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By R. Wiebe

During a recent investigation the authors were interested in determining: (1) How many points were necessary to locate the deviation curve for copper-constantan thermocouples within an accuracy of about 0.05° C., used in connection with the, "standard" thermocouple of L. H. Adams (2) Whether copper-constantan thermocouples showing considerable deviations from the "standard" were consistent throughout their calibration. (3) How reliable the extrapolated portion is - that is, the interval between -183 and -220° C. of the "standard" thermocouple.

Jan 1, 1931

By J. H. Holden, C. C. Shale, G. R. Strimbeck, W. S. Bowie

Electrical characteristics of positive corona are presented for air in a 2 - in - diam electrostatic precipitator operating under dynamic conditions at temperatures of 600 ° to 1,500 ° F and pressures of 0 to 80 psig . Results show that current - voltage relationships depend solely on air density . Comparison of data on positive corona with previously published data on negative corona demonstrates a higher sparkover voltage and a wider range of operability for positive corona at temperatures above 375 ° F. The possibility of achieving higher voltages with positive polarity as indicated by these experiments implies several advantages for the use of positive corona in precipitators to allow better removal of suspended material from hot gases . Based on the physics of an ion in an electrical field , a theoretical equation is derived to define current - voltage characteristics of positive corona in terms of air density . Constants for the equation are evaluated from Calculated current - voltage values at different air densities agree reasonably well with experimental data .

Jan 1, 1964

By Signe Kjelstrup, Leiv Kolbeinsen, Marit Takla, Odne Burheim

"This paper presents a Seebeck-type solid state thermoelectric power generator unit, designed to investigate the possible recovery of radiant waste heat at a silicon plant in Norway where roughly 703 of the total input energy leaves the process as waste heat. The unit is 0.5 m x 0.5 m and is built of 36 commercially available thermoelectric devices based on bismuth telluride p - and n - type semiconductors. Thermoelectric devices directly convert fractions of a heat flux into an electric current (and vice versa) and may therefore be convenient for recovery of waste heat when the heat source is discontinuously available. The purpose of the thermoelectric unit is to give a proof of principle of direct thermoelectric energy conversion on a large scale. We present the initial test results for the generator. At an average temperature difference between the heat reservoir and the heat sink of 98°C, we measured an open ciruit potential of 23.44 ± 0.06 V and the matched load power output was 39.4 W. At a temperature difference of 220°C, we predict the generator open circuit potential to be 40.8 V, which corresponds to an efficient Seebeck coefficient of 242 µV /K, and matched load power output to be 120 W.IntroductionThe world's power demand increases, driven by population growth and increase in living standards and simultaneously global warming is recognized as one of our most serious environmental problems. According to the International Energy Agency[l], the industrial sector accounted for approximately one third of the total global power consumption in 2005. Increasing the energy efficiency of industrial processes thus represents a benign and substantial route for addressing environmental concerns and energy security.In accordance with the second law of thermodynamics, all real processes are associated with lost work which is energy being dissipated as heat to the surroundings[2]. Improving the energy efficiency of industrial processes is about finding the process path associated with a minimum of lost work. The more evenly the losses are distributed, the smaller are the losses [3, 4]. In addition, exploiting the unavoidable waste heat will contribute to improve the energy efficiency. The waste heat may be utilized for heating purposes and/or it can be upgraded to work for instance via some sort of heat engine."

Jan 1, 2012

By Kurt Tischler

This paper presents the field experience of Siemens with regard to Gearless Drives in the mining industry ? We consider the elapsed production hours of Siemens Gearless Drives to be extensive enough to provide a reliable estimation of availability calculated on the basis of data representing repair time, downtime, and operating time. The users of Siemens Gearless Drives confirm an availability of more than 98% after exclusion of some major issues. The paper addresses all of these major issues of Siemens Gearless Drives, describes successfully applied corrective measures, explains the influences on the design of the drives, and lists the downtimes associated with each of these issues.

