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By Ray E. Harris

Introduction A resource of more than 122 Gt (134 billion st) of minable trona and mixed trona and halite underlies an area of about 3400 km2 (1300 sq miles) west of Green River, WY (Culbertson, in preparation) (Fig. 1). In 1982, the total domestic consumption of soda ash (refined trona) was 6 Mt (6.7 million st) (Kostick, 1983). About 90% of this came from Wyoming trona. This enormous deposit occurs in the Wilkins Peak Member of the Green River Formation that is of Eocene age. This formation is derived from sediments deposited in a large lake named Gosiute. Lake Gosiute occupied the Green River Basin in southwestern Wyoming some 38 to 54 million years ago. The Wilkins Peak Member represents a restricted, evaporite-rich cycle of deposition when the trona deposits were formed. A total of 42 trona beds are known. Of these, 25 are of sufficient thickness and extent to be considered minable (Culbertson, in preparation). The production of sodium compounds from the trona deposits in the Wilkins Peak Member began in 1896 when wells were drilled within the present boundaries of the town of Green River. The purpose of the drilling was for extraction of sodium carbonate brines. Sodium carbonate (sal soda) was removed from these brines at a plant in Green River. Bedded trona was discovered in 1938 in a core from an oil well drilled south of Westvaco. In 1947, the underground mining of trona began. Production has continued from 1948 to date. Currently, five companies are mining trona and producing soda ash from the Wilkins Peak Member in Wyoming. Additionally, Allied Chemical Co. mines and processes trona for Church and Dwight's sodium bicarbonate (baking soda) operation in Green River. Competition in the soda ash industry depends primarily on the efficiency of mining and refining, allowing for lower-cost production. Newer plants and mine designs should increase efficiency. Solution mining holds promise as an even lower-cost method of mining. Employment in the soda ash industry is declining since the newer mining and refining methods are less labor intensive. Declines in employment, however, may be offset as production increases. Due to the large resource, the availability of minable trona should not be a problem for perhaps hundreds of years. Geology of Wyoming trona deposits Forty-two beds of trona or mixed trona and halite occur in the

Jan 10, 1985

By Michael Allen, Paul Worsey

In underground blasting, the pull of the initial cut is the limiting factor for the success of the rest of the round. By improving the pull of the first cut, a critical step is made towards improving the entire round. This project attempted to optimize a burn cut’s effective pull by varying the depths of the relief holes in the burn. The effect of varying the depths of the relief holes was investigated, including depths longer than that of the cut’s charged holes. The overall objective was to consistently achieve greater pull than in a standard burn, using an identical amount of explosives. Increased pull results in savings of both time and cost in underground heading advance.

Jan 1, 2015

By Beardsmore G. R

Geothermal gradients in the Gippsland Basin commonly exceed 35¦ C/km. Consequently models of thermal maturation may indicate exploration targets with an anomalous age/depth distribution. However regional geothermal models are constrained primarily by observations of surface heat flow. High geothermal gradients may simply reflect the presence of low conductivity coal beds within the basin. Heat flow data are not readily available for the Gippsland Basin. Normally special purpose drill holes are required to provide direct determinations of surface heat flow. These provide core samples for thermal conductivity and allow measurements of a stable geothermal gradient at least one year after drilling. Different indirect procedures are now required to provide estimates for the Gippsland Basin. Bottom hole temperatures can be used with suitable corrections to provide an indication of the regional geothermal gradient. However the corresponding thermal conductivities are more difficult to determine. Geophysical logs can be used to detect the major lithologies but detailed statistical analysis is required for numerical estimates. Complex mixing models are now suggested for geothermal surveys linking physical properties to variations in the mineralogy of each well. Allowing for low conductivity coal measures the data in the Gippsland Basin suggest values for heat flow consistent with regional trends in Australia. Interpretation is complicated by overprinting of transient thermal events with different time scales. Apart from the tectonics of basin evolution geothermal signatures may be complicated by regional ground water migration, the 'hot spot' trace associated with southward younging of Cainozoic volcanism, diagenesis, and basin refraction.

