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By P. Lafleur

All indications point to a growing market for thermal coal in Japan as part of the country's current energy policy formulation process. The Ministry of International Trade and Industry forecasts imports of 16 million tons a year in 1985 and 40 million tons in 1990-a twenty-fold and forty-fold increase over the present level. This potential reflects Japan's over-all serious and increasing concern for security of energy supplies and its resultant need to seek alternative sources. Nuclear power will be the main alternative source, but, because it is expected that its development will be slow, imported thermal coal will assume greater importance. Canada, with large resources of all types of coal, could fill a portion of this market. Thermal coal could come from specific thermal coal developments or from metallurgical coal mines, which usually produce a certain amount of coal not amenable to coking, but suitable for power purposes. However, penetration of this Japanese market by Canadian thermal coal will depend on the resolution of a number of problems. On the demand side, siting, environmental aspects, the need for a coal unloading and trans-shipment centre, and the added cost of installing coal-fired stations could be major constraints. Although Canada has ample high-quality resources, any new development tied to the Japanese market will require improvement in prices to cover the high costs associated with transportation, the construction of new mines and the provision of new infrastructure.

Jan 1, 1979

In the exploration of an area proposed for the establishment of an underground colliery, consideration of all land and mining titles and consents has early priority. Environmental aspects have become more meaningful. Preliminary assessments of previous geological knowledge, together with new geological and geophysical data from surface investigations, condition the decision to proceed with costly diamond drilling programmes. Methods other than fully cored diamond drilling have a useful application in appropriate circumstances. Drilling exploration is conducted in stages of increasing density of-hole spacing to the point where, with holes at 1 km centres, reserves are categorized as measured. The programme is subject to constant review in the light of market changes.

Jan 1, 1976

By S. S. Nosseir

INTRODUCTION General Quebec Cartier Mining Co. (QCM) , Canadian subsidiary of U . S. Steel Corporation, operates two iron ore concentrators at the North Shore of Quebec, Canada. In its own operation at Mount-Wright, over 45 million tons per year of crude ore are ground, fully autogenous in six 32' x 11-1/2 Dominion Engineering mills. At Fire Lake/Lac Jeannine operation, property of Sidbec Normines Incorporated (SNI), over 11 million tons per year of crude ore are now ground, fully autogenous, in twelve 18' x 5' Hardinge mills. The Lac Jeannine concentrator was originally constructed by Q.C.M. in 1960 and. was since operated, in beneficiating the Lac Jeannine ore deposit until fully depleted in 1977, at an annual capacity of 18 million tons of crude per year. In 1976, the new company, Sidbec Normines, was incorporated by Sidbec Corporation, British Steel Corporation and Quebec Cartier Mining Co., in proportional holding of approximately 51 to 41 to 8 percent respectively. Since the acquisition of the Fire Lake ore deposit and Jeannine concentrator by the new company, QCM has continued managing the mine and concentrator operaions for S idbec Normines Inc . Flow-Sheet Design Jeannine concentrator comprises twelve identical mill lines grinding the ROM from 8" top size to 14 mesh nominal size range. Driven by 600 H.P. motor at 13.4 RPM corresponding to 73% critical speed, each mill is operated in a closed circuit with two 5' x 12' vibrating screens dressed with 2.5 x 25 mm slot opening cloth. The ground product or screen undersize at an average grade of 33.4% Fe is beneficiated by gravity separation to produce 66.5% Fe concentrate grade at 42.7% weight recovery. At the rougher stage, each mill line con-tains 128 Humphrey 13- 1/2" pitch spirals which produce a final tailing, middling and concentrate products. The rougher concentrate - so produced - is classified by 64 Humphrey pocket sizers into an underflow, which is a final concentrate product and an overflow which is further upgraded by 64 cleaner spirals. The cleaner concentrate together with the pocket sizer 's underflow are dewatered on a 13'[6] horizontal filter. The rougher middling together with the cleaner tailing are recycled in a closed circuit with the spirals. The rougher tailing after dewatering by hydrocyclones is disposed of by a

