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By T. Mutoh

Tellurium in raw slime has recently been recovered as copper telluride in Onahama Smelter & Refinery. The slime is decopperized with sulfuric acid solution in conventional leaching tanks. The pregnant leach solution containing 45 g/l of copper and 1 g/l of tellurium is introduced to a copper telluride recovering reactor. The tail solution from the reactor containing less than 20 mg/l of tellurium is recycled directly to circulation tanks of copper electrolysis. The impurities of the product copper telluride is kept below 1% without any purification.

Jan 1, 1990

By W. J. Guay

Scrubbing of simulated copper reverberatory furnace gases containing 1.0 percent sulfur dioxide with the minus 74 ~m fraction of the San Manuel tailings has shown sulfur dioxide removals of almost 100 percent over an effluent pH range of 3.1 to 4.6 and a wide range of liquid to gas ratios with absorptions of 11 to 17 Kg of sulfur dioxide per tonne of minus 74 um slimes. The high reactivity of the tailings slimes with S02 indicates that the reaction rate is not controlled by the slow dissolution of calcium carbonate in sulfurous acid which characterizes scrubbers using ground limestone. The interpretation of these results has been considerably enhanced by wet chemical analysis and emission spectrographic analysis which show that calcium and iron account for about 90 percent of the SO2 absorption with the rest being accounted for by aluminum, magnesium, potassium, and sodium. Mineralogic examination confirms the, chemical and spectrographic analyses showing that the major constituent removed from the slimes is calcium carbonate, with lesser amounts of chlorite and montmorillonite (silicates containing iron, magnesium, aluminum, and calcium) being removed.

Jan 1, 1981

By Luis Bergh, Iván Rojas, Juan Yianatos, Luis Vinnett

"At present, flotation rate characterization follows standard measurements to identify the overall flotation performance looking at the feed, tailings and concentrate in flotation cells or banks. This classical approach does not take into account the evolution of the true collection rate down the flotation banks explicitly. The potential for identifying the impact of the mineral characteristics (size and liberation) as well as the effect of different manipulated variables (reagents, froth depth, gas dispersion) on the true flotation process remains hindered. Top-of-froth (TOF) measurements, which consist of sampling the first layer on the froth surface, have been used to characterize the mineral collected by true flotation in rougher banks. The information provided by TOF samples allows evaluating the floatable mineral evolution (grade, particle size, liberation) down the bank. In this work, an indirect approach to estimate the flotation rate along rougher flotation banks is proposed. The new approach is based on the decreasing of collected mineral grades (on top of froth) and the feed characteristics. Flotation rates per liberation classes were used to reconstruct the TOF grades from the feed information. This approach requires a simple froth surface sampling, without constraints typically observed during mass balance surveys and uncertainties on the mineral recovery estimation. The proposed methodology was successfully applied at industrial scale using TOF measurements together with QEMSCAN information."

Jan 1, 2014

By A. Bhattacherjee

Industries in general and the mining industry in particular have become more safe than ever before. However, there is a need to increase the search for the causes of mining work-related injuries and to contribute to their reduction through job design, work procedures, and worker training. Mine accident and hazard control has to be practiced in a manner which is consistent with the overall objectives of the mine management, among which are the optimum allocation and effective utilization of the resources. The purposes of this paper are to (i) review the role risk analysis in safety management with references from mining and other industries; (ii) discuss the risk measures appropriate for injury analysis; (iii) present a set of analytical tools to injury experience data in under-ground coal mines; (i v) apply these tools on case study example; (v) discuss the results of the case study; and (vi) amplify the application limitations and the future research needs.

Jan 1, 1991

By R Memary

The environmental and economic impacts of a significant dependence on fossil fuels are affecting the future of sectors such as of mining. These impacts are prompting the Australian Government to seek solutions for reducing its dependence on fossil fuels more generally, such developing clean energy and improving energy efficiency. However, limited research has been undertaken to assess the potential synergies between clean energy and mining in an uncertain global future. This paper analyses current energy use by mining in Australia and reviews the drivers and opportunities for energy efficiency and cleaner energy technologies to be coupled to mining under three future scenarios. Linkages between mining and clean energy are investigated for three global scenarios for mining and metals to 2030, developed by the World Economic Forum (WEF), namely Green Trade Alliance, Rebased Globalism and Resource Security. These scenarios are applied to assess how they could change the barriers, opportunities and trade-offs required for the development of a more sustainable energy sources by the minerals industry in Australia.

