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By J. E. Urosek

Decisions made during a response to a mine fire or an explosion greatly affect the final outcome. The safety of miners should be the primary concern with accounting for all of the miners the first issue for resolution. If miners have not safely evacuated from the mine, the last known location of the miners at the time of the event and anticipated travel routes are primary exploration areas. After the mine is evacuated, there are many very important decisions that must be made quickly and often under great stress. It is critical that the mine operator establish an orderly method to direct the mine emergency response. Designation of a Command Center, staffed with personnel charged with developing plans, is a common method of establishing control. Scheduling of key mine managers will be critical, since decisions must be made 24 hours a day and people working for extended periods with little or no sleep do not always make clear or cognizant decisions. Internal communications, passing information on to subsequent shifts, and external communications with families and media must be accurate and timely. Assembling resources for responding to the mine emergency is critical for an effective response, and pre-planning can pave the way to a successful recovery. Sampling mine gasses and accurately determining the composition of gas mixtures is a common tool used to develop response plans in all fires and explosions. It is essential that preparations for emergency situations are made well in advance of a disaster. Effective communications are essential for mine management to successfully respond to a mine emergency. This paper discusses some considerations which need to be addressed in directing a response to a mine fire or explosion.

Jan 1, 2009

Employee safety and health is of paramount importance for SME and its members. Many SME members work daily in our Nation's mines or have a direct impact on others that work in the mines. SME supports the mission and purpose of the U.S. Mine Safety and Health Administration (MSHA), which is to prevent all injuries and disease from mining and to promote safe and healthful workplaces for the Nation's miners. SME supports the National Institute for Occupational Safety and Health and university research geared toward prevention of all occupational injuries and illnesses. SME maintains that laws and regulations governing the mining industry need to be based on sound scientific principles to ensure that workplace solutions can be readily implemented and that solutions to safety and health problems are fully realized.

Jan 1, 2011

By Nick Rose, Robert Sharon, Mark Rantapaa

Development of the Northeast Layback of Barrick’s Betze-Post open pit commenced in June 2000 and was successfully completed to a height of 400m (1,300 ft) in January 2003. Following a brief exploration drilling campaign at the toe of the final slope, in-pit waste rock backfilling commenced, which will ultimately buttress the final wall. Instability initially occurred in late 2000, above the 5040 Level, as the slope height approached 120m (400 ft). As mining reached the 4680 Level, significant deformation was experienced over a slope height of 230m (760 ft). Slope stability was managed and targeted reserve recovery was achieved by executing complicated modifications of the mine plan, including splitting layback development, well placed offloading cuts, step-outs and mid-slope waste rock buttresses. Decision on timing of these modifying events was often dictated by review of deformation magnitudes and rates determined from continuous slope monitoring records. Design modifications were developed through continuing interpretive refinement of structural geology controls and groundwater distribution, and through stability re-assessments. This document presents an overview of the geological setting and material and strength conditions of the northeast sector of the Betze-Post open pit, followed by development experience leading to design and development of the Northeast Layback. Rock mechanics modeling, design details and geotechnical performance monitoring are then presented. Development experience, stabilizing adjustments to the original design and safety procedures for development and exploration activities are described. The document is finalized with conclusions and acknowledgements.

Jan 1, 2005

By D. Mohapatra

Extraction of Al(III) from aqueous sulfuric acid solutions into organic Cyanex 272®-carbon tetrachloride systems was investigated from a multi-component mixture containing aluminum, cobalt and nickel. Al(III) extraction efficiency was quantitative with 1.0 M Cyanex 272® in two stages at an aqueous: organic (A:O) phase ratio of 1:1 and an equilibrium pH of 3.2. The stripping of Al(III) from the loaded organic (LO) with different acids indicated sulfuric acid to be the best stripping agent. More than 99% stripping of Al(III) from the LO was achieved using 2 M H2SO4 at an A:O phase ratio of 1:1 in a single stage. The stoichiometry of the extracted species of Al(III) was determined by the slope analysis method. The extraction reaction proceeded via the cation exchange mechanism and the extracted species was assumed to be AlA3?3HA, where HA refers to the dimeric and A the anionic form of the extractant, Cyanex 272®. The extraction of Al(III) was studied in the presence of various ions to ascertain the tolerance limit of individual ions.

