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By D. R. Wilburn

This summary of international mineral exploration activities for the year 2010 draws upon available information from industry sources, published literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analyses of exploration activities performed by the mineral industry. Three sources of information are reported and analyzed in this annual review of international exploration for the year 2010: 1) budgetary statistics expressed in U.S. nominal dollars provided by Metals Economics Group (MEG) of Halifax, Nova Scotia; 2) regional and site-specific exploration activities that took place in 2010, as compiled by the USGS, and 3) regional events including economic, social and political conditions that affected exploration activities. These were derived from published sources and unpublished discussions with USGS and industry specialists.

Jan 1, 2011

[Scott Aberle Western Energy Co POB 99 Colstrip, MT 59323-0099 Randy L. Acre Joy Mining Machinery 2569 Silver Oak Ct. Grand Junction, CO 81505 Brian L. Acton Oxbow Carbon & Minerals Inc 1601 Forum Pl-#P2 West Palm Beach, FL 33401 Laine W. Adair Genwal Resources Inc POB 1420 Huntington, UT 84528-1420 Thomas D. Aderman The North American Coal Corp 14785 Preston Rd #1100 Dallas, TX 75240-7891]

Jan 1, 2000

By J. H. Jacobs

In late 1946, research was begun at the Bureau of Mines Electrometallurgical Laboratory at Boulder City, Nev., to determine the possibility of electrowinning manganese from chloride electrolytes on a continuous basis. All phases of electrodeposition were investigated on a small scale it the laboratory, and the results were reported by Jacobs and Churchward. These results indicated that a chloride process had certain possible advantages over the sulfate process that made it worthwhile to continue the investigation on a semi-pilot-plant basis, and this paper reports the results of this work. Research and development work on a process for electrowinning manganese from low-grade ores has been carried on intermittently by the Bureau of Mines since 1936. A process was developed, using sulfate electrolyte, that has been extensively described in the literature.

Jan 1, 1951

By D. P. Tao, J. G. Groppo, R. Killmeyer, W. W. Wen, B. K. Parekh

Economical dewatering of ultra-fine (minus 74 m) clean coal slurry produced in column flotation to a 20 percent or lower moisture level will be an important step in successful implementation of the advanced fine coal cleaning processes. The main objective of the present study was to evaluate efficiency and effectiveness of three dewatering techniques, namely, hyperbaric, vacuum and screen bowl centrifuge, in dewatering of ultra-fine (D50 ~ 25 m) clean coal slurry produced by the `Ken-Flote' columns operating at the Powell Mountain Coal Company, St. Charles, Virginia. he hyperbaric filter using 3 bar pressure and 165o cake formation angle, provided a filter cake with 23.6percent moisture with a throughput of 800 Kg/m2-h and air consumption of 868 Nm3/t (460 scfm/t). The vacuum filter with 30 percent submergence provided a filter cake with 27.8 percent moisture with a throughput of 122 Kg/m2-h. The screen bowl centrifuge provided a dewatered product containing 32.9 percent moisture at a feed rate of 450 Kg/hr, however, the solids capture was only65 percent. Addition of 1 Kg/t of a cationic surfactant provided filter cakes with 19.1 percent, 23percent, and 34 percent moisture using hyperbaric, vacuum, and centrifuge, respectively. Similarly, addition of 0.5 Kg/ton of copper chloride lowered filter cake moisture to 20.7 percent and 24.8percent, using hyperbaric and vacuum. With the centrifuge no improvement in filter cake moisture was noted. However, use of 80 Kg/ton of `orimulsion' in the centrifuge provided dewatered product containing 26 percent moisture, and the solids capture increased from 65 to 95 percent. The dewatered product appeared dry and was easily handleable.

Jan 1, 1999

By W. Dan Walker

In recent years the Federal Bureau of Mines tested and approved four new types of self-contained breathing apparatus and a facepiece designed for use with the McCaa 2-hour self-contained oxygen breathing apparatus. The Bureau also developed and perfected a battery-powered lifeline telephone for use in mine rescue and recovery operations. Some of this equipment is described in Bureau of Mines Information Circular 7413.4/ This publication is a revision of information Circular 7413 and presents pertinent information on more recently developed mine rescue equipment. The breathing apparatus described herein are 1/2- and 3/4-hour sell-contained types of much simpler design than the conventional 2-hour self-contained oxygen breathing apparatus ordinarily used by mine rescue crews; however, it is just as important to select rescue crews carefully and to train them properly in the use, care, and limitations of the newer types of apparatus as well as the older, established types, if the newer types are to be used safely. The Bureau of Mines recommends that 1/2- and 3/4-hour self-contained breathing apparatus be used only as auxiliary equipment in mine rescue and recovery work and that the capabilities and limitations of the apparatus should be well understood by those who wear the equipment.

Jan 1, 1957

By G. Stecklein

This report summarizes the results of research into the areas of the fragmentation and entrainment of Airborne Respirable Dust (ARD). The objectives of this program were four-fold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust becomes entrained; third, to specify the informational requirements to verify or nullify these hypotheses; and fourth, to relate experimental techniques that will produce that required information. Additionally, insights are provided regarding potential methods of extraction and/or treatment which may reduce the concentration of ARD.