Nov 22, 2011

The Role of the Drilling Contractor BY FERRIS E. SAINSBURY Ron Haxby, Occidental Minerals What is the best method for drilling a 12-in. diam hole to a depth of 1200 ft and maintaining the deflection within 25ft from vertical? Ferris Sainsbury: In order to drill a 12-111. hole down to 1200 ft, In most places you would have to employ a rotary tricone bit With a down-the-hole hammer, I expect by that depth significant Inflows of water would be experienced Even with foams, we would not be able to get the water out of a hole of that diameter So the down-the-hole tricone method of drilling would be best. To keep it straight, we would probably employ the largest square drill stem compatible with the diameter of the hole. Ron Haxby: Is it common in drilling contracts to put in a vertical hole clause? Ferris Sainsbury: You can put in the vertical hole clause Ron Haxby: Does it cost more? Ferris Sainsbury: Normally, if the hole deviates, the driller can correct it with deflection wedges and will charge it back to you at cost, plus 10% or somewhere along that range Any drill hole has a tendency to go perpendicular to the dip, and there are times when stabilization systems are not successful in preventing the hole from turning into the dip of the formation. The only solution, in this situation, is to go in with an oriented wedge and kick the hole back out.

Jan 1, 1979

By Bruce Bryant

Silver ore was discovered at Aspen in 1879, but the district did not reach full production until 1888 after lawsuits were settled and railroads furnished less expensive transportation to the outside world. The boom years were 1888-92; production declined thereafter. From the middle 1920's until 1950, the Midnight mine in the Richmond Hill district furnished most of the output in the Aspen quadrangle. Since 1950, little mining has been done at Aspen. The metals produced were silver, lead and zinc. Native silver dissolved from the sulfide ores was redeposited by waters circulating as deep as 300 m below the land surface, resulting in great secondary enrichment of many of the deposits. Over 100 million ounces of silver were produced in the Aspen quadrangle. Low-grade lead-zinc deposits remain between the old workings locally, and data available suggest that primary ore below levels mined is also of low grade. The ore occurs in the Mississippian Leadville Limestone and the lower part of the Pennsylvanian Belden Formation in sites that were made favorable for deposition by a number of stratigraphic and structural factors.

Jan 1, 1982

By A. Burduk

The traditional approach to managing information flow between a mine underground and overground, applied in copper mines of KGHM Polska Miedz S.A., is mostly based on exchanging spoken information using the mine telephone network and printed documentation. This way of information flow significantly influences effective use of time of a shift foreman employed at a mining division. In order to minimise multiplication of significant information generated as paper documentation, a concept of an IT system module to input basic data concerning operation of the mining division was developed. The idea is based on computer software that permits inputting data in the underground and their immediate sending to the overground. The above-mentioned solution will permit significant reduction of administrative work time that each foreman has to do on each shift. The time saved on filling forms and communication will permit the foreman and the other workers involved in information flow to spend more time for execution of their basic duties. In the case of the supervision employees working in the overground, the IT system will allow all the interested persons to be informed directly, with no necessity to transfer the information on the situation in the given mining division by turns from one to another. On the other hand, saving time on administrative works will permit the foreman employed in the underground executing more detailed inspection of workplaces in his subordinate mine division. Thus, availability of the foreman for the mining division operation will be improved. KEYWORDS

Aug 1, 2013

By Noel N. Moebs

The Bureau of Mines studied the feasibility of water diversion and overburden dewatering for underground coal mines in the Appalachian region. All relevant published literature pertaining to the occurrence and control of surface and ground water in underground coal mines was reviewed, and the impacts of mine water with respect to health and safety, production, environment, and costs were assessed and are described in this report. The report also identifies the sources of water inflow into underground coal mines, and gives a summary description and evaluation of techniques that can be used to reduce the amount of water entering these mines. Engineering practices currently used by operating coal mines in the Appalachian region to prevent the movement of ground and surface water into active coal workings were reviewed and are summarized. Major emphasis has been placed on the identification of geologic and hydrologic conditions of the site, the water control methods used, and an evaluation of their technical and cost effectiveness.

Jan 1, 1985

By S. Foged

Umicore and MWH jointly demonstrated that mechanical dewatering of goethite and neutralised tailings significantly increased the life of a 30 ha tailings pond and improved the operation of the pond. Umicore operates one of its zinc production plants in Balen, Belgium. As part of its production process, an excess of neutralised and goethite¬containing tailings is generated. These have historically been stored inside large lined ponds. As the storage area of the current goethite pond was nearing its capacity, Umicore studied the potential for an extension to the existing embankment. However, this extension would face intense regulatory scrutiny, because the environmental and safety impacts were considered important. Together with Umicore, MWH suggested and investigated an alternative treatment approach consisting of mechanical dewatering prior to storage. A feasibility study was prepared where wet storage was compared to dry storage. Differences in safety risks, environmental impacts and economic costs were outlined. The study demonstrated that the life of the tailings pond could be increased from 6 to 22 years, seriously reducing the environmental impacts and safety risks at no significantly higher cost than would have been incurred with the continued operation of the existing pond. The results of the study are presented in this paper.

