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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 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 Julie N. Walker

This U.S. Bureau of Mines report reviews the first 2 years of the agency's progress in implementing total quality management (TQM), which the agency refers to as Quality Improvement (QI). All employees have been trained in basic TQM concepts, a cadre of facilitators has been selected and trained, and 13 Bureauwide teams are addressing specific issues that were identified by Bureau employees nationwide as problem areas. Also in place are a Quality Council composed of the Bureau's top executives, a Quality Management Board, and eight QI Working Groups to provide a national 01 infrastructure. There are also Quality Steering Groups at each Bureau location nationwide to address local concerns. In addition to the narrative text, the texts of salient memoranda and other documents are included as appendixes.

Jan 1, 1992

IN the irregularly shaped ore-bodies of the North Mount Lyell mine by overhead stoping, the method of filling the is a special feature.The situation of the mine two miles from the smelter and mill at an devation of 1000 ft. above the latter, precluded the economical use of granulated furnace or the mill tailings, even if these materials were as suitable for the purpose as the rock nowquarried at North Lyell methods at Mount Lyell have already been described in Proceedings of the Institute.*The breaking the ore in large dome-shaped stopes is still the rule, but the slope or "rill" is much flatter now than formerly. Owing the greater fluidity of the filling now in use, it is sometimes necessary to resort to square-sets, both at the ground floor and above, the roofs and walls are generally enough to permit stoping without timber, except for ground and occasional stacks on the rills.Sufficient area of ground floor has been beaten out to start overhead stoping, the dome back is partly formed, with its apex a rise which connects with the mullock-pass reticulation.(Sce 1 showing this reticulation in diagrammatic form.)

Jan 1, 1927

By J D. St George

Flyrock is the unexpected and undesirable projection of rock fragments during detonation of a blast and managing this risk is becoming an increasing challenge as urban development encroach toward mineral extraction sites. The basic factors associated with flyrock are discussed in relation to geology, blast design and management. Published data of historical flyrock events are investigated and compared with local information on incidents. Good agreement was found between the data sets. A computer program of flyrock was developed using projectile motion based on launch velocity and angle, rock size, shape and density. This deterministic model was coupled with a probability model to simulate blast events. The impulse time ?t of the explosive pressure was taken as the stochastic variable to replace launch velocity. The variables were calibrated to replicate field data. A simulation was executed to demonstrate the capability of the approach to defining flyrock danger zones. For a simplistic situation it was identified that an appropriate distance to be cordoned off for the blast danger zone is a radius of 120 m in front of the blast and 65 m behind.

Jan 1, 2001

By L O. Filippov, C H. Veloso de Melo, A Correa De Araujo

Froth flotation of iron ores is one of the most widely used methods to upgrade iron ore into high-grade concentrates. In recent years, reverse cationic flotation of iron ores has been specifically the subject of several studies. Since quartz is the most common gangue mineral in iron ores, understanding the behaviour of this mineral was the main target of the majority of such studies. However, with the depletion of mineral deposits considered rich and easy to process, it has become more common to find iron ores with complex gangue minerals, which are composed not only of quartz but by a variety of silicates. The mineralogical composition of the ore is an important factor for determining reagents and mineral processing parameters. The mineralogical suite of an ore also presents a paramount role for operational optimisation of any given flotation process. Some studies were performed with different types of amphiboles and other Fe-bearing silicates, for example, but the influence of the mineralogical nature of these silicates in reverse cationic flotation has not been fully explored and will be discussed here. Changes in the traditionally used reagent scheme for reverse cationic flotation, generally including alkaline pH values, polysaccharides as depressant (mainly starches) and primary ether amines and diamines, are expected when dealing with iron ores with complex silicate gangue composition.CITATION:Veloso de Melo, C H, Correa de Araujo, A and Filippov, L O, 2017. Reverse cationic flotation of iron ores with complex silicate gangue minerals, in Proceedings Iron Ore 2017, pp 241–244 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By J. A. Kost

A survey of 80 coal producers was conducted to determine the extent and scope of respirable dust control research for underground coal mines and the current methods employed to control respirable dust. Results of the survey showed that proper face ventilation and an adequate water spray system are sufficient to comply with mandatory standards in room and pillar mining. Difficulties still exist with longwall equipment, auger miners and buring machines. In these cases, known dust control techniques are not sufficient to obtain compliance. Present state-of-the-art face ventilation and water systems were discussed in addition to the sampling program.

