Search Documents

By Amir Rehmat

The Institute of Gas Technology has developed a fluidized-bed process for recovering direct reduced iron from blast furnace flue dust a material currently considered to be a waste from the iron and steel industry. In the process, a portion of the carbon in the flue dust is combusted to supply energy for the endothermic reaction between carbon and steam. The reaction produces reducing gases comprised of carbon monoxide and hydrogen both of which react with iron oxides to produce reduced iron. Up to 95 percent of the iron oxides contained in the waste stream can be reduced to elemental iron. The vitiated reducing gases emanating from the process can be used as fuel in the plant. The yield of iron depends upon the quantity of iron oxide present in the flue dust and generally ranges from 20 to 30 percent of the waste stream. The investment cost estimated for a single processing train dedicated to one steel plant can be recovered in less than one year.

Jan 1, 1996

By Dave Bulled

"This paper describes the design of a molybdenite flotation circuit using FLEET technology applied to kinetics data produced from laboratory flotation testing and distributed across the blocks of a mine plan using a geostatistical approach. The geostatistics assigned the statistical error that arises from having a limited amount of sample testing data to the kinetics estimates of each block of ore in the mine plan. The final design then included a quantification of risk based on the accuracy of the block flotation kinetics and model fitting. The design made reference to the extensive technical reports describing earlier metallurgical test work including some pilot plant work over thirty years ago.The testing involved conducting MinnovEX Flotation Tests (MFT) to determine the rougher flotation kinetics at the specified reagent conditions and rougher-cleaner tests to determine the change in kinetics resulting from regrind. These flotation kinetics were used within FLEET simulations to create a full-scale flowsheet and plant design including recommended equipment sizes and the forecast of operating results. Measurement of detailed flotation kinetics for a wide range of samples allowed the effect of size of grind and efficiency of classification (i.e. width of size distribution) to be predicted for the whole ore body.INTRODUCTIONAdanac Moly Corp. proposed to develop a 20,000 ton per day mill to produce high quality molybdenite concentrate from its Ruby Creek resource in north-western British Columbia. It is a relatively clean low grade porphyry-monzonite occurrence containing minimal quantities of other sulphides such as chalcopyrite, pyrite, sphalerite and galena. Molybdenite occurs mainly as coarse flakes with lesser amounts of finer sized values. An optimum plant design was required to can achieve the predicted operating results, at a known level of risk, while treating the variability inherent in the ore body."

Jan 1, 2007

By John H. Perry

Strata III is a full-spectrum roof control system which provides the mine operator the ability to upgrade his roof control in place. The procedure is easily adaptable with current roof bolting techniques. To use the system, the operator starts by installing a special hollow core mechanically anchored roof belt during the roof bolting cycle. This bolt can be upgraded to a fully grouted tensioned rebar bolt by injecting StrataGee G-300, a special polyurethane grout, around the bolt through an injection port in the roof plate. This same bolt can then be used to inject RokLok binders for roof consolidation by pumping the binders through the core of the bolt. This concept in roof control was developed to provide the mine operator a flexible way to maintain roof control in areas which deteriorate over time, or must be kept open for long periods of time. Possible locations of use would be: longwall set-up rooms, recovery rooms, headgates, intersections, and belt entries.

Jan 1, 1987

To provide a flexible, low-maintenance, low-cost continuous mine air monitoring system as an alternative to conventional fixed-point, electronic monitoring systems. Background Continuous monitoring of mine air is highly desirable (and often required) not only to improve miner safety, but also to increase mine productivity. Continuous air monitoring systems can provide earl" warning of developing fires, excessive methane accumulation, reduced oxygen levels, and other developing problems in remote, inaccessible or sealed areas, and in active workings. Fixed-point, electronic systems require one Sensor for every gas to be measured at every defined monitoring location. As the number of monitoring locations increases, so does the cost, along with increases in the time required for routine maintenance and calibration of the sensor System cost also increases when monitoring locations are identified for mine areas requiring permissible electrical equipment.

