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By Clifford Britch

"Kaiser Resources Ltd. has completed feasibility studies resulting in approval of $277,500,000 for the construction of the Greenhills Surface Coal Mine, located 35 km north of Sparwood, B.C. The mine is designed to produce 1,800,000 tonnes per year of metallurgical coal over a 20-year period by conventional truck /shovel methods.The project is in the detailed design phase, with some preparation work being carried out on the site. The major construction activities are scheduled to commence in the spring of 1981. Mine development and pre-stripping will commence in July 1981, with first coal production scheduled for mid 1983.This paper will be a general description of the project and will include a discussion of the geology, reserves, mine planning, coal handling and processing, surface facilities and related topics.IntroductionProject DefinitionThe Greenhills Project is designed to produce, by conventional truck I shovel surface mining methods, 1,800,000 clean tonnes of metallurgical coal per year for twenty years . The production/ life constraints were chosen as being meaningful for planning and evaluation purposes after appraisal of the market potential and are not limited .by economic reserves. Substantial additional strippable reserves are available which would facilitate expansion of the proposed mine life and/ or capacity. In fact , all the facilities are designed so that they can be expanded in the future to accommodate a doubling of annual coal production, and certain portions of the coal processing facilities are being installed with an annual capacity of 3,600,000 tonnes. The mine will also produce approximately 2,400,000 clean tonnes of oxidized thermal coal, mostly in the first decade."

Jan 1, 1981

By Bowang Xiao

Recently more and more attentions are paid to high pressure hydrogen quenching (HPHQ) for its advantages such as environmental friendliness, low distortion, etc, compared to oil and water quenching. In HPHQ process, heat transfer coefficient (HTC) usually varies from part surface to surface because of the intense variation of gas velocity around the part. This article studies the effect of HTC distribution on part distortion after HPHQ and shows that finite element simulations considering HTC distribution predict different distortion from these without considering HTC distribution. It is also pointed out in this article that HTC distribution can be optimized by adjusting part orientation and HPHQ condition so that part distortion is minimized.

Jan 1, 2010

The Stawell Goldfield, the westernmost of the main Victorian fields, has produced over a million and a quarter ounces of gold from one and three-quarter million tons of ore. The lodes are quartz reefs and sulphide bodies occurring in sediments of lower Ordovician or upper Cambrian age. The lodes are confined to a relatively narrow suite of weak rocks lying between stronger ones above and below and there is a definite relationship between fold structure, pitch and strength of folding and ore.LOCATION HISTORY AND PAST PRODUCTIONThe town of Stawell, situated 150 miles north-westerly from Melbourne on the main railway and road to Adelaide, is the most westerly of the main gold areas of Victoria. Alluvial gold was found at Pleasant Creek (now Stawell West) in 1853 and the usual "rush" followed. Numerous alluvial leads, some surface, others buried under up to 100 ft. of Tertiary sediments were worked. The alluvial gold was soon exhausted, but in 1857 gold-bearing reefs were found on the slopes of a prominent ridge on the northern edgeof the present town. Early reef mining was by small working parties mining to shallow depths only and treating their ore at public crushing plants. Some of the early returns were very high grade. The next stage was the amalgamation of claims and the formation of companies, with their own treatment plants. This stage continued till the last mine closed in 1921. These companies had, by present standards, small holdings and far too many shafts were sunk, resulting in less efficient prospecting and operation.Since 1921 there have been one or two small scale attempts to revive mining but without success. Of recent years Gold...

Jan 1, 1960

By T. Skinner, M. Sahebkar

"In recent years, the mining industry has been inundated with new technologies and software systems to aid in productivity improvement. Accompanying this increased level of technology and computer systems has been the exponential growth in data sources and sinks for all aspects of a mining operation. This rapid growth in data and technology has evolved through vendor “push” approaches and user “pull” scenarios, the result of which has been that currently, no standards exist defining how data from new technology should be accessed and transferred from surface mining equipment and systems. Consequently, many incremental benefits of the systems have not been realized. This paper will present a discussion of this important issue and introduce a new committee formed to address standards to assist the industry in making effective use of current and future technology. Potential benefits accruing from the development of these standards will be illustrated through the use of a case study at Fording Coal Limited. IntroductionThe mining industry is currently faced with a rapid evolution in the computing-based systems capabilities of mobile production equipment. At the same time, there is a trend toward the introduction of even larger machines, with novel designs or incorporation of new technologies within existing designs. Computing and control technology will be required to operate and acquire knowledge about equipment operation, utilization, and performance. Such knowledge has the potential to lead to enhanced equipment design, more appropriate equipment selection, and optimized equipment performance. The equipment systems will be required to be integrated with mine production monitoring systems, maintenance management software, and a wealth of other information systems to provide a complete understanding of the effects of various factors such as maintenance, equipment design and production on economics (Roman and Daneshmend, 2001). This will lead to a better understanding and implementation of the opportunities to enhance the performance of the mine through interaction of the mine operations."

