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By Serge L. Delinois

President Kennedy said that before 1970 this country will send a man to the Moon and get him back on Earth safely. Today, no one doubts that his promise will become reality. He who asks "What, then, is next for us in space?" is no longer considered a dreamer. And one of the very first things he discovers in trying to answer this question is that in whatever does come next, geologists and mining engineers will play a prominent role. This will be true not only in the conquest of the Moon, but also in that of the whole solar system. After 1970, it is very likely that a permanent lunar camp will be established. This beachhead, supplied entirely from Earth, in the beginning, will gradually develop into a research complex where virtually all scientific disciplines are investigated.

Jan 1, 1966

By M. M. Fine

"Button" type ore from the Cason mine, Batesville, Ark., can be up-graded to plus-40-percent manganese by mineral-dressing procedures. A simple process including gravity concentration and. magnetic separation yielded more than 50-percent recovery of concentrates containing 38.1 to 40.6 percent manganese. These values in turn could be raised to 41.4 and 42.8 percent, respectively, upon sintering to conform to size specifications. The Bureau of Mines in the past has surveyed and tested many manganese ores and prospects in an endeavor to alleviate the shortage of manganese. The present period of emergency again emphasizes the strategic position of the metal, and manganese investigative work is being stressed to find new ore bodies and to apply newer beneficiation techniques to the known deposits.

Jan 1, 1953

"One of the major issues that the Rare Earth Elements Mining Industry has to deal with is the legislation vacuum that exists in many countries around the world. Among these, are countries which have long history and tradition in mining. In many cases the lack of direct legislation for REE mine management as well as for other potentially polluting industries can be a barrier to sustainable development. Moreover, the case of lax legislation in China has led to environmental pollution problems and extended smuggling of rare earth elements. This paper looks into the current regulatory status on the mining of REEs, identifies the loopholes and suggests some elements for a new global legislation framework for sustainable development in the REE mining industry. The setting of this regulatory framework will be in line with the present and future challenges of the rare earths market as well as with the policy strategies that are defined internationally. The aim of such a legislative framework will be to strengthen the global rare earth elements supply chain, appease social concerns and ensure the preservation and conservation of the environment. INTRODUCTION The general public received their first introduction to rare earth elements (REEs) in 2010, when the previously inconspicuous commodities became the subjects of front-page headlines. It was when China created a furore in global high-tech markets after imposing an embargo on Japan following a minor marine dispute (Barakos et al. 2015b). Soon enough the Chinese embargo was extended on REE export restrictions all over the world and thus aroused concerns to many countries over potential supply disruptions. The world had suddenly realized that these wonder materials underpin products that they care about. Governmental and industry executives, policymakers and material scientists voiced concerns and conducted numerous reports stating the situation and the risks of a supply crisis. The price spike of 2011 intensified the crisis and the public turmoil, yet the drama did not last for long as the prices declined significantly in 2012. Nevertheless, the world was nonplussed by the fact that China has the total control of the market with more or less the 90% of the global production. More potential entrants became interested, thus initiating an exploration boom during the recent years that has resulted in a significant increase in known global REE reserves that could have potentials for exploitation."

Jan 1, 2016

By S. Power Warren

Introduction It is generally conceded by flotation men that the condition at the surface of a particle of mineral or gangue is the most important factor controlling its behaviour in a flotation cell. Much research work has been devoted to the study of the forces that are active at the surface of the particle and of the effect of the surrounding solution upon these forces. Study of the relationship between mineral or gangue particles and gas bubbles indicates that, in the main at least, flotation is a physical phenomenon. The important factor, that of mineral-gas-bubble attachment, is unquestionably physical; however, modifications may be effected by chemical means, whereby the nature either of the surface of the particle or of the surrounding solution may be changed. For example, the coating of lead sulphide that forms on lead-carbonate ore particles when sodium sulphide is added greatly aids the flotation of the carbonate particles. Without going into the question as to why, under certain surface conditions, mineral particles will attach themselves to gas bubbles whereas under other conditions they will remain unaffected, it may be stated that there are three general conditions in a flotation pulp which control the attachment of the particle and the gas bubble.

