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By C. I. Basilio

The adsorption of O-isopropyl-N-ethylthionocarbamate (IPETC) and O-isobutyl-N-ethoxycarbonylthionocarbamate (IBECTC) on chalcocite, chalcopyrite and pyrite has been studied using UV and in-situ FTIR~ATR spectroscopy. Thionocarbamates were found -to adsorb strongly on chalcocite at pH 4-10, but consider-ably less on chalcopyrite and pyrite. The FTIR spectra show that the surface species of thiono-carbamates are bonded to metal atoms on the mineral surfaces. However, at high concentrations, IBECTC also forms physically-adsorbed species. Adsorption of these thionocarbamates cannot remove or prevent the formation of sulfoxy oxidation products on pyrite, unlike the case with the xanthate-pyrite system. This finding may account for the observed flotation selectivity of these reagents against pyrite. The spectroscopic information is compared with flotation test results.

Jan 1, 1988

By Duk-Won Park

Since geologic anomalies are one of the governing factors of instability of underground openings, it is extremely important to know in advance the locations and extent of these anomalies such as faults and weak zones. At an underground coal mine in the Black Warrior Basin, core drilling was conducted to find a fault in an area where they were planning to locate longwall panels and possibly a shaft. Core logging did not provide sufficient information to delineate the exact location, strike, and dip of the fault. However, a high resolution reflection seismic study successfully solved this problem. This experience proved the seismic exploration technique could be used for premining coal exploration by reducing drilling costs and providing more accurate and detailed information about geologic anomalies.

Jan 1, 1988

By J. Pang

The mechanisms of chalcopyrite oxidation in alkaline solutions have been studied using cyclic voltammetry and AC impedance spectroscopy techniques. Analysis of the impedance spectra using equivalent circuit models has made it possible to suggest layerwise growth of surface films. From the value of equivalent circuit parameters, properties of the surface layers are inferred. These properties change substantially with the change in oxygen and/or collector concentration in solution and give rise to changes In contact angle and flotation response. In agreement with prior investigations, the present study shows that flotation recoveries alone cannot be used to determine the effect of collector on flotation of chalcopyrite. The rate of flotation is a more sensitive parameter to determine the role of collector on floatability of chalcopyrite.

Jan 1, 1989

By D. A. Stanley

The Bureau of Mines has developed an equation which describes the dewatering of clay slurries with polyethylene oxide. This dewatering equation is An _ kC + b where n, k. and b are empirical constants and C is the concentration of polymer solution used for dewatering. The minimum amount of polymer required for dewatering. A is determined by titration of the clay slurry with a polymer solution. In this report, the dewatering equation is applied to data obtained for a polyacrylamide dewatering sequence. Fundamental similarities between the dewatering properties of clays and the viscosity of polymer solutions were observed. These similarities were explained by correlating an equation describing polymer configuration in solution with the dewatering equation. This correlation showed that amount of polymer required for dewatering and polymer solution viscosity are both consequences of the frictional interaction of entangled polymer coils.

Jan 1, 1989

By William T. Griswold

Few metals or industrial minerals can boast a better growth record over the past fifteen years than the borates. This period of growth occurred before the influence of any large-scale use in plastics or high-energy fuels. These new developments not only provide expanding markets, but the programs related to their development are generating research information that will lead to many other new uses. The most dynamic growth areas for refined products of boron or borates are in the acid, the oxide and the reduced forms, such as the metal and the hydrides. Expanding requirements for these products will modify the emphasis on the use of naturally occurring sodium borates. Any borate from which boron can be economically extracted will become a potentially important ore. This is particularly true of the calcium borate, colemanite. Only one large deposit in the Western World has ever been developed where the principal economic minerals are sodium borates, This factor alone would discourage any exploration program directed solely toward the discovery of these ores; on the other hand, ample exploration opportunities for calcium borates exist in the desert regions of California and Nevada. It is therefore reasonable to restrict a program to this region, in spite of geologically favorable areas in foreign countries such as Turkey, Argentina and Chile.

Jan 1, 1959

By E. M. Frizzell

This paper addresses the use of the microcomputer programs BACKONE and BACKWEDG for an estimation of rock mass strength characteristics by back analysis of plane and wedge failures. The artificial support requirements are also determined by the programs PLANE2, BOLTPAT, and BOLTWEDG in terms of rock anchor installation angles, tensions, and installation patterns. These programs have been combined into a package called BACKPACK, which can be applied in open pit mines where some failures have already occurred.

Jan 1, 1988

By P. Worley

With Utah Power & Light Mining Division's commitment to operate the safest and most productive mines possible, a decision was made to purchase and install mine-wide monitoring systems for use in the mines. After review of several different systems the Conspec Senturion 200 system was chosen. Three separate systems were ordered to fulfill the monitoring requirements of the six mines in operation: one system for the Deer Creek Mine one for the Wilberg/Cottonwood complex, and one for the Deseret, Beehive and Little Dove complex.