Jan 1, 1992

By K. Galovich, P. Krivokuca

"Quinsam coal mine is located about 25 km west of Campbell River on the east coast of Vancouver Island, British Columbia. Using continuous miners in a fully mechanized retreat room-and-pillar operation, it produces low sulphur, “super compliance” thermal coal for domestic and international markets at a rate of about 2600 t/d. Currently, 65 people work at the site, including some corporate employees.Opened in 1993, the Quinsam mine had a dismal safety record until 1997. Lost time injuries and medical aids were unacceptably high. In 1998, a change in corporate structure brought a change in safety attitudes; a total and unequivocal commitment to safety as job No.1 by corporate and site management. This commitment was clearly spelled out in a new mission statement, circulated to all employees by the new President and CEO, David Slater: “Safety is job No. 1; Production flows from safety; and Think safety at all times.” As well as re-defining workplace safety practices, QCC tightened engineering controls and enforced strict adherence to mine plans.This paper provides a general background to the mining operation, and describes the safety practices that have resulted in an enviable safety record in recent years, reflected by provincial and national recognition."

Jan 1, 2004

By Jonathan Baggett, Nino Ripepi, Amin Abbasi, Richard Bishop, Juan Monsalve, John Hole

This work focuses on the operational and safety issues associated with karst voids in large opening underground mines. Issues include water inrush, structural instability, and engineering uncertainty in these environments. Coupled with the fracturing prevalent in folded sedimentary rocks, karst voids are complex and challenging ground-control risks. Traditional methods of predicting karst void locations, such as probe drilling, are impeded by the inconsistent spatial distribution and variable sizes of the features as reported by Li et al. (J Rock Mechan Geotech Eng:232–242, 2010) and Hassan et al. (Procedia Chem 19:737–742, 2016). Ground-penetrating radar (GPR) is a geophysical technique that transmits radio waves into a medium and subsequently detects reflected waves via a receiver. The travel time and energy of received signals are then processed and interpreted. The difference in conductivity and dielectric permittivity between limestone and open karst cavities causes strong reflections. GPR is frequently used as a geophysical surveying technique in several industries; however, there is a lack of published research on underground mining GPR applications as reported by Zhao et al. (2015a; Geophys J Int:62–71, 2015b) and Eskelinen and Pellinen (Constr Build Mater:888–898, 2018). The purpose of this work is to demonstrate the use of GPR in an underground stone mine and to discuss the importance of karst void detection ahead of mining.

By Yongbin Yang

Cathodic reduction of oxygen is a process involved in many fields. As is well known, the mechanism of oxygen reduction usually varies considerably with electrode substrates. In this paper, cathodic reduction of oxygen on gold electrode was studied by linear sweep voltammetry with regards to cyanide leaching of gold. As the results shows, the electron transfer number increases as potential shifted negatively and decreases as pH value increases. Besides, the increment of electron transfer number as a function of potential decreases when pH value increases. When pH increases to 13.0, the volt-ampere curve exhibits a relative flat section with currents approximate to the limit current density of a 2e process. By varying dissolved oxygen concentration, the electron transfer number was calculated for pH11.0 at different potentials, the results being 2.387e, 2.732e, 2.982e, and 3.227e at, -0.35V, -0.40V, -0.45V, and 0.50V, respectively. The calculated current densities are in good conformity with measured results.

Jan 1, 2010

By R. G. Gürtunca, J. A. Breslin

This paper briefly describes the progress in mine safety in the United States, with emphasis on recent events that have followed since the explosion at the Sago Mine in January 2006. Legislation following the mine accidents last year and areas of work carried out by the National Institute for Occupational Safety and Health (NIOSH) related to the accidents are discussed. American coal production in 2006 was 1,150 million short tons. Most of this coal is consumed domestically, with annual exports of coal about 50 million tons. One third of annual production is produced at surface mines and the rest from underground. This coal is produced by about 82,000 miners working at 1,400 coal mines. Major improvements in coal mine safety have been made in the US since the Federal Mine Safety and Health Act of 1977. The fatal injury rate in underground coal mines between 1977 and 2004 was reduced by 47.8% to 0.036. The annual number of fatalities dropped from 112 to 14 during that period. Likewise, the non-fatal days-lost injury rate was reduced by 42.6% from 10.87 to 6.24. The improvements in mine safety during this period can be seen in the graph of underground coal mine explosion fatalities and injuries from 1980 to present, which is shown in Figure 1. Between 1984 and 1993 (9 year period) there were 5 explosions and one major mine fire, for a total of 55 fatalities. Over the seven year period from 1993 to 1999 there were no fatalities from coal mine fires and explosions. However, in the six years since 2000 there have been 5 explosions and one fire, which have caused 37 fatalities. [ ]

By O. Naiker, T. Riley

Keywords: Pyrometallurgy, furnace, Xstrata, ferrochromium, Premus Technology The presentation will give a basic overview of Xstrata Alloys. Included will be a brief history of the Alloys division as well as of each plant within the division. The Xstrata chrome plants utilise a wide variety of production processes, including Xstrata's Premus process, the Outokumpu process, and the conventional process. Xstrata?s Lion Project is underway, with commissioning expected in the third quarter of 2006. The new smelter will utilize Xstrata?s patented Premus process, and the competitiveness of the Premus process is discussed.

