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By Y. Astafyev

Autotransport is one of the most conventional kinds of transport in iron ore open-pits. It. is successfully used both independently and in combination with other kinds of transport. In the Krtvoy Rog Basin open-pits annual truck transportation accounts for more than 235 million tons of ore and waste rock. In the process of operation trucks make up various transport streams depending on - the development of autoroads in the open-pits; - the capacity and the number of loading equipment ; - the load carrying capacity and the speed characteristics of trucks

Jan 1, 1979

By Paul W. Patton, Christopher Scott Smith

The use of ceramic-in-rubber pulley lagging on bulk material belt conveyors is increasing. Many of the applications have been on pulleys originally installed with rubber lagging. There is a consensus that the fiction characteristics of the ceramic material are significantly better but the factors quoted vary, possibly because the more complex traction mechanism of the dimpled ceramic elements on the belt is not well understood. In this paper we will report and evaluate field data from a number of field installations to provide a study of actual friction characteristics in successful applications for those who desire reliable data for using ceramic-in-rubber lagging in new conveyor designs.

Jan 1, 2004

By S. D. Thompson, G. T. Lineberry, A. J. Basu

Conveyor belt haulage has become the preferred mainline transport method in underground coal mining, especially for multi-unit mines. Proper designs for belts (width and speed) and surge bins (placement, capacity, and discharge rate) are necessary to achieve efficient mine haul- age. Two computer simulation models, CMBCS and BELTSIM, available for designing these parameters were compared. These comparisons included modeling, input data requirements, statistical flexibility, accuracy of simulated loading, and execution time.

Jan 1, 1991

By Herbert E. Allen, Andrew F. Kingery, Spyros P. Pavlou

This paper examines and compares the role that chemical speciation plays in the environmental aquatic toxicity of two metals - copper and arsenic. Copper is shown to have well-understood chemical speciation equilibria, but poorly known species toxicities. Arsenic presents the opposite case, with unpredictable speciation in aquatic systems, but is relatively easy to evaluate toxicologically. Speciation is not currently incorporated into Water Quality Standards. This can have a major impact on the cost of environmental containment and cleanup.

Jan 1, 1992

By R. L. Grayson, M. P. Miano, S. Yuan

Matching the productivity gains of continuous mining machines with the increasing performance levels achieved by longwall units has required creative thinking to assure that development is completed in time for uninterrupted longwall production. By using management information systems to coordinate support operations, the most productive planning decisions can be made. This paper focuses on the role of computer technology tools in achieving improved productivity from both longwall and continuous miner sections. The primary emphasis is on the planning process and the methodology developed to guarantee the best allocation of management and manpower resources.

Jan 1, 1995

By Arol, A. I., I. Iwasaki

The presence of calcium ion in iron ore pulps causes heterocoagulation of rnontmorillonite on hematite leading to indiscriminate dispersion. Two methods were investigated to control the adverse effect of montmorillonite: a chemical method using such complexing agents as EDTA and sodium tripoly- phosphate, and a mechanical method involving ultra- sonic treatment. Their roles in controlling the adverse effect were investigated by zeta potential measurements, starch adsorption tests, and flocculation and selective flocculation tests.

Jan 1, 1988

By Boshou Bian

Air quantity is the primary parameter governing the working condition of a mine fan. In order to improve the fan performance and efficiency, reduce its energy consumption, and guarantee mine safety, it is very important to obtain an accurate value. However, generally speaking, the fan ducting or drift on surface is very short in distance and contains sharp bends. The air quantity of the mine is so concentrated in this way that the air velocity becomes very high, and the airflow, either in the fan drift before the fan impeller or at the downstream diffuser, is very turbulent. Therefore, no anemometer is satisfactory because there is too much difference between the measured value and the actual value of air quantity at the mine fan.

Jan 1, 1989

By A. Iordanidis

Fly ash samples were collected from two large lignite-fired power plants of Ptolemais region, northern Greece. Environmental Scanning Electron Microscopy (ESEM) was applied for the characterisation of the samples. ESEM coupled with Energy Dispersive System (EDS) provided fast and accurate results on the morphology, mineralogy and chemical composition of the fly ash particles. Fly ash consists mainly of aluminosilicate glass, silicates, oxides-hydroxides, sulphates, carbonates and char. Various types of chars, spheres (e.g. ferrospheres, cenosphers, plerospheres etc.), spheroids, agglomerates and mineral crystalls were observed. The size distribution of the fly ash particles was correlated with their mineralogical and chemical composition. Possible environmental impacts and potential utilization is also discussed in this study.

Jan 1, 2005

By E. Cetin

The authors describe the general problem of cut-off grade optimisation for multi-mineral deposits and outline the use of genetic algorithms for optimal cut-off grade schedules for deposits with up to three constituent minerals. Case studies are given and a comparison is made with Lane's multi- mineral cut-off grade algorithm.

Jan 1, 2002

By T. F. Torries

The primary criteria used by the mining industry to judge the merit of a project is internal rate of return (IRR) rather than net present value (NPV), although NPV is favored by academicians. This paper discusses the problems of IRR and NPV and compares the multigoal nature of the decision¬makers and their need for informa¬tion having the characteristics of NPV and IRR. The conclusions reached are that both NPV and IRR can be used for investment ranking, that NPV suffers the same multiple root problem as does IRR, and the use of conventional incremental IRR to reach NPV¬consistent project ranking is mis¬leading.