Jan 1, 1989

By G. J. Schneider

The higher stress zone adjacent to an underground opening causes a velocity anomaly that can be mapped in favorable conditions with an acoustic cross-borehole logging system. Bureau personnel used a specialized system at the Colorado School of Mines test site near Idaho Springs, Colorado, to locate the Edgar Mine tunnel and its associated stress anomaly. Data from the logging system' were processed with a tomographic image reconstruction algorithm to map the opening and the location of the high velocity zone around the opening. The velocity imagery from tomographic analysis compared favorably with predictions from numerical modelling of the location of the stress anomaly.

Jan 1, 1988

By G. L. Merritt

The implementation of the Surface Mining Control and Reclamation Act of 1977 (SMCRA) has evolved into one of the most complex environmental protection programs to come out of the late 1970's. The level of detail in the statute and the regulations have resulted in a rigid and complex set of requirements for the administration, permit-ting, inspection and enforcement of the program. In addition, the constant change of the federal program caused by regulatory changes, reorganization of the Office of Sur-face Mining Reclamation and Enforcement (OSMRE), ongoing litigation involving OSMRE, and the use of the budget to establish additional mandates on OSMRE and the State Regulatory Authorities have resulted in an unstable program. The instability of the program makes it extremely difficult for the States to implement their programs and to achieve the goals of SMCRA.

Jan 1, 1988

By E. Bonates

Truck/shovel systems are a major form of materials handling in open-pit mines in spite of the high associated capital and operating costs. Mine management is usually faced with a decision to purchase new equipment in order to support the steadily increasing on production. These decisions involve a high degree of uncertainty with respect to future demands and technical developments. This paper describes a computer simulation model for evaluating the optimum equipment fleet in an open-pit mining operation. The system is based on a stochastic simulation program which accounts for the various mining and economic parameters. It calculates the type of equipment and the optimal number of trucks needed to meet the production targets. Two types of selection criteria: maximum rate of production or minimum cost can be applied.

Jan 1, 1989

By R. R. Klimpel

The use of froth flotation as a means of separating and upgrading sulfide mineral concentrates is standard industrial practice throughout the world. Froth flotation is also widely recognized to be a very complex system having highly interactive and often self-compensating factors at work. Several summary articles have been recently published which discuss at length some of the important practical aspects of optimizing the use of existing commercial flotation reagents. Klimpel (1987). Klimpel and Hansen (1987a), Klimpel and Hansen (1987b), and Klimpel (1988). It is apparent from monitoring the industrial practice of sulfide mineral flotation over the last decade that considerable progress has been made in optimizing the operating aspects of flotation. For example, the availability of improved instrumentation and related computer devices, modified mechanical flotation cell designs, better reagent dosage control leading to less reagent usage per ton of ore, blending of feed ores, more attention to coarse and fine particle flotations, etc., are all examples of this progress.

Jan 1, 1988

By F. Kennedy

Consolidation Coal Company (Consol) supports an active R&D effort to improve the safe, productive mining of coal and to utilize coal in an environmentally acceptable manner. Attention will be focused on degasification of coal seams, continuous coal transport systems, earth sciences activities, and coal combustion. Brief mention will be made regarding the SO2 emissions control programs. The research program constitutes about 1.0% of Consol coal sales which positions Consol as the preeminent coal company supporting broad-based research addressing the full spectrum of the various problems associated with utilizing the nation's abundant reserves of economical, readily available fuel.

Jan 1, 1989

By V. F. Hollister

The Ivanhoe district, Elko Co., Nevada, is located in the northern part of the Carlin trend of epithermal gold-deposits, but it differs from most mines in the belt in that Ivanhoe epithermal gold ores are found in 14 m.y. old Tertiary volcanic rocks as well as in the better known Paleozoic sediments. Within the Ivanhoe district U.S. Steel (USX Corp.) discovered and partly developed an epithermal gold deposit largely hosted by Tertiary rocks that, with a 167-hole program, was found to contain an open ended probable reserve of 4.0 million tons of heap leachable open pit oxide ore averaging .042 opt Au. An additional 4.0 m.t. of open pit sulfide ore averaging .048 opt Au were also developed. The U.S. Steel orebody was a blind discovery in that it just barely outcropped, and it was found by drilling through a premineral but barren cover of altered Tertiary volcanic rocks.

Jan 1, 1988

By H. E. Bonner

The recovery of fine coal has historically had limited success due to the intimate clay association on the surfaces of the coal particles. This clay presence has detrimentally affected conventional beneficiation techniques resulting in a recovered product containing unacceptably high concentrations of ash and moisture. An ultrasonically activated tray that operates in a continuous fashion has been developed that separates the clay film from each particle's surfaces. This separation is of sufficient duration to allow conventional beneficiation techniques to be utilized more efficiently.