Jan 1, 2003

By David Schlain

"IntroductionThe purpose of this investigation was to study the characteristics of the high-acid electrolytic manganese cell with the idea of fitting it into one of the flow sheets being worked out by the Metallurgical Division of the Bureau of Mines for the recovery of manganese from low-grade domestic ores.In construction, the high-acid cell 3/ differs from the low-acid type in that the cathode and anode compartments are separated by a diaphragm of relatively low porosity, such as alundum. This is necessary because in the high-acid cell the two electrolytes are circulated separately. The anolyte is 15 to 30 percent H2SO4. The catholyte consists of a solution of ammonium sulfate and manganese sulfate with a OH of 4 to 3. The only mixing of electrolytes is that resulting from flow through the diaphragms. In the low-acid cell the two electrolytes are not circulated separately and do not differ so widely in hydrogen-ion concentration. Hence, the canvas diaphragm is sufficient.During operation of the cell, manganese is deposited on the cathode, and sulfuric acid is produced in the anode compartments. Various other reactions take place in the cell. There is considerable decomposition of water; hydrogen is evolved at the cathode, and oxygen is liberated at the anode. When lead anodes are used, some hydrated oxides of manganese are formed at the anodes. The quantity of oxides formed is not as great as it is in the low-acid cell, because fewer Mn++ reach the vicinity of the anodes."

Jul 1, 1942

By J. H. D. Hargrove, A. F. Snowball

Atmospheric pollution control has become increasingly important in re-cent years with laws and public opinion having required the reduction of contaminants from industrial gas effluents. Treatment methods have advanced to make possible, with proper plant design and operation, a satisfactory removal of these contaminants. Gases from Cominco's metallurgical operations at Trail, approximating 900,000 c.f.m., are treated by baghouses, electrostatic precipitators, cyclones, or wet scrubbers. The tabulated data include gas and dust conditions, plant performance, and some details of plant equipment. Discussion emphasizes the special features, scope of application, and basic design principles of the treatment methods, all based on Cominco experience. Recovery of over 99 per cent of the fume and dust is achieved by the major installations from which effluent gases go to atmosphere. Cooling of gases for baghouse recovery and conditioning for electrostatic precipitation are mentioned. Co3ts are tabulated for some of the installations on the basis of a unit of 1,000 cubic feet of gas. Suggestions are made on the procedure for assessing a smoke treatment problem and for selection of suitable equipment.

Jan 1, 1959

By P. Sklenicka

Remediation of the environmental (and social) disturbances caused by opencast brown coal mining in the past in north-west Bohemia isa priority for state environmental policy. In order to provide a concept for full restoration of land following disturbance by opencast mining, a special interdisciplinary project supported by a grant from the Czech Ministry of Environment was started in 2000. The initial stage of the project was intended to summarize and evaluate the findings and the works carried out in connection with various reclamation activities in the afflicted area over a period of more than 50 years. The main aims of the three-year project are to make use of the best available landscape environmental management knowledge in order to harmonize the ecological, aesthetic, productive and social functions of new valuable landscape, including the recovery of historical continuity and an understanding of ?landscape memory?. The basic landscape functions were assessed on two different scale levels. On a large scale, the relevant attributes were investigated over the whole area of the Sokolov brown coal basin (220 km2). The data and experience acquired were used to define large-scale guiding principles for the rehabilitation of a post-mining landscape. On a small scale, the basic characteristics and functions of the landscape were analysed in the Litov-Chlum model area (2 km2). The information derived from this analysis was used to formulate a small-scale approach for the rehabilitation of the model area and also to define general methodological principles. Keywords: rehabilitation, post-mining landscape, degraded landscape, non-productive priorities

Jan 1, 2004

By Mike Boissonneault

It was three years ago when the “storm of the century” had taken a firm grip over the Pacific West Coast and inland areas. At the Big Sky ski resort in Montana on Christmas morning two ski patrollers set out to perform an explosives “hand charge” avalanche control mission that would see only one return. It has been difficult to determine exactly what happened. Investigators do know that there were three separate and consecutive attempts to light a safety fuse, when it had apparently been burning since the first attempt. Time ran out after the third attempt. Although this accident has had a profound impact on North American avalanche control programs, I am sure it pales in contrast to the shock and grief experienced by family members who lost a loved one.