Jan 1, 1988

By Kefton H. Teague

This paper deals with the practical application of the Dutch State Mines cyclone separator for fine-coal cleaning. The more important operating variables are discussed, and results of a number of continuous-scale tests on various fine coals with a 6-in. cyclone separator are given. Descriptions of the Cyanamid Pilot Plant and the 50 tph Cyclone Separator Plant at the Emma Washery in Holland are included.

Jan 1, 1950

THIS excellent volumetric method commends itself as a means of estimating the fineness of silver firstly, owing to the large number of possible impurities which do not affect its accuracy (these impurities include Cu-up to 70 % Au, Ph, Zn, Bi, Cd, Fe, Mn, Sb, and As); secondly, the method combines accuracy with speed. The above impurities are the only ones likely to be present in the B. H. A. S. Pty. Ltd. refined silver, and, with the exception of Cu and Au, the others, if present at all, would be well under 0.1 parts per 1000.Briefly stated, the method consists in the solution of the refined silver in HN03 , addition of ferric alum (indicator), and titration with an alkaline (either ammonium or potassium) thiocyanate solution until the brown ferric thiocyanate is formed, and gives a definite tint to the solution. The method is used at the Port Pirie smelters, and the outstanding feature in the method as there applied is the type of burette employed. This burette enables the operator to read 0.01 of a cc. with ease, whereas, with the ordinary burette fitted with a float, 0.05 of a cc., when a number of readings have to be taken, becomes very straining to the eyes. Moreover, waiting for the float to rise, and dislodging air bubbles from it, hinders rapid working.A description of the burette and fittings is appended with fig. 2. DETAILS OF THE METHODSolutions required are:a) Stock Solutions:(1) Ammonium thiocyanate, 40 grm. per litre of water; 30 litres are prepared and placed in a carboy with glass syphon attached.(2) Ferric alum, 250 grnl. per litre; two litres are prepared.

Jan 1, 1922

By Max W. Ball

Our ever-increasing use of minerals has been the outstanding fact in our American economic development. The rise in our standard of living in the past century is without equal in human history. Nowhere in time or place has the man who works lived so well, or the man who cannot work been so well cared for. We live in a new world, even the poorest of us, that our forebears of 1849 could not have dreamed. That new world has come mainly from our use of minerals. Our per capita use of nonmineral products has grown too, but by only a modest amount. Food consumption per person has grown about 15 per cent in the past fifty years; lumber use per person ,has fallen 56 per cent and that of wood for fuel 65 per cent. Of all the products of field and forest, our use, per capita, may have increased by one fifth during the present century. In contrast, our per capita use of minerals has multiplied several times. Each of us uses 2% times as much steel and 16% times as much petroleum as our fathers used in 1900. In less than half a century our per capita consumption of all minerals has probably risen by 200 to 250 'per cent. Man once built with wood; today he builds mainly with brick and stone and steel. Once he traveled by the power of hay and oats; today he travels by the power of coal and oil. Rubber made from minerals is already better for some uses than rubber tapped from trees; before long it will be better for most and perhaps all uses. Even our ladies' graceful legs are clad in mineral fiber, where once animal or vegetable fiber would have covered them. Our high standard of living is a product of the machine.. The machine is made of minerals. The machine is driven by minerals. The machine age is a mineral age.

