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By B. W. Clyburn

"Coals from the Corporation's Lingan and No. 26 mines are classified as high-volatile A bituminous, with a very low inherent ash and containing a/l essential properties to provide metallurgical coal, with the exception of a high sulphur content. Only through proper cleaning at low specific gravity can the pyritic sulphur fraction of the coal be liberated to an extent where final sulphur meets coking standards. This first section of the paper deals with the operation of a Dutch State Mines heavy-media cyclone circuit to achieve an actual separation in the region of 1.30 specific gravity. A discussion of the parameter of control which must be applied along with an appraisal of the results obtained is included in the paper.IntroductionVery high fluidity and unusually low ash are the outstanding characteristics of coal from Devco's mines in the Harbour seam of the Sydney coal field.However, sulphur content, mainly pyritic, ranges from 1 to 2.5070. To obtain the low and consistent sulphur level required in metallurgical coking coals, preparation at low specific gravity is required .Metallurgical coke is used as the fuel in an iron blast furnace. Its sulphur content largely determines the quantity of slag required to remove it and therefore influences furnace productivity and unit costs.Typical data on the various coal properties of importance in the production of coke are included in Table I. Necessity of Low-Gravity SeparationThe design of any coal preparation plant requires the study of washability properties of the coal to be treated to determine the quantity and quality of coal produced at a given specific gravity along with the difficulty in accomplishing that separation.Their low ash content allows the important washability aspects of Harbour seam coals to be represented by sulphur! specific gravity curves (Fig. I). This particular example indicates that a yield of 54.5% is attained, at a sulphur content of 1.20%, for a perfect separating device operating with a 1.29 S.G. cut point.Material rejected from this separation still contains usable coal, which is recovered as middlings by separating at a higher gravity."

Jan 1, 1980

By Atsushi Shibayama, Toyohisa Fujita, Wan-Tai Yen, Ke-jun Liu

"In this investigation, a sponge gold sample (99.92% pure) has been leached with ammonium thiosulfate solution. The effects of CuSO4, (NH4)2S2O3, (NH4)2SO4, NH4OH and retention time on the gold leaching % (extraction %) and thiosulfate oxidation % (consumption %) have been studied. The copper ion acts as a catalyst in gold dissolution. On the other hand, it also accelerates oxidation of thiosulfate (consumption). It was found in this study that the best gold extraction condition was obtained at 43.2 ks with 0.8 - 1.0x103 mol/m3 (NH4)2S2O3, 30 mol/m3 CuSO4, 2.0 - 3.0x103 mol/m3 NH4OH, 0.4 - 0.5x103 mol/m3 (NH4)2SO4, pH 10±0.2 and 150 rpm. The thiosulfate oxidation was about 15% of the initial concentration.For gold recovery from the pregnant solution, the trioctylmethyl ammonium chloride (TOMAC) was used in this investigation as an extractant to extract gold from thiosulfate solution without pH and other adjustments. The effects of gold concentration, pH, ammonia, thiosulfate and cupric ionic concentrations, extractant and diluent concentrations and retention time on the gold recovery were investigated. It was found that 180 mol/m3 extractant diluted with n-octant at O/A ratio of 1:1 could extracted the 100% of gold in 0.6 ks from the thiosulfate solution at the optimal leaching conditions. The 100% gold stripping could be achieved with 10% thiourea solution."

Jan 1, 2003

Jan 1, 1923

Jan 1, 1923

By W. L. Dare

This information circular is one of a series the Bureau of Mines plans to publish describing the methods and costs of mining uranium on the Colorado Plateau. The Big Buck mine is one of the larger underground uranium-vanadium ore mines on the plateau. The mine is about 39 miles southeast of Moab in the Big Indian mining district, San Juan County, Utah. The Big Buck claims were located late in 1947, when uranium mineralization was discovered in the Cutler formation at its outcrop along the escarpment that forms the west side of Big Indian Wash. Charles A. Steen made the first major discovery of uranium ore in the Chinle formation in the Big Indian mining district on July 6, 1952, when 14 feet of high-grade uranium ore was encountered in a diamond-drill hole drilled on his Mi Vida claim. The Big Buck ore body now being mined by Standard Uranium Corp. is a southeast extension of Steen's original discovery.

