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By Mukhopadhaya K. K, Cory A. H

The concept of using travelling magnetic fields created by linear motors was stimulated by Laithwaite who advanced ideas on motors with shaded poles (Laithwaite, 1968), rack and pinion motors (Laithwaite, 1970) as well as low speed, brushless motors and three dimensional motors (Laithwaite, 1973a and 1973b).Sudan (1963) and Sundberg (1969) had applied the concept to metallurgical processes. However, the use of travelling magnetic fields has not been used widely to produce conditions for the separation of magnetic from non-magnetic minera1s or even magnetic materials from non-magnetic materials, although some attempts were made by McCarthy (1922), Davis (1934), Dean, Gottschalk and Davis (1934) and Gottschalk (1934).Laithwaite (1973, a) while working with linear motors made suggestions for designing separators and in the work described here, the observations of Laithwaite and others are extended to determine the characteristics of the motor with a view to using it as a magnetic separator.

Jan 1, 1980

By Christopher J. Bambridge, Lee Seng Hoor

The Stormwater Management and Road Tunnel (SMART) Tunnel is a world first in the use of tunnel space transmitting both road and water through the same spatial envelope. The unique aspect of the SMART project is that the highway decks are used periodically for the conveyance of water. This aspect of the project has posed its own technical challenges that have been overcome in the design stage of the work allowing the project to be taken forward to construction with confidence in the systems to be Installed in the tunnel.

Jan 1, 2005

By T. F. Anstett

The Bureau of Mines estimated the potential availability of tungsten from 57 mines and deposits in 19 market economy countries. The tungsten resources of China and the U.S.S.R. were also estimated. This resulted from an evaluation of tonnage-cost relationships indicating the quantity of tungsten available as ammonium paratungstate (APT), artificial and natural scheelite, and ferrotungsten at various average total costs of production including 0- and 15-pct rates of return on invested capital. The evaluated deposits contain 1.2 million metric tons (t) of recoverable WO3, of which approximately 52,000 t of AEYT can be produced at the January 1983 market price of $5.37/lb, 89,000 t of natural and artificial scheelite at a market price of $3.63/lb, and 1,700 t of ferrotungsten at $5.61/lb of tungsten. An annual availability analysis indicates that by the early 1990's new deposit discoveries, development of known prospects, or expansions of producing mines will be necessary to meet projected tungsten demand.

Jan 1, 1985

By Joan T. May

Federal Bureau of Mines studies showed that some organic amine hydrochlorides can be used as dehydrating agents for producing anhydrous magnesium chloride from hydrates and brines. Laboratory-scale tests showed that double salts are formed by reacting 35 percent magnesium chloride brine or spray-dried magnesium chloride with pyridine hydrochloride. Heating decomposed these double salts to anhydrous magnesium chloride and recycle pyridine hydrochloride. Pyridine hydrochloride also chlorinated any magnesium oxide in the spray-dried magnesium chloride. The anhydrous magnesium chloride obtained by the method described contained less than 0.8 percent oxygen. More than 98 percent of the organic amine hydrochloride was recovered.

Jan 1, 1978

By Hillis R

As part of BHP Iron Ore's policy and goal of achieving a high standard of environmental management within its operations, a protocol for mine closure has evolved. The need to demonstrate sound environmental management with respect to site decommissioning meant that a comprehensive, environmentally sensitive closure protocol was required. Within this framework, a four-phase protocol was developed, the first phase was the determination of objectives in relation to site rehabilitation and end land use. The second phase was the determination of the process required to achieve these objectives. The third phase was the application of this process in a site specific manner. The fourth and final phase was monitoring of the site with regard to the achievement of determined objectives. The protocol was originally developed to direct the closure and decommissioning of the Goldsworthy site in 1992. This being the first total site decommissioning for BHP Iron Ore. Since that time the protocol has been successfully utilised for the closure of the Yampi (Koolan Island) operations (in 1993/94) and the Shay Gap/Nimingarra Operations (in 1994/95).