Jan 1, 1949

By C. Wade, A. Swart, M. Dworzanowski

AngloGold Ashanti operate a pyrite flotation plant at their East Gold Plant, Acid Plant and Flotation Plant (EGAF) metallurgical complex within their Vaal River operations in the North West province in South Africa. The flotation plant feed is reclaimed pyrite rich tailings and the concentrate produced is used as the source of sulphur for the EGAF acid plant. The sulphuric acid produced is in turn used for the recovery of uranium at the Vaal River South uranium plant. The original flotation plant built in 1960 was based on the use of many small volume flotation cells and was becoming very expensive to operate and its age severely limited further operation. A decision was taken in 2005 to replace this plant with a new one based on fewer, larger volume flotation cells. This paper describes the benefits of using larger volume flotation cells in this new flotation plant when compared to the smaller volume flotation cells in the old plant. The benefits of the new plant include a smaller plant footprint, fewer flotation cells, fewer pumps, no distribution boxes, simpler piping, a greater flotation volume and a reduction in installed power. The saving in capital cost could not be quantified because of the age of the old plant. The savings in operating cost will arise from fewer operators, less maintenance and reduced power consumption. The new plant has not been in operation long enough to quantify the benefits in operating cost and metallurgical performance. However, recovery improvements can be expected given the greater flotation volume (increased residence time) and the installation of larger, more efficient flotation cells.

Jan 1, 2007

By A. David MacPhail

"Highland Valley Copper is a large volume producer of copper and molybdenum concentrates. Production is by conventional truck and shovel operation combined with an extensive ore handling in-pit crushing and conveying system.Grade of the two orebodies is low at 0.4% copper and 0.007% molybdenum and this demands a production rate in excess of 260 000 tpd at a stripping ratio of 1: 1. Mining cost has to be kept at minimum levels to keep the mine profitable and thus, it is necessary to keep in the forefront: of technology. As well as the in-pit crushing system, the mine has pioneered the use of shovel weighing coupled with a state-of-the-art dispatch system.Maintenance of the equipment is carried out at the on-site mine maintenance shop with assistance from local shops for engine and wheel motor rebuilds and other large jobs such as those requiring stress relieving. Shovel and truck rebuilds are undertaken by mine crews. Both long- and short-term planning is designed and scheduled in the mine engineering section. Outside consultants are used to assist in slope design, reclamation and blasting technology."

Jan 1, 1992

By David B. George

Kennecott Utah Copper adopted Outokumpu Flash Smelting and Kennecott-Outokumpu Flash Converting in 1995, a process based on granulating high grade copper matte. While nickel mattes and very small quantities of copper matte had been commercially granulated for years, no large scale copper matte granulation system had been built. This paper summarizes the history and benefits of copper matte granulation, the Kennecott design basis, the successful operation for over 10 years and potential problems inherent in some matte granulation approaches.

Jan 1, 2006

THE hall of the Western Iron and Nail Associations having kindly been placed at the service of the Institute, the opening session was held at 3 o'clock, Tuesday afternoon, May 13th, with an attendance of about one hundred and twenty-five members. Mr. William Metcalf, of Pittsburgh, read an address of welcome on behalf of the Local Committee of Arrangements, to which President E. B. Coxe responded. The following papers were then read and discussed : Regenerative Stoves; a Sketch of their History and Notes on their Use, by John M. Hartman, of Philadelphia. Some Curious Phenomena Observed on Making a Test of a Piece of Bessemer Steel, by William Kent, of Pittsburgh. On the Use of Determining Slag Densities in Smelting, by Thomas Macfarlane, of Wyandotte, Michigan. After the reading of these papers each member was presented by the Local Committee with a schedule of excursions, a specially prepared map of Pittsburgh and surroundings, and a directory of industrial works, all tastefully bound, and also with a metal badge bearing the seal of the Institute, to be worn on the excursions. The second session was held on Tuesday evening. The following persons, duly proposed for members and associates of the Institute, were, on the recommendation of the Council, unan¬imously elected. (In this list are included those elected at the final session on Friday morning.) George Bartol, - Cleveland, Ohio. Luther S. Bent, - Steelton, Dauphin Co., Pa. Octave Chanute, - New York City. Albert H. Childs, - Allegheny, Pa. Theodore Cooper, - New York City. Andrew Cosgriff, - Brewster, Putnam Co., N. Y. William B. Crocker, - New York City. Henry M. Curry, - Pittsburgh, Pa. Charles Davis, - Allegheny, Pa. Henry F. De Bardeleben, - Birmingham, Ala. Herbert Du Puy, - Pittsburgh, Pa. Charles L. Fitzhugh, - Pittsburgh, Pa. W. S. Franklin, - Ashland, Md. F. G. Fricke, - Pittsburgh, Pa. Paul A. Fusz, - St. Louis, Mo. Ignatius Hahn, . Pittsburgh, Pa. Henry Hargreaves, - South Pittsburgh, Tenn.