Jan 1, 1956

By S. P. Sandoval

The U.S. Bureau of Mines investigated the separation of aluminum from copper dump leaching liquors using a supported liquid membrane. Aluminum was selectively transported through porous polypropylene impregnated with di (2-ethylhexyl) phosphoric acid in an aliphatic diluent. The effects of variables, such as solution composition, temperature, and extractant concentration, were measured with a three-level fractional factorial experimental design. Experimental results were used to derive equations for predicting transport rates for aluminum, iron, and copper. The major variables influencing aluminum transport were solution temperature, feed solution pH, aluminum concentration in the feed solution, and extractant concentration. Copper and iron transport rates were almost zero when aluminum transport rates were high. Measured aluminum transport rates under the best conditions of 55° C, pH 3.0, 16 g/L A13+, and 65 pct extractant solution confIrmed the predicted value of 210 f.'g/(cm2.h). Transport rates for iron and copper were less than 5 ug/(cm2.h) under these conditions. Aluminum was recovered from the stripping solutions by sparging with gaseous hydrogen chloride to crystallize aluminum chloride hexahydrate, which was calcined to alumina. Sparging crystallization regenerated the stripping acid for recycle.

Jan 1, 1989

By J. R. Thoenen

In June 1929 the Bureau of Mines issued a 13-page information circular entitled "Mineral Wool," which was one of the first publications to present to the public Rome technical aspects of the mineral-wool industry. Since then several articles on the subject have appeared in the technical press as well as in publications of State organizations. Inquiries for information on mineral wool have continued to be received by the Bureau of Mines in large number, and in 1935 it was decided to make a field survey of the plants then producing and to collect therefrom technical data to be compiled in a paper for nubile distribution. With the cooperation of the industry, this survey was made, and Information Circular 6984, Mineral Wool, was published in January 1930. The issue was exhausted after a few months, and requests for copies continued to come to the Bureau. As opportunity arose, further field studies were made in American as well as Canadian plants. The present circular contains the essential information in Information Circular 6994 together with date from later field studies.

Jan 1, 1939

By Jr. Goller

You and I can visit cement plants, inspect the various rotary kiln systems and find some equipment or some burning techniques that waste energy--fuel and power. After we have made such a visit and studied a few ideas, we could recommend ways to eliminate much of this waste. Probably every idea would cost money to bring into action. For our discussion, let us arbitrarily set an upper limit of $1,000,000 on the recommendations that we are allowed to make. Call these "low-cost" or "short-term" measures. They are improvements that do not require more than say, three months to complete; they do not require a major revision to the process. Other recommendations are "high-cost" or "long-term"; they are outside the scope of this discussion. Some of our "low-cost" recommendations would offer a satisfactory return on the money that they cost; the remainder would not. Now, is there some way that we can rather quickly pick out the "low-cost" measures that will show a satisfactory return and spend our time making these improvements first? Can we separate these items from those where the return is less likely to be good? I feel that we can pick some of these items quickly if we have a kiln system that has consistently non-uniform day-to-day operation. If the operation is uniform we probably cannot pick them quickly.

Jan 1, 1977

By Kendall W. T C

This paper provides a brief overview of the history of the Chaffers Dewatering Project which was successfully commissioned in August 1993. Until the end of 1992 the `Superpit' and the deep mines of the Golden Mile had all been dewatered by a staged pumping system from the 28 level in the Lake View Shaft, which was removed at that time when the Lake View Mine was absorbed into the Superpit. Feasibility analysis had indicated that adaptation of oil industry technology offered the greatest potential for a low cost solution to the problem of dewatering the open pit and deep mines. A KCGM engineer and one of the authors visited the Jackson oilfields to look at the deep well pumping technology in use there in early-1991. In the final analysis a new dewatering station was established in the 23 level crushing station of the Chaffers Shaft using conventional plunger pumps, but the rising main was screwed 178 mm OD (7 inch) casing the suspended from the surface to a depth of 686 metres, and was installed using oilfield personnel and methods. Only the second installation of its kind in Australia, the project achieved the dewatering objective at about half of the capital cost of the more conventional approach and at lower operating costs as well.