Jan 1, 1996

In response to increased aluminum demand, U.S. producers have begun reactivating primary aluminum capacity which was shutdown during the 1974-1975 recession. Reynolds Metals Company started up almost 80,000 tons per year of idled capacity at Listerhill, Alabama, and Jones Mills and Arkadelphia, Arkansas plants. Howmet Aluminum Corporation and Alumax announced that the operating rate at their jointly owned facility at Frederick, Maryland was being increased from 75 percent to 100 percent, equivalent to a 44,000 ton-per-year increase in output. Kaiser Aluminum and Chemical Corp. expected to restart one of the two idled potlines at its Mead, Washington facility in May raising its production rate by 27,000 tons per year. ANTHRACITE - The anthracite market for the larger sizes continues at a good level, and although the demand for industrial sizes has been weak, the current trend indicates an increased demand for industrial fines by the steel, auto, and other industries.

Jan 1, 1976

By Takashi Furuyama, Sukeyuki Mori, Abel Bissombolo

"In flotation practice, a good recovery of minerals largely depends on the degree to which the valuable minerals have been liberated from the associated gangue during the grinding process. Therefore, a regular measurement of the degree of liberation can provide data for the assessment of the quality of separation and predicts the effect of changes in the grinding-classifying circuit on flotation process. Generally, the standard procedure for measuring the degree of liberation requires the preparation of polished sections - a time consuming operation that also has the disadvantage of providing an overestimated number of free particles because of the stereological nature of produced samples.The present work is an alternative approach to avoid these miscalculations and establish a system of control for fluorite flotation plants. The system deals no only with the state of liberation but also the dynamic behavior of individuals particles and mineral components within the grinding-classifying and flotation circuits. It involves methods such as sieving, x-ray diffraction analysis, study of polished sections and microscopic counting of preliminarily sieved minerals particles from a fluorite processing plant, randomly dispersed on a glass slide, but not embedded in a resin mounting medium. If a complete information on the textural properties of minerals in the ore (including its mineral components distribution) can be obtained through x-ray diffraction analysis and study of polished sections, the microscopic counting is used to determinate with enough accuracy the mineral liberation, estimate the grade of fluorite ore and products, determinate the deportment and approximate recovery of individuals particles and mineral components within the investigated circuit. For a count of 100-1000 particles in each n-size range, the counting method was found to be a particularly reliable and less time consuming operation that could substitute the chemical analysis of fluorite ore for an estimate of the grade:"

Jan 1, 2003

A unique sluicing process for recovering tailing impounded in a valley was developed by Electrolytic Zinc Company of Australasia Ltd., West Coast Mines, Rosebery, Tasmania.Earthmoving equipment could not be used as most of the material to be recovered was semi-fluid. A conventional sluking method was also impracticable as there was no suitable working face from which the process could be commenced.Operations started from a flat surface, using special techniques for sinking through the tailing and establishing producing working faces as the sinking process continued.After about 2 years the bottom of the dam was reached and conventional sluicing methods could be used.

Jan 1, 1973

By H. L. Anthony, A. C. Richardson, G. D. Coe

"INTRODUCTION The Warrior View mine of the Seaboard Coal Corporation is located in Tuscaloosa County on the Warrior River about 14 miles northeast of Tuscaloosa, Ala. The Brookwood bed at this point yields a coal with fair coking qualities, and the product from neighboring mines on this bed has been used for the manufacture of blast furnace coke. The output of the Warrior View mine, however, is used exclusively for domestic and steam-raising purposes.This paper continues the series° of reports on the washability of Alabama coals which are based upon the study of coal preparation in Alabama now being conducted by the U. S. Bureau of Mines and the University of Alabama with the cooperation of the different coal mining companies. This paper contains screen-sizing and float-and-sink tests of a representative sample of run-of-mine coal, and flakiness and crushing tests on certain sizes.Published information on the Brookwood bed is very meager. Fieldner6 gives the proximate and ultimate analyses for a number of seam samples taken from representative mines working this bed. Gandrud and Britton7 show sections of this bed taken at Searles, Ala. They also give the specific gravities of the coal, the bone, and the shale partings.Table 1 give the proximate and ultimate analyses for the 3/4 to 3/16 inch size of raw coal. Table 2 gives the sulphur content and the ash fusibility temperatures of the float-and-sink fractions for this same size. The character of the coal is very uniform throughout the range of sizes produced and, as it was not convenient to have these analyses on all sizes, this size was chosen as being representative of the coal. From the information available it is evident that the coal preparation problem is restricted to one of ash reduction.SAMPLING AT THE MINEAt the Warrior View mine the run-of-mine coal is dumped from the mine cars upon a 3-inch grizzly. The oversize is crushed in rolls set at 24 inches and joins the undersize before being elevated to the raw-coal bin ahead of the jig. The sample was caught at the point where elevates discharges into the raw-coal bin, by taking a proportional amount of the coal at 10-minute intervals over the period of a day's run, The total sample amounting to 2.7 tons was shipped to the laboratory at Tuscaloosa for the washability studies."