Jan 1, 1933

By Jing Zhou

In view of the state of the long time use of sodium cyanide in lead-zinc-sulfur-silver multimetallic ore production, we propose alternative reagents system through experimental research. The experiment first used TJ, sodium sulfide to adjust the flotation pulp, after that, zinc sulfate, sodium sulfite was added to low alkaline pulp to inhibiting zinc sulfur mineral and adapted MB, 25# aerofloat and diethyl dithiocarbamate combination collectors to float lead minerals. The obtained test index is as follows: lead concentrate recovery rate of small scale test was increased by 5 to 10%, the recovery rates of gold and silver in lead concentrate were increased by 7% and 11% respectively; the industrial test is conducted under the condition that the total grade of lead and zinc content in raw ore decreased by 4.81%, the total recovery rate of lead and zinc increased by 7%, recovery rates of gold and silver in lead concentrate were increased by 7.62% and 9.65% respectively. So it successfully realizes the target to replace the sodium cyanide, using low-alkaline non-toxic reagents system in mineral processing practice of three kinds of complex lead-zinc-sulfur ore of this mine. Keywords: refractory lead-zinc-sulfur ore, depressant, non-cyanide flotation

Sep 1, 2012

By R. HAYDEN, H. B. HALLOWELL, H. O. Hofman

THE object of refining copper in the reverberatory furnace is to obtain a metal which will have the highest attainable degree of malleability, ductility and electric conductivity, and present at the same time a level surface when it solidifies in the mold after casting. These desirable physical properties are governed by the character of the impurities and the forms in which they are present, by the amount of cuprous oxide retained by the copper, by the quantity of gas held in solid solution, by the casting-temperature, and by the thickness of the casting. The effects of impurities, of cuprous oxide and of gases upon the mechanical properties of copper have been studied by Hampe in his classical paper "Contributions to the Metallurgy of Copper." The most recent research into the effect of metals upon the electrical conductivity of copper is that of Addicks.2 The influence of cuprous oxide upon the electrical conductivity has been investigated by Walker' and Addicks.4 The absorption of gases has received' attention by Hampe,5 Stahl 6 and Heyn.7 The effects of casting-temperature have been noted by Stahl.8

Mar 1, 1907

By Mark S. Sanders

Based on laboratory tests and preliminary field tests of off-the-shelf steel toed rubber boots, a molded sole design was developed to provide increased traction over conventional calendared sole miners' boots. The pattern provided sharp edges perpendicular to both lateral and fore-aft slip vectors. The sole was designed to reduce mud caking. An instep lace-up capability was added to better secure the foot inside the boot. A five month field evaluation compared the prototype boots to the boots the participants usually wear. Although objective slip and fall data showed no significant advantage for the prototype, subjective evaluations made by the participants indicated increased traction for the prototype boots. Approximately 75 percent preferred the prototype to their own boot. Approximately one-third used the lace-up capability. It was concluded that molded soles provide better traction than calendared soles for the underground mining environment.

Jan 1, 1982

Terminology. The term potash originated in "pot ashes" produced by burning wood to ashes in iron pots and then leaching out the soluble salts, chiefly potassium carbonate, from the residue. In modern usage potash is a generic term for various potassium salts used in agriculture and industry. More specifically, it denotes the oxide of potassium, K2O, and the content of potassium in ores and products is stated as weight percent of K2O present. Its salts are commonly referred to as muriate of potash, sulfate of potash, etc. The presence of an adequate supply of available potassium in the soil promotes the health and improves the quality of the plant. insures greater efficiency in photosynthesis, increases resistance to certain diseases, offsets the effect of an oversupply of nitrogen, and helps the plant to utilize soil moisture more advantageously. ("Soils and Men," U.S. Dept. of Agriculture Yearbook 1938.) Occurrence. Potassium ranks seventh among the elements in abundance. It is estimated to constitute some 2.6% of the lithosphere and is found in soluble forms in the oceans, lakes, rivers, and subsurface waters. It is also an important constituent of plant and animal life. Commercially significant accumulations of potassium salts occur in underground deposits formed in past geologic times by evaporation of ancient bodies of saltwater, inland drainage basins, and shallow sea lagoons. The potash content of such waters was the end result of weathering and leaching of insoluble potash-bearing aluminosilicates, such as feldspars, micas, leucitcs, and others. The concentrations of potassium salts in the natural brines of some lakes in the arid and semiarid regions of the continents are also important as sources of potash; the brines of the Dead Sea in Asia Minor, the Great Salt Lake in Utah, and Searles Lake in California typify such concentrations. Every continent has major potash deposits as listed in Table 1 adopted from Cawley.1