Jan 1, 1999

By Arthur F. Moss

Smallbore tunnels in urban environments often present more technical and managerial problems than major large diameter schemes carried out for transportion, water supply and hydro-electric facilities. The 1.8 km Bath scheme was designed for construction in tunnel using the pipe jacking system. Unforeseen ground conditions meant other techniques were needed during construction. The paper describes the problems encountered and how they were overcome.

Jan 1, 1981

By S. S. Mauney

Natural and synthetic colors are used in almost every facet of daily life as a means of communication and expression. Natural ochres, umbers, hematites and magnetites were once used in their crude or semiprocessed state for their pigment value in construction products and low-end coatings applications. In recent years, though, they have yielded to synthetically produced iron oxides for more sophisticated products. Today, through innovative mining processing and marketing techniques, natural iron oxide pigments are once again gaining strong inroads into products and markets requiring precise chemical and physical characteristics. With the focus on environmental consciousness and resource conservation, value added natural iron oxides provide an economical and responsible alternative to color needs.

Jan 1, 1995

By S. E. Clay, P. R. Taylor

A physical model for the diffusion and flow of gases through porous solids, which accounts for the random nature of individual gas molecules moving through a solid of definite structure, has been formulated. The model was solved using' the Monte-Carlo technique. It was then used to evaluate specific constants related to the dusty gas model and to describe the gas-porous solid diffusion phenomena. Experimental results were used to validate the stochastic model.

Jan 1, 1988

By K. Hebbar, R. G. Reddy

The viscosities of various FeO-SiO2 slags were calculated using a previously developed structural-based model. Using hole theory and the atomic pair model, an expression was derived to relate the viscosity to temperature and the fraction of the bridging oxygen in silicate melts. The deduced equation was successfully applied to predict the viscosities of FeO-SiO2 slags in the composition range of 0.1 < XSi02 < 0.423 for several temperatures. The calculated data agree well with the experimental viscosity data.

Jan 1, 2002

By Luis Dr. Sobral

In this study, the removal of zinc, cadmium and copper from an aqueous sulphate solution, derived from the biomass desorption process, was examined by using a reaction system with a three-dimensional high surface area electrode (RNiF). This reaction system was found to be extremely effective in reducing metal concentrations to the ppb range. The effect of cathode potential and flow rate were studied for three different nickel foam porosities. In addition, current- potential curves were recorded, at a rotating vitreous carbon electrode, to deter- mine the possibility of depositing the aforementioned metals separately.

Jan 1, 1998

By Roshan B. Bhappu

The extraction of gemstones, except for diamonds, continues to be a more or less handpicking type operation all over the world. However, considering the physical properties of gemstones such as density (sp.gr.), color, size, shape, luster, brilliance, reflection of light and the like in contrast to the relatively ‘dull’ physical characterization of the associated gangue minerals, it should be feasible to recover several gemstones using modern mineral processing techniques. This paper illustrates the unique physical characterization of several gemstones and suggests appropriate mineral processing techniques that could be used to recover these precious stones. Special emphasis is placed on the versatility of the Heavy Media Separation (HMS) process for processing of the gemstones. Finally, a few examples of commercially viable operations involved in the recovery of emeralds and rubies are presented.

Jan 1, 2005

By James K. Grunig, Rodney J. Anderson

A process consisting of leach, continuous countercurrent decantation, resin-in-column ion exchange, evaporative crystallization of beryllium sulfate, and decomposition of the sulfate was developed for Spor Mountain, Utah, ores. The process is metallurgically sound, has a minimum of process steps, and is applicable to a wide variety of beryllium ores. The most novel aspect of the process is a resin system of ion exchange which is highly selective for beryllium and which rejects substantially all impurities except for minor amounts of aluminum, magnesium, fluorine, and sulfate in addition to beryllium. The oxide from sulfate decomposition meets specifications of potential users.

Jan 1, 1983

By Otis M. Clarke

The 34th Forum on the Geology of Industrial Minerals gave members a chance to see the geology of various stone and ore deposits displayed graphically in quarry walls and also provided an opportunity to hear and see first-rate papers and posters on the geology of industrial minerals. Also, some field trips passed through areas of spectacular scenery. As a bonus, participants saw scenic mines, some of which are "pretty as a picture." Watercolor paintings prove it. At the Oklahoma Forum, the writer displayed a number of paintings of mines and other landscapes seen during previous Forum trips. These paintings and this brief article are part of a crusade to prove that some mines and geologic vistas are scenic wonders and belong in our visual heritage. It is a plea to save some of our best geologic exposures for future geologists, tourists, and artists.

Jan 1, 1999

By Deepak Malhotra

Comminution circuits in general account for fifty percent of capital and operating costs for a processing plant. Significant advances have been made in optimization of these circuits. One would expect a few circuits to be the favored designs for plants. Review of grinding circuits worldwide indicates that a variety of circuit designs are utilized for non-technical reasons. A brief review of circuits and reasons for their selection is given in this paper.

Jan 1, 1998

By E. M. Van Eeckhout

The National Uranium Resource Evaluation Program (NURE) has produced a mass of geochemical data in the form of data files on tapes. This paper presents a methodology for utilizing those tapes in a simple, practical manner. An example is given of an analysis of the Butte quadrangle, Montana, tape obtained from the Los Alamos National Laboratory (LANL). The example details the sequence of splitting the data file, plotting histograms, cumulative frequency curves, concentration plots, and methods for evaluation. All programs are written in FORTRAN. The case study was performed using a mini- computer (DEC PDP 11/70) and standard plotting subroutines.

Jan 1, 1982