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By Y. H. Chia, P. Somasundaran

Carrier flotation of anatase from clay using coarse calcite is investigated, together with relevant basic properties of the system including aggregation and zeta potential, under different chemical and hydrodynamic conditions The roles of carrier sue and amount also are considered Mechanisms responsible for selective aggregation and flotation are reviewed

Jan 1, 1983

By Carolyn S. Watkins, Thomas E. Ward, Debby F. Bruhn, Vern Winston, Mary Lou Rowland, Deborah K. Bulmer

The genetic characteristics of members of the genus Acidiphilium are poorly understood. As part of our study of the genetics of these bacteria, a search was made for an endogenous bacteriophage. Such a bacteriophage has been discovered. Several properties of the phage have been investigated. The phage has a lambdoid morphology and is somewhat larger than lambda. A variety of factors which affect phage stability have been investigated. The bacteriophage infects several of the strains that have been tested. Study of this bacteriophage should greatly increase our understanding of genetic mechanisms in Acidiphilium.

Jan 1, 1989

By K. Kim, T. M. Yegulalp

A numerical model is being developed to assess the enhancement of ore permeability by improving fracture connectivity with micro-hydrofracturing. As part of this project, a generic two-dimensional percolation model was developed to test the impact of various field conditions on permeability. Field data from Cyprus Minerals' Mineral Park mine was used to establish the statistical properties of the observed fracture systems. Results of statistical analyses of field data and examples of the use of the percolation model are presented

Jan 1, 1997

By H. Lyn Bourne

The is the 13th year for this column and the 12th in which the royalty data have been tabulated. There still exist some holes in the list of royalties that readers hopefully will fill. The most common mineral commodity is construction aggregates - either sand and gravel or crushed stone. In spite of their pervasive use nationwide, there are states from which the author has no information about royalties for either of these commodities. The reader can help - share information about these missing states and next year there will be fewer states without information. Severn Brown again sends helpful information from the Prospectors and Developers Association of Canada (PDAC). The PDAC Digest contained an article that distinguished between ‘net smelter return royalty' and ‘net profits royalty’ (Haase). The article also lists clauses and details that Brown suggests should be included in a net profits royalty contract.

Jan 1, 1994

By L. S. Jen

The seven most important base and precious metals produced in Canada are copper, nickel, lead, zinc, molybdenum, gold and silver. Because much of Canada's mineral production is exported in the form of concentrates, it is of special interest to keep track of the production of these various concentrates and the capacity utilization of the concentrators producing them. Annual data surveys on individual concentrators, coupled with the interactive capabilities of the computerized mineral product ion system through a custom-tailored, fairly low-cost computer system configuration are used for ongoing monitoring. Rapid analysis of concentrator production can be carried out on a disaggregated basis that allows policymakers to see specific reasons for significant changes over the years.

Jan 1, 1986

By Y. M. Jiang, R. L. Sanford, D. W. Park

Artificial intelligence has emerged over the past two decades as an important problem-solving tool. Techniques include expert systems, neural networks, free classification, fuzzy logic and genetic algorithm. These methods can be employed to solve rock mechanics and ground-control problems associated with the highly complex nature of rock masses and ground conditions. A current study focuses on the development of an artificial-intelligence system for real-time interpretation of data collected from longwall monitoring stations and on the development of an early warning system for the prediction of undesired conditions and the prevention of longwall-mine instability problems. The successful application of these artificial-intelligence techniques will contribute to a safer and healthier mining environment.

Jan 1, 1997

By J. P. Nairn, C. M. McCulloch

More and more underground mining is being conducted using the long wall method. Likewise, many new surface mines use area or mountaintop removal methods. These methods can have a significant impact on surface and ground water resources. The overall study of the effects on surface and ground water from mining is referred to as the probable hydrologic consequences (PHC) determination of mining and reclamation. Collection and interpretation of information concerning ground water and surface water quality and quantity, as well as detailed geologic analysis, is required to adequately define the impacts of mining. This paper discusses the present day requirements and methodology of preparing a PHC for a large mining operation in the eastern coalfields.