Jan 1, 2012

By H. Allenius

Today, most requests for quotations force all bidders to follow the bid document to the letter. The choice is then made based on price since it is the only difference in technically identical offers. However, clients allow and even encourage suppliers to come up with alternatives. Overall economy again, is much more than low investment costs. Operation costs may affect the economy of a project far more than a million saved in investment. There is almost always the choice: Should we go for the cheapest solution or should we go for the most economical solution? We strongly recommend the study of the long-term effects on investments as they often surpass any apparent savings in capital expenditure. With high operating costs, time is never on our side. Almost all relevant inputs and outputs in a concentrator have a value that can be expressed in a suitable currency. Unit prices may differ substantially from one operation to the other, but everything has a price tag and globalization has made it possible to move both goods and services to almost any place in the world. Even a rather simple exercise can give a good indication on which process improvements are worth pursuing when investing in new systems or equipment. The ones that do not qualify, as money earners, will naturally appear as clearly. No ?rocket science? is required, just process knowledge, practical experience, an open mind and some common sense and the reward may be the difference of having a good or an excellent project. The model we have developed can be made as detailed as required, but we do not recommend too much detail, as it sometimes tends to distract work and obscure the important issues. Two different process solutions compared in a simplified example illustrate the importance of evaluating a project based on its long-term effects rather than focusing on the investment costs only.

Jan 1, 2014

By Henry E. Keniston

In every business today costs come under almost microscopic scrutiny. It's hard to conceive that less than 30 years ago there was no such cost consciousness apparent in overall industry. Railroads, through their almost absolute monopoly on freight handling, were one of the industries where little thought was given to overall costs. True regulation kept rates in line, but railroads did very little in the area of supplying equipment intended to help the shipper minimize his costs and at the same time result in savings to the rail carrier. During this period, except for isolated cases, railroads placed standard cars for loading. Most railroad car fleets consisted of box cars, hopper cars, flat cars and low side gondola cars certain roads having unique movements developed special cars to accommodate the particular product, but seldom did these cars move in general interchange service. Most of you are aware that several large companies built railroads of their own as an integral part of raw materials handling from remote sources to production plants located near concentrations of usage. On these railroads special cars were built with little thought to inter-change service. Examples of such railroads are the Duluth, Missabe and Iron Range, the Elgin, Joliet and Eastern, the Union Railroad, the Bessemer and Lake Erie and the Birmingham Southern.

Jan 1, 1972

By John P. Gooch

The solubility of 1,1,2,2-tetrabromoethane (TBE) in water was determined from 1.0° to 97.0° C. The solubility (S) of TBE in grams of solute per 100 grams water was correlated with [S = 1,920.55 [exp (40292L7 11, T2 10 T 737.577 + 9.923962 ] where T is in degrees Kelvin. A thermodynamic analysis conducted on a system consisting of a TBE phase and a water phase in equilibrium with a vapor phase led to the calculation of the activity coefficient, vapor-liquid equilibrium distribution coefficient, relative volatility, and heat of mixing for saturated solutions of TBE in water. Data required for these calculations were the solubility of TBE in water and the vapor pressures of TBE and water as a function of temperature.

Jan 1, 1972

By Collon C. Kennedy, Frances C. Hartogh, C. Joel Casburn

INTRODUCTION During the nineteenth century, the federal mining law was enacted with the objective of promoting the development of the western United States by providing unrestricted access to vast areas of federal land for mineral exploration. Prior to the advent of comprehensive federal, state and local land use plans, there was little, if any, regulation or restriction of mineral exploration activities. Today, the laissez-faire policies of the past that encouraged mineral exploration have gradually given way to the public's legitimate concerns regarding environmental protection, multiple use and planned land development. As a result, the contemporary prospector confronts a maze of statutes, ordinances and regulations with which he must comply to obtain the requisite approvals and permits before commencing mineral exploration on federal, state or private lands. This presentation will provide a broad overview of the exploration permitting process. The first section of this paper recommends certain general management practices to follow when attempting to obtain exploration permits. The second section presents two hypothetical cases, one involving a drilling program on private property in California and the other involving a drilling program and the removal of a bulk sample for metallurgical tests from federal land in Nevada. The cases are used to discuss jurisdictional issues and application of certain federal, state and county laws and regulations that pertain to mineral exploration. The final section contains a brief analysis of three important recent United States Supreme Court decisions. These decisions address the scope of the federal pre-emption doctrine as it applies to activities conducted on unpatented mining claims and the constitutional limits of permissible state and local land use and zoning regulations. PERMITTING PRACTICES The environmental impacts associated with mineral exploration generally result from the construction of drill sites, roads or trenches. Consequently, after the regulatory authority has considered the issues of permissible land use, the primary emphasis of the permitting process is to address problems related to pre-construction site identification and clearance, and post-construction site reclamation. The approaches taken to address these and other related issues vary with the scope of proposed work, the site, the appli-

Jan 1, 1987

By LefTvre Y

In May 1991, AZSA commissioned a new conventional Cell House. This paper focuses on the major improvements introduced in the design and the construction of the equipment, machinery and control. An effective control system together with good reporting and routine operation has resulted in quality control of the Cell House at the highest possible level. Consequently the monthly current efficiency consistently averages above 93 per cent with a total energy usage of 3000 AC kWh/t of cathode zinc. The new concept for the year 2000 and beyond is introduced.