Jan 1, 1880

By Thomas Barkley

Mining tradition holds that a parallel round underground can not be any deeper than it’s smallest face dimension. ln other words, a mine using a 12’ (3.7 m) high by 24’ (7.3 m) wide room and pillar mine, the deepest pull that can be achieved is plus or minus 12’ (3.7 m). After experience with decking of rounds in a 12’ (3.7 m) diameter shaft to achieve more than 12’ (3.7 m) advance per round, the concept of deepening the pull on horizontal parallel rounds seemed to be a feasible concept. Tests were conducted in a conventional room and pillar metal mine with a round size of 12’ (3.7 m) high by 24’(7.3 m) wide. Standard rounds were drilled with a 16’ (4.9 m) steel as parallel rounds to an average depth of 14.5’ (4.4 m). The average depth of pull on these rounds was about 13’ (4.0 m). Using the available drilling equipment, 20’ (6.1 m) drill steel was used to drill holes to an average depth of 18’ (5.5 m). Five rounds were drilled and shot with a resulting aven$e pull of 16.2’ (4.9 m) or 90 % of drilled depth. Rounds were designed with decked bum cuts to maximize depth of pull in the cut area An innovative method of de&mining drilling accuraq was used to estimate it’s effect on depth of pull in the rounds. This method used a standard automatic 35-mm camera and scaling to determine the average drill deviation for many of the holes in the rounds.

Jan 1, 2000

By M Fahey

Large volumes of tailings are produced annually by the goldmining industry of Western Australia. This material ishydraulically discharged into large storage facilities usingsub-aerial deposition methods. Much of the gold comes fromhighly weathered rock, resulting in tailings with significant claycontents. Consolidation of these materials can be very slow,particularly if occurring under the effects of self-weight alone.To optimise the consolidation behaviour of the tailings, disposalstrategies can take advantage of the effects of evaporation byallowing each tailings layer to dry before the next layer isdeposited. In the last 20 years, much of the gold processing inWestern Australia has utilised saline groundwater. As the salinetailings dry, the surface will develop a thin salt crust. Laboratorytests have shown that these crusts can drastically reduce thesurface evaporation, adversely affecting the behaviour of thestorage. This problem has been the focus of an extensive researchprogramme, with the objective of obtaining a fullerunderstanding of the mechanisms controlling the coupledconsolidation and evaporation behaviour of saline gold tailings.Part of this study involved site investigations of a wide range ofstorages to ascertain their current states. Methods of gainingaccess to the tailings following deposition were developed.In situ testing and high quality sampling were conducted on each storage and samples returned to the laboratory for analysis. These investigations have enabled full characterisation of the storages to be accomplished. Examples of data are shown herein and the implications of the results are discussed.

Jan 1, 2001

By F. W. Petersen

The Conference Minerals & Materials '96 was held in Somerset West, South Africa, from 31st July to 2nd August, 1996. It was organized by the Universities of Stellenbosch and Cape Town, the Cape Technikon, and the Western Cape Branch of The South African institute of Mining and Metallurgy (SAIMM). The three-day Conference was attended by 180 delegates, representing countries such as Australia, South Africa, United Kingdom, Finland, Sweden, Germany, Poland, Zambia, and Zimbabwe. The programme and associated exhibition were well organized, and each of the delegates received two volumes of proceedings containing the 77 papers presented at the Conference.

