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By Morris M. Fine, Norwood B. Melcher

It is out of the question, at this time, to select any one prereduction process as superior to the others. It is apparent that several share a basic similarity and that within the groups listed in Part 1, the reduction vessel is sometimes the only significant variable. Claims as to the virtues of one machine over another are difficult to substantiate: one may be rapid, another thermally frugal. Based on published data, however, all seem to be performing adequately. It would appear that processes based on carbonized pellets are most applicable to foundry iron at low production rates. Adaptation to large scale manufacture of blast furnace hot metal or to agglomeration of fine concentrates at the mine site is much less likely.

Jan 8, 1966

By David Sinclair

THE dimensions and shapes of mine structures may at present be determined by (1) field experience, (2) structural calculations, and (3) barodynamic tests.§ None of these, however, provide information as to the stresses, their direction and distribution in a mine structure. For the design of pillars, the placing of openings relative to working places such as gangways, haulage levels, etc., this information is desirable. Photoelastic methods provide this and, while relatively new, their appli-cation in all engineering fields is assuming increasing importance. This paper, therefore, will present the method with a few applications to mining, and with sufficient reference for further study by the reader. PART I THE PHOTOELASTIC METHOD The photoelastic method of stress measurement determines the stress distribution in a two-dimensional model by optical means. It makes use of the fact that when a piece of isotropic transparent material, such as glass, celluloid, or Bakelite, is stressed and viewed in polarized** light a picture is seen which indicates by its color bands of light, or fringes, the magnitude of the stresses, their direction and their distribution.

Jan 1, 1940

By J Knoblauch, D, P J. J Strobos, C Foggo

The Sally Malay Project is located 120 km north of Halls Creek in the eastern Kimberley region. Since commissioning, ongoing improvements on the plant have resulted in recoveries now greatly exceeding the initial design targets. The continual optimisation endeavours of the Sally Malay metallurgy department included an automation project that was done in close collaboration with Mintek. In this team effort, several problem areas were addressed and the FloatStar advance control system was successfully commissioned to stabilise and optimise the flotation circuit. The remote location of the Kimberley Nickel Mines operation, fly-in, fly-out roster and the current mining boom makes the acquisition of experienced flotation staff difficult. The implementation of an automated flotation control system reduces this burden and contributes to the training of inexperienced staff. This paper illustrates not only the process control improvements achieved as a result of the installation of the FloatStarÖ advanced control system, but also how it has assisted operational personnel with their understanding of the process.

Jan 1, 2006

By C. R. Edwards

"Equity Silver Mines Limited, Canada's largest silver mine, has designed, built and operated a leach plant to reduce the levels of antimony and arsenic in its silver-gold-copper flotation concentrate. The orebody contained deleterious antimony and arsenic minerals in such proportions that the economic long-term sales contracts necessary to obtain project financing could not be procured. Construction of the leach plant therefore allowed development of the mine to proceed. Although the plant took some time to reach design throughput and product specifications, due to the complex and unique nature of the operation, these goals were successfully met and surpassed. This paper describes the physical plant and/or process technology modifications made to mold the main processes-concentrate leaching and filtering, autoclaving and filtration of by-products, and crystallization of salt cake-into an effective, economic operation.IntroductionEquity Silver Mines Limited, a member of the Placer Development Group, owns and operates an open-pit silver mine and related facilities located 37 kilometres southeast of Houston in north-central British Columbia. The mine occupies a 44 I-hectare (1089 acre) site at an elevation of 1300 metres (4265 feet) on the Nechako Plateau. Producing a copper concentrate containing high values of silver and gold, it is the largest silver mine in Canada and one of the largest in the western world. Equity stresses open communications, positive motivation, and production with safety, and achieved the best mine safety record in western Canada in 1984."

Jan 1, 1985

By SONGHE WANG, YI XUE, PENG HOU, CAIHUI ZHU, XUANYE JIAO, Feng Gao

The abstract discusses the challenges of coalbed methane development in China due to low coal seam permeability. It highlights protective layer mining as a method to reduce in-situ stress and enhance permeability for improved gas drainage and disaster prevention. The study involves experimental and numerical simulations to analyze gas migration and permeability changes during stress release. It includes a stress-strain-seepage coupled test on coal, development of a mathematical model for coal seepage under mining unloading, and a numerical model based on the Wulan coal mine to explore in-situ stress release, permeability evolution, and gas drainage in an unloaded coal seam. The aim is to demonstrate the effectiveness of combining protective layer mining and gas drainage technology for gas outburst risk elimination.