Jan 1, 1993

By N. N. Orekhova, I. V. Shadrunova, N. G. Novikova, N. ?. Volkova

The purpose of the research is scientific substantiation and formulation of strategy and technical solutions of handling liquid wastes of plants producing and refining copper-zink pyritic ores. In the course of research studied are chemical composition of technogenic waters of mining plants as well as water and alluvia of intake river within and outside a sanitary zone of Southern Ural mining plant using inductively coupled plasma mass-spectrometry and X-ray fluorescence analysis techniques. A particular focus is made on microcomponent composition. Novel data on Cd, Li, Be, Mn, Co, Cu, Zn migration with technogenic flows and accumulation of these elements in alluvia is obtained. It is showed that extraction of valuable components from technogenic waters is a novel problem for refiners that can be solved only in cooperation with mining industry ecologists. Laboratory research of selective copper and zink extraction into corresponding practical products by galvanocoagulation and sulphide precipitation is carried out. Common factors of phase formation are studied using physicochemical modeling, X-ray phase analysis and electronic microscopy. Methods of intensification of processes and increasing of extraction ratio of metals in products are elaborated. A technology of comprehensive processing of undersoil waters is proposed. Enlarged laboratory and pilot plant tests of technological solutions for protecting hydrosphere and extracting metals from mine waters carried out on several plants of UMMC-Holding Corporation showed a possibility of obtaining additional products having weight content of metal which is profitable for consequent metallurgical processing and purification of waters to comply with quality standards. A possibility of transformation of technological chain depending on season variability of water quality is put behind the designed technological schemes.

Jan 1, 2018

Up to thirty years ago, coal preparation in western Canada, except at four plants, had not included actual coal washing. The exceptions were at Nanaimo and Royston, B.C., where tub washers and wet tables were in use; at Hosmer, B.C., using. Robinson cones; and at Leitch Collieries, Passburg, Alta., using a feldspar jig. The two last named collieries had a short life and were not operating in 1920. The industry was divided, as at the present day, into two sections, steam (bituminous) coal and domestic (largely sub-bituminous) coal, the first generally supplying industrial needs and the second householcl and other heating requirements. The two sections overlap to some small degree today as prepared sizes, chiefly stoker, and briquettes, from steam coal are shipped for house-hold use, and domestic slacks are used in certain industrial plants. The .domestic operator, for reasons shown later, was not primarily concerned with actual coal washing as a phase of coal preparation, and bent his efforts to improvement of screening and loading plants, with hand-picking of coarse sizes. The bituminous operator, on the other hand, felt it necessary by 1920 to consider coal washing. When the mines were comparatively young, coal quality could be controlled to a considerable degree by selective mining, by leaving behind some of the seam or by-passing districts in a mine where the coal was of inferior quality to that in other districts. This obviously had its limitations, and so the next step was coal washing.

Jan 1, 1952

By P. R. Taylor

A review of the advantages and disadvantages of plasma technology for metal and mineral wastes is presented. Examples of the use of plasma systems are given and possible future uses are outlined. Among the potential uses are treatment of electric arc furnace (EAF) dusts, the vitrification of nuclear wastes and the removal of toxic metals. Over the past few decades, plasma technology has been studied for potential applications over a wide range of metals/materials processing areas. One promising area of plasma technology applications is the treatment of industrial hazardous waste. The potential generation of hazardous and toxic waste by various industries has become a matter of public and political awareness. Environmental regulations have put stringent toxicity emission limits on disposable waste streams. An intensive research effort is currently underway in the area of hazardous waste treatment.