Jan 1, 1980

By D. F. Malan

This paper presents an overview of work conducted over several years to investigate the continuous stope closure profiles recorded in tabular excavations and the use of this data as a hazard indicator. In spite of the brittle nature of the rock, measurements in gold mines and intermediate depth platinum mines revealed a significant time-dependent closure component. Various approaches to simulate the time-dependent closure have been investigated. Viscoelastic theory is able to simulate the time-dependent closure behaviour, but there are subtle problems with the use of this theory as it cannot simulate the failure processes in the rock. To overcome these problems, continuum and discontinuum elasto-viscoplastic models were developed by the authors. Discontinuum models have the advantage of being able to simulate the creep behaviour of prominent discontinuities. Development of these models has led to useful insights into rock mass deformation and has made the numerical simulation of parameters, such as rate of mining, possible for the first time. A number of practical applications for the mining industry have been developed from this study. Among these are the delineation of geotechnical areas using closure data, use of the data as a hazard indicator and to give warning of large collapses in the platinum mines, identification of areas to be preconditioned in the gold mines, measurement of the effectiveness of preconditioning and improved da

Jan 1, 2007

By Ernie Doell, Trung Nguyen

"In early 1995 Cluff Mining commissioned a newly constructed high density tailings thickener at its Cluff Lake uranium mill. The 85 ft diameter high density thickener is one of the first of its kind in North America, and incorporates the novel paste technology in its design to produce densified (in the range of 60 -65% solids) mill tailings suitable for stable deposition in the tailings management area. This paper discusses the impetus behind the installation of such an unconventional thickener, and the many trying experiences in making it operational.IntroductionCluff Mining, a wholly owned subsidiary of Cogema Resources Inc., is the operator of a uranium mine and mill complex at Cluff Lake which is located in northern Saskatchewan. Since 1980, the company has developed and mined out several different ore bodies within the Cluff Lake region for the production of uranium concentrates, commonly known as yellow cake. Based on the known ore reserves, the Cluff Lake operations are projected to last till the early 2000's.Tailings from the Cluff Lake mill have been discharged to a tailings management area consisting of a tailings pond and two facilities for primary and secondary treatment systems. The tailings pond has an impervious bentonite lined dam, and it is divided into a solids and a liquids holding areas. Until the beginning of 1995, the mill tailings were discharged in two separate lines to the solids pond; one line carried the slurry residue of 45-50% solids (w/w) from the CCD circuit, and the other discharged raffinate tails containing less than 1 % (w/w) gypsum precipitate. Supernatant in the solids pond is treated in the primary treatment system prior to discharging to the liquids pond. Figure 1 shows the site plan of Cluff Lake tailings management area.It has been estimated that by the end of 1995 the solids pond would be filled to about 60% of its design capacity, and probably would be full before the year 2000. Therefore, Cluff Mining had to consider a more efficient tailings disposal method that could extend the service life of the existing Cluff Lake tailings management area. A high density tailings thickener was believed to be the most practical and economical system for tailings disposal at Cluff Lake mine."