Jan 1, 2008

Based on X-ray phase analysis and exploratory experiments, a new technology was developed to recycle multiple valuable elements in spent Al2O3-based catalyst. The experimental results showed that after roasting at 750°C for 30 minutes at an Na2O:Al2O3 mol ratio of 1.2, the leaching recoveries of alumina, vanadium and molybdenum from the spent catalyst were 97.2%, 95.8% and 98.9%, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by barium hydroxide and barium aluminate. The precipitation recovery of vanadium and molybdenum was 94.8% and 92.6%, respectively. Al(OH)3 is prepared from sodium aluminate solution using the carbonation decomposition process. The purity of Al2O3 is 99.9% after calcinations, and the recovery of alumina can reach 90.6% in the whole process. The Ni-Co concentrate was leached with sulfuric acid, and a nickel recovery of 98.2% and a cobalt recovery of more than 98.5% were obtained under the experimental condition of 30% (w/w) H2SO4, 80°C, a liquid: solid ratio of 8:1 (by weight), a reaction time of 4 hours and a stirring rate of 800 rpm.

Jan 1, 2007

By William R. Yernberg

In October 1999, Liebherr-America, Liebherr Construction and Liebherr Mining Equipment held anopen house at its Newport News, VA, plant. The open house was held to celebrate the company’s50th anniversary and to demonstrate the new TI 272mining truck. Attending the open house members of the media, vendors and company representatives from all over the world. In his introductory comments, company president Peter Eller announced Liebherr’s dedication to expanding its presence in North America. Liebherr now has 30 dealers across the United States. As part of the open house, a brief history of Liebherr was presented, beginning with its creation in1949. Liebherr engineering and sales representatives were available to answer questions.

Jan 1, 2000

By X. Zhou

In this study, the cyclonic static microbubble flotation column (FCSMC) was investigated for fluorite beneficiation. The structure and principle of the specially designed column are described. Fluorite samples from the tungsten separation tailings of the Shizhuyuan Mine, Chenzhou, Hunan Province, P.R. China, were tested using a small-scale continuous flotation test unit, and concentrates with a fluorite grade higher than 98% were obtained. One rougher and three cleaner stages in the FCSMC achieved the same separation performance as one rougher and eight cleaners in conventional flotation cells. This greatly simplified the flotation circuit and reduced operating costs.

Jan 1, 2007

By John D. Morton, J. H. LaVerne Palmer, Douglas J. Belshaw

An extensive programme of ground instrumentation and observation was carried out for the West Duff in Outfall Sewer tunnel project prior to and during construction, to establish the performance characteristics of the rock through which the tunnel and appurtenant openings were dug and to examine the nature of the lining-to-ground interaction. The existence of high horizontal residual ground stresses was confirmed, and values established by overcoring. Rock deformations and stress changes were monitored during tunnelling. Permanent stress and strain monitoring devices were set into the final lining and these are continuing to operate. INTRODUCTION The site is located on the north shore of Lake Ontario at Pickering, some 20 miles (32 kilometres) east of Toronto, Canada where a variable thickness of glacial or interglacial sediments overlies bituminous shale bedrock of. the Collingwood Formation which is lower Ordovician age. Approximately 50 feet (15 metres) of glacial cover exists at the shaft, though this thins abruptly at the regressing cliffed shoreline such that several small areas of exposed bedrock exist in the lakebed. The general location, overall geological section and detailed site plan and profile are illustrated in Figs.1,2 and 3 respectively. General properties of the rock as established during an extensive test drilling and site investigation programme are listed in Table 1, while stress determination by USER overcoring stress meter device are given in Table ll. These data formed the basis of analyses which were done to examine the intended outfall design, and to detail the construction procedure and the observational instrumentation programme.

