfield, approximately 337 highly mechanized longwall faces are in operation. Out of these 337 faces, 301 longwall faces are caved. One of the main requirements for effective and safe coal extraction is a suitable method for strata control. We can divide the complex process of strata control into four steps: 1. Strata investigations 2. Selection of supports for roadways 3. Selection of supports for longwall 4. Rock bursts and other hazards protection STRATA INVESTIGATIONS Estimation of the structure and physico-mechanical properties of the rock mass surrounding the workings is an important constituent of strata control. These factors definitely influence the rock stability, support load, working conditions as well as the mining technology. Complex methods of strata investigations involve a set of indicators enabling the estimation of the stability of the roof rock, strength of the coal seam and load bearing capacity of the floor. The basis for the evaluation of roof stability for a coal seam is the classification according to the resistance to bed separation (1). The bed separation resistance is equal to the strength of the rock in tension perpendicular to the bedding plane. In order to properly classify a rock, it is indispensable to make continuous profiles of the bed separation resistance from the immediate roof up to a distance of three times the thickness of the coal seam. The profiles are developed by utilizing mine roof investigations with the hydraulic borehole penetrometer. (Fig. 1) The penetration resistance is determined by the critical pressure required to cause crushing of the rock by the penetrometer indentor (2). The classification of roof rocks and their ability to cave spontaneously during longwall mining is shown in [Fig. 2]. The measurement of the critical pressure also allows for the determination of the compressive strength of the rock, the index of workability and roof fissuration.

Jan 1, 1982

By Lawrence K. Nordell

Historical methods of designing steel cord belt splices are compared with modern finite element modeling (FEM) methods. Dependence of the belt strength rating on the splice dynamic fatigue strengths is reviewed. A number of splice schematics are examined, using simple spring theory and FEM methods. Steel cord wire rope design is discussed. The importance of the insulation gum rubber properties and their splice dimensional factors and tolerances are analyzed. Splice fatigue lie analysis procedure is reviewed. This may be used to predict splice life or time of failure, depending on how the conveyor belt is operated.

Jan 1, 1993

By Robin J. Batterham, Stephen H. Algie

It is often stated that innovation is central to the economic survival of mining and mineral processing in the face of global competition, and yet technology is often far from a core strategy in our industry - hence the concerns that are often voiced about the apparent slow rate at which new technology is applied. Much of the discussion stems from a lack of understanding of the role of technology in innovation, and of the role of R&D within the innovation process. To a large extent this has all been said, however, the messages are clear and deserve repetition. This paper expresses the personal views of the authors, based on experience in government-funded (CSIRO and universities) research, and in CRA Ltd, a large mining and mineral processing company. Further than this, it explains how our own development unit within the CRA Group has come to see its key roles as including the transfer of technology, and the training of technologists to move into the operating business units. We conclude that these critical tasks are the keys to creating the environment that will allow us to maximise the contribution of technology.

Jan 1, 1995