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By Terry S. Cory

This report covers magnetic field strength measurements vs range and frequency In low-medium coal mines. Both quasi-conductor-free and conductor-proximity areas were Investigated. The program covered 5 mines, 4 seams, 6 measurement sets, and 3 geographic areas, The results have been summarized In terms of maximum communication range expected per seam and noise condition. Scatter gain Is further explored as a simple measure of energy coupled to conductors.

Jan 1, 1978

By William R. Yernberg

SME’s Arizona Conference was held at the Doubletree Hotel at Reid Park in Tucson on Dec. 4 and 5, 2005. The annual conference is organized by the Arizona Conference Board of Directors, which represents SME sections in Arizona and adjacent areas. The conference provides an opportunity for individuals and corporations associated with mining in the region to get together once each year to discuss the status of the industry. Important topics discussed among the attendees included the price of copper, community relations and education.

Jan 1, 2006

By Phillip R. Moyle

A basic precept in mineral exploration is that the best places to prospect are where minerals have already been found. The California desert has many old mining districts once thought to be "played out" that are currently producing more mineral wealth than at any time in the past. Because no "crystal ball" exists that will enable us to predict the Nation's future mineral needs, land management plans must be flexible enough to respond to these often unforeseen needs. MANAGEMENT ISSUES The California Desert Conservation Area (CDCA) (figure 1) encompasses 25 minion acres, nearly one-quarter of the total area of California. Passage of the Federal Land Policy and Management Act of 1976 (FLPMA) launched an intensive program by the Bureau of Land Management (BLM) to study this vast area. Painstaking scientific investigations were made of wildlife and plant populations, soil, air, and mineral resources, range use, and wilderness characteristics, among other environmental concerns.

Jan 1, 1992

By A. G. Yapo, T. W. Camm

"All-in sustaining cost is a metric used by mining companies to reflect the cost of gold mining in a consistent format useful to both investors and mining professionals. Cost reporting focused on the direct cost of mining and processing ore was summarized in the non-GAAP cash cost developed by the Gold Institute in 1996. In 2013, a group of mining companies, working with the World Gold Council, developed a more inclusive approach to reporting costs designed to solve the dilemma of showing a more comprehensive reflection of recurring costs involved in producing gold, without discouraging investors. INTRODUCTION Mining today plays a key role in the development of our civilization as a source of essential raw material and provider of essential fuels, producer of jobs, and a factor in support of the international balance of monetary payment (Camm, 2014). Professionals in mining locate, develop, design and manage ore deposits in an environmentally safe and profitable manner. As mineral deposits become increasingly scarce, new challenges face the industry. A current trend is to an increased emphasis on underground mining techniques for deeper deposits. Operations are safer today than before as companies understand better their work environment and the importance of mining responsibly. A continual challenge for the industry is accurately reflecting the costs and selling price of ore. An enduring characteristic of mining is the situation where the market typically determines the price of a commodity; the main control a company has on the bottom line is to control the cost of production. An attempt to bring light and clarity on the cost of their business will give a better idea to investors on the true profitability of the mining business. Gold producers face this struggle to accurately reflect the cost of production while also seeking to attract the interest of the investment community (Hill, 2013). In order to have a consistent format to report on their production costs, leading gold producers through their alliance inside the World Gold Council (WGC), worked on the adoption of a new cost framework: the All-in Sustaining Cost (AISC) and All-in Cost (AIC). Since 1996, the traditional cash cost reporting has focused only on the mining and processing costs incurred in mining an ounce of gold, which included the costs of goods sold (labor, energy, and consumables costs) and royalties (Table 1). But cash cost reporting ignores many important aspects, like sustaining capital, general and administrative expenses, and site rehabilitation at the end of the mine life (Whelan, 2013). The cash cost was used to attract many investors into the business. In fact the high gross margin (sales minus cash costs) has been promoted the past decades by the industry instead of the net or operating margin. As a result, even when the gold price was high, nearly $1900 per ounce in August 2011, gold producers were not reporting excessive profits in their cash flow / income statements, to the disappointment and incomprehension of investors (Milstead, 2014). The truth was simply that the other costs omitted in the traditional cash cost were reducing the apparent profits."