May 1, 1932

By George S. Rice

In response to numerous requests for information as to the status of internal-combustion mine locomotives of the Diesel type that use heavy or nonvolatile oil for fuel, with special reference to their safe use in coal mines, the United States Bureau of Mines is issuing this t port. Data were obtained on application of such locomotives to coal mining only in Belgium, France, Germany, and Great Britain. The locomotives are used in coal mining in other countries, as well as in potash, iron, and other kinds of mining, but their chief development has been in coal mining in Germany, France, and Belgium. Recently popular interest in the Diesel type of engine for motive purposes was aroused in this country by the successful application of Diesel engines to railroad locomotives hauling fast transcontinental trains, and, according to published statements, at a low cost of fuel per mile of run.

Jan 1, 1936

By Y. Boissonnas

INTRODUCTION, The transalpine rail routes in Switzerland are well over one hundred years old. As the established routes no longer meet the demands of the continually increasing volumes of rail traffic between north and south, two new routes through the Alps were planed. The old Gotthard rail line is in fact a mountain railway. The northern and the southern access ramps?with a maximum speed of 80 km/h and a maximum slope of 2.2%?reach the old Gotthard rail tunnel at an elevation of approximately 1,100 m above sea level. This is approximately 900 m higher than the city of Milan. In 1992, the Swiss electorate people voted with an overwhelming majority in favor of the project to build the new base routes through the Alps. The Swiss voted again in 1998 in favor of the financing proposal for the new infrastructure. Swiss Federal Railways together with the BLS Lötschbergbahn were commissioned for the realization and management of the Gotthard and Lötschberg routes. AlpTransit Gotthard Ltd., founded by Swiss Federal Railways, was given the task of managing the design and realization of the Gotthard route until the start of regular service. In the meantime the shorter Lötschberg Base Tunnel was open to traffic in 2007

By Ryan Walton

The Flash Converting Furnace at Kennecott Utah Copper converted over 465kmt of high-grade matte in 2002 but was restricted due to low matte production to 395kmt in 2003. This paper presents updated operational performance data and describes improvements implemented since the mid 2001 rebuild. Matte burner feed distribution, silica and arsenic impacts on settler lime-based slag operability, blister laundering, uptake/boiler accretion control, and dust sulfation will be discussed, as well as current development requirements dictated by operational imperatives and furnace modification plans.

Jan 1, 2005

By L. B. Hales

Image analysis for feed belts and flotation has been used for over 20 years. It has been shown to aid in the modelling and optimization of Sag Mill circuits, and any improvements in the image analysis result in improvements in the model for control. Using a laser to measure the height-profile of rocks on the conveyor has been shown to increase the accuracy of the size classification. We have developed a system using two cameras in a stereoscopic configuration to provide height-profile measurement without the added expense and safety concerns of using a laser. Additionally, we have developed a novel technique for calibration of the system, using artificial intelligence techniques to optimize the model fit by adjusting the image analysis tuning parameters to values resulting in the best classification.

Feb 27, 2013

The physical setting and background to mining operations on Misima Island and the overall plant lay-out are outlined. Developments and changes made to each section of the plant are described as they were encountered during commissioning and initial operation.

