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By P. R. A. Andrews, R. K. Collings

The beneficiation of barite has been the subject of many investigations at CANMET, thus reflecting barite's importance as an industrial mineral. Fifty-one studies relating to various aspects of beneficiation were conducted between 1920 and 1986, and a review of some of the more important studies is presented. The information, including mineralogy, beneficiation methods and results, flotation parameters, and reagent concentration data, is presented in tabular form. By so arranging the principal data, the research worker and production metallurgist will be assisted in the evaluation of barite ores from a variety of origins.

Jan 1, 1990

By S. Zaman, John Bulter, M. E. Defoe, Franklin T. Davis

This section deals with the carbon minerals and materials: graphite, tar sands, gilsonite, and diamond. as well as sulfur and the sulfides of mercury, arsenic, antimony, and bismuth. Table I contains the production figures for each of these commodities in the United States and in the world. Specifications for concentrates are also summarized as are prices for concentrates at the time the section was written. In each chapter an attempt has teen made to describe the more common commercial mineral involved with the commodity, the processes used to recover and concentrate the minerals, as well as geographical areas where these processes are utilized.

Jan 1, 1985

By Marian W. Otrebski, Julian A. Korneck

Long distance, overland conveyors require significant capital outlay of which up to 70% may be contributed to the cost of belting. Significant savings may be achieved by identifying possible risk areas and applying modern technology methods to reduce or eliminate risk. Recently, Sasol Coal commissioned an overland belt conveyor system comprising three belt conveyors of 7 km, 5 km and 4.5 km in length. These were designed and constructed taking the above into consideration. Contained in the paper are the belt conveyor system requirements, designing assumptions and methods applied in the designing process as well as ways and means to eliminate or at least reduce risks.

Jan 1, 1998

By Robert G. Moorhead

Fine-coal screening can be one of the most critical operations in a modern coal-cleaning plant. The yield and quality of clean coal produced in fine-coal circuits is controlled as much by how efficiently 0.15 mm (100 mesh) particles are sized as on the performance traits of the fine-coal cleaning device itself. In addition, the increased interest in effective fine-coal sizing operations indicates that many operators have also discovered its importance in affecting the quality and yield of clean coal produced in fine-coal circuits. This paper describes the three most prevalently used fine-coal screening technologies and discusses their sizing mechanism, performance, and application.

Jan 1, 1988

By S. Subbarayan, S. Chander, M. S. Klima

A laboratory study was conducted to investigate the potential for recovering anthracite from coal preparation-plant tailings. The study included washability analyses, cyclone simulations and froth flotation testing Samples were collected from either the tailings streams or the slurry ponds of five anthracite-cleaning plants. From each sample, a washability analysis was conducted on the 28x100 and 100x200-mesh fractions. Using the above data, along with published partition data, simulations were performed with various cyclone-staging arrangements for both water-only and dense-medium cyclones treating the 28x200-mesh fractions. Separate froth -flotation tests were conducted on the 28x100- and 100x200-mesh fractions from three of the plant samples. The washability, simulation and flotation results are presented as grade-yield curves.

Jan 1, 1996

By C. Steiakakis

Over recent years large construction projects have taken place and will be taking place in complex geological environments. In order to reduce costs and increase safety, a detailed geotechnical evaluation of local conditions is very important. This issue has been addressed in much detail for soils and hard rocks but there is a gap in intermediate geomaterials such as soft or altered rocks. In order to overcome this problem geotechnical engineers usually adopt principles and methods meant either for soil or hard rocks. The rock mass classification systems such as RMR, GSI etc. are the ones predominantly used. The users of these systems are of-ten unaware of the theory, limitations or the data behind these systems. The aim of this paper is to demonstrate problems or misuses of rock mass classification systems in intermediate geo-materials. The main focus is on the GSI classification system since it is widely used in Greece. Complex geological environments, altered, weathered or poor rock materials are addressed and suggestions on how they should be evaluated with the use of rock mass classification systems are discussed. Situations where the use of these systems produce erroneous results not due to their limitations but rather due to lack of experience and incorrect use are also discussed. Finally, recommendations are made for better use of these systems in practical problems

Jan 1, 2005

By J. A. King, D. R. Weir, P. C. Robinson

Preconcentration of Porgera ore results in high recoveries of gold into gravity and flotation concentrates. The bulk of the gold is contained in auriferous pyrite flotation concentrate and is not readily recoverable by direct cyanidation. Oxidation in autoclaves at high pressure and temperature produces a residue that contains the gold in recoverable form. Pilot plant treatment of the autoclave residue is described, through washing and jarosite decomposition stages, to cyanide leaching and recovery of gold and silver by carbon-in-pulp techniques. The concern associated with disposal of plant effluents are also addressed.