Jan 1, 2006

By F. P. Haver

The Federal Bureau of Mines developed a 10,000-ampere cell to determine the economic feasibility of producing high-purity electrolytic titanium from mill scrap or offgrade sponge. Operating variables were investigated, matetial handling procedures were established, and the cost of electrorefining titanium was determined. The prototype cell produced premium-grade metal (<100 Brinell hardness number (B.h.n.)) from very impure Kroll sponge at a processing cost of less than $0.60 per pound. Refined metal was deposited at the cathode in the form of coarse (85 percent plus 34-mesh), hexagonal crystals of a titanium when the cell was operated an 850° C. A cathode current density of 1,000 amperes per square foot and a molten sodium chloride electrolyte containing approximately 5 percent by weight of soluble titanium were used. In continuous operation, at the optimum number of ampere-hours, (40,000), the current efficiency averaged slightly less than 60 percent. It was possible to supply large enough amounts of electric current for electrolysis to maintain the temperature of the bath, thus reducing overall power consumption to less than 5 kilowatt-hours per pound of metal refined.

Jan 1, 1961

By José Carlos D?Abreu

The Tecnored process is a new ironmaking technology, developed on a unique approach that combined empirical and theoretical knowledge backed by extensive tests carried out in a dedicated pilot-plant and with close support of universities and research centers. Campaigns in the pilot-plant focused on operate different reactors of different sizes, including a full size slice of the industrial furnace. This approach provided actual conditions to develop the main features of the process such as the internal dimensions, raceway pattern, thermal and gaseous profiles, etc, besides provide reliable data to feed and calibrate a specific mathematical process modeling. This paper presents the first computer model used by the Tecnored technical staff, focusing the behavior of a self reducing agglomerate in the upper shaft of the furnace (zone of solid state reduction). Some results of this model are given and discussed.

Jan 1, 2006

By C. Swart

Automation technologies are increasingly adopted in different mines world-wide. This paper presents the technical aspects of vehicle automation applications at two Noranda operating mines. Teleoperation of 5 LHDs at Noranda?s Bell Allard mine is used in order to meet aggressive mining requirements under difficult conditions. The equipment is performing under high demand for reliability and performance. In order to further increase performance, automated loading has been commissioned on one of the LHDs and is being tested. Results to date indicate improved performance with respect to an operator through better filling of the bucket, fewer passes at the muck pile and shorter cycles. Noranda?s Brunswick mine is currently commissioning an automated haulage zone where two optically guided trucks transport ore from a remotely operated chute to two ore passes. Expected operational advantages include increased system capacity and enhanced safety and comfort for the operator. Monitoring to date indicates that the trucks can operate reliably under the conditions imposed by mine production.

Jan 1, 2002

By H. Utsunomiya, J. Su, K. S. Tamimi, S. Yue, M. Sanjari, L. Kestens, Hara, A. S. Kabir, R. Petrov

Manufacturing of thin sheet is difficult in industries. Some approaches, such as small-draft multi-pass rolling, intermediate annealing, isothermal rolling and high-speed rolling were proposed to overcome the deformability. In this study, different rolling speeds from 15 to 1000 m/min were employed to twin rolled cast AZ31B magnesium alloy to different reductions. The results show thatAZ31B sheets rolled at 15 m/min and 100 °C has fractured for reductions of more than 30% per pass. However, by increasing the rolling speed to 1000 m/min the rollability was improved significantly and the material can be rolled to reductions of more than 70% per pass. The high speed and heavily deformed materials are fully recrystallized even at 100 °C.