Jan 1, 2006

By J. R. Thoenen

This paper outlines briefly results of seismic measurements recorded in the vicinity of quarry blasting under practical operating conditions. The data cover field work done from January to the middle of August 1930, during which time records were made of 61 blasts in 19 quarries. Of the tests made, one was in biotite-gneiss, two in dolomite, two in a flintlike volcanic complex, three in gabbrodiorite, five in trap rock, and six in limestone. One quarry was in Alabama, two were in South Carolina, two in New York, four in Kentucky, five in Connecticut, and five in Massachusetts. Explosive charges ranged from 0.30 pound to 41,900 pounds, and the method of shooting varied from mud caps through hammer and wagon drill holes to churn drill holes and coyote tunnel shots.

Jan 1, 1937

By Staff

In 2012, the estimated value of mineral production increased in the United States for the third consecutive year. Production and prices increased for most industrial mineral commodities mined in the United States. While production for most metals remained relatively unchanged, with the notable exception of gold, the prices for most metals declined. Minerals remained fundamental to the U.S. economy, contributing to the real gross domestic product (GDP) at several levels, including mining, processing and manufacturing finished products. Minerals? contribution to the GDP increased for the second consecutive year. Trends in other sectors of the domestic economy were similar to those in mineral production and consumption rates (Table 1). After continued decline following the 2008-2009 recession, the construction industry began to show signs of improvement late in 2011 and throughout 2012, with increased production and consumption of cement, construction sand and gravel, crushed stone and gypsum, mineral commodities that are used almost exclusively in construction.

May 1, 2013

By J. B. Goddard

Abstract. Leaching of, uranium in situ from sandstone deposits with ammonium carbonate solution containing: dissolved oxygen occurs rapidly compared with the leaching of the bulk of the sulfur present as FeS2. However because of their high reducing, capacity and their relative abundance, the FeS2 minerals consume; the bulk of the oxidants A pressure leach apparatus was-construtted which permitted the measurement of oxygen consumtion by FeS2. Oxygen consumption by FeS2 is best described by a first-order reaction. The experimental rate constants for various cores are roughly proportional to their FeS2 contents.

Jan 1, 1980

By Juan M. Pestana-Nascimento, Robert G. Bea, Hamed Hamedifar, Emery M. Roe

The current State-of-the-Practice is grounded heavily on deterministic characterization and assessment of the performance of civil engineering infrastructure. In particular, flood defense systems, such as levees, have been evaluated within the context of the Factor-of-Safety where the computed capacity of the system is compared with the code specified demand forces. Uncertainties associated with the capacity and demand forces render deterministic modeling incomplete. In particular, two structures with the same Factor of Safety can have vastly different probabilities of failure. While efforts have been made to assess levee vulnerability, results from traditional engineering approaches omit important factors because they do not account for uncertainties included in analytical modeling, and natural variabilities, or human and organization factors. This paper utilizes risk assessment methods to advance methods for quantifying the contribution of uncertainties to engineering analyses, and thereby provide additional information to help assess sustainability of geotechnically engineered systems. The probability of failure of a geotechnically engineered system is directly impacted by how well the system is understood, and how uncertainties are incorporated in development of understanding of the system. This paper presents methods to evaluate two types of uncertainties for three potential failure modes of flood protection levees: underseepage, slope (or levee) instability, and overtopping/erosion. These analyses account for two types of uncertainty: 1) Type I – inherent uncertainty, 2) Type II – analytical modeling uncertainty. Human and organizational task performance and information development and utilization uncertainties are not included in these analyses. This paper focuses on the behavior of the flood protection levee system for Sherman Island, a western island in California’s Delta. Sherman Island is of critical importance to California because of the very important infrastructure systems that pass under, on, over, and adjacent to Sherman Island, including: natural gas pipelines, regional and interregional electricity transmission lines and telecommunication facilities, two deepwater shipping channels; and State Highway 160, a link between major transportation expressways. The work evaluates current (year 2010) and future conditions (year 2100) and incorporates variations in capacity and demand arising from projected human response activities and global climate change.