Jan 1, 1979

By K. M. Mohamed, R. K. Zipf

The shear strength properties of generic cement foam material and cement foam/concrete interfaces were examined at three testing scales. In laboratory direct shear tests on specimens with average shearing area of 0.006 m2 (10 in.2), the cement foam material had average peak and residual shear strengths of 0.88 MPa (128 psi) and 0.39 MPa (56 psi), respectively. Depending on the concrete strength, the cement foam/concrete interfaces had peak and residual shear strengths ranging from 0.71 to 0.81 MPa (103 to 117 psi) and from 0.27 to 0.29 MPa (39 to 42 psi), respectively. In laboratory direct double shear tests on specimens with average shearing area of 0.084 m2 (130 in.2), the cement foam/concrete interfaces had average peak and residual shear strengths of 0.17 to 0.30 MPa (25 to 44 psi) and of 0.11 to 0.23 MPa (16 to 33 psi), respectively. In large shear tests of simulated cement foam seals with the Mine Roof Simulator (MRS) test frame, cement foam/concrete interfaces with shearing area of 1.486 m2 (2,304 in.2) had average shear strengths of about 0.08 and 0.16 MPa (11 and 23 psi) along the roof and floor interfaces, respectively. The average shear strength through the cement foam material was 0.38 MPa (55.3 psi). Finite element analysis of the large seal tests and the back analysis of the shear strength of full-scale cement foam seals conducted at the NIOSH Lake Lynn Laboratory confirmed shear strength of about 0.14 MPa (20 psi) along the seal/rock interfaces. The study concluded that the structural analysis of cement foam seals should be based on their residual shear strength determined from small laboratoryscale tests of the cement foam/concrete or rock interface and not be based on their peak strength.

Jan 1, 2014

The 112th Annual National Western Mining Conference (NWMC) hosted by the Colorado Mining Association (CMA) drew some political heavyweights, if by voice only, into the fray of two of the hottest topics that the mining industry is currently facing ? climate change and the new energy economy. A changing political landscape in Colorado, as well as in Washington D.C., has given rise to questions about the economic future of the United States and the mining industry?s role in that future. While there has been a recent push away from traditional energy sources to a ?new energy economy? that is rich in renewable energy sources such as wind and solar, the NWMC?s agenda emphasized the role that minerals will play in new energy technologies. The conference was also full of talks about the industry?s role in reducing the United States? reliance on foreign oil and other mineral commodities. To that end, an impressive lineup of speakers were invited to attend the three-day conference Feb. 8-11, in Denver, CO. Unfortunately, Mother Nature had other plans and three of the four headliners, including Denver?s mayor and Democratic candidate for governor of Colorado, John Hickenlooper, were unable to get to the conference because of a massive blizzard on the East Coast locked them in Washington, D.C. However, with modern technology, a full auditorium heard presentations from Hickenlooper, National Mining Association (NMA) president and chief executive officer Hal Quinn and Glenn Kelly, vice president, government affairs for NMA. Republican candidate for governor of Colorado, Scott McInnis, did speak to the crowd in person.

Jan 4, 2010

By J. Geisler

When addressing Germany’s resource supplies, we need to distinguish between those domestically available and imported ones. Resource extraction ostensibly competes with the designation of protection areas. However, the parallel existence of wildlife and plant life, and operations in the areas used for resource extractions is continually underestimated. The European Commission has compiled guidance documents facilitating the extraction of resources from protected areas. With regard to resource productivity, the market appears to be the appropriate instrument for minimising resource consumption. Policy makers are now called upon to create a legal framework leading to a consensus accepted by society.

Jan 1, 2011

By I. Tsolas

This paper presents the use of non-parametric approach (i.e., data envelopment analysis, DEA) for the development of environmental sustainability indicators in mineral processing using environmental, economic and/or integrated indicators (i.e., indicators that interrelate two dimensions of sustainability). A case study based on real publicly available data is presented to illustrate how the proposed approach can be implemented in practice. The merit of this approach, which is based on the productive efficiency framework, is that it provides environmental sustainability indicators that can be used internally for benchmarking purposes and externally for sustainability reporting.

Jan 1, 2008

By R. Barthel, O. Nitzsche, J. Pateiro Fernández, T. Cramer

The Hong Gai coal field in northeast Vietnam has been the main coal mining area of Vietnam for more than 150 years. Anthracite coal is produced from several open pit and underground mines situated close to the UNESCO world natural heritage site Ha Long Bay. The mining-induced environmental impacts such as dust emissions, acid mine drainage, and visual impairments due to waste dumps resulted in severe conflicts of interests regarding future land use and the protection of the world natural heritage site Ha Long Bay. Within the RAME project (Research Association Mining and Environment in Vietnam), Brenk Systemplanung is contributing to an improved environmental and sustainable planning in Vietnam's mining industry and the reduction of environmental impacts on Ha Long Bay by developing suitable and sustainable technology and planning measures (e.g. for dump construction/rehabilitation, predictive modelling, and/or monitoring) for Vietnam's leading coal producer.