Mar 14, 2022

Gold has been known and mined in Australia for over 150 years. It occurs and is mined in all States and the Northern Territory. In the past 30 years approximately 8300 t of gold has been mined and gold exports have contributed over $106 billion to the Australian economy. In the first three quarters of the Australian financial year 2006 - 07 (ending 30 June 2007) gold exports were valued at $7.3 billion, which was 13 per cent of the value of all minerals exported and five per cent of AustraliaÆs total goods and services exports over the period. Clearly gold has been and remains a very important component of the Australian economy.

Jan 1, 2007

By Frank L. Hess

BERYLLIUM is demanding more of the limelight, and the output of beryllium copper (containing 2% to~ 3 per cent of beryllium) seems to have grown 60 per cent above that of 1936, which was double that of 1935. There is increasing interest in beryllium-aluminum alloys and small quantities are being marketed at $50 per lb. for the contained beryllium. Other alloys also can be produced. Further price decreases for beryllium copper (now $23 per lb. for the contained beryllium) seem , possible and desirable. No difficulty has been experienced in obtaining beryl and a 'reserve stock has been built up. One supplier heretofore found reliable has offered to furnish 200 tons per month. Supplies during 1937 have come from the Black Hills in South Dakota, Colorado. India, and South America

Jan 1, 1938

By KENNETH CROPPER

USUALLY we forget about the things which move along smoothly. There are no causes for worry when there are no troubles. But when troubles arise we must put forth some thought and effort to alleviate them. No one "worries about his automobile until it begins to knock, develop flat tires, or refuses to start. However, when these ailments become apparent we get wide awake on the spot, and do our best to repair the car. So we find ourselves now. The old bus seems to hit all the ditches. There is rough ground on all sides and none of us is able to do anything toward improvement. A state of pessimism stares us in the face, and there is sufficient cause for it. With lead at 3.75 cents, copper about 8 cents, zinc under 4 cents, -and silver about 26 cents, one has a reason for grief. When we think of the 5000 or less men employed in Utah mines and smelters in 1931, as compared with about 12,000 in 1929, the calamity seems even worse. In view of the present economic crisis we cannot even think of new men getting a job.

Jan 1, 1931

By Lowell B. Moon

Concern over possible wartime shortages finally resulted in passage of the Strategic Materials Act in 1939. As authorized by one section of this legislation, the Bureau of Mines proceeded to investigate deposits of seven strategic minerals with the objective of developing tonnages of low-grade material that could be mined in an emergency. During the war, the size of the program and the number of strategic minerals were increased, and the objective was the more immediate one of aiding production. Since the war, the size of the program has been reduced, but the number of minerals on the strategic list continues to be large. The objective has returned to that of 1939. In the course of the program, more than 10,000 examinations were made and about 1,300 projects were run on deposits of 33 different commodities. A considerable contribution to war production was made in six of the commodities investigated, and a minor contribution was made in twelve others. Substantial reserves have been indicated in 19 minerals. Private interest is currently active in some of the deposits developed in 14 commodities.

Jan 1, 1950

By E. H. Wells, A. Andreas

Greater progress than in any previous year was accomplished by the oil industry in New Mexico in 1936. The total number of completions in the state was 631, of which 549 were oil wells, 21 were hydrocarbon gas wells, three were carbon dioxide gas wells, and 58 were dry holes. The total oil production for the year was 26,804,446 bbl. Compared with the production for 1935 of 20,228,947 bbl., this represented a gain of 32.5 per cent. Of the total production, 25,337,382 bbl. came from Lea County. The average daily nonmarginal well allowable for that county was 115 bbl. the first of the year and 86 bbl. at the close. Production was regulated by the New Mexico Oil Conservation Commission,

