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By W. Petruk

An investigation was conducted to determine the minimum number of samples that must be studied by image analysis of polished sections in order to characterize a mill product and to determine the apparent mineral liberation. It was found that a representive polished section cannot be prepared from an unscreened sample that has a wide size range of particles. Similarly individual screened' fractions are not representative of the sample because minerals are partitioned during screening. Consequently the quantities of soft brittle minerals are increased in fine grained fractions and quantities of hard minerals are increased in coarse grained fractions. It is assumed that results obtained by combining data for a series of narrow size range screened fractions (1 Tyler size range) are representative of the sample, and relatively accurate apparent mineral liberation data can be obtained for a mill product by analysing each fraction and combining the data. Somewhat less accurate data would be obtained by analysing a series of screened, fractions that have a wider size range of particles (5 Tyler size ranges). Mineral liberation analyses show that the most reliable apparent mineral liberation in each screened fraction is a value taken from a smooth curve drawn through the lowest points on a graph of % free vs size. A correlation between the apparent mineral liberation in screened fractions and calculated mineral liberations using Kings liberation model is good for sphalerite but not for chalcopyrite and galena.

Jan 1, 1985

By J. Alderman

In modern industry, cost and productivity concerns and environmental concerns are sometimes incompatible, but at other times only appear to be incompatible. Surface disposal of wastes from coal preparation plants appears to be an area of the production system with little opportunity for initiating measures which cut costs and concurrently benefit the environment. However, improving the recovery efficiency of fine coal circuitry can cost-effectively reduce the plant waste environmental burden by a substantial amount. Studies at Jim Walter Resources indicate that fine-coal waste measuring 50% ash contains over 50% recoverable, marketable coal. Modifications to the plant circuitry which reduce the amount of misplaced coal in the fine-coal waste stream could substantially reduce the volume of fine waste disposed aboveground. Studies at Jim Walter Resources indicated that episodic overloads of the vacuum filters in the fine-coal circuits at the preparation plants were a source of misplaced coal in the fine-waste stream of the cleaning plants. To improve the filtration rate and reduce overload episodes, conventional rotary blowers were replaced with high pressure air blasters on most of the filters. Subsequent testing indicated that measurable benefits can be derived from this modification.

Jan 1, 1990

By M. L. Free

Acid consumption in copper heap leaching is determined by the minerals present in the ore. Gangue minerals such as biotite and chlorite consume acid together with copper-bearing minerals such as chrysocolla and malachite. Acid consumption is affected by the rate of acid application and the particle size. Some gangue minerals undergo alterations and cause precipitate formation during acid leaching. Other minerals form due to precipitation as dissolved ion concentrations from a variety of mineral sources combine to exceed saturation levels. Copper recovery is related to all of these events. This study presents information on acid consumption of various gangue minerals as well as data for copper recovery from an associated copper ore.

Jan 1, 2010

By G. A. Kordosky

Solution mining followed by solvent extraction-electrowinning (SX-EW) is one possible way to economically extract copper from ore bodies which cannot otherwise be profitably exploited. Published costs for the unit processes of SX and EW are out of date especially in view of the newer reagents now available and the newer circuit configurations, This paper updates the costs for SX-EW in 1985 dollars and also discusses some of the trade-offs which must be made when designing an SX-W plant.

Jan 1, 1986

By Ronald J. Roman

As in every business venture, the primary objective of a mining operation is to make money for those who supply the venture capital. Therefore, all decisions concerning the operation of the mining operation should be made in light of the resulting effect on profit. The ultimate control is on profit, but the process is controlled, for example, by aiming for a recovery or concentrate grade knowing its effect on profit. The normal procedure used to determi.ne the profitability of a venture is to "present worth" all costs and incomes back to some arbitrary year zero. Every company has formed a management decision as to what it will require as a minimum return before it will undertake an investment. Once the economic analysis is completed, investment will be made only if the venture shows a positive present worth. If two alternatives are available, the alternative with the larger positive present worth is the one chosen. The same principles can be applied to the selection of a production schedule.

Jan 1, 1971

By G. Heinrichs

This paper is intended to provide information for one to be able to determine the slurry system head curve for pump applications. The slurry characteristics are the basis for what the size, material of construction, and critical carrying velocity of the pipe will be. The system head curve is adjusted by use of the pipe friction coefficient factor and slurry derate factors. An example using multi-staging of slurry pump curves is presented to compare the wear life relationship of pump parts for a tailing pipeline system head curve.

Jan 1, 1996

By S. K. Kawatra

A high calcium fluid-bed combustor ash has been shown to be an effective binder at dosages of 1 to 2% of the magnetite concentrate weight. Magnetite pellets 1.3 cm (1/2 inch) in diameter were produced with dry crushing strengths greater than 22.3 Newtons/pellet (5.0 pounds force/pellet), which is comparable to the results produced using conventional bentonite binder. The effectiveness of fly-ash-based binders was considerably improved when calcium chloride was added as an accelerator. Addition of calcium chloride at a rate of 0.1 to 0.2% of the total powder weight increased the strength of dried pellets by as much as 22% compared to the strength of pellets made using fly-ash without accelerators.