Jan 1, 1985

By D. A. Rice

As part of its mission, the U.S. Bureau of Mines continues to develop technologies that will enable cost-effective compliance with environmental requirements. To this end, investigations to improve the kinetics of chalcopyrite dissolution by simultaneous grinding-leaching in ferric sulfate solution were conducted using the Bureau-designed turbo mill. The development of such a hydrometallurgical process would provide a nonpolluting alternative to conventional smelter technology. The effects of mill rotational speed and volume percent solids on the leaching time and energy required for copper extraction from chalcopyrite were evaluated. The results of this laboratory study have shown that the simultaneous grinding-leaching of chalcopyrite concentrate using the turbomill is technically feasible with essentially 100 pet extraction of copper being possible at 90° C. An optimal energy consumption of 1,153 kW?h/st of copper leached was found in batch testing with the mill operating at 400 rpm with a slurry containing 35 vol pet chalcopyrite. This energy consumption, while higher than other proposed leaching processes (about 600 kW?h/st), is of the same order of magnitude. Further refinement of the energy requirements would require additional testing using a continuous circuit. Leaching times of less than 1 h, for 80 pct copper extraction, are achievable using the turbomill grind-leach process.

Jan 1, 2010

By Frederick Bloetscher

An improved parachute-type stopping for changing the course of mine ventilation air during mine emergencies has been developed by Goodyear Aerospace Corporation for The Bureau of Mines. The stopping can be quickly deployed by one man from a single attachment point and provides excellent stopping performance with the flow in the design direction. Adding pin and foam attachments between its skirt and the passage-way surfaces improves its performance with flow in the design direction and maintains the stopping with zero or reverse air flows. Stopping performance results for a range of airway sizes including 7.5 X 10 ft simulated airway with pressure differentials of up to 3.0 inches of water are presented. Predicted performance values for this stopping design for larger passageways are also presented.

Jan 1, 1977

By S. Chander

A series of nonionic and anionic surfactants were tested to enhance the flotation response of a low rank coal. An ethoxylated octyl phenol and several polypropylene polyethylene block copolymers were tested as nonionic surfactants. The anionic surfactant was a dioctyl sulfosuccinate. All the surfactants employed improved the yield significantly but the influence on grade was complex. Separate studies were conducted to determine the emulsification behavior of the surfactants. For the nonionic water soluble reagents tested, a correlation between emulsifying power of the surfactant and flotation was observed. An increase in the number of droplets produced in surfactant containing systems was considered to be the main reason for increase in the yield. Since it increased the number of collisions between dodecane droplets and coal particles. When a surfactant was introduced into the flotation pulp prior to addition of dodecane, it decreased the benefits of the surfactant significantly. The decrease was attributed to an increase in the wettability of coal and a decrease in the surfactant available for emulsification. When a suitable surfactant was added as a solution dissolved in the oily collector, a considerable increase in yield was observed.

