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By John E. Wiegand

This study will discuss the AMAX Coal Co., Penndiana Pipeline Project, which was conducted in conjunction with the following parties: AMAX Coal Industries, (U.S.B.O.M.) United States Bureau of Mines, (I.D.O.R.) Indiana Division of Reclamation, Ohio Valley Pipeline, Inc., New Mexico Tech, and ourselves, VIBRONICS, INC., Evansville, Indiana. The purpose of this study was to find a safe vibration level for active gas transmission pipelines near surface coal operations.

Jan 1, 1994

By G. A. Harrison

The introduction of extra low profile (XLP) mechanized equipment within Anglo Platinum is aligned with the overall New Mining Technologies strategy to focus on continuing modernization of our mining operations` incorporating injury-free production and cost-effective mining technologies. The method allows for the introduction of a suite of ultra-low profile equipment in narrow reef (1.2 m) stoping operations. For the first time it is now possible to achieve total trackless mechanization at these widths and indications are that XLP mining has the potential to add more value when benchmarked with conventional mining and low profile (1.8 m) room and pillar methods. Various mine layouts were tested at different sites within Anglo Platinum and the XLP breast mining layout proved to be the most effective. This paper describes the results of the trials at Waterval Shaft and concludes with recommendations on our future strategy on implementation of XLP technology within Anglo Platinum.

Jan 1, 2006

By Leonhard Weixler

The Bauer company was founded in 1790 by coppersmith Sebastian Bauer in Schrobenhausen, a small town north-west of Munich. The original workshop business carried out works including repairs to church roofs and brew kettles. Later the company expanded its operations to encompass water pipe installation, which it continued through to the 1980s. In addition to installing water pipes it then also began drilling wells, which were sometimes constructed using very simple methods, such as tripod frames (Figure 1).

Jan 1, 2011

By R. R. Sayers

"The number of investigations reported during the past year indicates that control of the health hazard due to abnormal air conditions is still a matter of serious consideration in the mining, metallurgical, and allied industries.Australia. - In an investigation into the health and working conditions of employees in the mining industry of Tasmania and Victoria3, it was found that although pulmonary tuberculosis may occur early in life, silicosis is e disease of slow evolution and does not appear frequently under the ace of 40. A period of at least ten years in the industry was found necessary to produce silicosis, and in no case was the disease found in those who had not worked underground. A very high incidence of silicosis was found in all fields among those who had worked underground 20 years and longer. There was some evidence that silicosis complicated by tuberculosis may occur earlier than uncomplicated silicosis.England. - In a paper presented before the Section on Occupational Diseases of the British Medical Association, Dr. E. L. Middleton, the medical inspector of factories, called attention4 to the occurrence of silicosis in various industries throughout the country.punitive on some quite harmless industries. Thus Middleton says: ""Where the amount of dust is small the action of the phagocytes is likely to be effective, but where it is great . . ."" What dosage is indicated by ""small"" and ""great"" in this connexion? If the meaning of ""small"" were known, would it be correct to go on to say, as he does, ""each successive dose of silica produces a summation of effects""? Then, again, would it be fair to say ""a comparatively brief period of exposure may be the only determining factor""? What, in minutes, hours, or days per week, per month,' or year, is intended by ""a comparatively brief period""? ""Intermittency of the process"" is another expression used in summing up the reasons for and against a standardization of air purity by a gravimetric process or enumeration of the particles; the arguments against such a standardization are, by Middleton, considered strong, but they are by no means convincing to us. A standard has been accepted in respect of the amount of lead in milligrams per 10 cubic metres of air; Dr. Ronald Lane showed in another paper read that adherence to this makes the occurrence of poisoning highly improbable. Mavrogordato has placed on record figures of silica dust at different stages of the improvements in the workings of the Rand mines, and such a control is in constant operation in them today.We emphasize these points because apparently the Government has taken the unusual course of legislating first and postponing inquiry to a later date, as in the ""Various Industries (Silicosis) Scheme, 1939."" The insurance companies also have a considerable interest in the matter of compensation for the silicosis risk. Where exposure - as in the refractories industries, the grinding industries, sandstone industry, and pottery industry - is day in and day out, they rightly demand a premium far higher than for any other disease scheduled under the Workmen's Compensation Act - 5 per cent on the wages bill. row every industrial employer, such as the paint and varnish manufacturer, who has a sack of crushed silica in his store .room, from which he extracts once a week enough to make a paste With spirit and add to his other ingredients in order to give them the necessary ""bite,"" becomes involved, and may have to abandon the use of the material or pay 8 per cent on his wages bill for an absolutely negligible risk.. For meting out justice standardization seems urgently called for."

