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By M. Deniz Turan, HASAN NIZAMOGLU, MÜCEVHER TURAN, RAMAZAN ORHAN

Tailings, or flotation waste, formed during copper production may be considered in the class of valuable wastes because of the amount of copper they contain. With the decreasing grade values of copper ores, the utilization of wastes like tailings that carry certain amounts of copper as secondary sources has become a necessity in both the economic and environmental senses. This study was carried out with the aim of using ammonium derivatives for the recovery of copper from tailings waste produced during copper production and utilizing their complex formation characteristics. In the conditions of six hours of leaching at 30 °C in the presence of 22.5 percent ammonium hydroxide and 100 g/L ammonium persulfate, 91.47 percent of the copper was transferred into the solution, while iron was not transferred, indicating that copper can be selectively recovered from tailings.

By G. J. C. Young

The paper describes the replacement of a conventional filtration, clarification and zinc precipitation plant by a carbon in pulp (CIP) electrowinning plant, with the objective of improving the recovery of gold from cyanide leached, acid plant calcines. The discussion covers the early laboratory studies to the design and erection of the full scale plant. Particular emphasis is placed on the problems encountered with commissioning and the strategies which were employed to solve them.

Jan 1, 1982

By A. Dell’Era, E. Ciro, C. Lupi

The paper explores the recovery of indium via electrowinning from sulfate baths, focusing on the impact of different cathodic supports (AISI 316L and nickel) on process parameters such as electrolyte composition, current density, and temperature. The study compares productivity, morphology, and structure of indium deposits on both cathodes, finding that nickel cathodes generally yield better results.

Nov 1, 2023

By Robert F. Kehrman

As part of the Bureau of Mines research on the In-Situ Uranium Leaching, various geophysical resistivity measuring techniques were -evaluated to identify a rapid reliable method for detecting the underground migration of lixiviant outside of the planned limits. Surface and downhole galvanic resistivity and controlled source audio-magnetotelluric (AMT) methods were tested at an in-situ uranium mine in Northern Wyoming during start-up of a new mining area. Downhole galvanic and AMT were the most promising techniques.

Jan 1, 1980

By R. R. Klimpel

The grinding of coal-water slurries has received increasing industrial attention during the last decade. In particular, there is long-term interest in the use of pulverized coal-water slurries to replace oil in combustion equipment and the development of coal gasification/liquefaction processes which require coal-water slurries as feed. More specifically, the use of coal-water slurries in gasification requires grinding a high density slurry containing the smallest amount of water consistent with slurry pumping and spraying. As part of a fundamental engineering research support program aimed at the industrial implementation of dense coal-water slurry grinding, this author has published several papers on how specific rates of breakage vary as a function of slurry rheology, Klimpel (1982, 1982/83). These papers demonstrated that there is a consistent pattern of change in specific rates of breakage of coal in dense slurries with controlled variations in slurry rheology. By matching rheological data with laboratory grinding results, it was possible to identify directly slurry conditions that correspond to: (1) slowing down of breakage rates, (2) the occasional acceleration of breakage of some sizes, and (3) conditions where chemical additives will increase rates of breakage.

Jan 1, 1990

By Langtry E. Lynd

The titanium dioxide pigment industry in the United States has always relied to varying degrees on imported titanium concentrates. Dependence on foreign ilmenite was especially high (generally over 85% of consumption) until 1942, when large-scale U.S. production of ilmenite began, and has since ranged from 12% to 47%. Rutile import reliance was generally in the 45% to 80% range until the early 1960's, when increased use in the chloride pigment process raised dependence on imported rutile to over 90% in most years since 1963. Import reliance of zircon, obtained almost entirely as a byproduct of titanium mineral production, has generally ranged from about 30% to 65% of consumption. This paper will examine the history of U.S. sources of these heavy mineral commodities, and will discuss the potential U.S. future supply in view of changing industrial uses and processes and the anticipated development of new heavy-mineral-sand processing operations, such as those at Richards Bay in the Republic of South Africa and in Sierra Leone.