Jan 1, 1997

By R. R. Klimpel

This paper describes a series of mechanical flotation cell results run with various chemical reagent schemes designed to economically improve the flotation performance associated with selected industrially available coals. The emphasis is on the identification of practical flotation methods of processing coals containing unusually coarse and/or fine feed sizes, of increasing the recovery of oxidized and/or difficult to float coal, and of increasing the selectivity of coal over pyrite in high sulfur coals.

Jan 1, 1991

By J. B. Lott

The authors' company has recently undertaken a development programme aimed at exploring the relationships between the variables of greatest importance in the design of mixer-settlers for metallurgical solvent extraction applications. Such applications vary from relatively small scale plants treating copper mine waters, nickel containing effluents, etc., where the total flowrates may be of the order of a few hundreds of gallons per minute, to very large scale plants treating several thousands of gallons per minute of leach liquors containing copper, uranium or other metals. This paper outlines the physical and mechanical factors which must be taken into account when designing mixer-settler systems for large scam. solvent extraction plants. The performance of the equipment will also be dependent upon the chemistry of the system, including the kinetics and thermodynamics of the ion exchange reaction itself, the effect of impurities flocculants, surfactants, temperature, etc., but these will not be dealt with here. Much of the laboratory work has been carried out using copper containing solutions and either LIX 64* or LIX 64N* as the solvent dissolved in various grades of kerosene. For simplicity, all the graphs and tables of results which are presented and discussed here will refer to the LIX-copper system, although the conclusions will in many cases be generally applicable to other systems also. The LIX-copper process is now sufficiently well known to obviate the need for a full description, however, an outline flowsheet of the process is shown in Figure 1. The ultimate objective of a laboratory programme for a particular extraction application is to provide data upon which a mixer-settler system can be designed to handle a given throughput of leach liquor and extract from this liquor the maximum quantity of metal for the minimum cost. In other words, the objective is to determine the design and operating parameters which achieve the optimum balance between capital and operating costs. * Trade-marks for General Mills solvents.

Jan 1, 1971

By Summers D. A.

A mining machine has been designed and fabricated to mine coal from room and pillar operations combining high pressure waterjet cutting and mechanical fragmentation. Waterjets are used to slot the coal face with an advancing plow wedge then breaking out larger coal pieces. The machine has the following advantages: - simply built around a disassembled longwall chock and gathering arm loader apron; - few moving parts which are simply and inexpensively maintained; provides immediate roof support in the face working area; - coal produced is larger, with resulting lower preparation cost; - no dust is generated; - risk of spark generation is virtually eliminated.

Jan 1, 1992

By J. E. Urosek

The Mine safety and Health Administration (MSHA) formed the Mine Ventilation Bleeder and Gob Training Committee in 1993. This committee was charged with developing a training course designed to enhance the knowledge and understanding of practical bleeder ventilation systems. The course will probably include a discussion on the theory behind bleeder system design, an in-depth look at the strengths and weaknesses of the basic bleeder system types, case studies, and a review of the systems currently in use. A database on active underground bituminous coal mines, gob areas, and the bleeder systems presently used was developed from questionnaires distributed to nine Coal Mine Safety and Health (CMS&H) districts. Representative systems were selected for thorough investigation to develop case studies. This paper introduces some of the material to be included in the course, including a description of basic bleeder system designs, a review of a portion of the database, and facts about the gob areas and bleeder systems investigated for the development of case studies.

Jan 1, 1995

By Allen Latham

It started' in 1936 when some Dutch adventurers wanted to scale the highest mountain in the South Pacific. Quite by accident, they discovered the Ertsberg, a contact deposit of magnetite laced with chalcopyrite, in a high mountain valley where it had been gouged at by glaciers and finally left as a solitary pillar for its discovery by a geologist who lent purpose to the expedition, Dr. J.J. Dozy. By the-.time a report was published describing the deposit, war had hit the Netherlands. Perhaps again by accident, the report was uncovered in 1959 by the East Borneo Company. At this point, Freeport entered the scene through its vice president for exploration, Forbes Wilson. During the course of a meeting on laterite prospects, the Ertsberg was introduced and he put the wheels into motion for Freeport to join in its exploration. You might, at this point, ask yourself whether you or your company would have taken on a venture to look at a reportedly large high grade copper outcrop in New Guinea, an unexplored land known best for its inhospitable climate, terrain and head-hunters. I heard the chief executive of one large mining company comment sometime back that neither he nor his company would have gotten involved. I won't attempt to describe the trials of the initial exploration expedition that passed through dense-man grove swamps, tropical jungle and across jagged mountains a distance of some 200 miles to get to the Ertsberg in 1960. It should be chronicled by its participants - Forbes Wilson, Del Flint, and John Bowenkamp. Needless to say, the participants relish the experience but wouldn't be among those volunteering for a return engagement. As a result, the Ertsberg changed from a reported outcrop to a mineral deposit containing an estimated 13 million tons with systematic surface sampling indicating a copper grade of over four percent. Moreover, the deposit extended to an indeterminate depth with the possibility of doubling or tripling. reserves well within reason.