Jan 1, 2011

By Mustafa Akser

The Pipestone Lake anorthosite complex in Manitoba, Canada, was recently been re-identified as a potential source for titanium, iron, and vanadium. The present study utilized a 350 kg hard rock sample, which originated from the "Main Central" zone of the deposit. Commercial pilot-size equipment, such as dry low intensity roll magnets, wet high intensity magnets (WHIMS), and high tension electro-dynamic roll separators, was employed. As products, ilmenite up to 48.5% TiO2, and magnetite concentrates up to 87.9% Fe3O4 with 5.25% TiO2 were obtained. The majority of the vanadium reported to the magnetite concentrate. Subsequent characterization of various separation products shed light on the potential grade and recovery of the minerals from this deposit.

Jan 1, 1996

By L. Ou

This paper reports on research on leaching pyrite in a germ-free system. The effects of mineral particle size, pulp potential and various oxidation agents on pyrite leaching were studied. The results indicated that a smaller mineral particle size leads to a higher leaching rate of pyrite. The optimum results were obtained with a mineral particle size of -0.037 mm. The pulp potential reflected the leaching process and an increasing pulp potential improved pyrite leaching. The leaching rate rapidly increased with the addition of oxidation agents such as Fe3+ and H2O2. However, the precipitate generated by ferric ion coated the surface of the pyrite and prevented further leaching.

Jan 1, 2007

By W. H. W. Husband

Rock salt has been mined by the solution method for many years in many countries. Attempts have been made in the past in Canada and various other countries to produce potash by the' same method. However, only Kalium Chemicals Limited (1) has been successful, possibly because the conditions in Saskatchewan are the most favorable conditions to be found so far for the development of a solution mining method for potash. There are significant differences in solution mining of rock salt and solution mining of potash. First, rock salt deposits are relatively pure in respect to soluble minerals, whereas potash is never found in the pure state and contains Substantial amounts of other soluble minerals, particularly rock salt. In comparison to rock salt, much less potash is dissolved and brought to the surface for the same amount of water circulated through the orebody. The amount of water to be evaporated per unit weight of product is a major difference. Much greater amounts of water must be evaporated when producing potash and the treatment of the brine is more complicated because other dissolved salts have to be separated. Secondly, the rock salt deposits, particularly the domes, are much thicker. Bed thickness is of prime importance because it determines the yield of a well and consequently the economics of the process. Furthermore, as rock salt provides a strong roof structure, larger cavities can be developed and this prolongs the life of the rock salt well.

Jan 1, 1971

By J. S. Stachulak

The Diesel Emissions Evaluation Program (DEEP), a research consortium formed in 1997 by Canadian mining companies, labour unions, and provincial and federal government departments, completed its work by mid-2006. This program, in which Vale Inco participated with both direct funding and in-kind contributions, investigated the ability of currently available technology to significantly reduce underground concentrations of diesel particulate matter (DPM) with high efficiency and low maintenance over a long-term period (years of life).While DEEP?s testing showed that engine maintenance is a critical component for lowering DPM, it was clear that reduction of DPM to the very low target levels of ~0.05 mg/m3 was not possible with maintenance alone. The best candidate technology for achieving low DPM levels was particulate filter systems. Furthermore, successful deployment of such systems was highly dependent on removing them from having to rely on human intervention for their regeneration. The search continues within Vale Inco to identify a reliable and rugged system.