Jan 1, 1937

By K. C. Dunham, M. Solomon, T. A. Rafter

Sulphur isotope ratios have been determined for 81 sulphides and S and O isotope ratios for 26 barites from the Alston Block in the northern Pennine ore field. In addition, both isotope ratios have been determined for 29 evaporitic anhydrites of various ages from European and Australian localities. The consistency of the sulphate isotope ratios over a wide area of the northern Pennines, and their similarity to values for Lower Carboniferous evaporites, suggests that the sulphate originated from Lower Carboniferous connate waters. It is suggested that these mingled with warm brines rising through granitic plutons beneath Tynehead and Upper Weardale, the aqueous sulphide ion in these brines having a delta34S value of approximately +10 per mille. The delta34S values for the sulphides range from +15.0 to -5.9 per mille and show an outward zoning with higher values in the central fluorite zones and mainly negative values in the outer barite zones. The wide range of delta34S values for the sulphide S is not characteristic of magmatic S and there is no adequate local source in the Carboniferous sediments. It is suggested that formation waters, probably mainly of connate origin, sank down sufficiently deep to become heated above 200°C before rising through Caledonian granite plutons into the Carboniferous sediments, where they spread laterally to mingle with cooler sulphatic connate water. The rising fluids were hypersaline brines carrying F, Ba, Pb, Zn, Cu and S. Temperatures of deposition calculated from galena-sphalerite isotope fractionation are similar to temperatures previously determined from fluid inclusion studies.

Dec 1, 1971

By M. H. Stanczyk, I. L. Feld

Dewatering of typical Florida phosphate rock slime by electro - osmotic techniques was investigated to determine if a compacted , plastic solid product could be obtained with simultaneous recovery of the water for re - use . Tests with porous cathodes and rod - type anodes imbedded in dilute slime charges of up to 4 tons in weight showed that the slime could be dewatered to about 35 percent solids . The dewatered products had the consistency of modeling clay . In the large - scale tests using 2.5 - foot electrode spacings , about 21 kilowatthours of power were consumed per ton of water removed in thickening the slime from 17 to 25 percent solids , but the rate of water removal was so slow that the process was not considered commercially feasible . Other tests made with electrode spacings of from 2.5 to 8 feet showed that more rapid dewatering could be obtained but that the power required was excessive . However , for special uses such as stabilizing slime pond dikes where the cost of dewatering might not be a prime requisite , high voltages could be used to rapidly remove the water . Tests of 400 - pound slime charges using a combination of electroosmosis and vacuum filtration showed that the rate of dewatering could be expedited . The average power required to thicken a ton of slime from 15 to 35 percent solids was 5 and 50 kilowatt - hours when operating the electroosmotic filtration cell at potentials of 20 and 100 volts , respectively . calculated filtration area of about 10 square feet per ton of slime treated per day was required to thicken the slime from 15 to 35 percent solids .

Jan 1, 1964

By D. M. Aloi

In today's evolving and globalized world, mining companies are being pressured to move beyond compliance towards long-term sustainability and sustainable development. Companies are expected to "engage" with communities and measure the success of these engagements without a clear understanding of "how" to do this. This move, away from "Corporate" Social Responsibility (CSR) and compliance, develops more of a focus on "Community" Social Responsibility and sustainability. This shift in focus leads to the development of world-class projects that provide sustainable development for people, reduces the incidence of costly delays, and promotes good global citizenship for corporations. The process of "engaging" communities in mining project design and development leads to a stronger license to operate and sustainable development. To create this mutually beneficial relationship between communities and companies, communities must be "engaged" in the mining process as early as possible, preferably during the exploration or the concept phases. How to create this "engagement" remains elusive. How to measure the progress of this engagement is also problematic. The quantitative and qualitative metrics needed to measure both positive and negative impacts of the mining and community relationship will be discussed.