Jan 1, 2001

By M. Q. W. Jones

This paper summarizes important features of a compilation of thermal properties of stratified rocks from Witwatersrand gold mining areas. The database consists of more than 1000 thermal conductivity measurements, more than 700 density measurements, and nearly 100 heat capacity measurements. Most important rock types and stratigraphic units are well represented. Heat capacity does not differ significantly from one rock type to another, and density is relatively uniform although particular rock types are characterized by distinct average values. Different rock types also have distinct thermal conductivities, but this parameter varies by a factor of four to five. Primary factors controlling the thermal properties are mineral composition, degree of metamorphism, and porosity. In addition, the temperature dependence of thermal conductivity and heat capacity of quartzite may significantly decrease the thermal diffusivity of this rock at deep mining levels.

Jan 1, 2003

Study on New Tungsten Beneficiation Technological Flow Sheet of Shizhuyuan Polymetallic Mine

Sep 13, 2010

By Tristan Worsey, Nathan Rouse

Florida legislature allocated funding for the Florida State Fire Marshal to review the applicability of the United States Bureau of Mines (USBM) Report of Investigations (RI) 8507 blast vibration limits with respect to Florida and its soils. The study also discusses whether the current blasting vibration limits set by statute are still appropriate, including a review of measured vibration amplitudes and frequencies, structure responses, and theoretical analyses of material strength and strains.

Jan 1, 2019

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 Lawrie D. C

Finely ground beryl was decomposed by mixing with ground limestone and soda ash and heating at 900°C for 4-6 hr. The sintered mater:al was then crushed and leached by boiling under reflux with 5N sulphuric acid for up to 4 hr. The liquor containing Be, AI, Fe and other elements as sulphates, was separated from the residue which consisted mainly of silica and gypsum, either by filtration or bydecantation washing.The clarified leach liquor was first treated to remove Fe+++ by contacting with a primary amine-kerosene solution in 2 countercurrent stages. The iron free liquor was then passed to a 4-stage counter-current extraction unit where it was contacted with O·5M di- (2 ethyl hexyl) phosphoric acid (EHPA) in kerosene. Under the operating conditions, 99 per cent of the Be and 7 per cent of the Al was extracted.The Be and Al were stripped from the organic phase by sodium hydroxide solution of suitable concentration to form soluble "beryllate" and "aluminate" respectively. Most of the Be was subsequently precipitatedas Be(OH)2 by heating the alkaline solution to 90°C, the Al remaining in solution. After filtration and washing, the Be(OH)2 could be ignited directly to BeO at about 1000°C or used as a feed to further purification stages if required.A small counter-current extraction unit was operated continuously using liquor derived from the sintering and leaching stages. Dataobtained in batch laboratory tests were confirmed. A product obtained by ignition of the washed "beryllate" precipitate contained more than 99 per cent BeO.INTRODUCTIONIn 1958 an investigation was commenced into the recovery of beryllium oxide from beryl, as part of a programme to utilize mineral resources of South Australia. A survey of the literature indicated that little work had been done on direct solvent extraction of beryllium from aqueous liquors, so it was decided to apply the experience gained in this field in uranium processing to the current problem.Preliminary extraction tests on solutions of beryllium...

Jan 1, 1965

By Richard J. Robbins

Mechanical moles have developed through a tedious process of evolution. At times it has seemed that tunnel borers have been subject to the same Darwinian rules of evolution as their zoological namesakes who, despite their efficiency, are highly specialized and still restricted to soft soil conditions near the surface of the ground. HISTORICAL HIGHLIGHTS The Robbins Co. began its work in this field in 1947 with the development of a twin-bore continuous coal miner. Although these machines were used primarily in coal, two of the early prototypes were used to bore tunnels through shale. Disk cutters were first used on these machines and showed promising results as core breakers between drag-bit kerfs. In 1953, James S. Robbins and Assocs. undertook the development of a 25-ft 9-in.-diam circular tunnel borer for Mittry Construction Co. to be used at Oahe Dam in South Dakota (Fig. 1). This is believed to be the first rock tunnel-boring machine built since the end of the 19th century when short sections of the Channel tunnel were successfully bored in chalk from both the English and French shores. Another Oahe Dam machine was built in 1955, and then a series of three small-diameter machines for the company's first real experience with medium-hard and hard rock (Fig. 2) None of these three could be considered a success, although they laid the groundwork for the success that followed. Interbedded shale and limestone in Pittsburgh and hard limestone in Chicago quickly pointed up the weaknesses in these machines which were used by Perini, Dravo, and Healey. Among the problems were the high breakage rate of tungsten-carbide drag bits, too much flexibility in the drive shafts, failure of high-pressure hydraulic systems, chain-conveyor failure, and general lack of rigidity and strength. In 1956 another attempt at medium-hard and hard rock-boring proved this time to be a success and a significant turning point in the development

