Search Documents

By R. B. Massy-Greene

Project engineering and development is a process of optimisation of capital, operating and financial costs, and extraction rates in the light of current and forecast economic conditions for the sale of the product. The aim of the process is to maximize financial returns to the sponsors (project owners) within many often conflicting constraints. Thus, the sponsor's engineering and financial staff have a common goal, with performance measured in financial terms. Consequently, each group must be aware of, and responsive to, the constraints imposed upon the other. For financial staff, the increasing size and complexity, and escalating capital costs of new ventures have required them to seek finance in larger amounts, and by non-traditional methods. In addition, senior management are requiring indications of the availability of finance as a pre-requisite to a decision to commence project development activities.

Jan 1, 1982

By Margaret Fuller Boos

Precambrian granitic pegmatites on the west, south west, south and southeast slopes of Storm Mountain, Larimer County, northern Colorado, were explored and mapped geologically 1956-1959. The area between Crystal Mountain Mining District on the north and Hyatt pegmatite mine area on the south was nearly inaccessible until a company built an access road, which was completed in 1959, into Roosevelt National Forest and its jeep-type roads. The area is extremely rugged, rising from some 6,000 feet on the highway at Drake, on Big Thompson River, to an altitude of over 10,000 feet at the summit ridge of Storm Mountain. Almost innumerable pegmatites of every possible type of granitic pegmatite intrusion infest the Precambrian gneisses and schists of the southwest-tilted fault block of Storm Mountain. The major bodies stand at least 100 to 200, feet high above the surrounding forest floor. Core drilling has shown that some extend to at least 200 feet below the surface. They blunt out at the southwest, some keel out below and others are faulted out at their southwest ends. Strike length ranges from 200 to 600 feet. The massive bulky bodies have nearly vertical walls. Contents are zoned or ribboned and layered. They consist of local commercial bodies of beryl, potash feldspar, mica, uranium minerals and quartz. As yet no lithium minerals have been encountered.

Jan 1, 1960

By Vijenac Quarry, A. Iljazagic, t. Knezicek, T. Omeragic

Limestone quarry Vijenac, is one of the key limestone producers in B&H. Conventional massive drilling and blasting is the technique applied for limestone exploitation. Utilized blasting scheme causes appearance of large oversize stone pieces, uncontrolled flying stone and undesirable seismic effects. In order to reduce or eliminate exposed disadvantages and to improve environment in the area of Vijenac quarry, an innovative blasting scheme was tested. Conventional blasting scheme was changed from single row, deep inclined blast holes combined with two lines short horizontal holes to multi row, inclined blast holes combined with a single line short horizontal blastholes. Applied innovative blasting scheme reduces negative blasting impact on the environment through safer working conditions, reduced amount of dust after blasting, reduced explosive and energy consumption, reduced appearance of explosive gasses and reduced earth and air vibrations as the result of seismic effects.

Jan 1, 2005

By Remi Tremblay

This paper describes the laboratory study which permitted an exploration of high grinding ball consumption in the secondary open circuit wet grinding mills at the Sidbec-Normines plant, Port Cartier, Québec. Corrosion undoubtedly exists but is of minor importance. Abrasion resulting from the physical nature of the company's iron concentrate is the main reason for the high ball wear. It was found that at least 30% reduction in ball consumption is possible by decreasing attrition grinding through the use of lifters in the mill. At the industrial level this would entail more lifters and/or higher lifters in the mill linings.

Jan 1, 1984

By V. A. L. Breguncci, A. H. Martins, C. P. Ribeiro Jr.

This work presents experimental results for the recovery of gold present in alkaline cyanide solutions by using the electroelution technique of strong-base anionic polymeric resins IRA 402-CL from Rhom and Haas-Brazil Ltd. loaded with gold. This technique of electroelution of anionic polymeric resins is based on the removal of metal ions adsorbed to the resin, resulting from a potential difference applied between the cathode and anode in an electrolytic cell. The electrolytic cell was composed of an aqueous solution with suitable chemical characteristics and an anionic polymeric resin bed loaded with gold. The resin used in the experiments was loaded using synthetic alkaline gold cyanide solution with 1.0 g/L of gold. The variables studied were electroelution time, cathode current density, distance between cathode and anode and the electrolyte chemical composition. Statistical methods made it possible to establish the optimum conditions that would achieve satisfactory gold recoveries by the electroelution technique. The statistically predicted response for the resin loaded with gold by percolation was 16.5% gold recovery, 2.0 A/m2 cathode current density, 20-mm distance between electrodes and 6.0 hrs electroelution time. For the centrifuging system, the statistically predicted response was 7.41% gold recovery under the following conditions: 0.25 A/m2 cathode current density, 1-mm distance between electrodes, 3.5 hrs electroelution time and 10.9% NaOH in the electrolyte chemical composition.