Jan 1, 2007

By Daniel G. DiCanio

Investigation of the costs of industrial accidents dates back to the 1920s. The Bureau of Mines was one of the pioneers in accident cost investigation with numerous studies published between 1928 and 1933. The bulk of these early investigations dealt only with costs which appeared as payouts on company books; that is, the direct cost of insurance premiums and the costs of medical expenses which resulted from industrial accidents. These early investigations, especially the Bureau's study of accident costs in Pennsylvania and Indiana coal mines provided the first real evidence that promotion of industrial safety pays back in dollars as well as in human life and wellbeing. In the 30s and 40s, investigations began to accumulate evidence that industrial accidents impacted more than just the direct operating expenses of a company (i.e., higher insurance premiums). The work of Heinrich pioneered these investigations, and produced strong evidence that the un¬insured costs of accidents far outweighed those costs covered by insurance. Heinrich developed and published a ratio of insured to uninsured costs of 1.4. Despite his cautionary statements about blanket application of this ratio it is used even today to estimate total costs of accidents. Simonds, in the late 40s and early 50s, extended the definitions of uninsured or indirect accident costs and developed what is now regarded as the principal method for estimating the total economic impact of industrial accidents. Simonds' method served as the basis for development of the logic of the Accident Cost Indicator Model (ACIM). However, several departures from Simonds' method were made to satisfy certain requirements imposed by the Bureau of Mines, and because information gathered during the course of our investigation justified a departure. These departures are noted in the discussion which follows.

Jan 1, 1977

By K. H. Johnston

This guide was written to furnish the coal industry with a description of techniques, instruments, and clues on how to find abandoned oil and gas wells that have penetrated coal seams. The report includes specific information on searching techniques currently in use by several coal mining companies, gas-transmission companies, and waterflood operators, as well as information on State agencies responsible for the enforcement of laws and the preservation and distribution of data pertaining to the drilling, development, and abandonment of oil and gas wells. Comparative tests were performed with several commercial electronic metal detectors to determine the feasibility of using them to aid in the search for abandoned wells and to determine the instrument most suited for that particular use. The role of methane detectors to locate abandoned wells is described, including a case history. Tests were made to develop an efficient procedure to follow in systematically searching an area for metallic clues or hydrocarbon evidence to abandoned wells. The guide describes, in detail, a search sequence, including the collection of basic data, preparation of the selected area, and the physical search. Methods are given for evaluating the results.

Jan 1, 1973

By Fiseha Tesfaye, Pekka Taskinen

"Thermodynamics of the equilibrium phase assemblage Ago_9Cul.lS-Cu2-xS-CuS have been studied by an EMF -method. The ternary phase was synthesized from the pure Cu2S and Ag2S in vacuum furnace at high-temperature and mixed with appropriate compositions of Cu2S and CuS to form the cathode electrode. The EMF-measurements were made on the solid-state galvanic cell Pt(-) I Ag I RbAg,ils I Ago9Cu1.1S-Cu2-xS-CuS I Pt(+), in a temperature range from 316 K to 498K.Based on the measured EMF vs. T relations, thermodynamic functions (?fG° , ?fS and ?fH°) of stromeyerite (Ag0.9Cu1.1S) in equilibrium with Cu2-xS and CuS have been determined. The obtained experimental values have been compared with the available literature values. New experimentally determined thermodynamic properties of the solid solution (Ag,Cu)2Sss were determined.IntroductionDue to intense mining of high grade sulfide ore minerals in the past, recently, the available sulfide ores are poor in metals and becoming increasingly complex; such that, the production of high grade metals by the conventional pyrometallurgical processes is compromised. Consequently, smelters are in need to modify their operating flow sheets and strategies for processing more complex feed materials economically, while meeting the strict environmental regulations. To make the appropriate modifications, accurate thermochemical data of phases and phase assemblages which exist in these complex ore minerals are essential.Silver-bearing sulfosalts are encountered in ore minerals for the production of base metals and are common sources of silver. Among the silver-based sulfosalts, stromeyerite (Ag0_9Cu1.1S) is relatively common ore mineral in most hydrothermal vein and replacement deposits [1]. Recently, the ternary chalcogenide compound Ago0.93Cu1,07S has been studied, intensively, due to its high ionic conductivity and gradual disorder in the sequential phase transitions [2]. Therefore, accurate knowledge of the thermodynamic properties of stromeyerite has considerable fundamental and practical interest in many aspects of extractive, chemical and physical metallurgy."