Jan 1, 1989

By G. J. Grott

Direct Production Costs for Solar Sa 1t approximate the trucking cost for 160 Km. Operations near markets appear unusually attractive at first look. However, many desert operations have been plagued by dust storms yielding salt too high in insolubles for most uses. This paper relates the history of a successful operation in a dust storm area. Saturated brine from the solution mining of LPG storage caverns is evaporated in solar ponds yielding 99.95% sodium chloride (dry basis). Purchased energy is one-eighth that of vacuum pan operations. Production scale tests have proved it works at another desert location using a more complex brine. A new approach for refining soluble salts at ambient temperatures is demonstrated by bench scale and pilot work. Again, savings in purchased energy exceed 80%, even when temperatures are raised to reduce refining time.

Jan 1, 1988

By M. C. Roberts

The success of any industrial mineral project requires an accurate forecast of the demand for the material. This paper develops a general method of evaluating these needs and applies it to the case of graphite. The basic method is to explain graphite consumption in each of its major uses by the output and manufacturing technology of the using industry. Once these underlying factors are determined, they can be projected to establish future requirements. This demand forecast is critical to the evaluation of a new source of supply, such as the graphite resources of upper Michigan.

Jan 1, 1989

A brief description of the mining method and ventilation system of the San Manuel Mine?s first presented; this is necessary to an understanding of the heat problem and cooling system. The problem of heat at San Manuel is discussed. Charts and graphs showing the relationships between ambient surface air and underground temperature conditions are given. A history of attempts to cool air at San Manuel is presented, starting with the first refrigeration type air coolers which were used in development headings, and followed by the underground water chillers that were used in conjunction with cooling coils. Goals for design of a centralized cooling system with ultimate heat rejection through surface cooling towers are presented. The problems found with using the centralized system in main cooling coils are discussed. Plans for modification of the centralized system as utilized is the summer of 1987 are given, along with results obtained and problems with the system. Plans for subsequent modifications are presented.

Jan 1, 1988

By A. M. Gaudin

The recent study by R. M. Hays(l) prompted the study summarized in this paper. In his Interesting paper, Mr. Hays shows fine results to be attainable by a relatively complex flowsheet on a semi-taconite, a manifestly difficult ore to treat. We obtained a semi -taconite from Minnesota, and treated this sample by wet magnetic separation alone. The device in which the separation was accomplished is the standard pilot-plant, laboratory separator in use at Magnetic Engineering Associates' laboratory (MEA) in Cambridge, Massachusetts. It consists of a cylindrical space which can be magnetized by turning on the magnet of the separator. In this cylindrical space, there is a canister which provides the special configuration of the magnetic field and magnetic field gradients that MEA considers to be required. The ore pulp is made to flow through the canister while the current is on. A portion of the pulp is retained in the canister, and the rest is evolved as a non-magnetic fraction. The laboratory device is cyclic, but it accurately predicts the results obtainable by an Industrial unit of either cyclic or continuous type (moving matrix). The ore tested was 99.5°%o -325 mesh, and approximately 75% -500 mesh. The concentrate from this ore was, therefore, eminently suitable for pelletizing. In passing the ore through the magnet, we had the choice of repeatedly passing the concentrate from the first step through the operation, or of repeatedly passing the non-magnetics. In our experiments, the first method was clearly superior from the stand¬point of the cleanliness of concentrate. Of the many tests which we have made, we think that we have to retain two which

Jan 1, 1971

By J. M. Mutmansky

The SIMAN (SIMulation ANalysis) computer language is a general-purpose, discrete-continuous simulation language for modeling a variety of multi-component systems. The language has been described by its author in a textbook (Pegden, 1985) and in a paper (Pegden, 1986) and is available in a mainframe version, a minicomputer version and a microcomputer version. The language was designed for and has been extensively used for modeling manufacturing systems but possesses many features that are advantageous in the modeling of mining materials handling systems. Consequently, the authors have applied the language to the simulation of an open pit shovel/truck operation to test its usefulness for simulating mine materials handling systems. This paper presents a short background on simulation languages, the capabilities and modeling framework of the SIMAN language, a description of the application of SIMAN to a shovel-track operation and some results and conclusions on the use of the language for mining materials handling systems.

Jan 1, 1988

By Edward R. Borcherdt

When one considers the advancements made during the 25 years prior to the late fifties, and compares these advances with the progress made in the past decade, the comparison is indeed startling. It was not until 1935 that trucks began to replace rail as a major hauling facility, Initially, the haulage capacity of end dump trucks was limited to 18 or 20 tons. "Straight stick" transmissions were utilized and the available horsepower was minimal. In the early forties single planetary axle 25 ton trucks were introduced, and shortly thereafter those were followed by 35 ton tandem axle units.

Jan 1, 1967