Jan 1, 2002

By T. Reed Scollon

Before we can attempt to answer the question of what can be expected from coal research, let us examine why research is done in other fields and what others expect for the money they spend on research and development. Up to 1900 almost all organized research was carried out at universities. Most of the support came from the university, and by present standards the amount of research was extremely small. The motivation for university research was basically discovery of new phenomena, with the objective of advancing knowledge. Side by, side with this organized effort was that of individual inventors who were primarily responsible for applying this new-found knowledge to useful purposes. During this period inventors were rarely supported by anyone, and experimentation was carried out either in their spare time or at the expense of earning a living. Men like Edison, I believe, were the first to demonstrate on a large scale that one could systematically apply newly discovered scientific principles to inventions that would serve useful purposes and would return a profit to those engaged in the effort. The tremendous expansion in research therefore began with the realization and demonstration that the scientific discovered could be applied in such a way as to return a' handsome profit to those who invested in it. The motivation of many of the research personnel however, remained the satisfaction associated with new discoveries, The money to support their efforts came from those interested in a return on their investments. Since the First World War and a rapidly accelerating rate since the Second World War another important motive for supporting research has appeared--the needs associated with national defense; this type of research has been supported almost exclusively by the Government.

Jan 1, 1959

By Harry Verakis

Electronic detonator systems are an advance in technology beyond conventional electric detonators for initiating explosives and blasting agents. Their use is widening into the mining operations of the U.S.A. Each electronic detonator system differs in design, construction, operation, and testing features and each system is different than “conventional” electric detonators. There are benefits of electronic detonator systems which serve to improve blasting safety. With the introduction of electronic detonator systems for mine blasting, issues were raised about the application of MSHA regulations for shunting and circuit testing. The MSHA regulations for surface and underground mine blasting operations address the use of “electric” detonators. Although electronic detonators are initiated by an electric pulse or current, their design is unlike “electric” detonators. To resolve the issues of shunting and circuit testing with respect to MSHA regulations, a technical and field evaluation of electronic detonators was made and the results are presented.

Jan 1, 2005

By K. F. Unrug

An overview of the history of mining technology, both past and present, shows that some of the new concepts being successfully applied have changed the reserve categorization and are having an overall impact on production. Past coal mining operations in the eastern coal fields, and especially in Appalachia, extensively utilized stripping with the predominately applied contour method. As a result, vast mountainous areas have abandoned benches left behind by past mining operations. While thicker seams previously stripped were usually mined by underground or mountain top removal methods, thin seams beyond technical or economical limits were left intact after contour mining had reached the ultimate height of the wall. These thin seams quite often contain high BTU, low ash and sulfur coal that makes them attractive for a secondary recovery due to the market requirements. Secondary highwall recovery has obvious potential and is economically attractive; however, with the present state of industrial experience and lack of analysis of site data, a trial and error approach is used by operators.

Jan 1, 1983

By William H. Lehr

A 4200 ton-per- hour marine transfer terminal, where river and oceangoing vessels simultaneously exchange cargos of coal and phosphate rock, is now in operation near the mouth of the Mississippi. Its materials handling machinery includes a bucket ladder barge unloader; a rope operated clamshell bucket unloader; a coal loader; and a rail mounted bucket wheel machine. The design and operation of this equipment is described as are the docks and conveying, breasting and barge-haul systems in use at the facility. Design considerations imposed by soil and river conditions, geography, operating needs and investment requirements are discussed. The economic significance of design and shipping innovations introduced by this facility is noted.