Jan 1, 2017

By K. K. Kershner

The purpose of this investigation was to develop methods, on a laboratory scale, for recovering tin from Bolivian metallurgical slimes. Petrographic and chemical analyses were made of slime ore fractions from several well-known tin operations. High percentages of the total tin were volatilized as chlorides at temperatures below 600° C. Under optimum conditions reaction rates were relatively rapid, and the chloridizing reaction approached completion. Owing to the low temperatures involved and the high yields of tin, the process was considered to have possibilities for treating Bolivian slimes on a commercial basis. ACKNOWLEDGMENTS Appreciation is hereby extended to the Patino Mines and Enterprises, Inc., of Bolivia, for supplying slimed tin ores that were used in the experimental work. This company has since been nationalized.

Jan 1, 1959

By K Ehrig

You are a geologist, geometallurgist, or metallurgist/process engineer and are fortunate enough to work for an organisation who asks you to design/execute a geometallurgy program. What seems like a simple request is actually not a trivial exercise. æRecipeÆ style manuals are not readily available. However, many æexpertsÆ are lurking around willing to deliver solutions which will solve all of your problems. Even though similar ore deposit styles (e.g. porphyry Cu, IOCG, Ni-laterites, calcrete hosted U, etc.) have many similar characteristics, each ore deposit is unique. Hence your geometallurgy program needs to be æfit-for-purposeÆ. This paper offers some insights gained via designing and executing geometallurgy programs from exploration through to production, and working at a mine where you are held accountable for your metallurgical performance predictors.CITATION:Ehrig, K, 2013. Geometallurgy - What do you really need to know from exploration through to production?, in Proceedings MetPlant 2013 , pp 28-33 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By J. Dean Warner

From 1984 through 1987, the Bureau of Mines investigated numerous prospects and new discoveries of columbium, rare-earth elements (REE), uranium, zirconium, and other metals associated with the multi-phased peralkaline granite at Bokan Mountain, southeastern Alaska. This report summarizes the mineral evaluations and estimates indicated and inferred resources for those prospects containing significant tonnage and grade. A total of approximately 96.2 MM lb Cb205 (43 pct of the tonnage at a grade exceeding 0.125 pct Cb205), and 11.8 MM lb U308, 27.9 MM lb Th02, 133.0 MM lb Y203, 637.6 MM lb ZrO2, and 241 MM lb REO are estimated to be contained within nine deposits totalling 37.8 million tons (at least 80 pct of resource tonnage also exceeds 0.5 pct Y203 + REO). Generally, half of the REO content is composed of the heavy yttrium subgroup. Several deposits also contain beryllium and tantalum; 2.1 MM lb of Ta205 and 8.9 MM lbs of BeO were estimated. These estimates would likely be substantially increased with additional exploration. Four deposit types were investigated; shear zones and fracture-related deposits, pegmatites, mineralized dikes, and placers. Mineralized dikes contain most of the beryllium, columbium, tantalum, yttrium, zirconium, and REE resources, whereas shear zones and fracture-related deposits (Ross-Adams mine) contain the principal of the uranium resource. Pegmatites are similarly mineralized as are dike deposits, and contain low levels of gold. Placer potential is suggested, but no deposits were found.

Jan 1, 2011

By William F. Keyes

Greensand, which is widely distributed in the Eastern United States, was produced in 1975 only by Inversand Co., a subsidiary of Hungerford & Terry, Inc., near Clayton, N.J. Production and sales information are not available for publication. Raw greensand produced by the company was sold for agricultural use as a soil conditioner. Processed greensand was used by manufacturers as filter media in equipment for the removal of manganese, iron and other elements from water. The University of Delaware received a grant of $17,051 from the Bureau of Mines early in 1976 to continue its studies of the effectiveness of greensand in removing metallic contaminants from waste waters.

Jan 1, 1977

By Roger A. Dworak

This report describes in detail the work done on the development of the Time Domain Reflectometry Microcomputer (TDRM). Modifications to the FMC-Model 302A Cable Fault Locator is described in Appendix D. The TDRM unit uses an 8080 microcomputer to accurately locate major faults in low capacitance cables to within ± 1 foot when properly calibrated. Major faults in high capacitance cables are usually located within ± 5 feet. The upper limits of fault detection are <1 kilohm shunt fault and >7 ohm series fault. In practice fault detection limits are reduced to <300 ohms shunt fault and >30 ohms series fault because of discontinuities caused by cable repair.