Jan 1, 2014

By Dunkin H. H

Flotation tests in a laboratory flotation cell at pH 8-8.5 and other sui}plementary tests were carried out on sphalerite-quartz and sphalerite-pyrite-&apos;quartz mixtures. Depression of sphalerite resulted vvhen the addition of copper sulphate exceeded an optimum value. Evidence that this depression was due to collector deficiency because of reaction between copper sulphate and collector is presented. It was not found possible to devise a direct analytical method suitable for .plant control of reagent addition. A possible means of control using potassium cyanide and a higher pH is discussed.INTRODUCTIONAt the Rosebery mill of Electrolytic Zinc Co. of Australasia Ltd., recovery &apos;of sphalerite in the zinc concentrate occasionally drops unexpectedly. Experiment in the mill and mill laboratory has suggested that one of the factors causing this may be the addition of more than an optimum amount of copper sulphate. On such occasions, an increase in the collector addition improves zinc recovery in the zinc concentrate, but only at the expense of sphalerite-pyrite selectivity.To examine the phenomenon more thoroughly, and if possible to find some means of determining the optimum addition of cepper sulphate and controlling the actual addition at this optimum, one of the authors (W. J. T.) was employed by the Electrolytic Zinc Co. of Australasia&apos; to carry out investigations in the Mining Department, University of Melbourne, under the joint direction of R. B...

Jan 1, 1954

By Mervin D. Marshall

A quick-reaction, mine permissible rescue vehicle (MERV) was developed for use by rescue teams. The MERV is a 6-wheeled, battery-powered unit with life support equipment and instrumentation; designed for a two-man team, with provisions for handling two victims or tools in a trailer. The vehicle is 100 inches long, 56 inches wide, and maximum height of 34 inches. It can be lowered down most mine shafts and has clearance to travel mine railways. The vehicle has power to all six wheels with power transmitted separately to either or both sets of wheels. Low-pressure, high-traction tires give the vehicle the ability to handle soft, muddy mine floors, flooded areas and significant obstacles, and can negotiate a 45% grade. Power and life support are sufficient for a 4-hour mission. The life support system is a commercially-available, approved unit currently used by MESA rescue personnel. A payout wire system provides communication between the vehicle and home base over a distance of 10,000 feet. On-board monitoring of carbon monoxide, methane and oxygen is provided, with master and individual alarms to warn of gas concentrations outside pre-set limits. A lightweight, water-tight trailer was developed for carrying victims or hauling tools and equipment.

Jan 1, 1979

By R. L. Guerguerian

Nowadays, most grinding mills driven by a wrap-around ring motor are operating successfully. Some of the earlier problems could be attributed to the lateral stiffness and stability of their bearings. As a result, modifications to the bearings included the rearrangement of the shoes, or the addition of more shoes, closer to the horizontal centerline. This technical paper reports a study of the effects of bearings on the lateral stiffness of grinding mills driven by a wrap-around ring motor. The discussions cover the design of the four shoe trunnion bearings and examine the effects of the angular location of the shoes.

Jan 1, 2000

The Calypso geothermal field, mapped by the R V Sonne (cruise SO-135) in 1998, includes four main sites, the Northern Vent Area (centred on 37¦ 36.7&apos;S, 177¦ 06.2&apos;E, area 1.5 km2), Central Vent Area (37¦ 39.4&apos;S, 177¦ 05.2&apos;E, 1 km2), Southern Vent Area (37¦ 41.7&apos;S, 177¦ 06.0&apos;E, 1 km2) and Mercury Vent Area (37¦ 41.3&apos;S, 177¦ 07.3 &apos;E, 0.5 km2). Hydrothermal activity at the vent sites is controlled by minor, sub-parallel NE-trending normal faults. Gas bubble trails (C02) and shimmering hot water vent from fractures and joints between large blocks of silicified volcaniclastics and in depressions in the sediments at the base of these outcrops. Measured maximum vent temperatures are between 180¦C and 201¦C. Venting fluids are at, or just below, boiling for water depths of 200 m. Rock samples recovered by dredge from the sites include massive anhydrite, clay-altered pumiceous ash, silicified volcaniclastic sediments and volcaniclastic breccias cemented by sulphur. Clay-altered samples, dominated by randomly interstratified illite-smectite and accessory chlorite, indicate formation environments of 70¦C to 90 ¦C. Native sulphur is abundant throughout the samples. Fine-grained (&lt;1 mm) disseminated pyrite and vein pyrite occurs in the clay-altered pumiceous volcaniclastics and argillites. In the Southern and Mercury Vent Areas, fine-grained orpiment, realgar and cinnabar have deposited in the sandy matrix of volcaniclastic breccias. Amongst the cinnabar, small (&lt;2 mm) beads of native Hg formed on the surface of several rocks following their recovery. These samples also contained abundant light hydrocarbons, which coat the rocks with an oily sheen.