Jan 1, 1987

By Kalliat T. Valsaraj, Louis J. Thibodeaux

A mathematical model is described for the transfer of hydrophobic compounds from aqueous to an immiscible organic phase using fine bubble aeration; the process otherwise known as "solvent sublation" an adsorptive bubble separation process. The limitations of the model are explored by simulating experimental results both for a batch scale process and a continuous process. The qualitative predictions of the model with respect to the influence of the organic layer (mineral oil) are tested by performing experiments using chloroform and 2,3,6-trichloroanisole as hydrophobic compounds in the aqueous phase. The continuous process is seen to be limited by the requirements of fine bubble generation and the ratio of influent feed rate to air flow rate.

Jan 1, 1989

By Samir Kumar Das

Presently Geographic Information System (GIs) is gaining wider acceptance id appreciation in various resource management surveys, generation of various thematic maps, various scientific investigations, environment assessment, disaster management, etc in India but they are general in nature. A huge number of Global Positioning System (GPS) based "Total Station" are playing good roles in India for accurate and quick surveying . The GPS based real time Mine Management and Truck Dispatching System for optimization of productivity is being installed in the Panchpatmali opencast bauxite mines of India. This paper dealt in depth on GIs and GPS and their present roles in the Indian mining scenario.

Jan 1, 2002

By Roger J. Hornberger, Paul F. Ziemkiewicz, Dirk J. A. vanZyl, Gene E. Krueger, Harry H. Posey, Kim A. Lapakko, Charles H. Buckmam

The Acid Drainage Technology Initiative (ADTI) was initiated in 1995 by federal agencies, the National Mining Association and the Interstate Mining Compact Commission to identify, evaluate and develop cost- effective and practical acid drainage technologies. In 1999 ADTI was expanded through the addition of the metal mining sector group, which began organization efforts in 1998. ADTI addresses drainage quality issues involving metal mining and related metallurgical operations and acid drainage from coal mines, for abandoned, active, and future mines. ADTI is a technology development program. It is not a regulatory or policy development program. The guiding principle of ADTI is to build a consensus among industry, federal and state regulatory agencies. ADTI is focusing these efforts on technology development and technology transfer in the areas of mine drainage sampling/monitoring, prediction, avoidance/remediation and modeling.

Jan 1, 2000

By Hasan Sevim

A computerized heuristic model for an efficient and economic design of belt haulage networks in underground coal mines is discussed. The model is versatile, easy to use, and is valid for all mining methods singly or in combination. It may be used to design new networks or to analyze existing networks. The input data required are 1. maximum production rates from a section, 2. probabilities of production rates, 3. equipment costs, and 4. data necessary for network coding to represent different cases. The objective function is the "expected minimum cost per ton of coal hauled" while meeting production requirements. The output includes belt width, motor horsepower, bin size etc. and also values of operating parameters for each belt such as belt speed, effective tension, power consumption etc. A detailed account of the cost involved is also provided for each unit as well as for the entire network. Description of the model and an example of the design of a belt network in a mine with two longwall and four development sections are presented.

Jan 1, 1986

By M. Karmis

Promoting a strong safety culture requires that the significance of unsafe acts be emphasized. This can be achieved vividly by accurate recreation of unsafe actions in the workplace, demonstrating explicitly how they resulted in a fatality or significant injury. Visual reconstructions of incidents can be realized today on personal computers. The approach described in this paper uses readily available PC software and hardware and results in output that can be presented to the intended audience using a variety of delivery methods. An actual incident involving a surface mining operation is reconstructed using Virtual Reality techniques. Use of the visualization approach to accident reconstruction as a training tool is discussed.

