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By M. S. Prasad

This paper presents the process methods of beneficiating various copper-cobalt and copper-zinc ores mined by Gecamines in Zaire. Geology and mineralization of both sedimentary and vein-type deposits are described with special emphasis on the production of oxide, dolomitic and sulfide concentrates. Description of different types of concentrators and their treatment methods are discussed for the production of sulfide, oxide and dolomitic concentrates. Production of concentrates, their consumption and stocks are briefly reviewed. Modernization of the concentrators with substantial investments on grinding, classification, flotation methods and tailings treatments are also discussed and to improve the metallurgical efficiency of 'the concentrators to improve the production quality and quantity of concentrates.

Jan 1, 1992

By P. R. A. Andrews

Magnesite, brucite and dolomite occur widely throughout Canada, but deposits of economic significance are found only in Quebec, Ontario and British Columbia. Magnesite occurs in all three provinces, brucite in Quebec and Ontario and dolomite in Ontario. Beneficiation of refractory magnesium minerals has been the subject of many investigations at CANMET and the former Mines Branch. Twenty-three magnesite, four brucite and nine dolomite evaluation studies were conducted between 1920 and 1974. A review of some of the more important studies is presented. The information includes mineralogy, beneficiation methods and flotation data.

Jan 1, 1995

By E. Forssberg, Y. Zeng

Fine crushing and rod grinding have been investigated using a laboratory-scale jaw crusher and a rod mill. The net energy consumption in both crushing and grinding was evaluated from torque measurements. An empirical relationship was established between energy consumption, particle size and operating parameters. When the mill feed size is reduced, through fine crushing, to about 80% passing 3 mm, the energy consumption will be minimized in a comminution chain of fine crushing and coarse rod grinding. The results in fine crushing were compared with a large-scale test.

Jan 1, 1993

By X. Zhou

A novel flotation device, cyclonic static micro-bubble column flotation (FCSMC), was introduced in this paper. FCSMC has been widely applied for fine coal preparation in China, and its application has been further expanded to the mineral processing industry. The FCSMC system features a unique cyclonic structure which enhances the separation performance of the column. In this paper, the cyclonic separation mechanism of FCSMC process was investigated, and corresponding kinetics equations were established to probe the separation principle of this device. Some typical examples of using FCSMC to separate different materials including coal, copper, fluorite, etc., were presented. Key words: cyclonic static micro-bubble flotation column, cyclonic separation

Jan 1, 2008

By Jose M. Milian, Raphael F. Matson

An intensive study was started in 1968 to determine the most economical process for winning nickel and cobalt from an extensive de- posit of complex, low grade nickel-cobalt ore (1.6% Ni, 0.10% CO) designated "the Greenvale ore." In 1974 the commercial plant at Yabulu, in Queensland, Australia, began processing the ore. In the interim, a great deal of laboratory and pilot-plant effort was applied to develop technical, process and commercial design data to demonstrate to potential financial backers and customers that a full-scale plant was feasible. The laboratory test work, pilot plant facilities and pro- gram are briefly reviewed in this paper.

Jan 1, 1979

By Richard M. Crowell, Laurie M. Tahija, Keith D. Dagel

Echo Bay Mines Ltd. operates a gold heap leach in Round Mountain, Nevada, U.S.A. In the past two years, the mine has expanded operations from 13.5 kt/d (15 kst/d) to 41.0 kt/d (45 kst/d), making it the world's largest gold heap leach operation. The expansion is a separate system from the previous 12 year old plant, yet very similar. The flowsheet contains open circuit primary, secondary, and tertiary crushing with interstage screening. A leach pad stacker loads reusable asphalt leach pads. The process plant features carbon adsorption, pressure strip, electrowinning, and electrorefining.

Jan 1, 1990

By J. Ragot, D. Maquin, N. Heraud

Acquisition of coherent and representative data about the state of processes remains a major problem of process control. This paper proposes an approach that ensures coherence in measurements on an operational industrial process. The basic technique employed relies on balance equilibration of resource mass flow. An interesting particularity of the set up is the ease with which it can be adapted to check productivity or detect sensor failures. In the case of sensor failure, it suffices to examine the evaluations before and after balance equilibration. The algorithm was tested by means of computer simulation using data from an industrial metallurgical flowsheet.