Jan 1, 1977

By R. S. Dean

In general, the Division conducts investigations relating to the treatment of ores and metallurgical products from the condition to which they are mined to the refined metal. At the object of conserving natural resources and eliminating waste by furnishing information on current methods of metallurgical practice making fig fundamental studies of metallurgical processes and developing new processes and alloys to the point of demonstrating their or value. Office of the Chief Engineer The functions of the technical units of the Office of the Chief Engineer are indicates

Jan 1, 1941

By Cary Hirner

The Metropolitan Water Reclamation District of Greater Chicago (District) is in the final phase of completing the Calumet System component of the Tunnel and Reservoir Plan (TARP) by bringing the Thornton Composite Reservoir online by 2014. The Thornton Composite Reservoir will provide nearly 30 billion liters (7.9 billion gallons) of additional storage for minimization of combined sewer overflows(CSO) and flooding in the Chicago metropolitan area. The project requires that the existing 6.7 m (22 ft) diameter Thorn Creek tunnel conveying overbank flood flows is re-routed and connected to the Thornton Composite Reservoir. This paper presents the components of the Thornton Composite Reservoir and specifically the detailed evaluation of a drill-blast tunnel. Other project features include an access shaft, control gate, energy dissipating structure, bulkheads, and live tunnel connection. The construction contract will be procured in late 2009.

By Syd S. Peng

Mountaintop removal (MTR) mining started in West Virginia nearly 30 years ago. This surface mining method can extract multiple coal seams as thin as a few inches in whole and minimum rock dilution in very steep mountainous terrain. MTR is highly efficient, even if coal seams are in close proximity and small in a real extent. Consequently, MTR has been widely used in the Central Appalachian coalfield (mainly Kentucky, Tennessee, Virginia and West Virginia) with great success. In that respect, there has been no demand for research and little scientific research has been performed to investigate its impact on the surrounding area. During the past two years, however, the debate over MTR mining has grown quickly and has become very intense. This article describes chronologically issues raised by various parties, legal actions, impacts on mining permit applications and research projects developed to address the issues.

Jan 1, 2000

Productivity in underground metal and nonmetal mines is contingent upon work methods, mine layout, and ore handling techniques. One of the most important factors impacting productivity is the efficient movement of men, materials and supplies from the surface into and throughout the mine. Various transportation systems such as man-trains, service shafts, rubber-tired diesel equipment, etc. are currently used to transport men and supplies in underground mines. In many underground mines, it is not uncommon for a worker to spend 25% of his eight-hour working day traveling from the surface to his work area and returning to the surface.

Jan 1, 1975

By Derek Ellis

Volume II of this two-part series on Submarine Tailings Disposal (STD) as a tailings management option for coastal and island mines contains descriptions of lesser known case histories. The Misima gold mine (Papua New Guinea) and the Black Angel lead-zinc mine (Greenland) are described in some detail as the best documented cases. Atlas copper mine (The Philippines) is less fully described due to relative lack of documentation. The Misima and Atlas STD systems are working to their design criteria. At Black Angel the system adopted did not prevent contamination for a number of reasons, which are now understood. Two cases are described where STD is being developed. They are the Cayeli Bakir copper mine Turkey), and the Toquepala and Cuajone mines (Peru). There is excellent documentation available for both cases. Three case histories are described where tailings have reached the sea either through beach or river discharge. In one case the STD option has been explored (Marcopper Mine, The Philippines). In the others we explore in hindsight whether STD might have been a viable alternative using the Screening Criteria that this Volume develops - see below. The mines are Bougainville Copper Mine in Papua New Guinea, and Jordan River Mine (Canada). There is potential for STD at all three sites. Finally, the Volume presents Screening Criteria for appraising STD, based on the experience in design, operation and environmental impact reviewed in the case histories.

