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By E. L. Gillenwater

Coal mine planning has three distinct decision levels: (1) decisions made at the upper level of management that determine production requirements for specific mines, (2) decisions made at the middle management level, the mine level, that determine how the mine satisfies its production requirements, and (3) decisions made at the operating level of management, the sectional level, that determine the sequencing of machine movements at the face. In this paper, the underground production scheduling problem is formulated in multi-stages using the Hierarchical Production Planning (HPP) approach. Two linear programming HPP models for accomplishing decisions at the first two levels are developed. Both models address the aggregate production planning process. The Mine Production Scheduling (MPS) model permits determination of monthly production and inventory levels. The Section Production Scheduling (SPS) model incorporates a quality blending requirement into the determination of weekly sectional production and inventory levels.

Jan 1, 1995

By W. K. Connor, O&apos

The Bureau of Mines is investigating the Co and Mn resource of the West-Central Arkansas District, including field investigations, mineralogical characterization, beneficiation, and hydrometallurgical tests. The deposits occur within the Ouachita Mountains and are con-trolled structurally, occurring along the axes of anticlines making up the mountain ridges. Brecciated novaculite is cemented with a mixture of Mn oxides, primarily cryptomelane and psilome-lane. Cobalt is concentrated within a particular Mn oxide phase, lithiophorite. Chemical analyses on head samples reported up to 25 pct Mn and 0.17 pct Co. Magnetic separation yielded products with up to 41 pct Mn and 0.22 pct Co at recoveries of 95 pct Mn and 93 pct Co.

Jan 1, 1991

By Tony Szwilski

A correlation between the rank, ash content and coal seam discontinuities and coal strength/stiffness is discussed. Rebound hammers were used to evaluate the strength properties of two coal seams. The coefficient of variability of the rebound tests are compared with those of laboratory compressive strength tests by other investigators.

Jan 1, 1985

By Felicia F. Peng

The plant data were collected from three streams around a dense medium drum for coarse coal cleaning operated at various volumetric ratio of medium-to-feed. The effect of the volumetric ratio of medium-to-feed (MF) and particle sizes on the performance criteria, g50 and Ep, of the dense medium drum. These measured data were adjusted and calculated for the yields and balanced relative density distributions by mass balanced method based on the statistic principle. These balanced data were then used to formulate the mathematical models of the separation distribution curves for the various feed size intervals. The correlation equations for the g50 and Ep as the function of inverse of the feed size, and MF and total throughput were established. A numerical algorithm utilizing the Secant method, based on the root searching principle, was developed for yield optimization and simulation of dense medium drum separation to improve the separation efficiency and hence the product yield. The relationships between the direct ash content and relative density of the particles in feed and the products were established and incorporated into the numerical algorithm for predicting the product quality.

Jan 1, 1996

By J. J. Poveromo

"Iron ore for alternate iron processes concerns alternate iron products designed for use in EAF (electric arc furnace) steelmaking processes. These alternate iron products include both DRI (direct reduced iron), HBI (hot briquetted iron) and merchant pig iron. Merchant pig iron can be produced in conventional blast furnaces, mini blast furnaces (including charcoal BF's) or novel processes such as RHF/SAF (rotary hearth furnace/submerged arc furnace) such as Iron Dynamics or RHF such as Mesabi Nugget. These novel processes are coal based and can use iron ore concentrates or recycled steel plant oxides. The blast furnace processes can use conventional feed materials: pellets, sinter, lump ore and coke. However, DRI and HBI processes are predominantly pellet based but require DR grade pellets that are low enough in acidic gangue (SiO2 and Al2O3) to avoid additional expense in the EAF process This paper will focus on the quality and availability of DR grade pellets for NAFTA DRI/HBI plants but also concentrates for fines based processes and feed materials for merchant pig iron production. INTRODUCTION This paper will outline alternative (to the blast furnace) competitive ironmaking processes and process routes. Within each section the types of iron ore to be utilized will be discussed. Before discussing some of the details of these processes, it may be appropriate to review some definitions and commonly used terms within this industry. DefinitionsDirect Reduction: Reduce iron oxide to metallic iron without melting. Unreduced ore compounds remain as undesirable oxides • Direct Reduced Iron: Iron oxide feedstock exits in same form as entered (pellets in, pellets out; lumps in, lumps out) • Hot Briquetted Iron: DRI that has been hot (1200°F, 650°C) briquetted to a high density pillow shaped briquette • Hot Metal: Molten iron in liquid form, above 2500°F, 1370°C • Pig Iron: Solid product of the iron blast furnace • Residuals: Undesirable elements such as copper, nickel, chromium, tin, sulfur, molybdenum and phosphorus • Gangue: Rock minerals in the iron ore such as silica (SiO2), alumina (A2O3), calcia (CaO), magnesia (MgO). These remain in the oxide form in DR processes. • Reduction: Fe2O3 + 3 CO = 2 Fe + 3CO2 2 Fe2O3 + 3 H2 = 2 Fe + 3H2O (Fe2O3 > Fe3O4 > FeO > Fe)"