Jan 1, 1997

By B. J. Arnold, F. F. Aplan, S. Chander

There is a broad range of chemical reagents of potential use to the coal preparation industry: flotation frothers, flotation collectors (for coal, ash minerals or pyrite) and collector-assisting (conditioning) agents, flotation depressants (for coal, ash minerals or pyrite), pH regulating agents, acid mine drainage treatment chemicals, flocculants, filtration aids, dispersants, dust suppressants (wetting agents and car-top or pile binders), freeze conditioning agents, water treatment chemicals (corrosion and scale inhibitors) and suspension stabilizing reagents (dispersants, stabilizers, biocides). The application of each of these types is discussed with particular attention paid to those of greatest importance: flotation frothers and collectors, pH regulators and acid mine drainage treatment chemicals, flocculants and freeze conditioning agents.

Jan 1, 1986

By D. D. Harbuck, G. K. Green

The Bokan Mountain area on Prince of Wales Island, AK, contains vast quantities of heavy rare earth minerals. To lessen the US dependence on foreign sources, the US Bureau of Mines (USBM) investigated yttrium recovery from this ore. By sulfating the ore at 250 ° C for 1 hr at an H2S04:ore ratio of 1:1 and then water leaching the sulfated material for 1 hr at 20% solids and 25ºC, over 74% of the yttrium, cerium, and lanthanum were solubilized. Solvent extraction (SX), using a synergistic combination of OPAP and DEHPA, selectively loaded 100% of the yttrium. Yttrium was stripped directly as a solid using a 2M, 35 ° C NaOH liquor. When the OPAP/DEHPA mixture was tested in a continuous SX circuit, yttrium loading and stripping were 100% and 96%, respectively. The organic showed excellent recyclability properties with minimal solvent loss.

Jan 1, 1996

By P. Mousset-Jones, F. Calizaya

Ultrasonic anemometry is a relatively new method of measuring the air velocity in underground excavations and is not widely used. The method has been mainly used for surface applications, such as meteorology and fluid flow measurement. Several instruments were looked at to determine their applicability for continuous underground monitoring systems. The units fall into two main categories: variable distance units and fined distance units. The method relies on the acceleration and deceleration of ultrasonic pulses transmitted through a moving airstream. This study presents some of the results of the testing of variable and fixed distance ultrasonic anemometers in a wind tunnel and a mine drift.

Jan 1, 1995

By J. C. May, G. M. Elliott, J. J. Brady

Increased clearance was required in two railroad tunnels that were built about the time of the Civil War. Clearance infringements, whether they be excavation tights or caused by ice accumulation, reduce tunnel serviceability. Achieving increased clearance often means disturbing the ground and old ground support structures. Access and transportation needs dictate how and when the work can be carried out, and strongly influence the design approach and the methods used by the contractor to execute the work. This paper explores the pertinent considerations of the owner, the designer, the field inspection team, and the contractor in bringing this project to a successful conclusion.

Jan 1, 1997

By Joachim H. Schubert, David G. Hulbert, Ian K. Craig, Roger G. D. Henning

This paper presents a stabilizing controller for flotation plants which uses a quasi-multivariable technique. The controller monitors all the levels in the plant, and by anticipating interactions between various parts of the plant, is able to stabilize the plant far more successfully than the normal plant control. Once stabilizing control has been achieved, optimization of the process becomes easier and more sustainable. An estimate of the improvement in metallurgical performance is made and a singular value analysis was conducted to verify that the multivariable algorithm will theoretically control better than a collection of individual PID loops. Metallurgical results are presented to show that the improvements are attainable in practice. Control by the Mintek algorithm was alternated with normal plant control, to show that the improvements are statistically significant.

Jan 1, 1995

By M. J. Klishis

This paper presents the findings of a study on roof bolter's hazard exposure. A "microanalysis" of accident data was combined with ergonomic observations of roof bolter operators to categorize bolting-related injuries, and, from this, a checklist was constructed. Bolting-related problems were identified as situations that could expose bolter operators to hazards. Approaches to avoid these situations were applied at six mining operations to evaluate specific problems in root bolting operations. The research emphasized the importance of analyzing worker behaviors in the context of mining situations and equipment-design problems that lead to human-error accidents.