Jan 1, 1967

By P. T. Bissert, J. P. Ducarme, J. L. Carr, A. K. Smith

"The continuous mining machine is a key piece of equipment used in underground coal mining operations. Over the past several decades these machines have been involved in a number of mine worker fatalities. Proximity detection systems have been developed to avert hazards associated with operating continuous mining machines. Incorporating intelligent design into proximity detection systems allows workers greater freedom to position themselves to see visual cues or avoid other hazards such as haulage equipment or unsupported roof or ribs. However, intelligent systems must be as safe as conventional proximity detection systems. An evaluation of the 39 fatal accidents for which the Mine Safety and Health Administration has published fatality investigation reports was conducted to determine whether the accident may have been prevented by conventional or intelligent proximity. Multiple zone configurations for the intelligent systems were studied to determine how system performance might be affected by the zone configuration. Researchers found that 32 of the 39 fatalities (82%) may have been prevented by both conventional and intelligent proximity systems. These results indicate that, by properly configuring the zones of an intelligent proximity detection system, equivalent protection to a conventional system is possible. INTRODUCTION Underground coal miners are exposed to a variety of hazards on a daily basis. Among coal and rock dust exposure, high noise levels, roof and rib falls, and the potential for fires and explosions, operating and working with heavy machinery poses a significant risk to miner safety. One of the most hazardous jobs is operating or working nearby a continuous mining machine (CMM). According to Mine Safety and Health Administration (MSHA) statistics, 39 miners have been fatally struck or pinned by a CMM since 1984. In an effort to prevent future striking and pinning fatalities from occurring, proximity detection systems have been developed and are now required on all operating CMMs in underground coal mines with the exception of full-face CMMs [1]. Commercially available proximity detection (cPD) systems are based on the principle of magnetic flux density (B-field). Typically, four magnetic field generators are positioned on a CMM, and personal alarm devices (PADs) are worn by the miners that detect magnetic flux density difference. As a miner wearing a PAD gets closer to the machine, the flux density increases. Zones can be constructed around the machine so that an alarm will trigger on the PAD based on the flux density."

Jan 1, 2016

By Bobby J. Timmons

Luck; blind, beginner's, fisherman's, or whatever type, plays an important role in romance, racing, football, gambling, and mineral exploration. However, for each of these; education, training, technique, and experience are necessary for a long, continuous, successful relationship. Success, no matter how obtained, is easier to defend than almost success, regardless of the education or the degree of refinement of the seeker. Similarly, investment dollars are more readily available to a successful, uneducated and unscientific practitioner than to his beginning or unlucky professional counterpart.

Jan 1, 1983

By Edwin B. Wilson

Electric power generation remains the greatest market for coal in the United States. In 1967, about 272 million tons of coal, amounting to over 51 percent of total coal consumption, were burned to satisfy this nation's hugh demand for power. The size of the utility market is currently five times that of 1941 and continues to grow with the demand for more and more energy. A major reason for this strong market has been the ability of the coal industry to supply a superior product for combustion while maintaining competitive prices. Now that the coal industry is engaged in intensive competition with nuclear power for future energy demand, it becomes ever more imperative that superior coal products are produced. One important problem when burning some coals is a liquid phase corrosive attack on boiler tube metal in the superheater and reheater areas of the furnace where steam temperatures may exceed 1050°F.

Jan 1, 1969

By J. B. Griffiths

Clearly there is a tremendous need for assistance in Eastern Europe since most industries must undergo major restructuring. The new governments face many dilemmas, the first task being to establish an order of priorities to deal with the numerous problems at hand. Issues such as the standard of living take low priority compared with market economy and ecological problems. The concept of a Comecon market is now virtually non-existent and trade in roubles ceased from 1991. From this time onwards countries were obliged to trade using free market prices. Governments must also avoid the economic mistakes of countries such as Poland with its high devaluation and lack of economic control and, if possible, contain inflation and unemployment. The privatization of Eastern European enterprises raises considerable difficulties, particularly for large corporations, employing anywhere from 50-100,000 people, which played a major role in the national economy. Whichever method is selected, however, still has to overcome the problem of lack of capital and evaluating the national property. For example, earnings represent only a small percentage of the value of these national industries and thus cannot convert to private ownership without foreign capital investment, either direct or as joint venture capital.

Jan 1, 1992

By R. A. Burns

The production of kaolin and calcium carbonate in North America exceeds 13 million tons sold into higher value market segments. With a few exceptions, the markets supplied exhibit mature growth rates. In some market sectors, technology changes have and continue to occur shifting pigment-type consumption and growth. New sources of supply will impact current businesses. New product and process developments for kaolin and calcium carbonates are continuing. Each of these issues is examined in developing a view of the future for kaolin and calcium carbonate in North America.