Jan 1, 2003

By J. Hanna

The University of Alabama Mineral Resources Institute (MRI) has developed a unique process for selective fatty acid flotation of carbonate gangue from sedimentary apatites (francolite) in the pH range of 4-6 without collector conditioning of the pulp. The process, which does not require an apatite depressant, was modified to benepciate a high- MgO siliceous phosphate matrix from south Florida. The modified process includes two flotation stages, one for car- bonate removal and the other for phosphate recovery from the siliceous gangue. The selective flotation separation of the carbonate and phosphate from siliceous constituents of the matrix at various pH levels and collector dosages are discussed. In the carbonate flotation stage, about 70% of the MgO was rejected in the froth. The phosphate flotation stage produced concentrates analyzing about 31% P2O5 0.7% ? 5 MgO, and 4% insol. The overall P2O5 recovery In the two stages was about 85%

Jan 1, 1991

By Pedro E. Rengifo

Splicing methods have undergone considerable developments over the last 2Oyears. Continuous conveyor belt service is dependent entirely on the strength and life of the splice to hold the two ends together. Ultimately, belting performance is dependent on the quality, efficiency, and technique of the splicer. As customers demand better belting performance and running tensions increase, the need for splices that perform as efficiently as the belting has increased also. Higher dynamic belt constructions have also dictated the need for "new"sp1icing techniques. Regardless of the belt type used or spliced, one item that is most necessary with all belt types is the quality of the workmanship and standardized splicing methods that employ all of the necessary elements required to ensure reliable field service. This paper will explore the use of Goodyear-issued internal standards for field splicing following the constraints of quality and efficiency for fabric and steel cord reinforced belting. Also included are the 10 most common mistakes made by splicers, Goodyear-issued Field Quality Assurance Standards, and check lists for end users to adhere to the manufacturers' requirements for splicing including materials and specifications for conveyor belt splicing and repairs.

Jan 1, 2004

By Robert Blair, David L. Fey, Stanley E. Church

Determination of the pre-mining geochemical baseline in bed sediments in watersheds impacted by historical mining activity is important in establishing watershed restoration goals. We have developed methods to solve this problem in the Animas River watershed, southwestern Colorado, using geomorphologic mapping to identify terraces that contain pre-mining sediments. Following a systematic evaluation of possible sites, we collected samples of pre-mining sediments in gravel deposits from 21 sites throughout the watershed. Geochemical analysis of individual layers has produced a chemical stratigraphy that can be tied to the historical record through geochronological and dendochronological studies. Analysis of geochemical data, when coupled with the historical record, clearly shows that there has been a major impact on the geochemistry in bed sediments in the active stream channel by past mining activities. Historical mining has resulted in a substantial increase in metals in the very fine sand to clay-sized component of the bed sediment of the upper Animas River, and Cement and Mineral Creeks, which are the major tributaries of the Animas River. Enrichment factors for metals in modem bed sediments, relative to the pre-mining sediments, range from 1 to 6 for arsenic, 1 to more than 10 for cadmium, 1 to about 15 for copper, 1 to more than 25 for lead, 1 to more than 10 for silver, and 1.6 to more than 12 for zinc. The pre-mining bed sediment geochemical baseline is high relative to average crustal abundance values of many metals. The Animas River watershed above Silverton, Colorado would be readily identified as a highly mineralized area suitable for mineral exploration if it were not disturbed by mining.

Jan 1, 2000

By P. Bevilacqua, G. Ferrara, U. Preti

In the last decade, Meloy developed the IAC - Interfacial Area Conservation - model of liberation. His work included three conservation laws and a mathematical tool called textural transform. This paper reviews the developments and applications of the IAC model. From simple spherical two-phase locked particles with planar interfaces, the model has been developed for curved interfaces and solids with complex textures. Moreover, complex shaped particles and ores having more than two phases have been considered. The model equations give the degree of liberation of the component phases for different ore textures – platy blocky and acicular - as well as for different sue distributions. Lockedness profiles are offered for defining the middlings composition, so that from the model it is possible to predict washability curves.