Jan 1, 1996

By Richard Deakin

This case study describes aspects of the design of bridge foundations using 320mm diameter steel tube piles in the vicinity of Montréal, Canada. In this area, these piles are a very commonly used and cost effective solution for deep foundations. Typically they are driven through thick Champlain Sea Clay to bear onto stiff, strong rock. However, in some locations there is a layer of glacial till between the base of the clay and the rock which cannot always be fully penetrated by the piles. There is currently little published information, about the bearing capacity of these piles in the local till, and this paper presents and discusses some pile-test data from a recent project. The nature of the glacial deposits in the study area is presented using information gained from published geological data, the project ground investigations and site observations. The design approach and assumptions are discussed, together with the aims and outcomes of preliminary field driving trials and pile tests. The paper then discusses the results of dynamic tests undertaken on production piles. Bearing capacity factors are back analysed from the dynamic test results and compared against values assumed within the design. Observations are made that designers of future foundations in similar conditions may find informative.

Jan 1, 2011

By Arun .. J. Basu

The paper introduces Intelligent Air Management (IAM) as the core activity of M&I Group of Companies (M&I) for providing a total solution to any air management problems for mining and mineral processing operations implementing a comprehensive systems approach through a world-wide network of strategic alliance partners and in-house engineering team and manufacturing facilities in Mississauga, Ontario, Canada. Recommendations for energy-efficient ventilation in a vibration and noise free environment are made with the patented and innovative solutions supported by extensive computational fluid dynamics (CFD) studies. The solution scope extends from an intelligent and integrated exhaust silencer to a complete ventilation sys-tem solution including inlet and outlet control design and ducting for diffusers and silencers.

Apr 1, 2005

By M. Onifade, O. S. Otuogbai, A. F. Mulaba-Bafubiandi, O. D. Eniowo, H. Grobler

Artisanal and small-scale miners in Nigeria struggle to attract formal financing to upgrade their operations to a more sustainable form of small-scale mining operation. Literature shows that for an investment to attract formal sources of financing; the business must be considered creditworthy by potential lenders. This means that the credit risks associated with the investment must be bearable for the potential lender. This study looks at how artisanal and small-scale miners can attract formal funding, which will help them take the leap from artisanal state to a form of sustainable small-scale mining operation. This study evaluates the creditworthiness of artisanal and small-scale mining operators using key credit risk parameters identified in the literature and through primary investigation. A quantitative study is conducted on a sample of 100 artisanal and small-scale miner establishments in Nigeria to evaluate the effect of these identified credit risk parameters on creditworthiness. It is shown in this study that being a member of a mining cooperative society, which is a form of social collateral, best improves the chances of access to formal financing for miners within the sample group. This underpins the role of social collateral, in both the formal and informal economy, and its influence in improving the creditworthiness of a typical artisanal and small-scale miner.

Jul 23, 2025

By Z. Hyder, M. Karmis

Underground or In-situ Coal Gasification (UCG or UICG), though not a new concept, is now attracting considerable global attention as a viable process to provide a "clean" and economic fuel from coal. Applying improved UICG technology to gasify deep, thin, and low-grade coal seams could vastly increase the amount of exploitable reserves. However, it is imperative that further development of this technology is based on integrating UCG practices and potential environmental impacts with accepted sustainability frameworks and processes. This paper evaluates the potential of UCG to conform to frameworks such as MMSD (Mining, Minerals and Sustainable Development), Natural Step and Green Engineering, in order to define its "sustainable" potential. The paper also discusses the potential contributions of UCG to sustainability during its design, operation, closure, and post-closure phases.

