Search Documents

By N. Langsford

The Archaean Yilgam craton has been a major gold province since 1888 with production and reserves of about 4700 tonnes. Production in 1994 was about 135 tonnes. The largest deposit, the famous Kalgoorlie Golden Mile, contains about 2000 tonnes of gold. About 40 deposits containing more than 35 tonnes (1Moz) of gold has been discovered so far in the Yilgarn. Most of the craton has deep weathering profiles inherited from previous tropical climatic conditions, modified by subsequent arid conditions. A mantle of transported material covers much of the variably stripped weathering profiles. Resolving the geology of the volcanic-sedimentary units (greenstones) and the structures that host the gold mineralization relies heavily on aeromagnetics and shallow drilling.

Jan 1, 1995

By N. Merriam

This report describes Koppelman's work to develop the K-Fuel® Series C Process used to dry and stabilize Powder River Basin coal. It also contains summaries of the results of bench-scale and pilot plant tests conducted to prove the Series C Process. The process is being used by the KFx-Thermo Ecotek partnership for a 500,000 ton per year commercial plant that has been constructed near Gillette, Wyoming. The plant is presently undergoing shakedown.

Jan 1, 1997

By T. R. Raponi, D. Barnes

The Williams Mine mines and mills 6000 t/d (6600 stp’d) of gold ore using SAG/ball milling, leaching and CIP, electrowinning and refining. Electrowinning, high-pressure cathode washing, filtering, retorting and refining are based around the use of knitted stainless steel mesh cathodes. Their primary advantage over conventional steel wool cathodes is that electrowon gold can be washed off and the cathode can then be reused. Typically, the knitted cathodes have a useful life of up to 15 months. Gold production of up to15 t/month (50,000 oz/month) is easily processed with this system. Presented is a description of this operation, including a review of the equipment and performance data.

Jan 1, 1992

By M. S. Riyazulla

The Hutti greenstone belt comprising predominantly of low-potassium tholeitic basalt has undergone regional metamorphism of a transition zone between greenchist to amphibolite facies. The important mineral constituents of the volcanic suite are amphibole and plagioclase which appear to be the product of regional metamorphism. These minerals have been recognized as the main indicators of metamorphic temperature and pressure. With a view to understand the P-T conditions of metamorphism of the belt, electron microprobe studies were carried out on amphibole and plagioclase and the chemical data was used to decipher the metamorphic conditions. The results obtained indicated a metamorphic temperature of about 6000 c and pressure of 5 kbs. for the Hutti greenstone belt.

Jan 1, 1996

By R. E. Ray

As coal reserves at shallow depths continue to be exhausted, a number of US coal companies are developing seams previously considered too deep to mine economically. Because of increased cover load, mines operating in deeper seams face unique ground control problems. In addition, the volume of methane gas in coal beds increases with depth, and ventilation requirements are much more stringent for deep mines than for shallower mines. When the longwall mining method is wed at great depths, ventilation, ground control, and operational considerations all influence the design of longwall panels. This paper examines these influences, particularly ventilation and operational considerations, on the feasibility of two-, three-, and four-entry longwall development panels in Jim Walter Resources' four deep mines.

Jan 1, 1988

By V. M. Lepetic

Large tonnages of copper and molybdenum sulfide ore are treated by flotation. Substantial savings could be realized, particularly in high-capacity concentrators, by use of a simplified flotation technique involving lower reagent consumption. Chalcopyrite and molybdenite from some deposits can be floated by use of only a frother as a single flotation reagent; acceptable concentrate grade and recovery can be obtained. Separation of molybdenite from copper sulfides may become simpler and less costly. The genesis of the ore and the ions present in the flotation pulp liquid phase appear to be the major success-determining factors.

Jan 1, 1972

By Liming Yuan, Wei Tang, RICHARD THOMAS, JOHN SOLES, DAVOOD BAHRAMI

The abstract discusses the issue of mine equipment fires caused by hot surface ignition of flammable liquids. The research investigates the ignition probability of liquid fuels (diesel, engine oil, hydraulic fluid) on different metal surfaces (stainless steel, cast iron, carbon steel) under various ventilation speeds. The results show that the type of metal and ventilation speed influence the ignition temperature, with diesel being the most easily ignited fuel and carbon steel requiring a higher ignition temperature. The study provides data for understanding equipment mine fires and developing mitigation strategies.

May 4, 2022

By Marcie A. Greenberg

The Fence Lake Project is located in the Salt Lake coal field, an extension of the San Juan Basin. Geologic formations exposed in the Project area range in age from late Cretaceous to Quaternary. Coal is encountered in the Moreno Hill Formation (upper Cretaceous). Salt River Project (SRP) followed the basic textbook approach for the exploration, regional appraisal, detailed reconnaissance, detailed surface appraisal and three dimensional sampling (physical exploration). SRP is exploring this property as a potential fuel source for the Coronado Generating Station. Therefore, for the physical exploration stage, the quality sampling program was designed from a utility company viewpoint to determine possible impacts to the Station. Exploration drilling was completed in spring, 1982; September, 1982, and summer, 1984. Engineering, environmental, and land acquisition studies were added in the Summer, 1984 Program to more closely evaluate the potential Fence Lake Project coal supply option for the Coronado Generating Station. Studies, including drilling, are ongoing-at this time.