Jan 1, 2018

By R. L. Grayson

Using powerful database management software, nested-field analysis and microanalysis of narratives have been made of West Virginia accident data, resulting in a new approach for targeting and prioritizing safety interventions by county, mine size, specific mine, job title, type injury, etc. and combinations of these parameters. The analyses have been useful in focusing training and discussion sessions on specific work problems, trends, conditions, and situations for targeted groups of miners. Application of the technique will be presented in this paper, along with comparisons of various mine performance measures.

Jan 1, 1997

By Dennis N. Poffenroth

One concern of the Mine Safety and Health Administration is the structural integrity of steel wire ropes used on mine personnel hoists and elevators. Failure of such ropes has resulted in loss of life and property. Although thorough and regular visual examinations are performed, hoist ropes may still fail from undetected internal wear, corrosion, and broken wires. To complement visual examinations, nondestructive rope inspection techniques have been developed to determine deterioration and removal criteria. The techniques use electromagnetic and permanent-magnet test instruments designed by a Canadian firm. This paper describes the operating principles, field and laboratory testing of these nondestructive testing instruments, and discusses the feasibility of using this type of testing as a supplement to visual examination and destructive tests.

Jan 1, 1983

By Edward A. Nowatzki

The purpose of this paper is to present an example of the application of a theoretically derived mathematical model for track-soil interaction to the evaluation of the mobility of large-scale mining equipment used in open pit operations. The model described by Karafiath and Nowatzki (1978) and presented in detail by Karafiath (1978) was used to predict the performance characteristics of four different bucket wheel excavators (BWEs) on rwo types of copper mill tailings at various moisture conditions. The BWEs considered In the analyses are two-and three-tracked continuous excavators. Most have boom-mounted rotating buckets and swinging side- or rear-discharge conveyors. The analyses were performed at the request of Dames and Moore for the Kennecott Corporation's proposed remining of selected tailings deposits at the McGill, Nevada, concentrator. The objectives of the analyses were to determine whether BWEs would have sufficient mobility In the tailings deposit to achieve satisfactory production rates, and TO compare the predicted performance of the various BWEs evaluated. Good qualitative agreement was obtained between the results of the theoretical analyses performed for the McGil1 operation and the actual performance of BWEs in two South African gold mine tailings impoundments.

Jan 1, 1980

By D. C. McLean

Early studies in the carbonate leaching of uranium ores led to the investigation of pressure leaching as a method to enhance the dissolution of the metal values in this system. The initial investigations conducted at the University of British Columbia supplemented by the work done by the group at the A.E.C. Grand Junction pilot plant, all established the higher efficiency and better economics of the alkaline pressure leaching system. This work was conducted either in laboratory autoclaves using oxygen overpressures, or in pilot plant sized horizontal autoclaves with air as an oxidant. Both of these testing vehicles utilized agitation provided by relatively high speed impellers (300 to 700 rpm), which apparently enhanced the oxidation of the uranium to the hexavalent state. The installation of vertical autoclaves on a production scale, which through design considerations require relatively slow agitator speeds (68 rpm), led to the studies of the utilization efficiency of the air addition and the use of catalytic type oxidants to effect a greater usage of the oxygen added through the aeration system. In addition to investigating the effects of the chemical additives, studies were also conducted on the effect of different impeller configurations on the extraction of uranium, which in itself is a measure of oxidation efficiency. The material presented in this paper was compiled in the Ambrosia Lake district of New Mexico, and the majority of the data was obtained in the Homestake- Sapin Partners mill, located at Grants, New Mexico.

Jan 1, 1960

By Robert C. Bates

Published information discussing uranium mine radon daughter controls and related costs was examined and used to develop an estimated (projected) cost per ton for any level of control. Results show a clear power function increase of cost for conventional dilution ventilation as the annual exposure limit is lowered. Projections can be made using any assumed changes in consumer price index (CPI) and radon daughter working level months exposure limit. Bounds on the estimated costs are provided, and applicability of the final equation is discussed.