Jan 1, 1995

By Z. Botha

Sheryl Sandberg, the COO of Facebook, published a book titled 'Lean In', where she invites women to sit at the table. In summary, to 'sit at the table' entails not only embracing opportunity, but to actively seek out opportunities in leadership positions. Sandberg points out that, unfortunately, apart from institutional obstacles, a woman's own perceived limitations have a negative impact on her leadership ambitions. To create an environment where diversity will flourish, where everyone has a seat at the table and everyone has a voice, safety must be established first. To establish safety within a diverse team, there is power in relationships and connections. This study will first and foremost review theories in literature as to why diversity and inclusion are so important and the value that diversity brings to our industry. The study also recommends a few focus areas for improving diversity and inclusion in the industry.

Sep 1, 2022

By K. Hasselwander, K. Knabel

"A significant area of Outotec’s business involves fluidized bed roasting. With several decades of experience, more than 300 reference plants and strong R&D capabilities, the company provides several industries with optimum processing solutions. Applications include oxidation and sulfation of sulfides found in copper, pyrite and zinc concentrates. Gold production and de-arsenifying roasting are also within this scope. This paper describes the latest furnace developments and includes novel trends. Moreover, hot and wet gas cleaning systems are examined focusing on unit operations related to the removal of components such as dust, SO2 for sulfuric acid production, fumes, halides, Hg, hydrocarbons, nitrous oxides and metals.INTRODUCTIONGenerally, when defining roasting processes, it can be stated that the respective primary pyrometallurgical reaction is exothermic, of gas-solid nature and relates to a value solid product. These processes are a key focus within Outotec’s scope and include: (i) dead roasting (ii) sulfating roasting (iii) partial de-arsenifying roasting and (iv) two-stage, de-arsenifying roasting.Dead roasting involves the oxidation of a given sulfide, thus allowing for a subsequent leaching process, and has been applied to producing ZnO. Dead roasting of pyrite has also been extensively utilized with a primary goal of producing sulfuric acid. In contrast, sulfating roasting involves converting a sulfide to its sulfate, enabling a selective sulfation of components, such as Cu or Co, and their separation from ferrous components during leaching (produced sulfates are soluble). Partial roasting involves partially oxidating the metal sulfide to its oxide with the simultaneous production of gaseous As4O6, which is handled during gas cleaning. The solid product, containing hardly any As, is rich in S and can be fed to a respective smelter (e.g. in the case of Cu). Alternatively, if the production of oxide is required, a dead roasting step is added after the partial roasting step, with the overall process considered as two-stage roasting."