Jan 1, 1992

By K. E. Kolm, W. H. Langer

Developing natural aggregate resources (sand, gravel and stone) creates environmental impacts. A systems analysis method was designed to characterize the components of the environmental system, identify potential impacts to those systems and evaluate the extent of those impacts. The stepwise method consists of problem definition, data collection, preliminary conceptualization and characterization, additional data collection, data analysis and refinement. The method requires analyzes of various systems making up the environment, including land surface, geomorphic, subsurface and groundwater systems. After system characterization is complete, the method focuses on identifying and evaluating potential environmental impacts to determine acceptable mining strategies.

Jan 1, 2003

By H. Y. Sohn, H. K. Lin

The leaching of primary porphyry chalcopyrite ore under simulated solution-mining conditions was studied using a packed-bed reactor. A mathematical model incorporating the intrinsic leaching kinetics of chalcopyrite and pyrite grains, the pore diffusion of dissolved oxygen within the ore fragments, liquid-solid mass transfer, and the effect of fluid flow and axial dispersion was formulated and tested for the overall leaching process. The dependence of oxygen solubility on ionic strength of the solution was also incorporated into the model. Satisfactory agreement between model pre- dictions and experimental data was obtained. The model can also predict the rate of the leaching process under different temperatures, oxygen pressures, solution flow rates, and different size distributions of ores.

Jan 1, 1991

By Peter K. Weissenborn, Robert J. Pugh

The contrasting behaviour of electrolytes in inhibiting coalescence of bubbles was explained by the positive and negative distribution of anions and cations at the gadwater interface. Further, the efficiency of electrolytes which do inhibit coalescence of gas bubbles can be linked to a counter ion hydration mechanism and the effect of electrolyte concentration on gas solubility. A correlation was found between the transition concentration of electrolyte needed to prevent the coalescence of bubbles and the reduction in gas solubility. Hence, the inhibition of bubble coalescence in electrolyte solutions appears to be linked with the utilization of water molecules in the hydration of cations and a consequent reduction of water available for gas solubility.

Jan 1, 1995

By J. C. McLaughlin, Bill A. Hancock, David J. Meacham

Great Salt Lake Minerals (GSLM) uses flotation to utilize low grade harvest evaporites in the leaching/ crystallization process. A final potash product coloration problems was encountered that was attributed to AERO• 801s promoter - magnesium ion precipitation in flotation which carried into the dissolution/crystallization circuit. Bench studies resulted in changing 801s to 845 which provided acceptable product brightnesses and higher flotation potassium recoveries. This is a case history reviewing the unique GSLM processing scheme, the bench and plant work identifying the potash quality problem, the bench work and solution, and subsequent process study and circuit optimization efforts.

Jan 1, 1993

By Edmond O’Donovan

Selection of conveyor drives is an area of great confusion that frequently leads to poor system performance or overcapitalization. Many papers have dealt with the performance characteristics of different drive types, but users have often found that this only leads to further confusion. This paper presents the drive requirements from the "conveyor's" point of view. The drive requirements of different classes of conveyors are examined to illustrate why some drive types work well in certain situations but poorly in others. The appropriateness and shortcomings of different drives are examined in this context, along with the recurrent issue of load sharing.

Jan 1, 2000

By James H. Lammers

Over the years, the chemical processing industries have con­tinued to move from batch to continuous processing in order to obtain better quality control, simpler designs, and often reduced capital and operating costs. One exception to this trend has been the carbon elution circuits in the gold industry. Although some successes have been achieved on a pilot scale, no continuous elu­tion circuit using Anglo American Research Laboratory (AARL) methods has ever been used on a commercial scale until now. This paper describes the continuous elution circuit which was recently commissioned at a major gold project. The paper also presents the economic justification for the selection of the process over conventional batch technology.

Jan 1, 1998

By Edward C. Spalding

The mineral estate of Arizona's State Trust lands, which are administered by the State Land Department for the benefit of the common schools and 14 other beneficiaries, totals more than 10.5 million acres, or almost 15 percent of the State's entire area. Trust lands exist in all 15 of the State's counties, with the most and least acreage found in Yavapai and Gila Counties, respectively. Revenues derived from the Trust mineral estate include royalties, rentals, and fees. In Fiscal Year 1983-84, these revenues amounted to $4.2 million, or 13.5 percent of all income received by the Trust during this period. Industrial minerals, led by sand and gravel, contributed $1.1 million from 82 active properties.