Jan 1, 1983

By C. C. Hatch

As part of a general project to simulate a concentrator, the Brenda Mines Limited secondary crushing plant, located near Peachland, B. C., was sampled during the summer and winter of 1975 to develop a digital crushing plant simulator specific to the Brenda operation. The purpose of this simulator was to study the influence of manipulable process variables on important responses and to permit study of alternative circuit configurations if desired. This paper describes the simulation methodology employed and presents the results of a computer study of the secondary crushing plant (1).

Jan 1, 1979

By A. Metzer

When paraffinic gases (ethane, propane, butane) are used as the gas phase in flotation systems, the initial rate of flotation and recovery are generally increased as compared with air. The mechanism of the effect of paraffinic gases in flotation was studied and it was shown that they co-adsorb with the collector ions on the mineral-aqueous solution interface. The effect of this co-adsorption was interpreted in terms of apparent increase of the effective chain length of the collector by the co-adsorbed gas. Adsorption densities, contact angles and flotation behaviour were studied on the following systems: a) Quartz - dodecyl ammonium chloride - ethane and propane b) Calcite - sodium oleate - propane and butane. The positive effect of the co-adsorbed gases is a maximum at low collector concentrations or where critical conditions for flotation with air prevail.

Jan 1, 1974

By David B. Brooks

I gratefully acknowledge the help of a number of American and Canadian geologists, in both federal surveys and in private firms, who took the time to discuss this problem with me. Hans Landsberg and Bruce Netschert also followed the study with interest and encouragement. In their 1961 monograph, THE FUTURE SUPPLY OF THE MAJOR METALS, Bruce Netschert and Hans Landsberg noted that identified potential resources (that is, known but submarginal resources) of lead and zinc were much lower relative to reserves (that is, known and supermarginal resources) than was the same ratio for other metals.1/ Put another way, it seemed that for such metals as iron, manganese, copper, and aluminum, slightly more favorable economic conditions or modest advances in technology would greatly increase reserves by permitting the exploitation of vest quantities of leaner or deeper or otherwise less valuable mineral deposits. But for lead and zinc, Netschert and Landsberg concluded that either: "(1) there is relatively little material below present cutoff grades; [or] (2) such material exists, but for some reason there are no data.? 2/ This situation, which they called "the lead-zinc anomaly" has been subsequently discussed by other authors. The purpose of this paper is to carry the discussion further by examining the evidence in favor of (1) and (2) and by advancing a third alternative.

Jan 1, 1967

By M. S. Frasad

The State of Minnesota is interested in stimulating the development of clay resources and recently supported a two year project to collect data on geological, mineralogical, processing, economic and environmental aspects of such potential developments. This paper presents the .various process options adopted on the bulk samples collected from the Minnesota River Valley area which is a primary deposit and contains a major silica fraction. A standard test flowsheet involving degritting, dispersion, HGMS, and cycloning was developed and for some samples yielded an acceptable filler grade product. Secondary streams containing relatively high grade kaolin but of coarse size were also obtained. Improvement in particle size distribution and in physical properties related to paper product specifications (brightness, viscosity) were obtained by size reduction processes. Market and economic considerations for kaolin consumption in the upper Midwest are analyzed. Current markets for paper grade kaolin in Minnesota were briefly discussed.

Jan 1, 1990

By K. L. Ludeke

For many reasons it appears that deep-rooted, perennial shrubs offer potential for improved stabilization and provide maintenance-free vegetative cover to harsh sites where perennial grasses have not been successful. The very fact that a drought-adapted shrub has a massive root system that can use moisture from a greater volume of mineral waste soil materials suggests that long-range arid environment resource development may be greatly enhanced by utilization of desirable forage shrubs. An effort is underway to assemble information and plant materials of promising species from many arid regions of the world. Surprisingly, many of the better plants for arid sites are quite high in protein content, and with proper management, breeding, and selection may prove to be very desirable livestock feed. Advancements in arid-land solid waste stabilization hold favorable promise for many industries that mine and mill in arid regions for effective reclamation of disturbed areas. Particularly exciting is the possibility of establishment of high density maintenance-free vegetative cover of climax vegetation that reclaims the disturbed area back to its original land use. Because of high shrub productivity, stabilization potential, nutritional quality, and reclamation success, greater use should be made of shrubs in disturbed land reclamation associated with mining and milling operations in harsh arid environments.