Jan 1, 2011

By P. Miranda, K. Le, G. Maes, R. Peters

"The Mount Milligan Mine, owned by Thompson Creek Metals Company Inc. (TCM), started operations in September of 2013. It is located between the communities of Fort St. James and Mackenzie and is the first major metal mine to open in British Columbia in 15 years. Based on reserves as of January 1, 2014, it has an estimated 22 year mine life with 2.1 billion pounds of copper and 6 million ounces of gold in reserves. Like all commissioning operations, there have been issues achieving design throughput and recovery due to flow sheet design, equipment failures, control philosophy, and reagent scheme. Efforts to improve overall mill performance include equipment modifications, reagent screening and testing, and grind size testing. Applying these changes to the mill and working closely with the mine has resulted in continuous improvement each month as Mount Milligan looks to achieve the nominal design capacity of 60,000 dry metric tonnes per day in the later part of 2015. Considerable focus is being placed into ensuring size reduction equipment is utilized effectively. Additional modifications and tests are being undertaken to steadily improve processes and alleviate restrictions in the mill. This paper will discuss the start-up and present ramp-up history of Mount Milligan, the current mill processes, and the steps taken to achieve expected production numbers.OPERATION BACKGROUNDMount Milligan is an open-pit copper and gold operation wholly owned and operated by Thompson Creek Metals. It is located approximately 155km northwest of Prince George, British Columbia, between the communities of Mackenzie and Fort St. James. The copper-gold porphyry deposit contains a Measured and Indicated Mineral Resource of 706.7 Mt at 0.18% Cu and 0.33 g/t Au, containing 2.84 billion lb. copper and 7.50 million oz. gold. Mine life is currently estimated at 22.1 years (“Feasibility Update – Mt. Milligan,” 2009). The mill is designed to process 60,000 dry metric tonnes per day and produce 400 dry metric tonnes of concentrate per day averaging 25.5% Cu and 40 ppm Au. Concentrate is delivered by truck and trailer to Mackenzie followed by rail to Vancouver for overseas shipping to various customers.Mount Milligan is considered a “zero discharge” operation meaning no process or surface water will be discharged to the environment. As well, stockpiling is very limited and is only permitted for a short period of time. This scenario presents several unique challenges. Scheduling of ore/waste production must be carefully planned as waste rock is used to build the tailings storage facility (TSF). Reagent selection is also important as persistent chemicals will have a tendency to build up in reclaim water which feeds the process water tank."

Jan 1, 2015

By A G. Mitchell

Stream sediment geochemical analyses were collated from open-file mining company reports and assembled in the REGCHEM computerised database at the Institute of Geological and Nuclear Sciences Limited. The database operates on an IBM-compatible PC microcomputer using an application programmed in dBASE IV and termed GEOEXPL. By August 1992, data for 6383 stream sediment samples from 6335 different sites in the Coromandel Peninsula region (Hauraki Goldfield) were entered, giving a total of 29 292 separate elemental analyses. Preliminary statistical analysis using PROBPLOT on a set of data collected by AMOCO from the Mahakirau-Whangapoua area shows that these data are a complex mix of subpopulations related to mineralisation and different source rock types. Thresholds of 37 ppm copper, 31 ppm lead, 112 ppm zinc, and 2.3 ppm molybdenum, defmed by arithmetic models for the combined data set, separate the individual element sets into 'first order anomalous/lesser anomalous and background' subpopulations as follows: copper five per cent/95 per cent, lead five per cent/95 per cent, zinc one per cent/99 per cent, and molybdenum 15 per cent/85 per cent.

Jan 1, 1992

By Rita D. Sylvester

THE BUREAU OF MINES was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve mineral resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting these industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to "disseminate information concerning these subjects 'in such manner as will best carry out the purposes of this Act.'" In accordance with that directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau sources. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes Bureau reports and articles published during the period January 1, 1960 to December 31, 1964. It, supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960,2 and the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960.3 It supersedes the annual lists of Bureau publications and articles from January 1 to December 31, 1960,4 from January 1 to December 31, 1961,5 from January 1 to December 31, 1962,6 and from January 1 to December 31, 1963.7 The leading general and technical libraries of the United States maintain files of the Bureau's publications. A list of these libraries appears immediately following this introduction.