Jan 1, 1971

By J. P. Allen

Cobalt, nickel, and manganese can be recovered quickly, cleanly, and selectively from cobalt-rich manganese crust by leaching in dilute acid solutions in the presence of hydrogen peroxide. Common selective precipitation methods can then be used to recover these metals from the leach liquor. The leaching reaction produces only oxygen as a byproduct, and the waste residue from leaching was tested and found to be non-hazardous under existing EPA specifications. The leaching process is effective in either fresh water or seawater. This research is a part of the Bureau of Mines program to identify the mineral resources of the Exclusive Economic Zone and devise methods for recovering their valuable components.

Jan 1, 1990

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 Artur Skoczylas, Paweł Stefaniak, Sergii Anufriiev, Wioletta Koperska, Maria Stachowiak

In many underground mines the excavated ore is produced during the blasting process. Drilling machines that are used to drill the blastholes, where later the explosives will be mounted, are crucial for this task. In order to optimize the currently used techniques, great emphasis is placed on increasing the efficiency and safety of blasthole drilling operations. The natural consequence is the development of monitoring systems and algorithms for processing operational and historical data. In this article, we present the result of the analysis of drilling data carried out as part of the IlluMINEation project. The paper proposes an algorithm for work cycle detection for drilling machines, together with the estimation of general operating parameters and diagnosing the drilling process on the basis of long-term data. Based on the available data, selected components of the drilling cycles have been indicated. Several approaches based on the parameters of the defined cycles are proposed. These approaches can be used in the future to create a full-fledged system for examining the effectiveness and safety of mining drilling rigs.

Jun 25, 2023

By J. Richard Tonry

In portland cement manufacturing, the raw materials axe changed to clinker in the burning operation. Generally the rotary kiln is used for this purpose and involves many processes, including pelletizing and nodelizing. This transformation is called clinkering, and is analyzed as now generally practiced in cement making, from the raw material to the resulting clinker.

Jan 1, 1963

By L. M. Gochioco

The Seismic Interactive Interpretation Workstation (IIW) integrates various sets of geophysical and geological data to form a network of information which is stored in a database. Computer models are generated from known drillhole information and later correlated with the processed seismic data. Seismic color processing adds another dimension to the interpretation process. Complex trace attributes provide better definition of subtle features not easily observed from black and white sections. Utilizing the computer workstation, the explorationist gains valuable insight and conducts more intelligent interpretation of seismic data through a more comprehensive network of data analysis.

Jan 1, 1989

By J. C. Irvine

A recent development in underground drilling has been the introduction of the down-the-hole drill, an old and very familiar tool to the surface operator. The idea of moving such a rig underground is not new. Tests were conducted at INCO in Canada and Mt. Isa, Australia in the early 1960's, and St. Joe used one for underground exploration in their Missouri lead mines in the mid-1960's. However, the trend to full scale production programs did not start until the mid-1970's. The first successful North American test was at INGO in early 1973. This led to a large-scale pillar recovery and open stoping program which en¬compassed 25 drilling units by mid-1976. Meramec Mining Company tested a unit using air boosted up to 200 psi (140, 000 kg(m2) in the summer of 1973 which by 1976 led to an open stope and pillar drilling program using 12 units. By mid-1976, production units using boosted air were also in use at Pilot Knob in Missouri and at St. Joe in Balmat, New York. Experimental and utility units were in use in several other mines and down-the-hole drills were being seriously considered for at least one major new underground mine.

Jan 1, 1976

By C. Cristoffanini

A real-time transient pipeline simulation was used to model the operational pressure response in the concentrate and tailings pipelines of the Minera Los Pelambres copper mine in Chile. A high-fidelity simulator was needed to train the operators on safe operation of the pipeline for different scenarios. A simulator that solves the transient equations was used to dynamically predict the pressure and flow throughout the pipeline to provide real-time responses to operational changes such as opening or closing a choke valve, or sending a water batch. Slurry rheological properties were incorporated into the model. This paper presents the technical background of the pipeline simulation model and the study of slurry properties. The paper shows the results of the transient simulation for different operating scenarios such as start-up, shutdown and leakage, by presenting the hydraulic gradient curves for each case. Finally, the paper briefly presents how the simulator was connected to an emulated control system and used to train the operator, it demonstrates the most effective tool available to learn to resolve undesirable conditions.

Feb 23, 2014

By M. Misra

Improved liberation and flotation of kerogen from eastern oil shale were accomplished with high-temperature grinding and a1 so with the addition of fuel oil during the grinding stage. Liberation measurements indicated that possible coalescence and aggregation phenomenon of kerogen particles during grinding may reflect this behavior. Additionally, ultrasonic treatment of the rougher concentrate prior to cleaning improved the quality of separation.

Jan 1, 1984