Search Documents

By W. K. O’Connor, J. C. White, P. C. Turner

The US Bureau of Mines is investigating the cobalt and manganese resource of the West-Central Arkansas district through field investigations, mineralogical characterization, beneficiation and hydrometallurgical tests. Located within the Ouachita Mountains, these structurally-controlled deposits occur along the axes of anticlines that form the mountain ridges. Brecciated novaculite is cemented with a mixture of manganese oxides, primarily cryptomelane and psilomelane. Cobalt is concentrated within lithiophorite, a particular Mnoxide phase. Chemical analyses of head samples reported up to 25% Mn and 0.17% Co. Magnetic separation yielded products containing up to 41 % Mn and 0.22% Co at recoveries of 95% and 93%, respectively.

Jan 1, 1993

By Terry S. Maley

Federally owned mineral deposits generally fall into one of three categories: (1) minerals locatable under the General Mining Law of 1872; (2) minerals leasable under the Mineral Leasing kt of 1920; and (3) minerals salable under the Materials Act of 1947. Unlike valuable deposits of gold, silver, copper, iron, lead, etc., which may be locatable, industrial minerals are acquired through a variety of methods depending on use, composition, and date of acquisition. Table 1 may be used to establish the method of acquisition for most industrial minerals.

Jan 1, 1987

By T. Winkler, J. Tokarczyk, D. Michalak, W. Chuchnowski, M. Dudek

Engineering Methods aiding Sustainable Development of Mining Systems will be presented, and especially: virtual prototyping for designing of Mining Systems with Health Protection and Safety criteria taken into consideration, modelling and assessment of technical and health hazards that can occur during operation of Mining Systems, creation of knowledge repositories that disseminate safe work methods with consideration of existing language and culture barriers, dissemination of the methods integrating world community and Mining Systems users.

Jan 1, 2011

By J. S. Lewis

Beneficiation and physical and chemical processing of non-terrestrial materials will borrow strongly from terrestrial experience but will also involve the necessity of handling literally unEarthly feedstocks, reagents and environmental conditions. The present state of scientific and engineering understanding of the processing of non-terrestrial minerals, gases and hydrocarbons is reviewed, with the production of rocket propellants, life-support fluids, structural metals and refractories as the goal.

Jan 1, 1994

By P. S. Parobeck, T. F. Tomb, R. S. Ondry

From October 1980 through August 1982, surveys were conducted on 19 longwall mining operations to obtain data relative to respirable dust levels associated with particular longwall operations and occupations, to make recommendations for enhancing dust control, and, where applicable, to evaluate the effectiveness of new technology implemented to control dust. The paper summarizes the data collected during these surveys and, where possible, draws conclusions and discusses actions that can be utilized to reduce exposures to respirable coal mine dust on longwall mining operations.

Jan 1, 1987

By Irwin R. Higgins, Joseph C. Milbourne

The selection of a suitable nitrate removal process depends on a variety of site-specific chemical and environmental issues. The dominant technologies for nitrate removal include biological denitrification and continuous countercurrent ion exchange. The decision to apply either of these technologies, or both together, depends on the nature of the waste water to be treated. Factors that affect the selection of the biological system include the feed composition and feed temperature. Ion exchange nitrate removal systems ere less sensitive to the feed composition but require disposal or destruction of the concentrated pregnant eluate. The paper discusses Tetra's continuous countercurrent ion exchange technology (CCIX™) and fixed film biological reactor, Denite®. The treatment of the ion exchange pregnant eluant is also discussed.

Jan 1, 1995

By H. Sevim

The logic and capabilities of a long-term production planning method for open pit mining are presented. This is a new method that can be used to obtain simultaneous solutions to the four interrelated parameters of open pit mining: mine life, specific blocks to be mined each year, the amount of ore and waste to be mined each year, and the ultimate pit limits. An efficient milling cutoff grade can also be obtained through a systematic analysis. A production plan for a real-life gold deposit is given to illustrate the logic and the capabilities of the method.

Jan 1, 1994

By M. S. Klima, A. Simard, M. L. Turek

Laboratory testing was carried out to evaluate several devices for recovering clean coal from bituminous coal refuse material. The bulk of the testing focused on using a dense-medium cyclone to process -0.6-mm refuse material. A hindered-settling column and a spiral concentrator were also used to process nominal 1.2 x 0.15-mm material. Product yields and ash contents were obtained for all tests, while partition curves were generated for selected tests from which the characteristic performance parameters (relative density of separation and probable error) were determined. The results indicated that the dense-medium cyclone was capable of cleaning down to 0.037 mm, while the other devices were effective to 0.15 mm. Keywords: Coal recovery, Coal refuse, Dense-medium cyclone, Hindered settling, Spiral concentration

Jan 1, 2003

By Thomas D. Barkand

Investigation of several serious hoisting accidents identified machine brake failure as the most common cause. The recent revelation of this potential hazard has prompted regulatory authorities to require an additional, independent, emergency braking system. As a result of this initiative, a new generation of braking systems have been developed and applied to mine elevators. This paper will discuss the design and testing of an electrical dynamic brake, pneumatic rope brake, and traction sheave brake. The effect of compound braking on hoisting systems equipped with multiple brakes will also be addressed.

Jan 1, 1992

By B. Cavender

The operating lifetime, or production rate, selected for a mining project is among the most important factors influencing the project's design and ultimate economic success. Incorrectly-determined lifetimes can lead to the erroneous rejection of projects as uneconomic as well as the suboptimal exploitation of producing properties. This paper examines the optimal lifetime calculation using traditional discounted cash flow and recently-proposed option pricing techniques. Using each method, the production rate is determined as that rate at which the project's net present value is maximized.