Jan 1, 2009

By T. Payne

Underground heat issues are mainly focused on the detrimental effects to a workers health. However, working in hot, humid conditions has other negative effects. Studies have shown that safety, productivity, workforce morale and operating cost are also worsened in these conditions. The human body has several mechanisms for rejecting heat and remaining cool. However, once the air temperature exceeds about 34°C, the only effective mechanism is by evaporation of sweat from the skin. This is assisted by acclimatisation which is the human body?s enhanced ability to combat extended exposure to heat. The body has to remain well hydrated when working in heat as even small degrees of dehydration cause significant decreases in the ability to work in heat. There are two ways in which heat load can be reduced: Through use of refrigeration/vent/cooling to reduce thermal stress on workers; Reduce the contribution that heat sources have to underground heat load (e.g. reduce idle time, fleet size, etc). Some of the sources of underground heat have the potential to be more manageable than others. Geothermal heat and heat from autocompression will be found in all mining situations in varying degrees depending on geothermal gradient and surface temperature, however, the use of equipment and blasting may be streamlined to reduce the underground heat load. It is through a combination of the available options that most mines will successfully control their heat related problems. Mt Isa, which has been a focus for heat related study in Australia, has successfully implemented protocols for working in heat. Through combining these with the installation of a surface bulk air cooling plant, Mt Isa has consistently reduced the incidence of heat illness. This is likely to be the most cost effective method of reducing heat load for deep mines in Australia. Shallower mines which may only occasionally encounter hot conditions should consider more portable cooling options. This study will review the heat issues in underground Australian metalliferous mines.

Jan 1, 2009

Queensland?s underground coal industry, as a whole, has arguably the best gas monitoring systems in the world. Each mine utilizes real time, tube bundle and onsite ultra fast gas chromatograph systems. Queensland?s mining legislation has specific requirements for mine gas monitoring but there is no requirement for all three techniques. Industry has however identified the need for all three and adopted this as a standard, resulting in over sixty thousand gas results collected each day. Automated monitoring systems are programmed to alarm for gas concentrations, gas ratios and explosibility. These alarms are then used to initiate predetermined actions to take control of the situation and prevent the compromise of safety to workers and the loss of resources. Dedicated software packages have been developed to assist in the interpretation of the large volume of results generated. The real time systems are used for real time warning, essential for incidents such as belt fires. Tube bundle systems suit long term trending used for identification of the onset of spontaneous combustion or for the determination of explosibility during the routine sealing of worked areas. Gas chromatograph analysis is used to provide a complete analysis and provides results for hydrogen and ethylene, key gases used in the assessment of spontaneous combustion. It is also crucial during significant spontaneous combustion events and coal fires to use gas chromatography to determine the explosibility status of the underground atmosphere otherwise the severity of the situation is likely to be under estimated. This paper outlines the need for all three techniques for assessing the underground status and outlines advantages and disadvantages of each.

Jan 1, 2009

By M. Gangal

CANMET-MMSL, in cooperation with Dry Systems Technologies and Quinsam Mine, conducted a study to determine the effects of B50 biodiesel on the emissions of a flameproof diesel power package in comparison with mining diesel fuel for application in underground coal mines. The emissions testing for coal mine application requires that the intake air mixture to the engine should be at 1.25 percent methane by volume in air. The tested power package system included a naturally aspirated, mechanically-controlled diesel engine with a diesel oxidation catalyst (DOC), a heat exchanger, flame arresters, and a low temperature disposable diesel particulate filter. The engine dynamometer tests were conducted at the CANMET-MMSL Diesel Emissions Research Laboratory in Ottawa using the ISO 8178-C1 test protocol. The separate and combined effects of a B50 biodiesel blended fuel, and with and without 1.25% methane enriched intake air were measured on a diesel power package. Fuelling the baseline engine (without methane), with B50 biodiesel blend reduced carbon monoxide (CO) by 44%, and increased nitrogen dioxide (NO2) by 19%, and particulate matter by 31% relative to the mining diesel fuel. Similarly, injection of 1.25% methane to the intake air for baseline engine with mining diesel fuel increased engine power by 15%, CO by 124%, and NO by 15%, and decreased NO2 by 13%. The effect of B50 biodiesel relative to the mining diesel for coal mines application (with methane for both fuels) was to reduce CO by 27%, and NO by 6%, and increase NO2 by 23%, with no change in engine power. The overall results indicate that the minimum ventilation rate for the equipment application in coal mines with B50 biodiesel was 4.11 m3/s (8,700 cfm), slightly higher than the ventilation rate of 4.01 m3/s (8,500 cfm) with the mining diesel fuel. This slight increase in ventilation rate for B50 biodiesel fuel was due to an increase in NO2 at one of the operating test points, and the ventilation rate for this equipment was governed by NO2 in the exhaust gas.

Jan 1, 2009