Jan 1, 1984

By David W. Wisecarver

Kennecott Copper Corporation and the U. S. Bureau of Mines cooperated in a full-scale slope stability research project at the Kimbley Pit near Ely, Nevada. The west wall of the Kimbley Pit was mined from an over-all slope angle of 45° to an over-all slope angle of 57° and the pit was deepened nearly 50 feet. Mining was begun February 10, 1966, and completed October 30, 1966. Approximately 2.55 million tons of ore and waste were mined. The project was designed and carried out to learn more about the behavior of a pit wall as its slope angle is steepened and to obtain a possible insight into engineering parameters for use in design of future slopes. Data from this project are presented as obtained from (1) instruments installed in two adits for deformation and displacement measurements, (2) a subsidence network installed on the surface above the steepened wall, (3) pre- and post-mining observations of stress in rock, (4) sonic-velocity measurements, and (5) seismic and microseismic investigations. Changes occurred in measured quantities as the slope was steepened but stopped when mining was completed. Agreement was noted between the measured changes and predicted changes obtained from calculations using the finite element technique. Subsidence surveys and microseismic studies show the steepened pit wall to be stable.

Jan 1, 1968

By J. Y. Hwang

Alunite has been utilized as raw materials for producing alumina and potassium sulfate fertilizer in Russia for many years. In the United States, this mineral has not been commercially processed though reserves of 5 to 10 billion tons of alunite ore have been estimated. Major constituents of these ores include quartz and alunite. The minerals are finely intergrown and liberation occurs below 10 microns. Adequate separation techniques for such fine particles have not been developed. A new method for the beneficiation of alunite ore is proposed in this study. 'Ibis method utilizes a small amount of fine magnetite upon which the liberated quartz is selectively flocculated. The co-flocculated magnetite and quartz are then separated from the alunite in a high gradient magnetic separator. Clean products, e.g. an alunite concentrate of 90% grade with 80% recovery, has been obtained from an Utah ore. Techniques for the selective co-flocculation of magnetite and quartz, the separation of the carried quartz, and the recovery of magnetite after separation are discussed.

Jan 1, 1985

By R. L. Bullock

For the past 30 years there has been a gradual evolution of mechanical excavating systems in underground hard rock mining applications. This paper traces many of the tests of various tools and methods to break hard rock, up to the present. The tools include impact hammers, boring machines, disc on boom mining machines, disc on revolving wheels and drums, picks and drag bits on revolving hubs, rock splitters, slot cutting systems, and with customized explosives/powder mini-blasting. While the progress has been slow, successes are being achieved in hard rock and more opportunities exist today than ever before.

Jan 1, 1995

By C. G. Anderson

Extraction of valuable resources from complex orebodies will become more common. This is obvious for two reasons. First, the cleaner and more readily processed ores have continually been depleted through centuries of mining. Second, new technologies have evolved for effectively handling complex ores. One of these new processes has been in place at Sunshine since 1984. Based on sulfuric acid oxygen pressure leaching with nitric acid as an oxidizer, this patented technology allows silver and copper to be efficiently recovered from a complex sulfide concentrate. As efficient as it is, this process represents novel technology found nowhere else on an industrial scale. As such, a research program was undertaken in 1989 to optimize this leach process and to better understand it. From this study, several potential plant improvements were found and recommended. As a result, two of these options, nitric acid replacement by sodium nitrite and concentrate regrind are now used in day to day operation at Sunshine. Patenting of these changes was recently accomplished (1). Thus, the development, perceived mechanisms, plant integration and potential applicability of this technology will be covered in this paper.

Jan 1, 1994

By E. A. Devuyst

Metallurgical processes involving the use of cyanide such as gold cyanidation, metal plating and flotation, generate effluents containing cyanide and cyanide in complex combinations with heavy metals in quantities exceeding those regarded as being safe for discharge into streams. A new process for destruction of free and complexed cyanide and related-species in wastewaters has been developed at the Inco research laboratories using sulfur dioxide, air and lime. High reaction rates are obtained in the presence of a small amount of copper which acts as a catalyst. Cyanide species can be reduced to as low as 0.1 mg/L in a very short treatment time. Examples of treatment of gold mill effluents and barren slurries, plating rinse waters and flotation liquors or tailing slurries are given.

Jan 1, 1982