Jan 1, 1996

By R. V. Ramani

This report is volume 3 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation,' and ventilation. This volume of the final report describes the Methane Generator subsystem of the Master Design Simulator. This subsystem is used to determine methane emission rates into the mine environment. These flow rates are then used by the simulator in planning primary and secondary ventilation systems, planning a methane drainage system, and analyzing complex ventilation networks. Both steady state and unsteady state gas flows are included, and have been modeled as second order nonlinear partial differential equations. Finite difference equations are used to obtain numerical solutions to the models using a central differencing scheme. An application of the model is presented. The appendices include derivation of the gas flow equations used in the model as well as a users manual for the computer program.

Jan 1, 1974

By G. E. Blight

Wind erosion can be a major cause of the loss and dispersion of tailings material from a tailings dam into its surrounding environment. Such dust dispersion can be a serious nuisance, as well as a health hazard to inhabitants in nearby settlements, and can also damage the health of animals, degrade crops, making them less marketable, and cause soil and water pollution. The problem of wind erosion can affect tailings dams in all types of climate, but becomes worse as climatic aridity increases. Because clouds of dust are often observed billowing across the top surfaces of tailings dams in dry windy weather, there is a common misconception that the dust arises from wind erosion of the top surface. As a result, much effort and money is vainly spent on treating the tops of tailings dams to prevent dust generation, whereas the slopes of the dams are the true major dust source. This paper briefly reviews what is known of erosion of tailings dams and then proceeds to describe the mechanics of wind erosion in general, and how it affects tailings dams in particular. Finally, recommendations are made for mitigating wind erosion of tailings dams and the resulting blowing dust.

Jan 1, 2007

By William E. Young

There are many large rhodonite-bearing veins containing manganese in the Eureka-Animas Forks area of the San Juan Mountains in Colorado. The Sunnyside vein is the largest known vein in the area. As observed on the surface, the vein is mineralized over 8,000 feet and attains a maximum width of 200 feet. The average width of the vein and its branches and ramifications is 58 feet in the area that was mapped in detail. The weighted-average analysis of surface and underground samples from the northeastern extension of the Sunnyside vein is 8 percent manganese. Most other known veins in the area have a similar manganese content. The Hidden Treasure vein lies southeast of the Sunnyside-No Name-Mastadon vein. The weighted average of the analyses of surface and underground samples from this vein is 13 percent manganese. Exposures of the Scotia-Silver Chord vein are visible over a strike length of 4,000 feet on Treasure Mountain. Diamond-drill holes show that the vein contains 10 percent or more manganese to a depth of 400 feet. The vein has an average width of 28 feet. The Independence vein is exposed on the surface for a distance of 600 feet and has an average width of 6 feet. Three cut samples taken across the vein had an average content of 20.7 percent manganese. Sampling of the outcrops of eight veins in the Placer Gulch area also indicates manganese. Numerous other veins cropping out in the surrounding area are similar to the outcrop of the Sunnyside vein system mineralogically and are worth investigating.

Jan 1, 1966

By Brad Marchant, Rick Lawrence, David Kratochvil

"BioteQ has successfully developed commercial operations for ARD treatment and selective metal recovery using the patented BioSulphide and Thiopaq® biological reduction technologies. The BioSulphide-Thiopaq process was developed to provide biogenic sulphide for the selective recovery of high purity metal concentrates from acidic wastewater, which are sold to recover capital costs and off-set water treatment costs. The BioSulphide-Thiopaq process can be used on a stand-alone basis or in conjunction with a lime circuit. Process advantages include: selective recovery of metals, very low metal concentrations in effluent, reduced waste sludge liability, reduced lime treatment costs and, in some cases, profitable sale of metal concentrates. Two case studies are presented to illustrate operations focused on metal recovery at the Caribou Mine, New Brunswick, Canada, and at Phelps Dodge, Arizona. A third case study is presented to highlight environmental control as well as metal recovery for treatment of ARD at the Raglan Mine in Northern Quebec. Process flowsheets, capital and operating costs are presented for the three case studies.INTRODUCTIONProtection of water quality has become one of the most important environmental challenges facing the mining industry. Although new mining projects can be designed to minimize impacts to the environment, many existing and abandoned mining operations have water quality problems. The principal cause of water contamination is acid rock drainage (ARD), which is generated when residual sulphide minerals in waste rock, tailings and other mine components and products are exposed to air and water. These reactions can produce acidity and elevated concentrations of metals in drainage and seepage that can adversely affect surface and groundwater resources. To meet regulatory criteria for water quality in the receiving environment, many mine operators must consider treatment of mine water and other effluents prior to discharge."