Jan 1, 2012

By G. M. J. van Heerden, R. C. W. Webber-Youngman

"This article describes the re-engineering principles applied in the design of a personnel transportation system for the Bafokeng Rasimone Platinum Mine in the Rustenburg area of South Africa. It incorporates conveyor belt travelling, chairlift operation, and also includes consideration of proposed changes/modifications to the existing conveyor belt infrastructure.The purpose of the project was to identify, through a process of evaluation, the appropriate option and/or combination of transportation options that would be safe in terms of personnel transportation as well as cost-effective. Alternative measures for transporting personnel (not using belt riding) would have a significant positive spin-off, increasing the availability of the belt and thereby increasing production. This paper explores the feasibility of interventions that would improve safety through eliminating risk associated with personnel transportation as well as contributing towards improving the mine’s position on the cost curve.The design in consideration at the Bafokeng Rasimone Platinum Mine consists of two shaft systems, namely the North Shaft and South Shaft, each comprising twin decline shafts. One of the decline shafts is equipped with a conveyor belt for rock and personnel transportation, and the other with a winder for trackbound material transport. The conveyor belt has been used for personnel transportation since the commissioning of the shafts. The conveyor belt is equipped with platforms for personnel getting off and on the belt and a number of safety devices designed to ensure safety while travelling on the belt. Intensive training in the practical aspects of belt riding is given to every person, and unsupervised riding on the belt is permitted only once belt riding competence is demonstrated. Despite this, the safety results were poor, with 106 injuries between 2006 and May 2013. Fortunately, no fatalities were reported during this period.An investigation of alternative means for personnel transportation or engineered solutions to the current conveyor belt infrastructure in the safest, most effective, and most economical way was therefore needed. There was a major risk of safety-related stoppages being imposed following another belt accident/incident. This would prevent the mine from transporting personnel underground by belt and result in major production losses. From the commissioning of the Phase 2 shaft deepening project on both shafts, dedicated chairlifts have been used for personnel transportation as opposed to the conveyor belt installed in the Phase 1 area. The chairlifts have been in operation since 2004 and no chairlift-related incidents have been recorded thus far. According to safety statistics, it is clear that the chairlift is the safer method for the transportation of people in the shaft.To fulfil the objectives/scope of this study, it was recommended that both primary (new chairlift decline with infrastructure) and secondary options (modifications to the current conveyor belt infrastructure) be considered for implementation on both the North Shaft and South Shaft to reduce or eliminate accidents/incidents as a result of belt transportation. The associated capital expenditure would be approximately R200 million. Considering the future impact on the business as a whole, this would definitely be capital well spent."

Jan 1, 2016

By J. W. Thompson

ESTATE IN MINERALS. Minerals beneath the surface may be made the subject of separate ownership either by a grant of the minerals by the owner of the land or by a grant of the land excepting the minerals, and thereby an estate in fee simple is created in the minerals, as corporeal things real. Colby, In re, Iowa, 169 Northwestern 443, p. 444. DEEDS EXCHANGING DIFFERENT MINERALS-RIGHTS OF PARTIES. The lands of two adjoining owners were underlaid with cement rock and clay at a depth of about 100 feet from the surface and with coal veins some 600 feet below the surface. By an exchange of deeds one of the land owners conveyed to the other the cement rock and clay with the right to mine and remove the same without entering upon the surface, but the deed contained no covenant not to injure the surface. The other deed conveyed the coal seam and so much of the rock and other minerals just above and below the coal as might be required in connection with the mining and removing of the coal, together with the right to mine and remove the same, and the adja- cent rock, clay, and other minerals, without entering upon or injuring the surface, with one immaterial exception. The deeds do not define the word "surface" and neither expressly nor by implication did they secure to the coal owner the right to subside the overlying cement rock; but the implication is to the contrary, as the deed gives the right to mine and remove coal without entering upon or injuring the surface. The provision that the coal owner should not enter upon or injure the surface amounts to a clause that the coal mine. shall not be worked so as to let down the surface and this does not create any inconsistency with the provision giving the right to mine and carry away the coal.

Jan 1, 1919

By AIME AIME

THE Institute of Metals Division of this Institute held a joint meeting with the American Foundry- men's Association on Oct. 5-9, at Syracuse, N. Y. The registration at this meeting was about 150. There were four meetings in all, three of which were in con- junction with the American Foundrymen's Association. This combination works out very nicely and gives the I Division a number of practical foundry papers that it would not get otherwise. The sessions were well attended and the discussion was active. The session on Monday morning was of a general nature and consisted of the following subjects : " Refractory Problems in the Non-ferrous Electric Furnace Casting Shop, " "Temperature Control of Non-ferrous Alloys," "Atomized Coal System of Non-ferrous Melting," "Material Handling in a Brass Foundry." On Tuesday morning, the session was on "Aluminum and Its Alloys." The paper on permanent mold castings created a large amount of discussion, in fact so much that it had to be renewed after the close of the regular program. Aluminum is assuming a more important place every year and adds greatly to the program as a whole. One of the most remarkable meetings that this Division has ever had was held on Tuesday at noon in the form of a Round Table discussion, headed by G. K. Elliott, chairman of the Division, Cincinnati, Ohio. Mr. Elliott divided the members present, numbering about 80, into groups as they were seated at the tables. Each of these groups suggested a topic for discussion. They were as follows : "Fluxes on Market ;" "Simplification of Alloys;" "Pyrometric Control;" "Effect of Gas- sing Metal and Control;" "Barium Sulfate Added to Electric Furnace to Create Slight Oxidation to Remove Aluminum and Silicon;" and" Nickel in Brass."