Jan 1, 1999

By Fuzail Siddiqui

"The SIDMIN program aims at filling the mineral processor’s need to know the deportment of ‘minerals of interest’ not just ‘elements of interest’ that pass through the processing plants. Generally, chemistry is used as a tool of routine monitoring on site. Mineralogy, which is relatively much slower, is used more as a tool of research and post mortem investigations and these services are usually provided by a distant facility. The SIDMIN program enables site management to receive chemical and quantitative mineralogical reports on their critical samples daily, simultaneously and affordably.The author developed the SIDMIN program at ZCCM Nchanga Division where it continues to be a powerful tool for monitoring the efficiency of operations. Outlines are given of procedures for quick sample preparation and quantification of significant minerals in process samples. A specimen report is presented, which shows the format of reporting the contributions of individual minerals to metal losses at critical stages of the circuit. It is shown that SIDMIN provides timely information to management, about trends and abrupt changes in the quality of ore, and its processing, in a way never achievable by chemical analyses alone. This greatly helps in resolving the age-old problem of ‘bad ore’ or ‘bad operations’ on a day-by-day basis. For example increase in copper mica in the feed indicates excessive ore dilution during mining. Increased loss of free sulphides was traced to insufficient reagent conditioning time at the Concentrator. Persistent losses of leachable oxides at the Tailings Leach Plant were traced to inadequate leach residence time.SIDMIN is affordable because it can be implemented using basic optical microscopes, minimal quantities of micro-chemical reagents and custom trained site staff who demonstrate good colour perception and an ability to follow laid down procedures consistently."

Jan 1, 2000

By Klaus L. Cappel

In 1972, the Bureau of Mines of the U. S. Department of the Interior commissioned the development and design of a Simulator for research and testing of mine roof supports used in long-wall mining. The purpose of the Simulator is to reproduce forces and displacements of a section of a mine roof in contact with one or more supports. This report is an account of the design process that resulted in the final configuration of the Simulator presented here. It includes discussions of engineering considerations that led to major changes in important details of the Simulator. These changes, however, did not substantially alter the basic design originally proposed, except for the elimination of certain originally-specified features that were adjudged as insufficiently cost-effective by both the Bureau of Mines and the design agent at an intermediate stage of the design.

Jan 1, 1974

By George H. K. Schenck

In this decade of the 1.970&apos;s it is forecast that eight billion cubic yards of rock will be excavated from 400, 000 miles of new tunnels, drifts and other underground workings in the western world, according to estimates in a report of the Organization for Economic Cooperation and Development (OECD). It is expected that the cost of this work will be in excess of $54 billion in constant 1970 dollars. Most of this underground excavation will be in mining -- 97% of the tunnel length and 89% of the volume - -the balance in construction. In addition to this huge excavating task, in the 18 developed nations of OECD, will be projects in the Communist Bloc and in the developing nations. Underground excavation requires the successful completion of three principle activities: A. Break -- to free rock from the solid work face. B. Remove-- to clear the work area of broken rock. C. Support -- to assure stability of rock surrounding the underground excavation and to eliminate risk of rock collapse. In today&apos;s fully mechanized excavation systems, continuous miners, roadheaders or tunnel borers, (A) break the rock loose from the face, and (B) remove broken rock with their mucking devices and load it onto belt conveyors, mine cars, trucks, or any other appropriate haulage system for disposal. Such operations contrast to the more complex, intermittent systems employed when

Jan 1, 1974

The presence of undetonated explosives in a rock face after firing constitutes a hazard which can result in a fatal or serious accident if undetected before drilling commences.Most accidents caused by drilling into explosives are the result of failure to examine the working face properly and lack of care in subsequent drilling operations; it is not always realized that explosive may be left in the butts of holes or may be driven into cracks or crevices in the rock.Obviously the best means of preventing accidents of this nature is to adopt methods of drilling, charging and firing which will reduce the hazard to a minimum.There are three ways in which undetonated explosives may be left in the rock face, namely:1. Misfires.2. Cut-off shots.3. Incomplete detonation or failure of the charge to propagate throughout.MisfiresNo attempt will be made in this paper to deal fully with the question of the prevention of misfires, as apart from the fact that most of the preventive methods are well known, it is believed that if the miner receives his explosives and means of initiation in good order, and proper care is taken in their use, the failure of a charge to fire will be a rare occurrence. The provision of central fuse capping stations on mines has gone a long way towards the elimination of misfires caused by the mishandling of safety fuse anddetonators.

Jan 1, 1956