Jan 1, 1991

A comparatively new and very promIsmg field for applying cemented tungsten-carbides is in the mining and quarrying industries. The economic advantages of this unique engineering material over the conventional hollow drill steel, or steel detachable bits, have proven so great that the use of "hard metals" promises, in some instances, to revolutionise the drilling of all manner of minerals. Early in the war years the Germans realised the tremendous advantages cemented carbides offered for holing hard rocks, and they proceeded to develop detachable percussion bits to do this work, at the same time evolving fast, comparatively light-hitting driliing machines, especially designed to suit the mechanical properties of the carbide.Here in Australia also, it has appeared that the detachable percussion bit offers the greatest economic benefits to consumers, although the author is well aware that carbide-tipped drill rods have, and may continue to work out satisfactorily in certain mines and quarries.Most drilling equipment at present installed in Australia may be described as being of the heavy hard-hitting variety, so that the designer of an efficient percussion bit has to take special precautions to overcome the problem of fatigue, and to ensure that the inserts are securely mounted in the body with the minimum of internal stress in the carbide.

Jan 1, 1950

By D A. Manhire, R M. Flores

The commercial develop of coalbed methane from the Powder River Basin has demonstrated that low-rank coals can be a viable source of gas. Currently over 20 000 coalbed methane wells exist in the Powder River and it is predicted that there will be 50 000 wells by 2010. What makes the Powder River Basin successful is the thickness of the coal (in excess of 30m) as well as the low ash content (

Jan 1, 2002

By ATF Publications

The following is a summary of the changes that were incorporated into the new Federal Explosives Regulations, 27 CFR Part 55, dated 9/2000. However, in light of the recent events of September 2001, additional changes in the Federal Explosives Laws and Regulations may be forthcoming. The nature and extent of any such potential changes are impossible to gauge at this time. However, this synopsis of the changes contained in the September 2000 Orange Book, ATF P 5400.7 was current at the time of this writing. Any questions regarding this paper should be directed to the Public Safety Branch in ATF Headquarters in Washington, D.C.

Jan 1, 2002

By Will Foreman, Douglas D. McLearie, Edwin K. H. Tong, William H. Hansmire

Hong Kong’s Strategic Sewage Disposal Scheme (SSDS) Stage I involves the provision of a system of deep tunnels for transporting to a central treatment works wastewater collected from a number of catchments around Victoria Harbour. For the SSDS Stage I works, about 24 km of tunnels have been excavated in hard rock at depths ranging from about 80 to 150 m below Victoria Harbour and the surrounding heavily developed areas of Kowloon and Hong Kong. Five tunnel boring machines(TBMs) with diameters ranging from 3.2 m to 4.3 m were used to excavate the tunnels. Tunnel excavation has been completed and tunnel linings are in progress. Major tunnelling issues such as ground stabilisation and water control encountered in the project are summarised. An overview of one of the possible future tunnel systems that might be adopted in subsequent stages of SSDS is also presented.

Jan 1, 2001

By D. Linzey

"History of Whitehorse Copper BeltThe first discovery of copper on the Whitehorse Copper Belt is reported to have been made by miners on their way to the Klondike in 1897. By 1899 the district had been well prospected and many of the presently known deposits had been staked.The first shipment of ore was from the Copper King property in 1900. This consisted of 9 tons of hand picked ore grading 46.4% copper. It was not until the period between 1912 and 1917, the production years of the Pueblo Mine, that significant ore shipments were made. Total production was 140,000 tons at 3.5% copper. An underground disaster killed six men and closed the mine in March 1917.Although the general area was dormant until after World War II, by 1947 geological mapping, magnetic surveys and diamond drilling had been done on the important showings. In 1954 Mr. Aubrey Simmonds directed the formation of Imperial Mines and Metals, which acquired by option and staking a large part of the Whitehorse Copper Belt. In 1957 Mr. Arnold Pitt reorganized the company as New Imperial Mines. With financing from Sumitomo and Toronto-Dominion Bank, a mill was built and production was started from the Little chief orebody by open pit in 1967."

Jan 1, 1977

By K. Whiting, R. Huffsmith, R. Olsen, D. Adams

Long-term closure alternative selection for heap leach pad effluent is a daunting task. Passive water treatment, if designed with enough long-term capacity, can minimize long term O&M while meeting water quality objectives. Leach pad effluent from a 30-acre leach pad at Basin Creek Mine, Basin, Montana was targeted for long-term water treatment using a passive water treatment system. The objectives and results of design and construction are: 1. Design a long-term passive system utilizing existing infrastructure. 2. Construct a field scale pilot test at the mine site.

Jan 1, 2002