Jan 1, 2014

By Stanley P. Jacobsen

Samples of fine coal refuse were obtained from 11 coal preparation plants throughout the United States. These samples were characterized by ash analysis, particle size, and mineral composition. From the characterization, geographical locations, and the dewatering equipment being used by the plants, five sites were selected for obtaining bulk fine refuse samples. The selected coal preparation plants were using for final dewatering thickeners followed by: a vacuum disc filter, a filter press, a belt press filter, a centrifuge, and a settling pond. None were using thermal drying. The moisture content of the final cake varied from approximately 23% to 50% depending upon the feed material, flocculant addition, and the type of equipment. The filter press gave the lowest moisture content followed by a belt press and then either a centrifuge or vacuum filter. The centrifuge products were all dried to an approximate 5% moisture in a thermal dryer.

Jan 1, 1981

By F. A. McLean

At the Annual Western Meeting held at Blairmore, Alta., October 1924, the writer presented a paper drawing attention -to the advantages of portable gas-driven equipment for developing isolated mining properties. This type of equipment was at that time practically in its infancy and the details of results actually accomplished were somewhat meagre. During the last year or so a number of these plants have been installed so that it is now possible to offer more definite information regarding the actual mining progress accomplished with such plants and their cost of operation in various parts of the country. This paper has been written with the idea of reviewing the work done during the past year, and to supply data which may be of interest to those wh9 are confronted with the problem of selecting equipment for development or assessment work. Because drilling operations play such an important part in mining, one of the first problems that usually confront the prospective? mine owner is the selection of the proper com-pressed-air plant. The size and type of equipment and the method of driving it require careful consideration. The size and type of equipment is determined largely by the funds available, transportation facilities, and the speed with which the programme of development is to be carried out. The selection of the proper method of drive usually depends on local conditions, such as the relative cost of various fuels, and has an important bearing on operating costs.

Jan 1, 1926

By Lev Filippov, Vyacheslav Severov, Inna Filippova

"Reverse cationic flotation is a very efficient method of beneficiation of oxidized iron ores when you need to separate hematite and quartz. This method can be also applied to reduce silica content in the magnetite concentrates obtained by wet low-intensity magnetic separation. However, cationic flotation in this case is less effective due to the presence of Fe-Mg-Al-bearing silicates as amphiboles in magnetite ores. These silicates are concentrated in magnetic products and determine the difficulties of their separation from iron oxides when amines and starches are used as collectors and depressants, respectively. The recalculation of the results of the electron microprobe analysis of three calcic Fe-Mg-Al-bearing amphiboles used to characterize cation distributions in structural units and to obtain structural formulas in accord with stoichiometric limits was conducted. The Mössbauer spectroscopy was used to examine the validity of the empirical estimation of cation distributions in amphiboles. The studied samples are metamorphic pargasite and ferrotschermakite and volcanic magnesiohornblende. The crystallographic analyses of the amphibole samples exhibited their heterogeneous surfaces explaining worse floatability of amphiboles with dodecylamine at pH 10. The electrokinetic measurements showed that the position of the isoelectric point of amphiboles is related to a substitution of Al3+ for Si4+ in tetrahedral sites and to an amount of Mg2+ cations in octahedral sites. Thus, the dodecylamine adsorption onto amphiboles through electrostatic interactions is mainly affected by a distribution of these cations in tetrahedral and octahedral sites of amphiboles. In addition, the effect of starch on the depression of Fe-Mg-Al-bearing amphiboles during flotation can be attributed to the presence of metal ions on the amphibole surface, which are capable of forming strong chemical complexes with starch molecules."

Jan 1, 2014

These proceedings consist of an overview of the in situ mining research currently being carried out by the Bureau of Mines. The following papers emphasize two general aspects of the in situ mining method: the environment and productivity. Both areas are extremely important, particularly because in situ leach mining is a relatively new mining method from a commercial point of view. Topics covered include the restoration of ground water, the selection of lixiviants, in situ mining of commodities other than uranium, in situ mining costs, the application of resistance measurements to in situ mining, an acid leach mining case history, and the use of branched boreholes for in situ mining. A bibliography of Bureau of Mines publications on in situ mining is appended.

Jan 1, 1981