Feb 1, 1930

By A. Takala, B Nielson, J. Schunicht

"Pre-concentration in minerals processing presents clear advantages in energy efficiency, water efficiency, reduction of consumables and minimization of capital and operating costs. Outotec’s sorting solutions are powered by Tomra Sorting in order to achieve pre-concentration of concentrator feed in a variety of mineral processing applications. Sensor based sorting combines advanced sensors with rapid computational evaluation and mechanical separation of valuable material from waste and/or gangue. Modern sensor based sorting machines typically use fine air jets to propel individual rocks, thus optimizing recovery and minimizing “mis-sorting”.Gold is generally present in such low concentrations that sensors suitable for ore sorting cannot directly detect it. Therefore, in order to sort gold ore, properties of associated host rock are used. Free and sulphidic gold is often hosted on the quartz-host rock contact zone. Laser scattering effect can be used to detect the surfaces of quartz and composite quartz-host rock particles for subsequent sorting with very high recovery of 95 to 99%. In addition, ore often preferentially fractures along the quartz-host rock contact zone in the crushing circuit. This behavior helps because it liberates more quartz for detection.The feasibility of sorting is investigated for four gold projects in Northern Europe with similar mineralogy. This includes geometallurgical evaluation, amenability testing, small scale “mini-bulk” factory testing in full scale sensor based sorting. The results of the various tests are presented and basic feasibility demonstrated with information on flow sheet development. In addition, the amenability process is evaluated and recommendations made for future projects."

Jan 1, 2017

By Paul D. Martinka

Coal is the principal energy source for the American Electric Power System (AEP System), which generates and delivers more electric energy to its customers within a seven-state area than any other investor- owned electric public utility. The company expected to burn 21.5 million tons of coal in 1968 at its coal-fired, steam-electric generating stations. About 4.3 million tons, representing 20% of the firm's total annual requirement, was the expected yield of its captive coal mines; the other 17.2 million tons were to be purchased from commercial mines in Ohio, West Virginia, Virginia, Kentucky, Indiana, and Illinois. American Electric's largest captive coal mining operation is conducted by Central Ohio Coal Co., a subsidiary of Ohio Power Co., at the Muskingum mine in the Meigs Creek No. 9 coal field of southeastern Ohio. The mine was started in 1953 to produce the coal requirements of the Philo and Muskingum River generating plants of Ohio Power Co., and it has been supplying their annual requirements in the range of 2.5 to 3.5 million tons since that time. The Muskingum River plant is one of the major steam-electric generating stations on the AEP System. This plant began operation in 1953 with a 215-megawatt unit and now has five generating units with a total plant capacity of 1,495 megawatts. The addition of the 615-megawatt Unit 5 in the summer of 1968 increased the total annual coal requirement of the plant from 2.6 to 4.4 million tons. In order to produce the additional 1.8 million tons of coal for the Unit 5 addition and to exploit the remaining coal reserves at the Muskingum mine most economically, Central Ohio Coal Co. has undertaken a $41 million expansion and modernization program, involving the world's largest dragline and an electric railroad.

Jan 1, 1969

By C. Bazin

Grinding circuits are operated in the presence of disturbances due to ore changes and equipment malfunctions. One of the challenges faced by the operators is the detection of a disturbance, the identification of its origin and of the action to correct the problem. Hydrocyclones overloading, worn or partly plugged apexes of the units of a nest, surging and internal liner detachment may cause a loss of classification capacity and quality leading to a less efficient grinding operation. A dynamic simulator is used to assess rules for the diagnosis of hydrocyclone faults from the trends produced by sensors.

Jan 1, 2009

By Parker A. J, Giles D. E

Solutions of copper(II) sulphate in acidified aqueous acetonitrile leach copper from copper-lead matte derived from the drossing of lead with sulphur to produce solutions of copper(I) sulphate. The reactivity of the matte constituents towards copper(II) sulphate is Cu2S> PbS > CuS > > Pb. According to the leach conditions, part or ,all of the copper may be leached 'leaving a residue of CuS/PbS, or S/CuS/PbS04, or S/PbS04, to be recycled to the lead smelter. Complete extraction of the copper requires leaching with oxygen which occurs under mild conditions in the presence of acetonitrile and sulphuric acid in water. Copper is selectively recovered as a pure product by electrochemical or thermal disproportionation of copper(I) sulphate solutions. A notional process is proposed.