Jan 1, 1993

By Longjiang Li, Mao Jiang, Zhihui Shen, Guizhou University, Yin Pan

This paper aims to study the influence and action mechanism of collector Y-89 on the flotation of auriferous pyrite. The measurement to identify adsorption quantity, IR and XPS spectrum analysis and flotation experiment made on the pure mineral were conducted. The research results show that when the dosage of MIBC is 20 mg/L, and pH of 8, the dosage of Y-89 over 60 mg/L, the pyrite recovery rate is greater than 80%.And when the dosage of Y-89is 60 mg/L, dosage of MIBC 20 mg/L, the pH in a wider range (pH=4~9), the recovery is greater than 75%. When the pH is above 10, the pyrite is depressed and its recovery rate is found to be dramatically dropping. Adsorption quantity measurement also shows that the strong alkaline conditions inhibit the adsorption of Y-89 on the surface of auriferous pyrite. IR measurement indicates that chemisorption of Y-89 occurs on the surface of auriferous pyrite. XPS spectrum analysis indicates that without adding Y-89, oxidation reaction occurs on the surface of pyrite. But when Y-89 is added, the chemical environment of Fe on the surface of pyrite has changed. Such findings indicate that with Y-89, chemisorption occurs on the surface of auriferous pyrite.

Jan 1, 2014

By M. Dayne Aldridge

A discussion of the definition of automation in mine ventilation applications is presented. The results of theoretical studies, experiments and practical experience from work in the United Kingdom, Belgium, Poland, the Soviet Union and the United States are summarized. Conclusions are drawn from these efforts and the prospects for the future development of automatic mine ventilation systems are explored.

Jan 1, 1978

By M. R. HULL

FOLLOWING the discovery of a body of ore that appears to have commercial possibilities there is a period of development work to determine its extent and grade and the most economical method of mining it. Laboratory tests are made in an effort to determine the most practicable and economical treatment for the extraction of the valuable constituents of the ore and these tests are carried farther and checked in a pilot or test mill. The rate at which the ore is to be mined and the daily capacity of the plants that are to treat it will depend on a number of important factors such as: The size of the orebody; the capital available for building the plants; the market or demand for the final product; the supply of skilled and common labor available for the construction, operation and maintenance of the plants; the quantity and quality of available water, and the amount and cost of power that can be purchased or that can be economically developed. Having decided on the treatment that is to be given to the ore and after full consideration of the above factors the management decides to erect a reduction plant of a given capacity.

Jan 1, 1926

By E. C. Baker

The capital investment and operating costs of two methane-control systems used during longwall mining operations are compared in this Bureau of Mines report. Costs are given for a surface gob hole drainage system and an underground cross-measure borehole drainage system to control methane gas in gobs in four coal mining areas--central Pennsylvania, northern West Virginia, southern Virginia, and northern Alabama. Present-worth analysis is used to determine the more cost-effective alternative in each location. The alternatives have equal lives and provide the same service based on a minimum rate of return of 15 pet. In central Pennsylvania and northern West Virginia, the gob hole system is more cost effective than the cross-measure system, by 10 and 18 pet, respectively. In southern Virginia and northern Alabama, the cross-measure system is more cost effective, by 29 and 38 pet., respecitively. Costs for other locations must be developed on a case-by-case basis.

Jan 1, 1988

Callie underground gold mine is part of the Newmont Tanami Operations, and is now the primary provider of ore to the Granites processing Mill. The Callie underground mine has produced in excess of 7.6 million tonnes (Mtpa) of ore, since production began in 1998, with a current production rate of 1.9 Mtpa. Callie underground uses sublevel open stoping with extraction through a combination of primary and secondary stopes. The primary stope filling strategy utilises cement aggregate fill (CAF) to allow full recovery of secondary stopes. The Callie backfill operation has had a continuous testing program in place during this time, which has resulted in a great deal of information available for post fill analysis. All CAF placement into primary stopes for Callie has been via surface boreholes and this has given Callie mine an understanding of some of the issues related to borehole design, type of linings to use depending on angle, depth and quantity of fill into stopes. Finally backfill barricades at Callie have undergone a number of changes during the time to optimise the design based on whether CAF or sand fill is used. This paper discusses the CAF backfill practices and testing methods used for backfilling operations at Callie.