Jan 1, 1982

By G. V. Raymor, James T. Waber, I. Rex Harris

The lattice parameters of a series of fcc alloys of cerium and thorium were measured at 93 " and 298OK. Lattice parameters were also estimated for 171OK. Substantial deviations, y, from Vegard's law were observed. Although y was negative at the two higher temperatures, it was positive and large at the lowest temperature. A variety of models, which have been proposed in the past, were considered, and the calculated values of y were compared with the observed values. The best agreement was achieved with values computed with Friedel's equation. THE purpose of this investigation was to determine the effect of temperature on the lattice parameter and on deviations from Vegard's law of Ce-Th alloys. A large negative deviation from Vegard's law was first observed independently by Weiner, Freeth, and Raynor' and Van vucht2 in the room-temperature lattice parameters of Ce-Th alloys that form a continuous series of solid solutions. This observation was confirmed by Evans and Raynor. The allotropy of unalloyed cerium was reviewed recently by Gschneidner, Elliott, and McDonald. In two subsequent papers,5" these authors reported the influence of various alloying additions on the y= transformation, which occurs below room temperature. Although other rare earths tend to stabilize the double-hexagonal phase, thorium, plutonium, and scandium as solutes tend to stabilize the normal fcc phase. With addition of sufficient thorium as a solute, there is evidence that the formation of is suppressed and it becomes possible to pass continuously with decreasing temperature from the room-temperature phase to the fcc a phase. Thus there is a closed loop which is similar in many ways to the y loop well-known in ferrous alloys. A closed field also occurs in the pressure-temperature "equilibrium" diagram of unalloyed cerium. Because of interest in the effect of thorium additions and their influence on the a and phases, lattice-parameter measurements were made at low temperatures on the fcc phase for a series of alloys ranging from 10 to 90 at. pct Th. The results obtained at three temperatures are shown in Fig. 1. Evans and Raynors analyzed the deviations from Vegard's law in Ce-Th alloys in terms of changes in the occupancy of the 4f electron level in cerium,

Jan 1, 1964

By H. H. Campbell

In the extending employment of open-hearth steel for structural purposes, it is a matter of prime importance that the test-piece shall represent with practical accuracy the characteristics of every portion of the heat from which it comes. In ordinary practice this homogeneity is assumed; but inasmuch as leading exponents of the revolving-hearth system have claimed that a reasonable uniformity could be obtained by their method alone, it may be pertinent to offer a few facts on the subject. The following heats made by the Pennsylvania Steel Company, for bridge-work, were tested by casting two four-inch ingots, one being taken during the first third and the other during the last third of the cast. Test-pieces obtained from these small ingots usually give results inferior to those obtained from larger sizes; but for purposes of cornparison they are equally conclusive. Many of the tests were made for experimental purposes within a few hours of the time of rolling, and before sufficient time had elapsed for the usual molecular redistribution necessary for the best results. All the tests were made on 3/4-inch rounds just as they left the rolls and without annealing; the results, therefore, are subject to the errors caused by variations in the diameter, and in the temperature at which the bar was finished. The tests from any one heat, however, were always nude as nearly as possible under the same conditions; and inasmuch as these data include the results of every heat so tested, and inasmuch as the errors could not by any chance always support any single theory, we may be certain that the unanimons testimony of the experiments indicates a valid conclusion.

Jan 1, 1886

By Ta M. Li

How will phosphate producers in southeastern Idaho fare with growing governmental regulations and environmentalism of the late 1970's? With a similarity that is reminiscent of the battles between the coal industry and environmental-conservation groups earlier in the decade, Idaho's future growth and a nation's need for phosphate fertilizer products remain uncertain. The catalyst that brought the issue to the forefront was the preparation of an Environmental Impact Statement (EIS) addressing the development of phosphate resources in southeastern Idaho. Although the final EIS was published in August 1977, resolution of rational and orderly growth in this potentially vital region remains stifled as Secretary of the Interior Cecil Andrus virtually "sits" on it.

Jan 1, 1978

The Library is a cooperative activity of the American Institute of Mining and Metallurgical Engineers, the American Society of Civil Engineers, the American Institute of Electrical Engineers and the American Society of Mechanical Engineers. It is administered as a public reference library of engineering and the allied sciences. It contains 133,000 volumes and pamphlets, 6700 maps and receives currently most of the important periodicals in its field. In order to place the resources of the Library at the disposal of those unable to visit it in person, the Library is prepared to furnish lists of references to engineering subjects, copies or translations of articles, and similar assistance. Charges sufficient to cover the cost of this work are made.