Jan 1, 1979

By Steve Kral

More than 124,000 people involved in the mining and construction industries throughout the world poured into Las Vegas, NV in March for ConExpo-Con/Agg ’99. Show organizers said this triennial exhibition is the largest equipment show in the Western Hemisphere and one of the largest exhibition of any industry. “Clearly, Con-Expo-Con/Agg ’99 was one of the largest trade shows of any industry ever held in the Western Hemisphere,” said Bruno Benna, co-chair of the event. Attendees included mining industry representatives, including aggregates, and sand and gravel producers. In addition, many of the attendees work in the construction, reclamation, forestry, asphalt paving, landscaping and concrete industries. According to show records, about 52% of those attending were company presidents, vice presidents, chief financial officers or managers.

Jan 1, 1999

By P. H. Williams, D. J. Morris

The co-disposal of coarse and fine coal wastes by combined pumping through a pipeline to subaerial deposition was pioneered in Australia in 1990 by Jeebropilly colliery in Queensland. Significant segregation of fines is found to occur in its co-disposal delta, leading to the formation of distinct mainly coarse upper and fine-dominated lower segments; the upper delta drains rapidly and is able to support traffic on its surface immediately after deposition. An existing theory of subaerial deposition, originally developed for mine tailings alone and later extended to trial co-disposal, is shown to apply also to the upper segment of the full-scale Jeebropilly delta

Jun 19, 1905

By A. P. Gize, J. F. W. Bowles, D. J. Vaughan, S. J. Norris

Paper presented at the IAGOD international symposium on mineralization related to mafic and ultramafic rocks held in Orleans, France, 1-3 September 1993. Geological evidence from tropical laterites indicates clearly that platinum group metals are taken into solution and precipitated to form grains larger than those in the source rocks. Platinum and palladium move differentially in the surface environment, with Pt partitioning into soils and eluvial or alluvial deposits while Pd remains more mobile in natural waters. Natural organic acids, particularly humic acid, can interact with platinum-group elements and concentrate them even in areas where their content in rocks is very low. Experimental work has confirmed that Pt and Pd can be taken into solution by humic acid at room temperature and in geologically short time-spans. Solubility and deposition may be controlled by physicochemical conditions, reaction kinetics or an adsorption effect, or there may be two competing reactions, solubilisation assisted by organic matter and a kinetically slower metal precipitation

Apr 1, 1994

COUNCIL OF EDUCATION OF AIME (Formerly Mineral Industry Education Division) Established as a Division January 15, 1932 Established as a Council February 26, 1957 John C Calhoun, Jr, Chairman 0 Cutler Shepard, Vice-Chairman Thomas A Read, Secretary-Treasurer Dept of Mining & Metallurgical Engrg University of Illinois Urbana, Illinois COUNCIL OF ECONOMICS OF AIME (Formerly Mineral Economics Division) Established as a Division December 15, 1948 Established as a Council February 26, 1957 Louis C Raymond, Chairman Lorin A Cranson, Vice-Chairman Henry T Mudd, Vice-Chairman Adam K Stricker, Jr, Vice-Chairman Paul F Yopes, Secretary-Treasurer U S Bureau of Mines Albany, Oregon

Jan 1, 1957

By V. Sastry

Signgareni Collieries Company Ltd. is operating the JK Opencast Project, at Yellandu, with a rated annual capacity of 1.6 Mt of coal with an average stripping ratio of 4.3. This opencast coal project has three working sections, OC-II block, C-Block and D-Block These workings are operating in close proximity to the JR-5 Longwall Shed, 26-Dip Incline, other structures of 26-Dip, and a Township. There were complaints about ground vibrations and fly rock problems caused due to blasting operations, especially in OC-II and D-Blocks. In view of this, studies were taken up to eliminate the problems of ground vibrations and fly rock.