Jan 1, 1997

By Hans E. Tausig

The economics of transporting minerals by sea in less than full cargo lots encompasses an analysis of production costs, sale and inventory calculations and a careful comparison of ocean freight costs all of which when pieced together will usually definitively indicate which of the ocean freight alternatives is the correct one for the economic factors involved. To illustrate: Let us assume that a production to be marketed yields 60,000 metric tons of copper concentrates over a twelve month period. Shipment is geographically viable through Vancouver, B.C. The production has been sold to a Japanese Smelter and the mine produces at a rate of 5,000 metric tons of concentrates per month. The copper has been sold CIF FO. The Seller has carefully investigated ocean freight rates Vancouver, B.C./Hibi, Japan and finds that he could obtain a twelve month freight contract at $15.00 per metric ton FIGS based on a loading/discharging speed of 4000/ 2000 metric tons per WWDSHEX (weather working day, Sundays and Holidays excluded) this freight rate being predicated on shipping in lots of minimum. 15,000 tons. A further freight investigation reveals that to ship at the same terms and conditions but in lots of 5,000 tons, and shipping each month (in accordance with the mine's actual production) would cost $20.00 per metric ton FIOS. The calculation that is now made is whether it is more desireable to pay a higher ocean freight by shipping in 5,000 ton lots or to pay the lower freight where here the ocean freight involves a difference of some $300,000.00.

Jan 1, 1979

By James D. Cooper

Technologic advances in materials utilization during the past two decades have brought is a long way toward the point where we can make the products we need from the materials we have readily available. Notable examples are the synthesis of diamond, zeolites, quartz crystal, mullite, and mica, and the development of phosphate bonded tale. Two of these--zeolites and mullite--involve the use of clays. There is little reason to doubt that equally important advances will be realized in the next decade, and that clays will play an important role in the developing materials technology. Indeed, the stage is already set for many of them. This discussion is concerned primarily with the high quality, relatively high priced clays, kaolin, bentonite, fuller's earth and ball clay. The first three have enjoyed demand growth rates over the past two decades which on the average exceeded the growth rate for the economy as a whole. There are indications that demand for ball clay will be growing at a faster rate in the future.

Jan 1, 1970

By P. T. Bissert, J. P. Ducarme, J. L. Carr, A. K. Smith

The continuous mining machine is a key piece of equipment used in underground coal mining operations. Over the past several decades these machines have been involved in a number of mine worker fatalities. Proximity detection systems have been developed to avert hazards associated with operating continuous mining machines. Incorporating intelligent design into proximity detection systems allows workers greater freedom to position themselves to see visual cues or avoid other hazards such as haulage equipment or unsupported roof or ribs. However, intelligent systems must be as safe as conventional proximity detection systems. An evaluation of the 39 fatal accidents for which the Mine Safety and Health Administration has published fatality investigation reports was conducted to determine whether the accident may have been prevented by conventional or intelligent proximity. Multiple zone configurations for the intelligent systems were studied to determine how system performance might be affected by the zone configuration. Researchers found that 32 of the 39 fatalities, or 82 percent, may have been prevented by both conventional and intelligent proximity systems. These results indicate that, by properly configuring the zones of an intelligent proximity detection system, equivalent protection to a conventional system is possible.

Jan 1, 2016

By A. Bruynesteyn

Results are presented from a series of tests designed to determine the beneficial effects of the microorganism Thiobacillus ferrooxidans upon the leaching of uranium from a pyritic uranium ore. Minus 1-inch (-25mm) 0.0711 percent uranium containing, pyritic ore from the Rio Algom Mine at Elliott Lake, Canada was leached with lixiviants of various Eh and pH as well as being subjected to a biologically-assisted ferric iron leach. In all cases, the biological leach gave superior extraction. At pH 1.6, the biological leach gave 100.6 percent extraction and the ferric iron leach 69.8 percent. This improvement in extraction is associated with a relatively rapid biological breakdown of the pyritic material, thus liberating uranium mineralization associated with these pyritic materials and regenerating the ferric sulphate lixiviant in situ.

Jan 1, 1981

By M. G. Ayat

Coal degradation is the breakage of coal particles to finer sizes due to the continuous forces of attrition and gravity to which coal is subjected during mining, handling and preparation. The objective of this paper is to determine the extent of degradation that a coal slurry experiences when transported through pumps and pipelines. The examination of degradation results for a number of different coal slurries have indicated that the extent of breakage is dependent upon the physical properties of coal and the time span of circulation. These results have also indicated that certain size fractions of coal are more susceptible to breakage than others.

Jan 1, 1986

By E. F. Draskovich

In 1984 a high temperature heat recuperation system was installed in the pellet plant of the National Steel Pellet Company located in Keewatin, Minnesota. The system is similar to those of Cleveland Cliffs Empire and U.S. Steel's Minntac operations. It recovers hot process air from the cooler by induced flow, and directs it to an intermediate zone between the drying and preheat zones on the grate machine. This system recently underwent further modifications in April 1985, following initial operation in 1984. The M. A. Hanna Company, which manages the property, developed the design criteria and made the subsequent recommendations for modification through its research facility in Nashwauk, Minnesota.

Jan 1, 1986