Jan 1, 1996

By Y. Luo, S. S. Peng

This paper presents some results obtained from research on long-term subsidence over and near chain pillar systems - the area available to long-term subsidence in longwall operations. Although the long-term subsidence for most longwall operations is insignificant, it does exist in some cases. In the cases that showed significant long-term subsidence, it was found that the development process could be expressed by an exponential decaying function. The stability factor of the chain pillar system and the potential for long-term subsidence are the two most important factors that control the magnitude and development characteristics of the long-term subsidence process.

Jan 1, 2000

By D. M. Bodily, R. Jin, W. Hu

Four methods to assess the relative floatability of fine coal have been tested: flotation with frother only, salt flotation, timed-release analysis, and flotation with frother and collector. A practical and simple criterion that combines the separation efficiency (capacity factor) and kinetic rate constant (intensity factor) has been suggested. Five coal Samples from Utah were tested. Based on test results, it was concluded that the floatability test with collector and frother is closer to practice, and according to the suggested floatability criterion, coal fines can be classified into four categories of relative floatability: very easy, easy, moderate, and difficult.

Jan 1, 1988

By J. C. Cawley

Improvements in today's maintenance practices are mandatory as more complex and productive machines evolve in the mining industry. By keeping machine reliability high through improved maintenance procedures, overall mining costs can be reduced. The Bureau of Mines is investigating diagnostic maintenance systems for underground mining machinery. A hydraulic expert diagnostic system and an electric motor predictive diagnostic system have been designed and installed on a Joy 16CM continuous miner. An electrical diagnostic system has been designed and installed on a Joy 14CM continuous miner. Each system is functionally described and the relative merits of expert diagnostic systems versus algorithmic diagnostic systems are discussed.

Jan 1, 1992

By B. K. Parekh, R. H. Mehta

The handling of fine coal is an important issue for both the coal and utility industries. Reconstitution of fine coal in the form of pellets or briquettes would be desirable if it could be done economically. This paper evaluates the effectiveness of three binders, asphalt-emulsion, corn starch and Brewex, informing pellets of ultrafine clean coal. It was found that asphalt-emulsion and corn starch were not effective binders. However, the use of Brewex resulted in pellets that exceeded all of the minimum quality requirements for coal pellets.

Jan 1, 1997

By A. M. Marabini, G. Belardi, E. Spaziani

The objective of this research was to investigate the possible application of integrated circuits to the concentration of talc from the Valmalenco mine, located in northern Italy. The investigation was aimed at producing a high-grade product (low in impurities such as iron and carbonate) that would be suitable for industrial applications. Because of the presence of accessory minerals, the talc concentrate from this ore is not, at the present time, suitable for industrial applications.

Jan 1, 1996

By N. P. Reddy, L. Adler

The valuable Maximum Utilization Factor (MUF) concept has been extended to other rotating excavators beyond Stripping Shovels and Draglines. In this concept the boom reach and bucket capacity are multiplied to get an MUF, then normalized by dividing by the equipment weight. Statistical analyses were applied to the remaining shovels (hydraulic and cable), draglines, and backhoes. Positive correlations were found. Stripping Shovels and Draglines were also re-examined. The results provide an estimate of equipment diggability and encourages versatility by the interchange of the boom and the bucket. The concept further clarifies the existing equipment classification by delineating General Excavating, Loading, and Stripping kinds. The results also forecast trends, and noted innovative advances and possible retrogression. Extension to other boom excavators, such as front-end loaders, is recommended. The MUF concept provides one of the few indices of gross external characteristics available to the engineer-user of equipment.

Jan 1, 1991

By James G. Sampson

The discarded phosphatic clays from mining operations have historically been stored behind earthen dams for long periods of time before any reclamation was accomplished. In efforts to expedite the dewatering and reclamation of the clay ponds, the phosphate industry explored alternatives to conventional clay disposal practices. One alternative, employed by CF Industries, Inc., combines the clay and the discarded sand prior to disposal behind earthen dams. The sand encourages the clays to 'give up' trapped water more readily resulting in enhanced consolidation behavior. This paper provides an overview of the sand-clay mix process including the reclamation of sand-clay disposal areas.

Jan 1, 1992