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By N. Arbiter

Evidence for the floatability of sulphide minerals without collector is analyzed and it is shown that results obtained with ores, in contrast to those with single minerals or mineral mixtures, depend on many additional variables, some identified and others not. Because of the prevailing low levels and costs of collectors for most sulphide ores, it is unlikely that collectorless flotation will have commercial applications, so that continued research on the subject may be justifiable on theoretical but not on practical grounds.

Jan 1, 1993

By P. C. Schmall

Ground freezing has been used for the sinking of deep mine shafts for more than 140 years. While advances in refrigeration technology have refined the overall freezing operation, the basic ground freezing concept remains the same. This paper presents an overview of the ground freezing process and the unique advantages that ground freezing brings to shaft construction. Design and construction considerations, including instrumentation and monitoring, are discussed. Case studies are presented to illustrate ground freezing applications for mine shaft installation.

Jan 1, 2010

By J. A. Domenico

A safe and precise mineral separation alternative to heavy liquids is being used for mineral sands exploration on large scale orebodies. The separation process, Magstream®, uses ferro-fluids and magnetic and centrifugal forces to produce precise split points over a range of specific gravities from 1.5 to 18.0 g/cc. This paper describes a commercial scale exploration program treating, roughly, 90 samples per day in Senegal (West Africa). Separation results comparing Magstream® and conventional heavy-liquid separation are presented.

Jan 1, 1994

By F. Dingwu

The demand of manufacturing high-purity magnetite concentrate leads to the advent of various magnetic separators. A novel magnetic drum separator has been developed with an optimal permanent magnet system and a complex-forces field is adopted, involving magnetic force, gravitation, fluid resistance, friction, inertial centrifugal force, etc. Proper ultrasonic probes are inserted into the bottom tank to break up the magnetic floes. The performance of magnetite in the complex-forces field is described and the optimal operation conditions are suggested.

Jan 1, 1995

By J. J. Webb

At Kerr-McGee's Galatia Mine in southern Illinois, the need for safe and efficient longwall moves prompted a detailed planning effort. Galatia Mine operates two longwalls on separate coal seams with different geologic conditions. An overview of the longwall move planning as related to manpower training, roof control, ventilation, transportation, equipment recovery and setup will be discussed. The impressive safety record achieved during each of the longwall moves at Galatia Mine verifies that health and safety planning does play a major role.

Jan 1, 1994

By J. G. Groppo

Laboratory settling and filtration testing was conducted on wet processed fly ash in order to determine the applicability of conventional dewatering techniques to reduce the moisture content prior to drying. Settling tests showed that acceptable clarity (<1.5 g/l suspended solids) could be achieved after as little as 6 minutes of settling. After settling to a consistency of 40 weight % solids, continuous laboratory vacuum filtration testing produced a cake containing below 20% moisture with throughput exceeding 150 lb/ft2/hr.

Jan 1, 1997

By J. J. Antony

The Cactus Gold Mine is a joint venture comprised of Middle Buttes Partners Ltd. (CoCa Mines, Inc.--operator, T. Congdon and W. Carey) and Compass Mining, Inc. The project includes 2.4 sq. miles of contiguous mining claims and leases in the Mojave Mining District, Kern County, California, approximately B5 miles northeast of Los Angeles. The property is readily accessible year round by all-weather roads and is within 6 miles of the main line of the Southern Pacific Railway.

Jan 1, 1988

By A. R. Laplante

The mineralogy of the Joe Mann mine differs from that of other deposits of the Chibougamau area that are exploited by Les Nines Camchib Inc. It is characterized by very fine first generation gold and very coarse second generation electrum. Successful processing required adjustments of the processing flowsheet, which includes gravity, flotation, and cyanidation. A study of coarse gold liberation in the gravity/grinding circuit is described. Modifications to the flotation circuit and the reconditioning of a small capacity cyanidation circuit are presented.

Jan 1, 1989

By E. Fahrenkrog

An intelligent supervisor developed using expert system tools and applied to a crushing plant is presented in this paper. The structure of this supervisor, based on a model of a human operator, consists of a Knowledge base containing a qualitative model of the process, and a Rules base with the heuristic logic used by an operator when supervising a plant. The simulation results obtained show the potential of this type of systems to supervise the automatic operation of a plant.

Jan 1, 1989

By R. O. Burt

The paper examines the role of gravity concentration in both an historical contest and within the modern mineral processing industry. It discusses the principles of the process on both a theoretical and practical level. The importance of ore mineralogy and its effect on the choice of the wide range of equipment available is discussed. The paper concludes with a discussion on the relative merits of gravity concentration to other forms of processing and seeks to answer the classical question - "Quo Vadis?"