Jan 1, 2001

By F. G. Pickard

"The Strathcona Concentrator is one of three concentrators presently operated in the Sudbury District by the Nickel Division of Falconbridge Nickel Mines Limited. Production commenced in 1968 at a milling rate of 6,300 tons per operating day. Milling capacity was increased in 1970 to 7,200 tons per operating day. 7he ore contains iron, nickel and copper primarily in the form of pyrrhotite, pentlandite and chalcopyrite, while the common gangue minerals are feldspar, quartz, mica, talc and chlorite. The primary function of the concentrators is not only to liberate sulphides from silicate gangue minerals but also to separate pyrrhotite from the more valuable minerals pentlandite and chalcopyrite.SummaryExcessive wear on steel liners and blinding of grates in a regrind pebble mill of the Hardy Concentrator was corrected by the use of rubber liners and grates. The success of these resulted in their installation as original linings In all grinding units except the rod mills at the Strathcona Concentrator. The operation of rubber liners and grates when sized mine ore was used as the grinding medium was satisfactory confirming the Hardy Concentrator experience. Problems developed when the grinding medium was changed from sized mine ore to steel balls in that blinding of the grates occurred. This resulted in conversion of the units to overflow type mills through removal of the grates. The lifter bar life was significantly increased by using higher lifter bars.Grinding PracticeOperation of a regrind pebble mill commenced in 1961 in the Hardy Concentrator. This operation demonstrated the economic feasibility of using sized mine ore as grinding medium. Problems caused by excessive wear of metal liners and grates combined with blinding of the grates were corrected in 1964 through installation of rubber liners and grates."

Jan 1, 1974

I had the opportunity recently to visit a magazine site of a major explosives company. It was fun to see the storage areas again and it was really interesting to see one of the old magazines that probably dated back before my time. Now that’s an old one. As son Tom says, “When Dad was young the Dead Sea was just sick.” While the magazine has been upgraded with a modern lock to match today’s standards it still has the old tumbler lock that is opened with the large bronze key. Those old tumbler locks were just about standard on magazines years ago. Those bronze keys were heavy and would make a good display item today or maybe a substitute for a blackjack. I don’t think the old locks would stop the modern criminal but then in those days we were all less sophisticated. And maybe I shouldn’t say this but honesty was a bit more prevalent then. Maybe ‘cause old fashioned police brutality still prevailed.

Jan 1, 2004

By G. M. Carrie

Introduction The subject of basic refractories is daily becoming of increased importance in metallurgical processes, and there is a constantly growing necessity for the development of better materials. This fact, together with the realization that Canada possesses one of the best sources of such refractories in the British Empire, if not in the world, made it appear? advisable that the subject be presented to the Empire Mining and Metallurgical Congress at the 1927 meeting. Having been in close touch with developments in the Canadian product during the past five years, G. M. Carrie was requested to prepare such a paper. The Canadian producers of magnesia refractories have succeeded in developing the product to a place where it has almost entirely displaced imported materials from the Canadian market. These developments were made possible by a close study of the methods of preparation of the material, and by an exceedingly careful control of the manufacturing process so as to obtain a thorough blending of the different constituents with the resultant uniformity of composition. This point is very important to the metallurgist, as un-uniform materials are a potent cause of difficulties in most manufacturing processes and the constant trend is towards their elimination. The temperature at which the Canadian material is burned ensures high specific gravity and thorough shrinkage. The grain size of the product is so controlled that the voids are only just sufficient to allow of proper bonding, thus making possible a dense, hard bottom affording high resistance to erosion and shock. Careful proportioning of the constituent elements absolutely prevents disintegration.

Jan 1, 1927

By Elbridge W. Gresseth

Rock deformational structures in a deep mine were analyzed by petrofabric techniques to learn (1) the relative magnitude and direction of the principal stresses involved in tectonic deformations prior to mining, (2) the preferred orientation of rock planar discontinuities which define rock anistropy prior to mining, and (3) the relationship of mining-induced rock failure to inherent rock stresses and inherent rock anisotropy. Rock fabric elements used for petrofabric analysis consisted of bedding planes, faults, joints, fractures, foliation, sericite plane (001), quartz axis [0001], quartz deformation lamellae, and microfractures. Structures and structural symmetries from different areas within the mine and from different scales of observation were compared to learn the nature of rock anisotropy and the orientation of the principal stresses defined by rock deformations. Analysis of such fabric as regional and macroscopic faults, b-c joints, quartz [0001], sericite (001), and microfractures, indicate that during the epochs of tectonic deformation, the maximum and minimum principal stresses were horizontally oriented and acted along northwest and northeast axes, respectively. This condition of regional stress appears to have continued during folding and the associated period of faulting. The most recent tectonic deformation represents a rotation of the minimum principal stresses into a vertical position, as shown by the development of a tensile joint system, quartz deformation lamellae, and microfractures. Good interscale correlation and statistical homogeneity of tectonic fabric indicate a stress field homogeneity in this area during tectonic deformation. Rock physical anisotropy is genetically associated with tectonic fabric and consists of preferentially oriented planar discontinuities intersecting along a nearly vertical axis. The mining-induced deformations were correlated with the inherent rock anisotropy which either directly controls or greatly affects their development. This phase of rock deformation shows a greater degree of stress field heterogeneity than was the case with tectonic deformations This is explained as a result of nonconfinement afforded by underground openings and the increase in ground stresses due to mining activity"