Jan 1, 1933

By Chengguo Zhang, Bruce Hebblewhite, Faham Tahmasebinia, lsmet Canbulat

"Coal burst is a dynamic release of energy within the rock (or coal) mass leading to high velocity expulsion of the broken/ failed material into mine openings. This phenomenon has been recognised as one of the most catastrophic failures associated with the coal mining industry, which can often lead to injuries and fatalities of miners as well as significant production losses. This paper aims to examine the mechanisms contributing to coal burst occurrence, with an emphasis on the energy release concept. In this study, a numerical modelling study has been conducted to evaluate the roles and contributions of difference energy components. The energy analysis presented in this paper can help to improve the understanding of energy release mechanisms especially under Australian conditions.INTRODUCTIONCoal burst is one of the most hazardous problems encountered in underground coal mines, which occurs at different locations in a variety of mining systems and operations. This phenomenon always involves a violent and dynamic energy release with large rock mass/coal deformation and ejection that can cause severe damage to openings, equipments and may result in fatalities and injuries.The first coal burst occurrence was reported in Britain in 1738 (Dou 2001). Since then, international experiences are available in Canada, South Africa, USA, former Soviet Union, China, India, France, Germany, Poland and Czechoslovakia. Rice (1935) classified coal bursts as two general types, namely excessive pressure bumps and shock bumps and he further mentioned that pressure bumps are caused when pillar stress exceeds bearing strength. Shock bumps are induced by the breaking of thick, massive strata at a considerable distance above the coal-bed, causing the immediate roof to transmit a shock wave to the coal."

Jan 1, 2016

By M. Prud’Homme

Potash is an important natural mineral used largely as a fertilizer in the production of food and fiber. About 93 percent of all potash consumed globally is used in agriculture as fertilizer. The balance is used to manufacture potassium chemicals. Most potash is extracted by conventional underground mining methods. Solution mining is used when underground deposits are irregular and very deep. The other main production method involves the evaporation of brines in shallow salt lakes, followed by the harvesting of potassium minerals.

Jan 1, 2005

CENTRAL EMERGENCY COMMITTEE Chairman, MRS. H. N. SPICER As no further requisition will be Made for knitted garments, for the boys of the 27th Engineers, all completed garments and wool have been collected and returned to Mr. W. R. Ingalls, and the activities of the

Jan 12, 1918

By R. E. Hanneman, A. N. Mariano

In conjunction with the need for accurate volumetric data in the Fe-V system for subsequent use in calculating the high-pressure diagrams, room- and high-temperature X-ray diffraction measurements have been carried out. No previous measurements have been published on lattice parameters or volume changes associated with the a transformation for Fe-V alloys. The existing literature on lattice-parameter data for the a and s phases has been reviewed by pearson1 with considerable uncertainty indicated in the data. In order to obtain a good estimate of ?Va-? for thermodynamic calculations of the a D ?(bee D fee) phase stability, high-temperature vacuum X-ray diffraction measurements were made on an Fe-V alloy of 0.92 wt pet V. The term ?Va-? is the difference of molar volumes of the limiting solubilities of the a and y phases at any given temperature; these values can be calculated readily from the appropriate lattice-parameter data. The equipment used was a commercially available MRC (Materials Research Corp.) high-temperature X-ray camera which was fitted to a Norelco diffractometer

Jan 1, 1964

By Miguel Pimentel

El presente trabajo describe el proceso implementado por la minera Yanacocha para el tratamiento de las aguas de exceso a través de la Tecnología de Membranas (EMS- Engineered Membranes System) o proceso de Osmosis Inversa, conocida también por las siglas en inglés de RO (Reverse Osmosis). El proceso RO tiene por objetivo tratar la solución barren proveniente de la planta de Merrill-Crowe para reducir el contenido de cianuro, así como los metales disueltos y otras sustancias como nitratos y nitritos en la solución.También, busca clarificar el agua tratada para cumplir con las exigencias que establece el Ministerio de Energía y Minas (MEM) y el Banco Mundial (IFC) en cuanto a límites de descarga permisibles. Una vez alcanzados los niveles establecidos, y con la aprobación del área interna de Control de Calidad, el agua tratada se descarga al medio ambiente.

Sep 12, 2005

By Theodore H. Eyde

In the southwest porphyry copper province, the virgin prospect with good copper mineralization cropping out has disappeared. Future discoveries will require an increasingly sophisticated arsenal of exploration techniques and concepts. One of the latter, stratigraphic analysis, is a technique which is often overlooked. A surprising number of exploration geologists still think of porphyry copper deposits as occurring wholly within intrusive bodies such as quartz monzonite or granodiorite. Disseminated copper mineralization, though genetically related to intrusive rocks, can occur within both the intrusive and the intruded rocks. At present, as much as 30% of the total copper produced from disseminated copper deposits in the Southwest originate from the intruded rocks rather than the intrusive. George M. Schwartz, in "Geology of the Porphyry Copper Deposits of Southwestern North America" points out that the host rocks at porphyry copper deposits include such diverse rock types as diabase, granite, limestone, dolomite, quartzite, skern, sericite schista, and others in addition to the more common monzonite, quartz-monzonite, and diorite porphyrys. Therefore, a porphyry copper can be defined as a disseminated copper deposit occurring either in or adjacent to a granitic-monzonitic-dioritic intrusive which can be exploited using bulk. mining techniques. The original definition of porphyry was originally applied to the early producers, such as Inspiration, Bingham, and Ajo, in which the copper mineralization occurred principally within the intrusive. A review of the geologic literature describing the porphyry geologic