Jan 1, 1992

Surface characterization techniques, i.e. contact angle measurement, atomic force microscopy (AFM) surface force and surface imaging measurement, were applied to investigate the molybdenite surface in aqueous solution. It was shown that the cleaved basal surface of molybdenite was very hydrophobic with a 92 degree water contact angle. The non-polar component of the solid surface free energy is 50.52 mJ/m2 while the polar components are almost zero. The solid surface was not reactive and was only weakly charged at the pH 6. When the aqueous media changes from water to 1×10-4 M KEX solution, the measured contact angle, adhesion force and surface roughness all increase slightly. However, ethanol rinsing made the surface change back to the bare substrate. It was suggested that the hydrophobic chemical, i.e. dixanthogen, which was shown in the morphology of patches by the AFM image, physically adsorbed on the hydrophobic molybdenite surface through the hydrophobic interaction.

Jan 1, 2009

By Randal J. Barnes

The nonlinear network optimization algorithm developed in this paper solves the following mine ventilation design problem: find the location and size of all fans and regulators which minimize the overall system power consumption while satisfying all physical, legal, and operational constraints. This work includes the formulation of the problem within the framework of mathematical optimization, the development of the computational theory, and the creation of an efficient solution methodology. The algorithm has been implemented on a microcomputer, and a small but representative example is included. The algorithm presented in this paper has four limitations. First, the optimization process is for a single point in time: the dynamic nature of a mine ventilation system in an evolving mine is not directly addressed. Second, the topology of the ventilation network is required input information. The mathematical algorithm does not optimize the size or location of the mine ventilation airways; however, the post optimality analysis techniques can be used to aid in topological decisions. Third, the problem is formulated using volumetric flow; thus, heat and moisture transfer are ignored. Fourth, the capital cost of ventilation equipment is not included in the formulation.

Jan 1, 1989

By Andrew I. Hustrulid

The discrete element method has successfully been used to model the behavior of material flow in transfer stations. With position, velocity, and applied forces for every particle and boundary in the simulation available at increments of 10-5 seconds, the next critical step is the presentation of this data in a concise and beneficial form. This paper discusses several methods of presenting the data from discrete element simulations that are used to improve the performance of a transfer station. These measurements are also used as a learning tool to better understand and visualize how material transfers from one belt to the next.

Jan 1, 1998

By James Stewart

"THAT WHICH WE CANNOT SEE" INTRODUCTION Often it has been stated that the greatest of all fears is fear itself - fear created only by that which we cannot see or by that which we fail to understand. The elimination or minimization of fear can best be accomplished by a thorough understanding of the underlying causes of the fear. As related to the mining industry the omnipresent fear is the dread of acquiring cancer through accumulated exposure to "that which we cannot see" - radioactivity. The understanding of the resulting exposure effects can best be obtained through acquisition of authentic data and the subsequent analysis of the same by a group of highly qualified specialists. I may point out that the nuclear industry and its source, uranium mining, greatly surpass any other industries in the degree of public awareness as to its potential environmental effects. Public out-cry has always influenced major decisions relating to how industries conduct their operations and much of their effort has resulted in many changes. The issues of health and safety in the mining industry have created considerable public concern, but intense concern to those of us directly involved within the industry. Increasing concern regarding the effect of human activity on the quality of the outer environment of air, land, and water has developed within the past two decades. There is now a growing concern about the health and safety of persons at work in their inner environment, of their working-places in industry. Hearings and investigations conducted in Canada by three appointed "Royal Commissions" have all confirmed that this concern is well justified when focused on the health and safety of workers in our mines. REGULATORY CONTROL OF URANIUM MINING OPERATIONS In Canada, the ownership of mineral resources and the control of their extraction, except for uranium, is vested under the "British North America Act" in the provinces. In all provinces the statutory basis for health and safety provisions in the mining industry can be found in the provincial "Mining Acts" with each province assuming the responsibility to produce its own "Mining Act". In particular, all of the Mining Acts in Canada place upon the management of a mine the responsibility to ensure that provincial provisions are met. The "Federal Register" and mining companies parallel this arrangement in the United States. Equivalent legal

Jan 1, 1981