Jan 1, 2017

By Mansoor Barati, Leili Tafaghodi Khajavi

"This study involves employing solvent refining as a purification process in which silicon recrystallization takes place from an iron-silicon melt. It is believed that iron will act as the impurity “getter” and purified silicon crystals will grow from the alloy melt, while the impurities are segregated to the liquid alloy. Phosphorous is a problematic impurity to remove since its segregation coefficient in pure silicon is relatively large. To assess the feasibility and efficiency of phosphorous removal through solvent refining, it is critical to study its equilibrium distribution between solid Si and the Fe–Si alloy phase.The distribution of phosphorous between solid silicon and iron-silicon melt at 1210-1310 °C was measured to evaluate the impurity removal potential of each alloy. Interaction parameter between phosphorous and iron was calculated by varying the concentration of phosphorous in silicon.IntroductionAmong various semiconductor materials for manufacture of solar cells, silicon accounts for over 90 percent of today's PV materials [1, 2].The major challenge in producing solar silicon that operates efficiently is to meet purity level requirement through a cost efficient route. Silicon solar cells can play a significant role in answering the world's need for energy if cost reductions can be achieved through manufacturing process. Considerable effort has been made to replace the expensive, complex vapor-phase purification by a simpler and less costly process. One of the refining approaches that have attracted wide research interests is producing low-cost solar grade silicon by purification of metallurgical grade silicon. Since metallurgical processes are selective in removing impurities, a combination of various purification processes can be used to reduce the impurity level in silicon. Considering different thermodynamic characteristics of impurities, each refining step is responsible for lowering specific impurities."

Jan 1, 2012

By Rita D. Sylvester

"THE BUREAU OF MINES was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve mineral resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting these industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with that directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau sources. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented III this special publication both necessary and valuable. This issue describes Bureau reports and articles published during the period January 1, 1960 to December 31, 1964. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960,2 and the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960.3 It supersedes the annual lists of Bureau publications and articles from January 1 to December 31, 1960/ from January 1 to December 31, 1961,5 from January 1 to December 31, 1962,6 and from January 1 to December 31, 1963,1 The leading general and technical libraries of the United States maintain files of the Bureau's publications. A list of these libraries appears immediately following this introduction. BUREAU PUBLICATIONSBecause some series of Bureau reports contain both free and sales publications, and because the cost of sales publications varies, prices are indicated in the individual listings of all publications for which charges are made."

Jan 1, 1964

Jan 1, 2001

By Thomas E. Lobb, Harry C. Verakis

Significant progress has been made in the reduction of serious injuries and fatalities resulting from mine blasting operations. Despite the progress, injuries and fatalities continue to occur. A leading cause of injuries and fatalities from blasting continues to be inadequate blast area security. Even though significant improvements in technology have been made, insuring adequate blast area security remains a challenge and requires constant vigilance. The advances in technology have created safer blasting products and have improved productivity and economics by enabling large, more efficient and effective blasts. However, as blasts grow larger in size, the complexity of adequately securing the blast area increases even more. Periodically the basic fundamentals involved in blasting safety should be reviewed, particularly for securing a blast site regardless of the size of the planned blast. Factors such as flyrock and toxic fumes must be taken into account to insure the safety of persons and property from the results of a blast. This paper examines the factors related to injuries due to inadequate blasting shelters and blast area security, and identifies mitigation techniques. The key concepts are: (a) accurate determination of the bounds of the blast area, (b) clearing employees from the blast area, (c) effective access control, (d) use of adequate blasting shelters, (e) efficient communications, and (f) training. Fundamentals are reviewed with an emphasis on analyzing task elements and identifying root causes for selected blasting accidents. Mitigating techniques are presented along with discussions and examples.

By K. Zabrusky

Epithermal vein systems are often modeled as simple, discrete high grade structures within low grade host rock. However, geologic setting and structural preparation influence how such vein systems form. In structurally complex areas, veins may follow several structural trends and occur on a variety of scales. Geologic and grade modeling within such complex structural regimes can be difficult as individual veins cannot be delineated from host rock based on grade alone. Structurally complex areas require a different approach than traditional discrete vein modeling. Presented herein is a study of a structurally complex area that hosts vein mineralization to be mined underground. All veins could not be modeled discretely, so an alternate approach was needed. Major structures were modeled using surface and underground mapping and were then used to create a structural trend for the area. This trend was used to guide 3D grade shell construction. The grade shells replaced 3D vein solids for grade estimation in order to mitigate the influence of high grade samples. Structurally guided grade shell construction offers a more effective modeling method than discrete vein modeling in deposits that are structurally complex.

Feb 23, 2014

By Arthur Grounds

Historical In the course of a paper which is necessarily limited in length, such as the present one, it is obviously impossible to describe in detail the history, development, and present position of coal preparation in Western Europe. Great Britain has been blessed with large deposits of excellent coal of nearly every type, ranging from the high-grade anthracites of South Wales, which are characterised by their very low ash and volatile con-tents, to the superb coking coals of South Wales and Durham -probably the finest in the world -with their low ash and sulphur contents, the latter constituent often well be-low l per cent. Gas coals abound in Lancashire and Yorkshire, while coals from the East Midlands, Northumberland, and Scotland are excellent for steam-raising and other industrial purposes. The excellent quality of these various coals has, in years gone by, ensured ready .sales abroad and it is not surprising, therefore; that methods of coal preparation were largely developed on the Continent in an endeavour to upgrade the inferior fuels found there, so that the prepared product could compete with British coals on the European market.

Jan 1, 1951