Jan 1, 1970

By Kenneth H. Johnston

This report describes in detail three waterflooding projects and a pres-sure-maintenance project in Butler and Cowley Counties, Kans., that will be visited on the 1963 annual spring tour of the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects are the flooding of five oil-producing horizons separately with injection water furnished by two water treating plants. Discussion of the individual projects includes information on their early history, the source and treatment of the injection fluids, oil production decline curves, and the results of water injection on oil production.

Jan 1, 1963

By David M. Jurich, Randy J. Essex, Alex de Aboitiz

An Automated People Mover (APM) transit system is planned for the growing Phoenix Sky Harbor International Airport. The APM will improve passenger movements between the terminals, and provide a link to parking facilities, a new rental car facility, and the planned metro Light Rail. The underground works will include shallow twin bored tunnels, taxiway crossings, and underground stations constructed beneath critical airport facilities. Challenging soft ground conditions will require extensive underpinning and ground improvements. Design is underway, and construction is scheduled to begin in 2007 with project completion in 2015. The owner’s planned delivery method for the APM Project will be Construction Manager at Risk (CMAR) with a Guaranteed Maximum Price.

Jan 1, 2005

By J M. F Clout

In the iron ore industry significant emphasis is placed throughout the mining process on meeting chemical composition specifications for the export of fine ores, however, little has been published on the implications of ore chemical composition for iron ore sinter and pellet product quality. The ore bulk composition, together with the nature of the minerals in the fine ore both play a critical role in determining the type of high temperature bonding phases that form during sintering and pelletising. This paper uses the experimental determination of phase relations in model sinter and pellet systems such as Fe2O3-CaO-SiO2 (FCS) and Fe2O3-Al2O3-CaO-SiO2 (FACS) to examine the links between iron ore chemical composition and the temperatures used during sintering and pellet firing. The phase relations help to establish the critical thermal and compositional parameters that control the bonding phase chemistry which in turn influences the physical characteristics of the sinter or pellet matrix. Results show that lower Fe-grade (

Jan 1, 2002

Many industries base their decisions on the assaying of tiny analytical sub-samples. The problem is that most of the time several sampling and sub-sampling stages are required before the laboratory provides its ultimate assays using advanced chemical and physical methods of analysis. As long as each sampling and sub-sampling stage is the object of due diligence using the theory of sampling it is likely that the integrity of the sought after information has not been altered and the generated database is still capable to fulfil its informative mission. Unfortunately, more often than not, unawareness of the basic properties of heterogeneous materials combined with the unawareness of stringent requirements listed in the theory of sampling, lead to the conclusion that massive discrepancies may be observed between the expensive outcome of along chain of sampling and analytical custody, and reality. There are no areas that are more vulnerable to such misfortune than sampling and assaying for trace amounts of constituents of interest in the environment, in high purity materials, in precious metals exploration, food chain, chemicals, and pharmaceutical products. Without the preventive suggestions of the theory of sampling serious difficulties may arise when making Gaussian approximations or even lognormal manipulations in the subsequent interpretations. A complementary understanding of Poisson processes injected in the theory of sampling may greatly help the practitioner understand structural sampling problems and prevent unfortunate mistakes from being repeated over and over until a crisis is reached. This paper presents an overview of the theoretical, practical and economic difficulties often vastly underestimated in the search for quantifying trace amounts of valuable or unwelcome components.