Jan 1, 1994

By J. L. Green

Virginia-Carolina Chemical Corp., in its Florida Operations, uses both roller mills and ball mills in dry grinding of phosphate rock. The roller mills have been in operation since 1954 in the Mining Department. The ball mills were installed and put in operation in 1960 in the Harding Concentrate Superphosphate Plant. The roller mills in the Mining Department are used to grind phosphate rock for outside customers. This involves short notice orders of varying grinds, grades and types of rock. The ball mills grind phosphate rock for use in V-C&apos;s own phosphoric acid and concentrated superphosphate plant. These mills grind generally two types of rock for one grind. In 1959, a 10% speed-up was made in the operating speed of the roller mills. This paper deals with the operational gains and resulting cost savings which evolved from this speed-up, and compares the present operations of the roller mills and of the ball mills in grinding phosphate rock. In January 1959 it was decided to determine the feasibility of reducing the grinding cost on the roller mills, per ton of rock ground, by speeding up the mill 10%. At this time, one mill was completely reconditioned so it would be in top condition. Extensive tests were then run both before and after the mill speed-up to determine the resultant cost savings. These tests showed that, due to this 10% speed-up, the mill capacity was increased approximately 20% and grinding power costs per ton were reduced approximately 10%. Table I shows the results of these tests. Each test run actually represents several of the same type rock and grind, averaged together. Each test run lasted approximately three hours. The validity of these runs has been confirmed by subsequent operation in grinding over 1,000,000 tons of phosphate rock. Accurate records have been kept on power consumption and repairs as well as tons produced. Two types of feed rock were used for the tests — pebble phosphate rock and flotation phosphate concentrate rock. The pebble phosphate rock size is approximately 80-90% plus 20 mesh. The flotation concentrate phosphate rock size is approximately 15% plus 20 mesh and 95% plus 100 mesh. The same two types of rock feed were used for all the test runs. Test Nos. 1, 2, and 3 were run at the original mill speed of 85.5 rpm on the vertical shaft. Test No. 1 was run with a feed of high grade flotation concentrates; the desired fineness attempted was 70% passing 200 mesh. Tests No. 2 and No. 3 were run with a feed of low grade pebble. Test No. 2 was run for a desired fineness of 70% passing 200 mesh. Test No. 3 was run for desired fineness of 50% passing 200 mesh.

Jan 1, 1963

By R. S. Dean

[In E;encralt the I~8:al:ul&apos;,~,C,-J. Div:&apos;sion conducts in\&apos;8stigations relat-ing to the treatment of OrGR o.nd L!\3tallurl..&apos;"lcal prod tctR froJ] t~e condi tion in :hich they are Itinod to t!1e refi!l(,u r.etal, . &apos; th &apos;the ob,icct of conserving natmal&apos; resources .e..nd 81:mir..3.tin~ wacte by furn.i:::hir..g :nforInf&apos;_tiou on current methods of metal11:.rgical practice, Tfu&apos;..:.kir..g fund T!l;ntal .;;.otudie&apos;" of metal-lurgical processe~, and de~eloping ~e~ proc6sses O~Q lloys to the point of dewonctrati:r:g the:&apos;..r practicab&apos;lity or va.lue}

Jan 1, 1941

By P Goblet, S A. Séguret, E Cordier, A Galli

In salar-type deposits, lithium grades can be measured by bailers introduced at different elevations in the drill holes at locations where, later, the brine will be pumped out to recover the metal. When they are duplicated, these a priori rudimentary measurements may show large differences without indicating whether this is due to the procedure itself or to some physical causes linked to the dynamic behaviour of the salar (seasonality, rainfall, underground flow etc). In the reservoir presented in the paper, the problem is complicated by the double lack of stationarity of the lithium grades: the grades not only increase importantly with the depth but at the same time their fluctuations decrease, making it necessary to use non-stationary geostatistical techniques to simulate them. Reservoir simulation is developed in two steps: first, geostatistical simulations of the lithium grade create possible realisations of the reservoir; then, each geostatistical simulation is followed by a pumping simulation that calculates, at each drill hole of a given extraction scenario, the lithium produced each year over 40 years. For the set of 100 simulations produced in this way, a scenario reduction is made to choose the five most representative simulations where more complex calculations will be carried out (for example, changing hydrogeological parameters such as porosity and permeability, or the elevation of the filters, the number and the location of the pumping and the reinjection drill holes etc). The paper first presents an analysis of the geostatistical model sensitivity to the grade uncertainty when measured by bailer. Among the 100 measurements at our disposal covering the future production domain, 50 per cent are duplicates measured at the same place but at different times. They are randomly sampled to produce five subsets of 75 values, which will constitute the future 3D conditioning points for the geostatistical analysis and the simulations. For each subset, trend, standard deviation and variogram models are fitted, leading to five sets of 20 geostatistical simulations of grades. In this way, the reliability of the different parameters involved in the procedure is evaluated, as well as its impact on the pumping results. Then, a reconciliation study is conducted between the non-stationary nugget effects encountered in the 3D variograms of the lithium grade and a pure statistical analysis of 25 duplicates measured at different locations and/or different times. The result is that if the nugget effect reaches 20 per cent, which is the case of three conditioning subsets out of five, the reconciliation is good and the nugget effect of the variogram model represents the bailer uncertainty, ie the measurement error. Since the geostatistical simulation incorporates a nugget effect, it handles the bailer uncertainty and the impact on the produced metal is included in the evaluation. The final conclusion is that, after the hydrogeological pumping simulations, the initial differences between the five geostatistical models do not influence the final results: lithium grades measured by bailers can lead to a robust evaluation of the extractable resources, a conclusion that conflicts with conventional wisdom.CITATION:Séguret, S A, Goblet, P, Cordier, E and Galli, A, 2017. Bailer uncertainty evaluation in a lithium salar deposit, in Proceedings Eighth World Conference on Sampling and Blending , pp 395–402 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Ning Wang, Tengfei Guo, Wanyan Li, Hanjie Wen, Hannian Gu, Zehai Li