Jan 1, 1971

By M N. Mian

The Cayeli volcanogenic massive sulphide deposit is located in Black Sea region of Turkey. Cayeli Bakir Isletmeleri (CBI) was formed as a joint venture between Inmet (Canada) and Eti Holding (Turkey). CBI is processing complex copper/zinc sulphide ores. The Cayeli concentrator was commissioned in 1994, with a design capacity of 600 000 tonnes/year. The grinding circuit was a classical rod mill/ball mill combination. The rod mill was converted to a primary ball mill in May 1997. The reasons for conversion were to use mill power more efficiently and eliminate feed interruptions during rod charging. The grinding circuit now has a primary ball mill in open circuit, and a secondary ball mill in closed circuit with hydrocyclones. Classification was originally done in two stages with hydrocyclones. Both mill discharges were combined and pumped to a primary cyclopack having two, 500 mm diameter cyclones. Primary cyclone overflow was pumped to a secondary cyclopack for further classification. The secondary cyclopack had ten, 200 mm cyclones. Both unit underflows were fed to a secondary ball mill by gravity. The secondary cyclone overflow, typically 62-64 per cent passing 36 ¦m, at around 42 per cent solids (w/w) was fed to flotation circuit. In order to increase circuit capacity to 1 000 000 tonnes/year and to improve control over the grinding circuit, it was decided to convert the classification circuit from two stage to one stage. For this purpose, six Warman Cavex cyclones having 400 mm diameter were installed. Now, the combined primary and secondary ball mill discharge was classified in single stage with the Warman cyclones in closed circuit with the secondary ball mill. The cyclone overflow goes directly to the copper rougher circuit as flotation feed. The grinding circuit is producing a flotation feed of 70 per cent passing 36 ¦m. The change over to single stage classification at Cayeli was successful. A mill throughput of 1 000 000 tonne/year is being achieved with better control over classification, and improved grind size. Results and comparison between the two classification circuits are presented in the paper.

Jan 1, 2003

By Zay Jeffries

The object of the present paper is to enlarge somewhat on the general principles advanced in my discussion1 of Mathewson and Phillips' article on The Recrystallization of Cold-Worked Alpha Brass on Anneal-- ing.2 It will also serve as an acknowledgment of Prof. Howe's most important remarks on my contribution. In this paper the writer has adopted Prof. Howe's suggestion to substitute the term "germinative temperature'' for "critical temperature for grain growth." Instead of being an exact or certain temperature it should be considered that the germinative temperature phenomenon exists throughout a small temperature range. v Factors Influencing Fast Growth Phenomena The development of grains of macroscopic size at the germinative temperature should be considered the extreme condition of a general rule. When considered in this light it is not strange that the development of these large grains should be the exception and not the rule. The principal factors influencing the operation of the laws of fast growth temperature are as follows: . 1. Rate of heating. In the original paper,' the germinative temperature was defined as "the minimum temperature at which two adjacent grains can coalesce to form one larger grain, provided that this larger grain will have sufficiently increased its power of attack, to enable it to absorb adjacent grains which cannot coalesce with each other. Time is always to be understood as a factor governing the first stage of grain growth." If the time of heating is short, the germinative temperature is raised. The formation of large grains in metals may occur at relatively high temperatures when the rate of heating is rapid. It is to be understood that in such cases, grain growth