Jan 1, 1982

By Colin D. Jardine

Rapidly increasing energy costs and more rigid customer quality requirements necessitate improved control of pelletizing processes. With the introduction of dedicated microprocessor-based controllers, sophisticated control strategies are now possible. A recent application of this technology at Carol Project has resulted in fuel savings, improved pellet quality, and standardization of operating procedures. This was accomplished with no production loss by the use of a "building block" approach to design and equipment selection. Details of this approach and the results obtained are described.

Jan 1, 1982

By K. Ueda

Lead concentrates from Kuroko (black ore) mines, which contain Cu 4 ? 7%, Pb 55%, Zn 3 - 7%, As 0.5 - 0.9% are treated by hydrometallurgical process in order to smelt the product by electric furnace smelting together with other lead resouces from Kuroko. The hydrometallurgical pretreatment involves sulfuric acid leaching at first stage, ferric leaching at second stage. This paper describes the short history of lead recovery from Kuroko and the performance of laboratory test, pilot plant and commercial operation.

Jan 1, 1982

By R. F. Davis

The evaluation and selection of coals for producing metallurgical coke is indeed a com- plex process simply because coal is a complex and variable substance which is sensitive to how it is treated from the time it is mined until it is transformed into coke. A review of the the more common evaluation tests made on coal and how the test results are applied in commercial practice. Parameters used to select coal blends for wet and preheated charges should also be of interest.

Jan 1, 1980

By A. MacG. Robertson

Where weak rock zones are encountered in the slopes of an open pit, they may control pit wall stability. Back analysis of slopes involving failure through weak rock enables an estimate to be made of the weak rock strength. A system of consistent rock mass classification is described which enables the weak rock mass material to be described and classified from drill hole core. Correlation with back analysis determined strength allows strength estimates to be assigned to each rock mass classification.

Jan 1, 1988

By J. L. Vanderbeek

Investigations have been conducted at Chino Mines Company into the effect that SAG mill recycle material (critical size) exerts on SAG mill throughput and specific energy requirements. Tests were conducted on the laboratory, pilot, and plant scales, to evaluate the merits of alternative treatment options. Removing critical size material from the SAG mill circuit has been shown to improve new feed rates by 34% with a reduction in specific energy (kWh/ton) of 33%. Test results obtained to date are presented.

Jan 1, 1985

By Kenneth A. Pietila

The thickening and dewatering characteristics of refuse slurries are as variable as the coal mining operations and preparation plants that create them. This paper discusses these characteristics based on field studies at a number of mine sites. The connection between bench and full scale performance is confirmed with the design, construction and operation of an integrated 18m (60 ft) diameter thickener and 2.5 meter belt filter press system in Western Kentucky. The data from this system are presented.

Jan 1, 1984

By D. L. Passmore

The development of microcomputer software that provides an analysis of pit-specific accident and production data for the mining industry is seen as a vital component in a total loss-control system. The Mine Injury Reporting System (MIRS) allows users to access accident and production data prepared by the Health and Safety Technology Center of the Mine Safety and Health Administration of the United States Department of Labor for any particular state and to generate a simple, yet informative, report.

Jan 1, 1988

By H. Colijn

Vibratory or oscillatory conveyors can be found in all types of industry, handling virtually any granular bulk material, often at elevated temperatures. These conveyors can be combined with other process functions, such as screening, cooling, drying and dewatering, while conveying. Although construction and installation is relatively simple, the engineering and design analysis of the vibratory mechanics is fairly complex. This paper will discuss the basic types of vibratory conveyors and the analysis of the material movement along the carrying trough.

Jan 1, 1985

By Robert H. Scott

Developments during the past few years have brought coal-based composite fuels to commercial readiness. During the next few years, composite fuels will become available from a number of suppliers. Potential users must evaluate the combustion properties of these fuels to determine equipment and operating changes required for their use. Most work to date has been done with boiler applications. However, many potential non-boiler applications exist in the metals and minerals industry. These applications require specific evaluations appropriate for the processes involved.

Jan 1, 1982

By Joseph M. McCann

The Brightwater regional wastewater treatment facility, under construction in King County, WA, includes an extensive conveyance system that will feature deep, soft-ground tunnels and shafts. Excavation of the Ballinger Way Receiving Portal to 65.8 m (216 ft) below grade through challenging geology was accomplished by means of artificial ground freezing. This paper discusses freeze design development, system installation and monitoring, and the contractual and construction challenges that were overcome, including work sequencing and excavation means and methods, together with lessons learned.