Jan 1, 2005

By A. W. Deurbrouck

Five preparation plants employing concentrating tables for washing 3/8- inch to 0 raw coal were tested. Two of the plants were washing Pittsburgh-bed coal, two were washing Pocahontas-bed coal, and one was washing Elkhorn-bed coal. Samples of the feed to and products from the tables were collected over the normal operating shift. These samples were analyzed, and complete performance criteria were determined. The results of this study show that the concentrating table is an effective fine-coal cleaner even when operating at 40 percent over the recommended 10 tons per hour feed rate. Recovery efficiencies for the 3/8-inch to 200- mesh size fraction ranged from 97.3 to 99.3 percent; maximum yield errors and ash errors were 2.4 and 1.0 percent, respectively; probable errors ranged from 0.074 to 0.115 specific gravity units and error areas from 52 to 73 square centimeters. The amount of minus 200-mesh material in the water used for feed water and dressing water to the table had no significant effect on the sharpness of the separation achieved but did have an effect on the ash content of the clean- coal product. In the one plant studied, the substitution of fresh water for plant circulating water reduced the ash content of the clean coal by about 6 percentage points.

Jan 1, 1963

By K. E. Tame

An alkaline leaching procedure for recovering uranium from a submarginal 0.1 percent Ug Og calcareous carnotite ore from the Shiprock , N. Mex . , area was investigated . A recovery of 72 percent of the uranium was attained in a preliminary test embodying the commonly accepted practice of ( 1 ) alkaline leaching at 90° C , ( 2 ) multiple stage filtration and washing for recovery of a clear pregnant solution , and ( 3 ) caustic precipitation of uranium as sodium diuranate , with recycle of the barren solution to the leaching and washing circuits . Ion exchange resins were used in a second , less orthodox test that comprised ( 1 ) sodium carbonate leaching of minus 10- mesh ore at 90 ° C to dissolve the uranium , ( 2 ) filtration to recover the leaching reagent for reuse , (3 ) recovery of the uranium- bearing solution in the filter cake as a pregnant slime slurry by repulping of the filter cake followed by a sand- slime separation and countercurrent decantation (CCD ) washing for rejection of the sand fraction , (4 ) recovery of the dissolved uranium from the pregnant slime slurry by resin- in- pulp (RIP ) , ( 5 ) elution of the uranium from the resin with a solution of ammonium chloride acidified with hydrochloric acid , and (6 ) precipitation of the uranium with ammonia gas . About 83 percent of the uranium was extracted from the ore and 95.5 percent of the dissolved uranium recovered by ion exchange . Improved laboratory results were obtained using the RIP process , but larger scale tests would be necessary for economic evaluation of the two processes .

Jan 1, 1964

By E. J. Gleim

In the mining of coal the trend is toward more and more mechanization. This increased use of machinery to replace hand labor is assuming many new forms and presents a constantly changing aspect. Safety engineers must be alert if the many electrical problems resulting from these new installations are to be handled safely. Some of these problems present possible electrical hazards that may be overlooked by the safety engineer unless they are called to his attention by one who has made a special study of the conditions. The foregoing is especially true of conveyor systems of mining. The terms "conveyor systems" and "conveyor mining" as used in this paper refer to those systems in which various types of conveyors are employed to transport coal away from the working place. In some mines this means complete elimination of track, cars, and locomotives. In others it means that conveyors take the coal from the working place to a convenient loading point, from which transportation is completed by cars and locomotives.

Jan 1, 1941

By Sarkar B. C, Sen A. K

India is well endowed with vast reserves of banded hematite ore, about 12 billion tonnes, estimated by some conventional methods. Various authors have assessed this huge reserve using some advanced geostatistical methods. A Banded Iron Formation (BIF) belt named the `Singhbhum-Keonjhar-Bonai' belt in India has been chosen as a case study. In this paper, the experiences of Chiria iron ore, in particular, have been described. This study will finally create a dynamic mineral inventory after standardising the geostatistical parameters which will help to cater for the needs of the stringent quality requirements of the Indian steel industries.

Jan 1, 1995