Jan 1, 1993

By Jan Leja

Surfaces of metal sulfides react readily with selected constituents of environment. Two types of reaction products may form: (1) primary, chemisorbed and hydrophobic surface products or primary hydrophilic surface products, and (2) secondary reaction products -- produced during continued oxidation-reduction processes. For flotation, the chemisorbed surface product and the secondary reaction products, elemental sulfur or metal xanthates, must provide sufficient hydrophobicity of the surface to ensure particle-bubble attachment.

Jan 1, 1986

By D. A. Stanley, B. J. Scheiner

The U.S. Bureau of Mines has thoroughly investigated the flocculation of phosphatic clay waste with polyethylene oxide (PEO). The studies included both theoretical and applied aspects of the flocculation sequence. The screen dewatering technique developed by the Bureau was field tested at four different Florida phosphate mines. The results of these field studies are presented. Also, to determine the mechanisms of the interaction of PEO with montmorillonite clays common to the phosphatic clay waste, a number of theoretical studies were conducted. An empirical equation was developed to describe the amount of PEO needed for flocculation. Infrared, ion exchange, and rheology techniques were used to study the interaction of PEO with Florida clays. The results of these studies are also presented.

Jan 1, 1993

By Y. T. John Kwong

Modified after procedures for assessing acid-generating potential of coal spoils, most acid-base-accounting (ABA) analyses inadequately characterize highly varied metal deposits. Although mineralogy critically controls acid generation and metal leaching, acquisition of appropriate data and their interpretation are poorly developed. Metal loading rates are commonly determined by kinetic testing, which rarely duplicate actual field samples and conditions. Accurate predictions and reduced assessment costs can conceivably be achieved by (i) use of geochemical analyses to define surrogate indicators; (ii) intelligent acquisition and use of mineralogical data; and, (iii) compilation of geo-environmental ore-deposit models to validate inference based on detailed geology.

Jan 1, 2000

By D. B. Jenkins, D. R. Taylor

Treatment of bentonite clay with mineral acids yields a modified clay product of high surface area and acidity that exhibits enhanced adsorptive and catalytic properties. A highly specialized segment of the clay industry based on this process has evolved into a worldwide business with a capacity of about 500 kt/a. This paper will present data on the chemistry, mining, manufacturing, and applications for acid-activated clays.

Jan 1, 1988

Conventional logging tools such as density, neutron, and acoustic have ranges of investigation of tens of centimeters. The borehole gravimeter, however, has a range up to hundreds of meters. For example, from the center of a cylindrical ore body 0.20 g/cm3 denser than its surroundings, one can detect the boundary of the ore body at a radius as large as five times its height. More complex structures can be investigated with computer programs. We can predict the usefulness of proposed gravity surveys, or decide which suggested structure is most likely to have caused the results of existing surveys.

Jan 1, 1988

By K. V. S. Sastry, A. J. Hunt, K. D. Lofftus

Sol-gel processing is rapidly becoming an important process for producing such advanced materials as high activity catalysts, fiber optics and ceramic precursors. These materials can be tailor made with properties unique to sol particles as well as the gel aggregates by controlling production of the sol, the formation of the gel, and the removal of the interstitial fluids. This paper presents colloidal and kinetic principles of sol generation and gel formation. Hydrolysis of alkoxides provides the best means of controlling sol production and electrostatic stabilization enables the formation of the most homogeneous gels. Gelation occurs by hierarchial aggregation which produces inhomogeneities much larger than the sol particles. Colloidal and kinetic principles can be applied to reduce the size of the inhomogeneities and obtain high performance transparent insulation and new ceramic composites.

Jan 1, 1990

By Franklin H. Sharp, R. Woods

The operation of the Magmont Concentrator located on the New Lead Belt of Southeast Missouri is described. Ore characteristics affecting lead-copper-zinc separation are enumerated, and the cur- rent methods of separation are detailed.

Jan 1, 1976

By K. S. Narayanan, Marcia L. Bartges, K. S. Venkataraman

The starting powders' physicochemical properties and consistency are essential for technical ceramic products to meet their performance specifications. The need for finer and more consistent powders has opened new technologies for synthesizing powders from atoms and molecules. However, submicron and near-micron powders obtained from conventional comminution and classification techniques are still competitive. This paper shows several examples from electronic ceramic applications of how we can use powder characteristics for micromanaging by design the ceramic properties such as the green and fired densities, slurry rheology, shrinkage during sintering, and the microstructure of the sintered bodies. The cross-disciplinary nature of the technology requires that the researcher not only should have a firm grip on the fundamentals of one or more disciplines, but also should be generally aware of the intricacies of other disciplines as well.

Jan 1, 1992

By Andrew I. Hustrulid

The Internet and World Wide Web create multiple opportunities to advance and change an industry. Scandura Conveyor Belting, a mid-sized manufacturing company supplying the mining industry, has embraced several of these opportunities that add value to the sale and service of the manufactured product. This paper presents a technical overview of available technology and how it is being applied to advance the conveyor belt industry. These technologies are used to provide historic catalog information, interactive troubleshooting, product installation and service instructions, detailed product information, technical calculations for the proper conveyor belt selection, and on-line site surveys and maintenance logs.

Jan 1, 2002

By L. Sletmoen, P. Rocque, E. DeSouza

Plans for achieving planned production rates at the Red Lake Mine High Grade Ore Zone required that the mine ventilation system be upgraded. Time constraints required that only a site assessment of the mine ventilation system be performed followed by recommendations for providing adequate ventilation conditions at the production zone. This paper describes the engineering assessment, design and commissioning of the ventilation system upgrade for achieving increased flows at the high grade ore zone. The work was successfully achieved with minimal capital expenditures and disruption to the mining cycle.

Jan 1, 2003