Jan 1, 1984

By A. I. Kalugin, A. A. Abramov, D. E. Kozlov, D. V. Magazanik

Based on theoretical and experimental researches of phosphate and carbonate minerals flotation in the presence of soluable glass at various pH values and sodium silicate concentrations, it has been established that the presence of soluble glass in solution leads to formation of silicate compounds on the surface of phosphate and carbonate minerals causing change in their floatability for the worse. The harmful influence of soluable salts is done by tying of collector as metallic soaps, forming precipitates on the surface of minerals to be floated and causing their depression of flotation, and breaching of the froth etc. Depressing action of slimes and products of interaction with collector depends on the ratio of values and signs of potentials of the mineral surfaces. The possibility of phosphate and gangue minerals separation can be evaluated by comparing the minimum-necessary concentrations of collector required for their flotation.

Jan 1, 2002

By A. J. Jeffery

Heat transfer to a fluid flowing through a rough duct has been shown by many researchers to be a function of surface roughness. The effect of roughness asperities on the duct surface is to turbulate the fluid as it flows through the duct, increasing frictional pressure losses and convective heat transfer rates, and also increasing the surface area per unit length available for heat transfer. These factors combine to increase the total costs to the mine in terms of refrigeration and fan power requirements. A measurement system designed to automate the collection of tunnel roughness information and based on an infra-red timed pulse laser has been developed at the Royal School of Mines in London. The system allows accurate, high resolution digital recordings of tunnel surfaces to be made in two or three dimensions. Software for analysing the data has been written, and the description of a complex surface via single numerical term has been explored. A relationship between the numerically measured surface roughness and the pressure loss of the ventilating air is being investigated with a view to establishing an alternative method of describing tunnel roughness. The paper describes the roughness measuring technique developed and the analytical techniques explored so far.

Jan 1, 1993

By Aixiang Wu, Minjie Zhang, Zhuen Ruan, Yiming Wang

 The paper combines theoretical and experimental analysis to improve the accuracy of predicting paste yield stress by slump flow. It derives an analytical model of slump flow for yield stress, providing a theoretical basis for quantifying the rheological properties of paste with slump flow. The study uses three different tailings-prepared pastes and constructs an empirical yield stress model, showing high accuracy and good generality.

Aug 1, 2023

In this paper, the logic and the capabilities of a long term production planning method for open pit mining are presented. The method is the first attempt in obtaining simultaneous solutions to the four interrelated parameters of open pit mining; 1) the mine life, 2) the specific blocks to be mined each year, 3) the amount of ore and waste to be mined each year, and 4) the ultimate pit limits. An efficient cutoff grade can also be obtained through a sensitivity analysis. None of the existing methods can bring such a comprehensive solution to the problem. A production plan for a real life gold deposit is given to illustrate the logic and the capabilities of the method.

Jan 1, 1993

By Otto Schumacher

Shortcut methods are commonly employed for estimating mining costs for prefeasibility studies. Most of these methods, however, are suitable for earliest stage studies or for internal discussion purposes only. The experts at InfoMine?s CostMine division recommend that any cost estimate completed for purposes of significant decisionmaking or for compliance with Canada?s NI 43-101 requirements be completed using a determinative itemized method. The same basic principles apply for an early stage, intermediate stage, or advanced stage estimate. The only difference is in the level of detail and effort employed. ? Based on the results of a completed resource estimate, an itemized cost estimate begins with development of a conceptual mine plan. Using a surface mine as an example, four elements are crucial no matter what level of study is initiated. Basic geometry of the ore deposit and waste material, with a determination of the expected ratio of waste to ore, a reasonable pit slope angle, possibly requiring the completion of geotechnical studies to predict the waste-to-ore ratio with certainty. ? Determination of the assumed ore and waste production rates. ? Locations of all ore stockpiles and waste dumps. ? Segmental haulage distances and gradients for ore and waste.