Jan 1, 1925

By Andrea Koschinsky, Sophie Paul

"INTRODUCTIONOnce again deep-sea mining has been receiving a lot of attention in recent years. Industrial and political advancements also call for environmental baseline studies and analyses to aid the development of standards and monitoring protocols. As part of the EU research project “JPI Oceans: Ecological Aspects of Deep-Sea Mining”, the RV Sonne cruise SO242 to the Peru Basin revisited the DISCOL area that had been artificially disturbed in 1989. This offered the unique opportunity to study a deep-sea site 26 years after a disturbance similar to manganese nodule mining had been carried out (Figure 1). A comparison of a variety of undisturbed and disturbed sites shed light on the re-establishment of a geochemical equilibrium and a range of baseline values. This information can help to inform standard development for monitoring and mining purposes.Heavy metal data and its applicationResearch findingsDuring the cruise, disturbed and undisturbed surface sediment was sampled. The pore water analyses show that the 26 years old disturbance is not visible in the metal profiles and that the pore water reaches equilibrium through diffusive fluxes relatively quickly. The sediment, however, shows some differences between disturbed and undisturbed sites in the upper 20 cm, even after 26 years. Lower concentrations in the usually manganese-oxide rich top layer, variations and “unnatural” peaks in the manganese profiles, for example, suggest removal or mixing of the top layer (Figure 2)."

Jan 1, 2017

By W. W. Adams

"The National Safety Competition of 1930, the seventh annual contest conducted by the United States Bureau of Mines to promote safety in the mines and quarries of the United States, has been concluded, and the five winners of the bronze trophies, The Sentinels of Safety,' which are provided by the Explosives Engineer magazine and awarded annually for the most excellent safety records, have been determined by the committee of award. One trophy was awarded to an anthracite mine in Pennsylvania, one to a bituminous coal mine in the same State, one to an iron-ore mine in Michigan one to a gypsum mine in Ohio, and one to an iron-ore opencut mine in Michigan.These trophies were awarded to the companies for having the smallest loss of time from accidents in proportion to the total number of man-hours worked by all employees at their mine or quarry. Honorable mention was awarded to each mine or quarry that ranked second, third, fourth, or fifth in its own ground and to all plants that were operated without a lost-time accident during the contest year. Eighty-four out of 337 plants that competed for the trophies were operated without an accident that disabled an employee beyond the day on which the accident occurred.Under the contest rules, all mines and quarries were divided into five groups, four of the groups representing different classes of underground mining operations (anthracite, bituminous coal, metallic ore, and nonmetallic mineral), and the fifth group repre-senting the quarrying or opencut mining of minerals whether metallic or nonmetallic. Twenty-seven mines were included in the anthracite group, 68 in the bituminous group, 52 in the metal group, 24 in the nonmetallic-mine group, and 166 in the quarry and opencut-mine group. The total of 337 mines and quarries was 26 more than the number of plants that completed the contest during the previous year.The committee of award which determined the winners of the contest was composed of seven members, all known throughout the mineral industry but not connected with the United States Bureau of Mines. The committee included W. H. Cameron, managing director of the National Safety Council; William Green, president of the American Federation of Labor; James F. Callbreath, Secretary of the American Mining Congress; T. T. Read, Vinton professor of mining of Columbia University and editor of Mining and Metallurgy; C. B. Huntress, executive secretary of the National Coal Association; A. J. Curtis, assistant to the general manager of the Portland Cement Association; A. T. Goldbeck, director of the bureau of engineering of the National Crushed Stone Association."