Jan 1, 1917

By Maria I. De Rosa

Table 1 and figure 1 show the number of fires and fire injuries that occurred in underground metal/nonmetal and stone mines by state during 1990-2001. Table 1 also shows the injury risk rates, employees' working hours, and lost workdays. Overall, 65 fires occurred in 20 states; these include 2 fires and no injuries for contractors. Six of the fires caused nine injuries. The yearly average was 5.4 fires and 0.75 injury. Forty-one fires with 2 injuries occurred in metal mines, 14 fires with 7 injuries occurred in nonmetal mines, and 10 fires with no injuries occurred in stone mines. The underground mine fires required 25 mine rescue team interventions and 30 mine/section evacuations. The Ewhr value was 260 x 10° hr (Irr = 0.007), and the LWD value was 83. Idaho had the most fires (eight fires and no injuries), followed by Louisiana (seven fires and two injuries), Michigan (six fires and six injuries), and Missouri (six fires and no injuries). Of these states, Michigan had the highest injury risk rate value (Irr = 0.146). Table 2, partly illustrated in figure 2, shows the number of fires, fire injuries, risk rates, employees' working hours, and lost workdays by time period. The number of fires during the six time periods show an increase during the fourth period followed by a sharp decrease during the fifth period and a sharp increase in the last period. The number of fire injuries show an increase followed by a decrease during most of the periods, accompanied by a decline in employees' working hours during most of the periods; an increase is seen during the third and fourth periods. The In values follow patterns similar to those shown by the injury values. Tables 3-8 show the number of fires by ignition source, method of detection and suppression, equipment involved, location, and burning material by time period. Figure 3 shows the major variables related to fires for 1990-2001. Table 9 shows the number of fire injuries per number of fires causing injuries and total fires by year, ignition source, equipment involved, and location.

Jan 1, 2004

The concepts of capacity and basicity have proved extremely useful in dealing with a wide range of solute species in metallurgical slags, and as a result have been widely applied. These two concepts are reviewed, and it is suggested that the Lewis approach to basicity has much to commend it. In some cases, it appears that the term capacity has been used without due consideration being given to the nature of the solution being formed, or even to whether a true solution was being formed at all. This paper proposes a rigorous definition of capacity, based on the true nature of the solution process in slags and glasses, and briefly reviews the repercussions of this approach on data available in the literature and the limitations which it may impose on future investigations in this area.

Jan 1, 1994

By Todd M. Ruff

Researchers at the National Institute for Occupational Safety and Health (NIOSH) are studying methods to prevent workers from being entangled in machinery used at mining operations. An analysis of mining accidents in the United States that resulted in a fatality or permanent disability from 2000 through 2005 showed 438 severe incidents that involved contact with machinery or equipment, an average of 73 per year. Researchers determined that the most common machinery involved in these severe accidents was conveyors. Also, a significant portion of the accidents occurred during machine maintenance and repair. Researchers are focusing on improved methods to prevent unintentional machine startup during maintenance activity and methods to detect workers near moving machine components. One new technology that shows promise for this application is intelligent video. Popular in the surveillance and security industries, these systems use cameras and computerized video analysis techniques to automatically detect the presence of people in preset zones within the camera?s field of view. A preliminary study has been initiated to determine if this technology could reliably detect the presence of workers in hazardous locations near machinery. Possible advantages of the use of this technology include improved detection zone demarcation and improved ability to distinguish between hazardous and non-hazardous proximity, compared to conventional proximity sensor techniques. Initial tests to detect a person near a conveyor system in daylight conditions showed promising results. A description of the technology, test procedures and results, implementation challenges, and future research needs are discussed.

Jan 1, 2008

HAVING told you of the practices of the arts involving other metals, I wish to tell you also of the practice of that of tin.* Indeed, since this is an easily melted metal, in common use for the utensils which are made for human needs, it is an art known not only to skilled men but also almost to children, wherefore I could proceed with- out telling of it. However, besides the production of plates and bowls and many other dishes for eating from and keeping things in, this embraces two other arts, both of which you should know about because they are useful and beautifid. One of these is the art .of making the letters with which books are printed, and the other is that of making the sheets from which organ pipes are built. The vessels, as perhaps you have seen, are cast one by one in moulds made of white tuff. Several pieces fastened together are then put on the iron axle of a wheel rotated by hand, and [138v] they are turned with a slightly bent tool which has a cutting edge. In this way they are made thin and of a good shape. Then they are polished with a piece of linen cloth and a little powdered tripoli, and thus they are finished. The letters for printing books are made of a composition of three parts of fine tin, an eighth part of black lead, and another eighth part of fused marcasite of antimony.t The desired quantities of these metals are melted

Jan 1, 1942

By Stephen H. Stow

The relationships between the amount of light reflected off 21 samples of Florida phosphate and the chemical, composition of the samples were examined. It was found that the reflectivity of a rock is directly related to its chemical composition and that darker phosphates (less light reflectance) have relatively high amounts of iron, organic C and sulfate while lighter-colored rocks were rich in phosphorus, fluorine and aluminum. The use of reflectivity measurements could have economic applications in the phosphate rock industry: color specifications for rock shipments could he met, beneficiations by optical sorting could be performed and semi-quantitative analyses could be made rapidly and inexpensively.

Jan 1, 1971