Bauxite residue (red mud) is an alkaline waste derived from the industrial process for extraction of alumina from bauxite ore. Some bauxite residues contain considerable concentrations of critical metals, for example, rare earth elements. Lithium in red mud was also reported as a potential resource. In the current study, a Li-rich red mud was leached using acetic acid to investigate the leaching behavior of lithium followed by neutralizing with hydrochloric or oxalic acid. By neutralizing red mud using diluted hydrochloric acid (0.01 mol/L), 58.04–60.27% of lithium was leached using 25% acetic acid at 95 °C for 60 min. In the meantime, more than 95% of sodium and 85% of calcium were also dissolved in the leachate solution. While oxalic acid (0.5 mol/L) was used to neutralize red mud prior to acetic acid leaching, lithium performed lower leaching efficiencies (42.41–46.88%) in comparison of using of hydrochloric acid–neutralized red mud. Nevertheless, these leaching efficiencies of lithium were close to that of calcium and much higher than those of sodium under the condition. In this study, 25% (v/v) of acetic acid, at 85 °C for 60 min, was demonstrated as optimum conditions for lithium extraction from oxalic acid–neutralized red mud using acetic acid. The results would be useful and of interest for lithium recovery and purification from red mud.

By Stephen D. Smith

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rim. Also included are tables that show the principal nonfuel mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of Volume I and in the State chapters of Volume II of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines.

Jan 1, 1988

By Robert Blickensderfer

Tungsten alloys with high-temperature strength properties, comparable to the best of alloys recently developed by others, were produced by a new process called here the oxyreaction process. The process involved additions of a powder of a reactive metal compound, ZrN, ZrW2, or HfW2, to a base metal powder, tungsten, which contained some oxygen. The powders were blended, compacted, sintered, and extruded. During sintering, diffusion and internal oxidation occurred to produce reactive-metal oxide particles and solid solutions. A dispersion of oxide particles could be precipitated by heat treating. The oxyreaction process circumvents many of the agglomerating and coarsening problems encountered in the current methods for dispersing a stable oxide in a metal. Oxyreaction strengthening results from solid-solution strengthening and from dispersion strengthening produced by the reactive metal and its oxides. At a test temperature of 1,650° C, the alloys prepared from WW, had tensile strengths up to 70,000 psi and stress-rupture lives up to 142 hr at 10,000 psi stress; the alloys prepared from ZrN powders had tensile strengths up to 80,000 psi and stress-rupture lives up to 27 hr at 10,000 psi stress. Tensile strengthening in the alloys was attributed to Zr in solid solution or to Zr-O-W structures too small to be observed in an electron microscope replica. Stress-rupture life was attributed to a dispersion of submicron Zr02 particles which precipitated and grew to 0.05-to 0.2-micron size during the test. Tensile strengthening and stress-rupture life were dependent upon both the zirconium and oxygen contents with the maximum occurring at roughly 0.9 atomic pot Zr and 0.9 atomic pot 0. Studies of the details of the oxyreaction process were made on the W-ZrW2 alloys and three general steps were determined: (1) The reaction of 0 in tungsten powder with ZrW2 to form relatively large Zr02 particles; (2) the dissolution of remaining ZrW2 into the W matrix and partial internal oxidation to form ultrafine but sparse zirconium oxide particles and possibly to establish Zr-O-W structures; (3) the development of ultrafine Zr02 particles during high-temperature aging.

Jan 1, 1971