Oct 1, 2013

By James A. Clem

Approximately 2,000 years ago, the Lord Admonished the Scribes (Lawyers) and Pharisees (Religious leaders of that time) that they had paid the tithe but had omitted the weightier matters of law, Judgement, Mercy, and Faith. (Matt. 23:23). I want to talk about "The Weightier Matters of Law." In a situation where big government is trying to have an effect on even small details of a work activity, otherwise simple situations become complex. Regulations are written to such detail that constant compliance with strict interpretations can be a nightmare--not to mention off the target of the intended purpose for the regulation. One soon re- cognizes the oneros characteristics of Federal statues

Jan 1, 1979

By Samuel S. Adams

The Permian Salado Formation of west Texas and southeastern New Mexico is composed of halite and subordinate amounts of anhydrite, clay and potassium and magnesium-bearing evaporite minerals. Aspects of the geochemistry of the Salado Formation have been investigated through studies of the stratigraphy, mineral assemblages, textures and minor element content of the salts. These studies provide information on the origin of the evaporites when combined with data on equilibria in saturated salt solutions. The principal potash ore zone in the district is composed essentially of halite (NaC1) and sylvite (KC1). Data on the color, bromide content, and proportions of halite and sylvite suggest that this simple assemblage is the product of a series of replacements rather than primary precipitation. The bromide content of the salts also indicates that the brine which precipitated the Salado Formation was derived from the dissolution of older evaporites rather than the simple evaporation of sea water.

Jan 1, 1966

By J. A. Lepinski

The FASTMETSM Process is a coal-based process for converting iron oxide fines into metallic iron. The end product, direct reduced iron (DRI) is used as a low residual charge material in electric arc furnace steelmaking. This paper describes the FASTMET Process and its potential application in the United States. Operating results from a 175 kg/h process simulator are presented. Characteristics of the end product are discussed. Process economics are reviewed along with plans for scaling-up the process to full commercial size.

Jan 1, 1993

By A. Janwong

Ion exchange technology is becoming more prevalent for metal recovery from low concentration solutions. The products of ion exchange are typically a metal free stream (product stream) and a concentrated metal stream (byproduct). The metals in the concentrate stream are usually precipitated and returned to the process or discarded. The unique features of emew® technology enable metals to be recovered directly from the concentrated stream. The advantage of the IX-emew® combination is the ability to have two product streams: 1) clean metal free solution and 2) metal product for sale. In addition to recovering metals from solution, it is also possible to separate metals from each other and recover more than one metal product. In this paper, examples of IX-emew® combinations are detailed including the recovery of copper, nickel and cobalt from an industrial waste stream, recovery of nickel from a spent electroless nickel plating solution and recovery of cobalt from an hydroxide cake.

Feb 23, 2014

By B. Mishra, A. Staley, D. Kirkpatrick

The major waste product of the alkaline extraction of alumina from bauxite (Bayer Process) is known as red mud. Approximately one ton of red mud is produced for every two tons of bauxite mined. The red mud produced from Jamaican bauxite is rich in hematite, alumina and titanium oxide. It has been shown that more than 90% (by weight) alumina can be recovered from red mud by soda ash sintering and caustic leaching. Hematite can be carbothermically reduced with a degree of metallization of more than 94%, resulting in attempts, for magnetic separation. These separations are desirable because there are no waste products generated. Consequently, there is an opportunity for complete utilization of the waste material. Conversely, the preseparated material could be charged through the tuyeres in an iron blast furnace, or it could be smelted to produce pig iron. If smelted, the concentration of titanium oxide in the slag would be high enough to justify its recovery by an established acid-leach process. This paper describes the results of alumina recovery and the plans for titanium oxide recovery from red-mud. In addition, the situation of ongoing efforts in iron extraction, particularly, the method of magnetic separation of the reduced material. The problems associated with the use of reduced red mud as an alternative to direct-reduced iron (DRI) is also discussed. A critical assessment of the recovery sequence chosen for the products is described based on economics. Key words: Red mud, Waste product utilization, Alumina recovery, Titanium oxide, Iron

Jan 1, 2003

By T. A. Lloyd

The use of tank cells over the years has provided a means for low cost, space efficient, extra capacity in existing flotation circuits. In some cases, new plants have selected tank cells as the machine of choice. Typical tank cells use high efficiency impellers for mixing, which results in low power draw. Unfortunately, these mixers have poor aerating characteristics that compromise metallurgical performance. This has all changed with Outokumpu's new flotation concepts. Outokumpu has recently developed the HG or High Grade flotation cell that can provide higher recovery with better selectivity while maintaining the simple operation of conventional cells.

Jan 1, 1993

By T. P. Meloy

A methodology is presented for finding feasible or locally optimal designs in the class of homogeneous, countercurrent, processing networks performing two-component non-sharp separations. The advantage of the methodology developed here is that given a set of independent performance criteria (specifications such as network separation factor, beneficiation ratio or recovery), a feasible or locally optimal countercurrent network design meeting those criteria can be found in one step. In the methodology, graph-theory was used to explicitly obtain the exact network responses of specific countercurrent networks. These responses were used to formulate the linear recursion equations whose solution gives the expressions for the countercurrent network responses which are a function of the stage transfer functions for two-component, non-sharp separations. These expressions are also functions of the network variables n and c. These expressions, together with the set of independent design criteria, were solved simultaneously for n and c using the Levenberg-Marquardt algorithm for systems of constrained, non-linear equations. The network variables n and c embody the coded network design information which is used to find the feasible network design which satisfies the set of independent performance criteria.

Jan 1, 1994