Jan 1, 1994

By D. E. Stone

Solid and liquid impurities must be removed almost completely from synthesis gas for the production of synthetic liquid fuels because of their effect on the synthesis catalyst and turbocompressors. The maximum permissible concentration of dust has been set at 0.05 grain per 100 cubic feet.5/ This is one part per million by weight, or about the same concentration as in average city air. The cost of synthesis gas is estimated to constitute 60 to 70 percent of the total cost of the synthetic liquid fuel. For this reason this station is developing processes using coal instead of the more valuable coke as raw material, which promises reduction in cost of the synthesis gas. This, however, increases the difficulty of attaining the above dust value. As failure of the dust-removing equipment to produce high-purity gas may ruin valuable equipment within a few minutes, it is imperative that a reliable and continuous method be obtained for determining such extremely low concentrations .of dust in the purified gas. A suitable device must also instantly sound an alarm and, if necessary, automatically actuate the proper valves to prevent damage. The Ess Instrument Co. designed and built an instrument which they believed might fulfill these specifications. It' continually compared, by means of photoelectric cells, the intensity of a light beam passing through the gas and a similar beam passing through clean air. For maximum sensitivity, the photocells were connected back to back, i.e., anode to cathode and cathode to anode. The difference in voltage produced by the two cells was amplified and operated an indicator.

Jan 1, 1951

By D. A. Sloan

"THE FIRST COMMENTATOR that I will call on is Mr. W. G. (Bill) Brissenden, Vice-President, Mines, Noranda Mines Ltd. Bill, would you care to comment.W. G. BRISSENDEN ...Mr. Chairman, Ladies and Gentlemen, I spent some time reading the four papers that were presented here, yesterday evening, and decided that the four to six minutes that I had been allotted for this afternoon were going to be pretty tough to meet. It's a very big subject and I just hope that I will be able to stay within my time limit. As has been so aptly demonstrated by the members of our panel here this afternoon young men in growing numbers continue to be attracted to careers in the mineral industry, especially to careers in mining engineering. Now from 80 the point of view that the profession may have regained its status this is indeed welcome news. However, perhaps all of the members seem to have the suspicion that the number of mining engineers that the industry can absorb is a much lower figure than previously forecast. It is said that technical school graduates are now occupying some of the jobs once considered the private preserve of the mining engineer and also that mining engineering undergraduates are having trouble locating summer employment. If these interpretations of mine are correct then we are now confronted not only with our old dilemma - whither the mining engineer - but also with an urgent need to solve it. We cannot allow our profession to become once again an undesirable one in the eyes of our youth because if we permit such a thing to happen a second time the profession may never recover."

Jan 1, 1972

By Charles A. Seitz

This Bureau of Mines report describes a chromatographic method for analyzing impurities in helium that utilizes a helium carrier gas contain-ing 25 to 30 ppm Ne. An example of the effect of trace amounts of nitrogen, methane, and moisture on the detector's response is shown. The added neon in the carrier does away with irregularities of the analysis which were experienced when the carrier contained up to 3 ppm Ne. The addition of 25 to 30 ppm Ne causes a loss of sensitivity, but the re-maining sensitivity is adequate for routine analyses. The high-neon carrier allows positive and more linear responses for eight impurities: neon, hydrogen, argon, oxygen, nitrogen, methane, carbon dioxide, and ethane. Neon concentration levels of 0.02 to 125 ppm in helium carrier gases were studied. The high-neon carrier has been in successful rou-tine use in Bureau of Mines helium facilities since October 1981.