Jan 1, 1978

By MAURICE SUNKPAL, Taghi Sherizadeh, ELAHEH TALEBI, PEDRAM ROGHANCHI

Excessive heat exposure is among the health and safety hazards for mine workers. The nature of the underground climate makes it a convenient avenue for heat generation and accumulation from several heat sources, including autocompression, equipment and heat from strata. This study investigates the effects of clothing insulation and acclimation on the thermal comfort of mine workers exposed to heat in underground working environments. Several clothing ensembles were considered to analyze the effect of the thermal resistance of clothing on the workers’ thermal comfort. To investigate the impact of clothing insulation, the thermal comfort limit of an underground miner was calculated in the form of maximum allowable exposure time for an eight-hour shift.

By Zhe Wang, Tichang Sun, Yongqiang Zhao, Zhengyao Li

Coal-based reduction followed by magnetic separation is a promising technology for processing refractory iron ores. Analysis of the size distribution of metallic iron particles is an effective approach for exploring the mechanisms of coal-based reduction. As metallic iron particles exhibit very complex shapes compared with nature ores, approaches for measuring and characterising metallic iron particles still remain unclear. In this study, the size of metallic iron particles was measured and characterised using manual point-counting by optical microscopy technics and image analysis. The effects of CaF2 as an additive on behaviour of the particle size distribution (i.e. mean size and cumulative frequency distribution) were also determined. Results indicate that CaF2 had a significant effect on the growth of metallic iron particles. When the CaF2 dosage increased from 0 to 8%, the mean size according to the area method increased from 9.03 to 16.28 μm, while the promotion effect gradually weakened and generated many fine metallic iron particles when the CaF2 dosage exceeded 8%. An increase in CaF2 dosage also led to cumulative distribution curves gradually shifting to the right mainly because F− can break the crystal structure of each phase during the carbothermic reduction of titanomagnetite and reduce the stability of the lattice structure, thus reducing the melting point and accelerating the growth of metallic iron grains. Compared to different measuring methods, the area method is a more suitable approach for measuring and characterising the size of metallic iron particles.

Sep 18, 2020

By Seokwon Jeon, Ho-Young Jeong

"Various numerical methods have been tried to estimate the cutting forces of a TBM disc cutter. In this study, SPH/FEM coupled method was newly employed to improve the traditional FEM analysis. The disc cutter and rock were modeled by Lagrange and SPH codes, respectively. The numerical cutting test was carried out for representative Korean rocks with different cutting conditions. The results show that the cutting forces obtained from numerical simulation had a good agreement with those from LCM tests, and that applying SPH method to rock cutting model has advantages and improvement compared to traditional FEM method. Erosion criterion and erosion limit were not required to simulate the rock fragmentation process, and the cutting forces from the numerical simulation was more stable and accurate. The results indicate that the numerical simulation can be successfully used to estimate cutting performance of a TBM. 1. INTRODUCTION Various numerical studies have been carried out to accurately simulate the limitations of linear cutting machine (LCM) tests. Numerical modelling methods have advantages comparing with full scale tests in terms of cost and time involved. Many numerical methods have been used to simulate rock cutting process by different cutting tools and the studies are summarized in Table 1.In 2D simulations listed in Table 1, because they do not take account of rolling force and horizontal rolling mechanism of a disc cutter, indenter was selected as cutting tool in their modelling. For these reason, 2D modelling is not suitable for rock cutting modelling using a disc cutter. In contrast, 3D numerical models can take account of the indentation process by thrust force and penetration processes controlled by rolling force."

Jan 1, 2016

By D. Donison

The practice of blasthole mining is typically applied in competent ground conditions, primarily because of the open stope dimensions. At Magma Copper -Superior Mine, a field pilot project was completed examining a variation of blasthole mining in poor ground conditions. The results were very encouraging not only from a technical viewpoint, but also productivity viewpoints. This paper describes the pilot project and the resulting implications.