Jan 1, 1968

By Rudolph P. Frizzi

Quality control is essential for augered cast-in-place (ACIP) piles (also known as continuous flight auger (CFA) piles outside the United States) and drilled displacement (DD) piles since the pile is constructed below the ground surface out of the direct sight of the personnel constructing and inspecting the pile. ACIP piles are being successfully constructed to support high-rise structures, hospitals, arenas and stadiums, mass transit systems, and power and industrial facilities. The use of DD pile technology is also gaining ground in the United States, typically utilizing proprietary systems such as Omega (currently utilized by Richard Goettle Inc., and LG Barcus and Sons, Inc.), Berkel, and DeWal (currently utilized by Morris-Shea). Different types of ACIP/DD pile installation equipment are shown in Figures 1 and 2. ACIP piles are installed into granular and cohesive soils, and soft rock to lengths currently approaching 130 ft (39.5 m), with diameters up to 24 to 36 inches (610 to 915 mm), and sustaining design loads approaching 900 kips (4000 kN). Current DD pile installation equipment in the United States is capable of installing up to 79-ft-long (24 m) piles with diameters ranging from 12 to 18 inches (305 mm to 460 mm).

Jan 1, 2004

By Qinghua Tian, Zhipeng Xu, Dong Li, Xueyi Guo, Liu Zhu

A possible process for extracting tellurium and antimony from a residue generated in alkaline sulfide leaching of telluriumbearing alkaline skimming slag was proposed. The central composite design was employed to define the optimal leaching conditions for tellurium and antimony extractions from the residue sample. Using a 23 factorial matrix, the best performance for tellurium and antimony extractions (96.36% and 99.64%) were obtained at 175 g L−1 Na2S concentration for 80 °C during 60 min. The notable degree for influencing tellurium and antimony extractions was leaching temperature, Na2S concentration, and leaching time. The analysis of variance results indicated that the regression model was significant and suitable to be used for the optimization of independent variables within the range. The model was validated under optimal operating conditions based on the experimental design results. Antimony and tellurium in the leach liquor were separated and recovered by H2O2 oxidation followed by Na2S-Na2SO3 reduction. 98.93% of antimony was precipitated selectively during H2O2 oxidation, while 95.06% of tellurium was precipitated during Na2S-Na2SO3 reduction. NaSb(OH)6 and elemental tellurium was obtained as the product.

By S. D. D. Welsby

"A pilot-scale flotation column was used to evaluate four polyglycol frothers at Teck’s Highland Valley Copper Mine. The column was fed with flotation plant feed from the grinding circuit cyclone overflow. Frother dosage was changed by controlled addition to the column feed. Pulp, froth and metallurgical performance were assessed using gas dispersion measurements, water recovery and copper, molybdenum and gangue grades and recoveries. Ranking the frothers based on pulp and froth phase performance using gas dispersion measurements and water recovery yielded contradictory rankings. All of the frothers changed the froth structure in a similar manner such that, at the same structural conditions, they all gave the same degree of separation between water and entrained solids. The only difference between the frothers was what dosage was required to achieve a certain structure. Changes in pulp structure appeared to be related to the critical coalescence concentration (CCC) for each frother. Changes in froth structure were not completely described by the CCC and involved other factors, such as the hydrophobicity of particles in the froth. All of the frothers were capable of achieving the same metallurgical result, just at different dosages. Optimal dosages for the frothers were anywhere from the CCC, where copper and molybdenum grades were maximised, to 2 to 3 or 4 to 7 times the CCC, where copper and molybdenum recoveries, respectively, were maximised.INTRODUCTION Background Due to supply issues, Teck’s Highland Valley Copper (HVC) Mine replaced Dowfroth 250C, their auxiliary frother, with Huntsman Polyfroth W31. The primary criterion for selection was that the new frother gave the same performance as Dowfroth 250C, minimising disruption to the circuit. Frothers play a dual role in flotation, altering the bubble size in the pulp zone and the stability of the froth. A stronger or weaker frother, or a blend of both, will alter the balance between pulp and froth effects and, ultimately, metallurgy. Dowfroth 250C and Polyfroth W31 may not necessarily be the best frothers for HVC from a metallurgical standpoint. There may be a different frother or frother blend that could deliver higher recovery in the bulk roughers."

Jan 1, 2014