Jan 1, 1985

By D. Campbell

Mining activity is increasing in northern boreal and subarctic regions of Canada. This is the case in the far north of Ontario, especially in and near the Hudson Bay Lowland (HBL). De Beers Canada opened the Victor diamond mine in the centre of the HBL in 2008, and advanced exploration and impact assessments are occurring to the west in the ?Ring of Fire? for ferrochrome, nickel/copper, iron/ vanadium and platinum-group elements, making it one of the richest mineral finds in Canada in recent years. However, the HBL is also a near-pristine, sensitive environment. Its peatlands forms the third largest wetland in the world and are globally important stores of terrestrial carbon. Human populations in the region are sparse, consisting almost entirely of First Nations communities. Local First Nations also have a strong land ethic and greatly influence mining developments. Through formal agreements, they have insisted on a gold standard for environmental management, including a small mine footprint and the return to representative native ecosystems after mine closure. However, knowledge on the revegetation of subarctic and northern boreal ecosystems is limited. Here, we are conducting research at the Victor mine to develop gold standard protocols for the revegetation of disturbed peatlands and mine waste uplands and present a summary of results. We first tested existing protocols for peatland restoration from southeastern Canada. We collected peat-forming plants from nearby muskeg, spread them sparsely over disturbed peatlands and applied a light phosphate fertilizer, but unlike southern protocols, no mulch appeared to be required to produce a representative cover of peat-forming plants within three years. A bigger challenge is the reclamation of uplands made of mine waste back to representative ecosystems. We first characterized reference conditions for uplands in the HBL, which are scarce in the region. Nearby natural uplands were divided into two classes, interior uplands and uplands along river valleys. Multiple parameters were examined at these sites including soil development, bulk density, soil chemistry in the rooting horizons, plant cover by stratum, plant species composition and dead wood. The mean condition and, more importantly, the range of these parameters allow us to set broad targets for progressive reclamation, which will facilitate success. Finally, we characterized local upland plant species through their functional traits to determine their likely abilities to colonize, grow and contribute to ecosystem processes. A classification of species by these simple functional attributes will help restoration managers to select candidate species to meet different goals at different successional stages (i.e. good versus poor dispersers or establishers). Research into these protocols remain in the early stages, but show promise that gold standards can be achieved to ensure that mining wastes can be reclaimed to productive ecosystems.

Aug 1, 2013

By M. M. Gilkey

This report describes the effects of water shortage on Arizona's mineral industries. The information presented was obtained in interviews with company representatives. Operations covered included all State metal mines using substantial quantities of water and all concentrators and smelters. Also included in the survey were 8 operations in the nonmetallic group; 22 in the plating, metal-fabricating, and metal-forming categories; 1 public-utility power company; and 6 water companies. The extent of the water shortage in Arizona is reflected in mineral- industry water-use practices, in the high cost and low quality of water used at many operations, and in the stringency of State control of well drilling and pumping. Many mineral-industry operations are among those users most seriously affected by the uneven water supply.

Jan 1, 1963

By M. M. Gilkey

This report describes the effects of water shortage on Arizona's mineral industries. The information presented was obtained in interviews with company representatives. Operations covered included all State metal mines using substantial quantities of water and all concentrators and smelters. Also included in the survey were 8 operations in the nonmetallic group; 22 in the plating, metal-fabricating, and metal-forming categories; 1 public-utility power company; and 6 water companies. The extent of the water shortage in Arizona is reflected in mineral- industry water-use practices, in the high cost and low quality of water used at many operations, and in the stringency of State control of well drilling and pumping. Many mineral-industry operations are among those users most seriously affected by the uneven water supply.

Jan 1, 1963

By William H. Peterson

How is the Government's oil import control program doing? In July 1954 Mr, Eisenhower established the Cabinet Committee on Energy Supplies and Resources Policy. On July 29, 1957, the Administration imposed "voluntary" company oil import quotas on American oil importers to maintain "a healthy domestic (oil) production industry" and safeguard "national security." On March 10, 1959 the President by proclamation made the voluntary program mandatory. But study of the program in practice shows that it is not working out as expected and-that there is some doubt that its aims and other related Administration purposes are being achieved. Take the Administration's anti-inflation policy. To be sure, the President apparently recognized in his March 10th proclamation that in restricting cheap imported oil in favor of more expensive-domestic oil he was making the inflation fight that much harder, for he called for Government surveillance of domestic oil prices to prevent them from getting out of hard, And indeed while domestic crude oil prices have not risen appreciably during 1959 neither have they fallen appreciably (although there has been some price weakness in the past few weeks).

Jan 1, 1960

By A J. Clough

There has been an unprecedented rise in the fatality rate in the Australian mining industry over the last few years. The factors behind this rise are not clear; however, it is noted that the increase in fatalities has occurred during a fall in commodity prices.This paper examines prevention methods and systems to deal with hazards that have the potential to result in either single or multiple fatalities. Managing the risks associated with mine ventilation is used to illustrate the principals behind the approach.The paper also touches on the broad science of human error and proposes a multifaceted approach to controlling and preventing fatal risks.A summary of the steps involved in developing an effective principal hazard management plan is provided.CITATION:Clough, A J, 2015. Ensuring an effective principal hazard management plan, in Proceedings The Australian Mine Ventilation Conference, pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015