Jan 1, 1994

By A. W. Khair

This paper deals with the evaluation of the interaction between rock and the cutting tool, and with methods for determination of workability, and abrasivity of rock. A description of instrumentation is included along with research on the wearing process of bit tips and pick consumption. Analyses of bit rotation, evaluation of cutting, normal forces and energy consumption is presented. Finally influence of the basic water jet parameters and water jet assistance on the cutting process of hard and abrasive sandstone is discussed.

Jan 1, 1995

By Roberto Pimentel de Souza

Since 1976 CVRD is carrying out tests to develop a type of pellet made with organic binder. One binder that showed good possibility to be used in industrial plants is Peridur. An extensive framework of tests was run in CVRD's pilot plant. The results are presented in this paper. Finally, the decision was taken to carry out an industrial production of 50.000 t of pellets. It was scheduled for March '81. The results are shown in this pager. It was not observed any detrimental effect of the peridur neither in the process nor in the product quality.

Jan 1, 1981

By T. Gouri Charan

Indian coals, which are of Gondwana origin, contain high amounts of mineral matter, wherein the extraneous material was intimately mixed in the coal matrix during the formation stage, causing a high level of impurity in the run-of-mine (ROM) material. These coals possess difficult to very difficult washability characteristics. Beneficiation of high-ash non-coking coals of India has become the prerequisite for improving the overall economics and efficiency of power generation. The use of dry cleaning systems in India for beneficiation of non-coking coals has gaining renewed interest recently. The benefit of the dry beneficiation process is to exploit the given resources while providing a more reliable and consistent quality fuel with a low operating cost. M/S Allmineral has introduced a technique for the dry beneficiation of coal, which is being tried in India for the treatment of high-ash non-coking coals. The first commercial air jig of 50 t/hr capacity was installed and commissioned to beneficiate high-ash coals of 40 x 5 mm feed with an ash content of 40%; a clean coal product of 33% ash was produced and is being used for a sponge iron plant.

Jan 1, 2011

By C. D. Elifrits

The required reclamation of land disturbed by surface coal mining often results in the creation of some over steepened slopes which are prone to rapid erosion and sediment production. This natural activity on such slopes is not desirable nor allowed under current regulations. Experience has indicated that novel approaches must be devised to address the problem. Research conducted on field sites in Missouri has indicated that construction, during the reclamation and grading processes, of a man-made drainage system will control the erosion. The drainage system must replicate or exceed the natural system in terms of drainage density and channel frequency. Basic design considerations will be summarized in this paper and field results shown.

Jan 1, 1986

By Zengwu Zhao, Peng Xu, Jieliang Wang, Qingwei Bai, Xinyang Liu, Xiao Lei

The paper investigates the capture and recovery of rare earth minerals from Bayan Obo ore using superconducting magnetic separation. A finite element model (FEM) was established to study the influence of various factors on the capture of rare earth minerals under a high-gradient superconducting magnetic field. The study aims to improve the efficiency of rare earth mineral separation and recovery.

Oct 1, 2023

By S. C. Tadolini

The use of resin-grouted cable supports to control large ground movements in several types of underground mines has increased substantially since being introduced in 1991. Cables offer several advantages over traditional support systems, having large support capacities coupled with the flexibility to be used in low openings. Cable slings have been designed to be installed on-cycle using no-spin technology or a two-piece unit that can be placed with hand-held drilling equipment. Additionally, yielding cable supports have been developed and are being used to control large amounts of movement in coal and evaporite deposits.