Jan 1, 2007

By E. G. Baglin

As part of an effort to decrease U.S. dependence on imports of critical and strategic metals, the Bureau of Mines investigated three leaching methods for extracting the base metals and recovering platinum-group metals (PGM) from matte prepared from Stillwater Complex flotation concentrates. Because of a limited supply of natural material, synthetic matte of composition similar to matte prepared from natural concentrates was used to devise the extraction sequences. The validity of the sequences was verified with matte prepared from Stillwater concentrates. In two-stage matte leaching, first-stage H2S04 leaching extracted 99 pct of the nickel and iron from the matte but negligible amounts of copper and PGM. Second-stage oxidative leaching with Fe2(S04)3 or FeC13 solubilized more than 98 pct of the copper and no precious metals. Sequential leaching, in which acid and oxidizing lixiviants were added sequentially to the matte without an intervening filtration step, extracted 99 pct of the Fe, Ni, and Cu. A roasting-leaching technique, in which the residue from first-stage leaching was roasted between 360° and 500° C before a second leaching with H2S04, solubilized 98 pct of the copper. The three leaching methods yielded high-grade PGM residues containing more than 98 pct of the PGM in the matte.

Jan 1, 1982

By R. A. Cattell

The conditions under which the researches of the Bureau of Mines on petroleum and natural gas were conducted in 1952 were little changed from those indicated in the last report,2/ which dealt with activities during 1951, immediately after crossing of the 38th Parallel by the North Korean Army. Although only a small part of the program was classified in the military sense, there was a feeling of the clash of world forces which called for even cheer scrutiny of the research problems so that the emphasis could be placed without delay where the greatest needs for na¬tional defense seemed to be. The reports of the work accomplished were so directed as to have the greatest immediate value to persons charged with supply planning for the military forces and included information on the availability and characteristics of a wide variety of crude oils, fuels, and other petroleum products. Actually, the approach, direction, and conduct of the work do not differ greatly under the two circumstances, as has been pointed out in earlier reports; only the tempo changes.

Jan 1, 1953

By L Langer, R Simcock, M Davis

Rehabilitation of mining sites helps to achieve the purpose 5(2c) of The Resource Management Act 1991 û æavoiding, remedying, or mitigating any adverse effects of activities on the environmentÆ. The environmental outcomes for recent and current mining operations on the West Coast are variable. There are some exemplary mining operations which are restoring or even improving land use and environmental factors in the region, particularly those operated by the larger mining companies. There are also examples of an exploitative mentality where the environment and land have been severely degraded by mining activities. Technology has been developed to prevent a repetition of the historical destruction of the environment through mining. Failure to rehabilitate mined land is no longer acceptable to the New Zealand public in the 1990s and damages the credibility of the mining industry. Examples of successful mine site rehabilitation to pastoral farming and to production or plantation forestry are illustrated from the alluvial gold mining industry. Planning, sequencing of operations, the utilization of sailor plant growth materials, and aftercare are key factors in successful land rehabilitation to these productive uses. There is also a recent focus on restoring indigenous forests and wetlands at both coal and gold mining sites, particularly for mines on or adjacent to the conservation estate. The results of scientific research and efforts by the industry on techniques for rehabilitating rainforest and pakihi wetland after mining are presented, particularly from the Giles Creek Dunoille Coal Mine. There is a need for further research and trials to apply and extend rehabilitation techniques to other geological and environmental situations, particularly to mines in mountainous areas and to difficult environments like the coal measures ecosystems of the plateaux above Westport.

Jan 1, 1996

By G. S. Rice, J. W. Paul, M. W. VONBERNEWITZ

This bulletin abstracts and reviews essential details of reports on 59 fires in different coal mines in the United States, describes the circumstances of origin and the methods of controlling or extinguishing the fires, and points out the lessons taught. all, the fires caused great damage to property and killed nearly 400 men. The data have been compiled from the records of the Bureau of Mines, which cover most of the major mine accidents in the United States since 1.908. The names of the mines concerned and of the persons connected with the management of those mines have been omitted in accordance with the usual policy of the bureau. The bureau hopes that this bulletin will be of service to all persons interested in lessening the fire hazard at coal mines and to all who may be called on to fight a mine fire.

Jan 1, 1927