Jan 1, 2003

By Andrew Matyas

"During the summer of 1968, the author was employed in the Research Department of Dominion Foundries and Steel, Limited, Hamilton, Ontario. Over the years, Dofasco has been conducting a program for developing more efficient control of its basic oxygen steelmaking process. The author was thus able to obtain a variety of viewpoints from both research engineers and furnace operators. He also had access to extensive literature dealing with BOF control schemes underway at other major steel producers. This paper describes the present state of developments in BOF steelmaking control.The necessity for efficient BOF control is pointed out. To appreciate the variables to be controlled, a brief outline of process fundamentals is included. Technical aspects of present methods of practical control are examined in detail; the relative merits of dynamic over static control models are emphasized. Finally, it is shown how an effective dymic-optimizing control scheme serves as the basis for closed-loop computer control of the process."

Jan 1, 1970

By J. L. Jambor, E. J. Reardon, E. C. Appleyard, J. A. Cherry

Abstract- Since the 1957 initiation of deposition of mill tailings at the Heath Steele mine, New Brunswick, periodic detailed studies of the tailings geochemistry and mineralogy have been con­ ducted, thereby providing a unique opportunity to examine the geochernical evolution of a sulfide- rich mine-tailings impoundment. When deposited, the tailings contained about 85 wt% sulfide minerals, 1 wt% to 3 wt% carbonate minerals, and 12 wt% to 14 wt% aluminosilicate minerals. Mineralogical examination of samples of the tailings from deep in the impoundment indicates that little oxidation occurred prior to tailings deposition. The mill process-water deposited with the tailings was neutral to slightly basic and contained low concentrations of Cu, Pb, Zn and As. Sampling of the tailings five years after deposition indicated that sulfide-oxidation reactions, occurring near the tailings surface, had decreased the tailings-water pH and increased the concentrations of Fe, SOi-, Cu, Zn and Pb (up to 10 000 mg/L, 25 000 mg/L, 2.5 mg/L, 200 mg/L, and 4.5 mg/L, respectively) . In 1975, ten years after decommissioning, the tailings could be divided into three zones: an upper oxidation zone in which sulfide oxidation is actively occurring, a hardpan layer, 15 cm to 20 cm thick, composed of tailings cemented by secondary Fe minerals, and an underlying reduction zone in which the tailings are relatively tinoxidized (Boorman and Watson, 1976). Chemical analyses indicated the presence of low-pH waters containing very high concentrations of SO42- , Fe, and other metals (up to 63 600 mg/L SO42-, 28 600 mg/L Fe, 10 mg/L Pb, 600 mg/L Cu and 4000 mg/L Zn), suggesting that there was a period of intense sulfide oxidation between five and ten years after tailings deposition. More recent sampling, conducted some 20 years after the end of tailings deposition, indicates that relatively little change has occurred in the last ten years, thereby suggesting that the hardpan layer has provided an impediment to the downward movement of dissolved constituents . Analyses of the tailings solids show increased accumulations of many metals at or near the depth of the hardpan layer. Evaluations of the long-term evolution of the tailings can be enhanced by comparison of descriptions of the tailings with descriptions of the gossan that overlay the massive­ sulfide orebody prior to mining. At Heath Steele, this comparison suggests that many of the mechanisms controlling the distribution of metals in the tailings will probably persist over geologic time.

Jan 1, 1992