Jan 1, 1998

By J. D. Miller

"It is now possible to use 3D X-ray tomography analysis for plant-site characterization of coarse particles at a sampling rate of about 3 kg/min for particles which range in size from 150 mm to 1 mm at a voxel resolution of about 150 microns. This is quite a significant advance in X-ray tomography technology and should be useful for plant-site coarse particle characterization (size, shape, composition, density, texture, grain exposure, mineral liberation) with a response time of minutes after receiving the sample. Applications in the mineral industries are discussed including the coal industry, aggregate industry, metal mining and the processing of industrial minerals. INTRODUCTION Plant-site characterization of coarse particles at coal preparation plants, crushed stone/aggregate plants, and mineral processing plants is needed to improve plant capacity, product quality, and/or process efficiency. Not much on-line coarse particle characterization is done at these plants. Some limited information regarding particle size is obtained on-line from reflected light images using systems such as the OPSA, Split, and WipFrag analyzers. Even laboratory analysis of coarse particles has been difficult because of the large amount of sample required to insure statistical significance of the results. During the past decades laboratory 3D characterization of particles from energy and mineral resources by X-ray tomography has been demonstrated and used to good advantage [1, 2]. 3D X-ray tomographic analysis had its origin in the medical services industry; it is used to provide internal images of the human body and now has also been developed for non-medical applications [3]. Figure 1 shows a schematic diagram for the cone-beam geometry micro-CT system. In our case X-rays from a microfocus X-ray generator are partially attenuated by the sample (a packed bed of particles) that is made to rotate in equal steps in a full circle about a single axis of the particle sample. At each rotational position, the surviving X-ray photons are detected by a planar two-dimensional array (image intensifier) large enough to contain the shadow of the specimen. These two dimensional projection images are collected using conventional video technology. The video signal for each projection is then converted to a two-dimensional digital array by an image processing system. Finally, a three-dimensional image is reconstructed from the collected set of projection images. With the availability of automated high speed X-ray tomography [4] it now seems possible to do plant-site particle characterization at a sampling rate of about 3 kg/min for particles which range in size from 150 mm to 1 mm at a voxel resolution of about 150 microns. This is quite a significant advance in X-ray tomography technology and should be useful for plant-site particle characterization (size, shape, composition, density, texture, grain exposure, mineral liberation) with a response time of minutes after receiving the sample. Applications in the mineral industries are discussed including the coal industry, aggregate industry, metal mining, and the processing of industrial minerals"

Jan 1, 2016

By Charles H. McGuirk

The Port of Conneaut, the largest bulk material handling and storage facility on the Great Lakes, is using the latest electronic and visual testing devices to augment and enhance its well established computerized preventive maintenance system. The results of this comprehensive program have been impressive. The remaining life of components can be accurately forcast, and replacement can be programmed around operations, resulting in a significant improvement in system availability and reduced costs for the dock operator and its customers.

Jan 1, 1983

By CLAIRE STREBINGER, ADITYA JUGANDA, JURGEN F. BRUNE, GREGORY E. BOGIN JR.

Methane gas explosions are a major risk in underground coal mining operations. The severity of such explosions can range from local area damage to massive loss of miners’ lives along with significant damage to mine infrastructure and ventilation controls that may lead to mine closure and loss of the entire operation. This study demonstrates the viability of integrating a computational fluid dynamics (CFD) combustion model into a longwall mine ventilation model to simulate methane gas explosions in the longwall face area. The resulting 3D methane gas explosion simulation can provide better understanding of the fundamental physics and the potential impact of an explosion in an underground longwall coal mine.

Aug 1, 2022

By W. C. Hirt

Selective flocculation was used to produce superclean zinc concentrate with minimized silica contamination. Research was carried out on a flotation concentrate from the Jersey Miniere Zinc Company (JMZ) in Gordonsville, Tennessee. The material was first dispersed with sodium silicate and then causticized tapioca starch was used to selectively flocculate the sphalerite, leaving the silica in suspension. This technique has been applied commercially to iron ore beneficiation but has never been used for processing zinc. The feed material assayed 0.45% Si02. Use of 0.56 kg/tonne (1.13 lb/st) of sodium silicate and 0.070 kg/tonne (0.141 lb/st) of causticized tapioca starch resulted in 98.2% zinc recovery in a purified zinc concentrate assaying 66.0% Zn and 0.24% silica. The present target level for silica contamination in JMZ zinc concentrates is 0.3% Si02. This work has shown that selective flocculation offers a potential method for cleaning flotation concentrates, particularly where low silica products are required.

Jan 1, 1993