Jan 1, 1987

By F. M. Doyle, S. M. El-Raghy, M. F. El-Demerdash, E. Peters

The Activity Distribution Diagrams (ADD) developed by the authors are computed for Cu-S-H2O and Mo-S-H2O systems. The distributions of metal and sulfur between all species are estimated against pH at different potential levels. Both M-H2O and S-H2O distributions are compared to the M-S-H2O distributions to estimate the changes occurring due to the presence of sulfur. The method of computation follows the Activity Term Criterion, taking into consideration the multi-equilibrium interrelations and conservation of mass. Results are analyzed in terms of dividing a distribution curve into three basic segments. These segments are formation, stability, and dissolution.

Jan 1, 1993

By H. Kandemir, G. Neeling, P. A. Spencer

Gold extractions from three refractory sulphide concentrates have been increased by bacterial oxidation with T. ferrooxidans prior to cyanide leaching. Arsenopyrite, pyrite and stibnite were the major sulphide components associated with gold in the concentrates examined. Kinetic oxidation tests were conducted for each concentrate by monitoring iron and arsenic levels in leach slurry. A correlation has been established between the level of bacterial oxidation and gold extraction from cyanide leaching of oxidised residues. High levels of bacterial oxidation have been achieved in approximately 8 days at pulp densities of 20-25/ w/v solids, resulting in 70-90% gold extraction.

Jan 1, 1987

By Jasna Jurjovec, David W. Blowes, Carol J. Ptacek

At the Kidd Creek site, natrojarosite residue, derived from the zinc refinery circuit, is mixed with mill tailings before final disposal in the tailings impoundment. Column experiments were conducted with fresh unoxidized mill tailings and a mixture of tailings containing the natrojarosite residue. Acidic water, simulating mine drainage water, was pumped through the columns. The effluent water geochemistry was interpreted with the assistance of MINTEQA2. The experimental results suggest that the effluent water pH was buffered by a series of acid neutralization reactions. The release of metals, including Cu, Pb and Zn, was affected by pore water pH, Eh and mineralogy of the tailings material.

Jan 1, 2000

By Robin B. Steven

Rio Tinto's Kennecott Bingham Canyon Mine is one of the largest open pit copper mines in the world. In 1988 they completed a $400 million project using a conveying system to transfer the ore from an in-pit crusher to the concentrator. The longest conveyor, C-6, was 17,352ft long and ran in a tunnel through the mountain-side to the concentrator. The belt was removed after 14+ years after carrying 700 million tons of 10 minus ore. The paper discusses the original G6 belt's performance and new splicing methods used to achieve a 60% dynamic splice efficiency on the replacement belt.

Jan 1, 2004

By K. H. McDaniel

Eight mine weather stations (MWSs) installed at the Waste Isolation Pilot Plant (WIPP) to monitor the underground ventilation system are helping to simulate real time ventilation scenarios. Seasonal weather extremes can result in variations in the natural ventilation pressure (NVP), which can significantly affect the ventilation system. The eight MWSs, which previously collected and stored temperature, barometric pressure and relative humidity data for subsequent NVP calculations, were upgraded to provide continuous real time data to the site-wide central monitoring system. These data can now be utilized by the ventilation engineer to create real time ventilation simulations and can indicate trends that assist in the prediction and mitigation of NVP and psychrometric related events.

Jan 1, 1999

By J. W. Wilson, Y. Ding

In the ultrafine coal-cleaning process, small coal particles (-400 mesh) are produced during the pulverizing operation. After the coal-cleaning process, these ultrafine particles are very difficult to dewater and create problems in coal transportation, storage and handling at utility plants. Research on ultrafine coal dewatering and briquetting resulted in the development of a single-stage operation that is potentially more effective and economical than conventional thermal drying and briquetting processes. The final coal product has a moisture content of less than 15% and possesses high strength and water resistance that satisfies coal transportation, storage and handling requirements.

Jan 1, 1996