Jan 1, 2010

By Ross Nairn

"Tulawaka Mine is a joint venture between Pangea Minerals Limited 70% (a wholly-owned subsidiary of Barrick Gold Corporation) and Northern Mining 30%. Tulawaka Mine is located in North West of Tanzania in the Lake Victoria Goldfields. Tulawaka Mine is scheduled to process 360,000 tonnes per year at an average 11.5 g/t head grade over a 4 year mine life.The Tulawaka Process Plant uses single stage crushing, single stage SAG milling, gravity, intensive leach of gravity concentrates, CIL, Zadra desorption and cyanide detoxification to process the ore. Gold recovery exceeds (or is expected to) 95%.The Process Plant was designed and constructed under the supervision of Ausenco Engineering of Australia. Site works commenced in January 2004, Process Plant construction commenced in July 2004 and the first ore was presented to the Process Plant 26th February 2005. The first gold was poured on 15th March 2005. All construction contractors were demobilized from site 7th April 2005. Major achievements have been 3.4 million hrs LTI free during construction and operation to date, training of the Tanzanian workforce at Bulyanhulu Mine prior to commissioning, a succession plan to replace expatriate personnel with Tanzanian staff and significant over performance of the Process Plant against design.INTRODUCTIONTulawaka Mine is situated approximately 160 km south west of Mwanza in the western Lake Victoria Goldfields District of north western Tanzania. The property is held under a joint venture between Pangea Goldfields Inc (70%), a wholly owned subsidiary of Barrick Gold Corporation, and Explorations Minieres Du Nord Ltée (30%). A location map showing the position of the operation in Tanzania is shown in Figure 1.Mine site staff at Tulawaka comprises a combination of Tanzanian and Expatriate personnel. All Pangea personnel live on site and commute to their place of residence for their R&R on a 9 weeks on 4 weeks off roster."

Jan 1, 2006

In most mines using presplitting the final excavated wall shows a zone of damage just below the crest and well defined presplit half barrels. The crest damage (surface dilation) zone varies and is added to by subsequent adjacent perimeter blasting operations. Keeping the preconditioning to a minimum is possible using the methods described in this paper, developed on several diverse and geographically distant mining operations to control crest dilation and preconditioning by presplitting in advance - not just laterally but vertically in advance. The first documented case (Delbridge, Marton and McSweeney, 2004) in the development of the concept was undertaken at AngloGold Australia Pty Ltd's Sunrise Dam Gold Mine (SDGM), located beside Lake Carey, some 730 km northeast of Perth, Western Australia. The mine had been developed in a series of cutbacks to a depth of over 300 m and began underground mining during the latter stages of open cut operations. This mine is fairly unique in that it utilised a single pass vertical presplit which initially extended over three bench heights and after the failure mechanisms were understood, over four benches. The presplit drilling for the three stacked benches started on the floor of the second bench so that any dilation was confined to the surface one bench above the crest and modified perimeter blasting was then developed to curtail damage from blasting adjacent to the new crest. The second case is based on a South African coal mine in the Witbank Coal Measures, 140 km northeast of Johannesburg, Republic of South Africa (RSA). It was important that blasting for optimal wall stability and minimal scaling was developed in advance. A dragline is scheduled to excavate the #2 seam midburden which is the lowest of the economically viable coal seams in the five seam Witbank Coal Measures. Mining of the overburden, coal and partings above the dragline midburden pass are by excavator and truck and each mining layer is individually blasted. The results of presplitting the midburden through the overlying coal seams and partings have provided a presplit with no surface dilation of the midburden crest and ensures any subsequent crest loss is solely due to blasting adjacent to the vertical presplit. Typical of all coal mines in South Africa only vertical presplits are used. Wall control is most commonly delivered by presplit blasting and one common sight after the dust clears is a ridge of broken blocks along the presplit row, usually with a main crack running between the presplit blastholes and often parallel cracks either side of the perimeter line. The surface rock strata or block structures have been dilated by the venting gases and shock waves. Decoupled, fully coupled, single or double deck charges are used depending on a variety of factors, anecdotal practices and perceived benefits. Preconditioning of the crest rock by blasting from above may not be visible to the naked eye (or non-existent in overburden in strip coal mines) but the high speed venting of explosives gases (and often the water in the presplits) preferentially follow existing cracks and structures because there is no developed presplit crack near the surface. This nearly always lifts, shifts and separates the surface structures and geological layers. Stopping the dilation by 'sacrificial' or 'in advance' presplitting has been shown to reduce the crest loss at both metal and coal mines. Drilling and presplit blasting through an upper level of bench or layer provides a degree of restraint to the target layer where the crest must be maintained and any damage caused by the venting gases will not cause concern as it is removed as planned, leaving a stable crest.

May 1, 2010