Jun 1, 1931

By D. L. H. Forbes

(New York Meeting, February, 1912.) Introduction.. THE application of the cyanide process to complex sulphide ores for the extraction of their bold and silver is no longer a novelty, but, as an example showing modern tendencies in this direction, the following description of the new milling process at the Lucky-Tiger mine is offered: The extraordinary richness of the ore in the upper workings of this mine made any thought of milling in its early hays seen unnecessary. Its location in an almost inaccessible part of the rugged mountains just south of the Arizona boundary-line, and 60 miles from the town of Douglas, made the expense of bringing in machinery and supplies a very serious consideration. But, after the property had been shipping high-grade ore on mule-back for a few years, there remained in the mine a considerable tonnage of vein-matter that was too low in value to ship, but which it was thought could be milled near the mine at a profit. The first milling-experiment consisted in the installation of Nissen stamps in conjunction with concentrating-tables and Frue vanners, but, as the ore from the upper workings contained most of its silver in the form of cerargyrite, this type of mill was not successful. The proximity of the mine to the great copper-concentrating mills of Cananea and Moctezuma naturally made the influence of copper-milling, ideas felt in the company's next installation. At considerable expense a stage-crushing concentrating-mill, with a capacity of 100 tons per day, was built. This mill was modeled along the lines of the most approved practice in copper-concentrators at that time, the main idea being that crushing by stages in rolls was necessary in order to prevent losses from ?sliming." Largely owing to the fact that, when the mill

Aug 1, 1912

By José Alberto da Cruz Junior

Aços multiconstituídos têm aplicações voltadas principalmente para o setor automobilístico. Isso porque esses apresentam uma boa combinação de elevada resistência, ductilidade e tenacidade. A elevada resistência desses aços é devida a martensita e aos finos feixes de ferrita bainítica, enquanto que a tenacidade e a ductilidade são atribuídas aos filmes finos de austenita retida presentes entre os feixes. Esses filmes contém uma maior concentração de carbono em relação aos blocos de austenita retida. Uma consequência é que estes se tornam mais estáveis mecanicamente e termicamente. Dessa forma, foi realizada a avaliação do desempenho mecânico de um aço tratado isotermicamente abaixo de Mi e revenidos a 400°C/1 h. Os resultados dos ensaios de impacto mostraram que quanto maior a fração volumétrica da austenita retida maior é a energia absorvida, independente da morfologia desse constituinte.

Aug 7, 2018

By G. E. McElroy

Ventilation-pressure surveys are required to determine the rates of pressure losses in various parts of mine-airway systems. These may be determined directly by differential pressure measurements or deduced from absolute pressure measurements, Despite the confusion caused by its inverted nonlinear scale, the altimeter has special application to pressure surveys in mines in which only small differences in elevation are involved, as is true for most of our large bituminous-coal mines in these, the judicious use of information obtained by pressure surveying can result in greatly improved working conditions as regards health and safety and, in many instances, can yield large financial returns. The main purposes of this report are to discuss methods of using altimeters for pressure surveys and to present the particular methods of making surveys and calculating the results of surveys used by the Mine Ventilation Section of the Bureau of Mines.

Jan 1, 1957

By AIME AIME

DOUBT in anyone's mind that this is the age of metals, industrially speaking, could easily have been dispelled by attending the National Metal Congress in Chicago, Sept. 22 to 26. Iron, copper and aluminum; zinc, lead and nickel, often alloyed with each other or with some of a dozen minor metals, make the materials without which the modern world could not run. Science, pure and applied, is doing marvels in finding new mixtures, new alloys to meet new needs; in developing new means of rolling, fabricating, casting and welding metals cheaply-and effectively. These and related matters were the subject of 100 papers presented at 33 seperate sessions of the organizations that participated in the congress.

Jan 1, 1930