Jan 1, 1982

Commercialisation of outcomes from research projects is a process often poorly understood and managed, but has the potential to achieve significant benefits for the industry and community as a whole. JKTech Pty Ltd was established in 1986 to transfer viable research outcomes from the Julius Kruttschnitt Mineral Research Centre (JKMRC) at The University of Queensland, Australia. This paper describes successful and unsuccessful examples of commercialisation by JKTech over the years, and draws some conclusions as to the factors that contribute to success and failure in technology transfer.

Jan 1, 2012

By G. Deschenes, W. Yen

Ammonium thiosulphate is a non-cyanide lixiviant for gold leaching. The major problem is the high reagent consumption. A combination of 0.3M (NH4)2S2O3, 0.03M CuSO4, 3M NH3 was used to leach a copper-bearing gold ore at pH 10.2 for 24 hours. 30 kg/t of thiosulphate was consumed. Oxygen and copper species were found to be responsible for thiosulphate decomposition. The thiosulphate consumption could be reduced to around 17 kg/t by adding chelating agent, reducing copper sulphate concentration to 0.001 M and replacing CuSO4 by NiSO4. The increase of pulp density might reduce the thiosulphate consumption to around 17 kg/t. By regulating the oxygen supply, the thiosulphate consumption could be reduced to 10 kg/t.

Jan 1, 2002

The heap leaching of base metal ores can be applied within a number of different scenarios, each requiring its own set of parameters to be determined during the metallurgical testwork programme. The occurrence of acid-gangue reactions and its concomitant precipitation reactions is a factor common to all cases, and requires that the optimal irrigation acid strength be found that optimises the combination of extraction kinetics, acid consumption and possible premature blinding of the heap due to precipitation reactions. For the heap bioleaching of base metal sulphide ores the oxygen requirement needs to be determined for the design of the aeration system, and the operating conditions employed need to also facilitate bacterial growth over and above the acid strength optimisation mentioned above. For the heap bioleaching of chalcopyrite, the need to preserve heat in the heap becomes yet a further parameter of critical importance. For the heap leaching of uranium ore a choice is required between either chemical or bacterial oxidation, based on economic and processing factors. Frequently the operating parameters need to be determined for a circuit in which heap leaching is combined with tank leaching and/or pressure leaching. The processing implications and metallurgical testwork approach for each case is discussed.

Jan 1, 2007

By Jr .. Ebbley

The investigation of mine shafts and underground workings at Leadville, Colo., was started in May 1946 and recessed in November 3, 1946. Thirty-eight shafts and connecting accessible underground workings, comprising about a third of the accessible shafts in the district, were investigated. The Leadville district, a former important producer of lead and zinc, was considered by the Bureau of Mines to be capable of bolstering 'the waning domestic output of .these important metal. Accordingly, the investigation was initiated for the purpose of. .obtaining more definite data on sulfide and oxide reserves, evidence to justify completion of the Leadville drainage tunnel, representative large samples of the complex oxidized and mixed ores for testing to determine methods, beneficiation factual data to be supplied to property owners in order to stimulate production, and to determine the more favorable areas for development by the Bureau.

Jan 1, 1949

The current global economic climate has adversely affected the resources industry in general. For the gold mining industry, even though the gold price has been stable as compared to other resources, there is still a need to cut costs even further in order to be profitable and sustainable. Of all the costs that are associated with mining, comminution of ore accounts for the majority. Comminution costs constitute mainly electricity, grinding balls and liners. Of these three components, grinding balls form the major portion of the consumable costs, and can be as high as 40%?45% of the total. As a result, proper grinding ball selection is a key consideration towards reducing mining costs. This paper discusses quality control procedures that can be conducted in order to select the best grinding balls for a particular application. Keywords: grinding balls, forged, semi steel, hardness, chemical, metallography, wear testing, impact test

Jan 1, 2009

By R. Pazhianur

Cathodic Protection using impressed current was employed to reduce the wear of the mill wall during ball mill grinding. Wear rates were determined from weight-loss measurements made on four, I-inch diameter, mild steel coupons installed flush with the interior surface of the mill wall. Grinding tests were conducted on quartz, pyrite and quartz-pyrite mixtures at pH values of 4.6, 7.1 and 9.2. Cathodic protection was shown to reduce mill wear by 40-60010. An examination of the coupon surfaces using scanning electron microscopy showed that cathodic protection greatly reduced pitting corrosion. The presence of a sulfide mineral, such as pyrite, was found to increase the wear rate significantly, possibly due to galvanic interactions. It is also found that the wear rate is significantly higher than the sum of abrasive wear and the corrosive wear, due to a synergistic effect.

Jan 1, 1996

By S. Acar, M. Botz

Introduction In 2007, Newmont Mining Corporation will begin construction of a milling and cyanidation leaching circuit for the Yanacocha site in Peru. Ore to be processed in the circuit contains a relatively high level of cyanide-soluble copper, and as a result, leach solutions are expected to contain elevated levels of copper and WAD cyanide. As the means of controlling copper levels in leach solution, a circuit will be installed to precipitate copper sulfide from barren solution using sodium hydrosulfide. In addition, a circuit will be installed to recover cyanide from barren solution, with recovered cyanide to be returned to the leaching circuit and treated solution to be utilized as make-up in existing heap leaching facilities. As needed to support design of the copper precipitation and cyanide recovery circuits, pilot testing was conducted in 2005 to determine preferred operating conditions and evaluate the performance of the processes. This paper presents results from the pilot testing where 99% copper reduction was achieved and 95% to 98% cyanide recovery was achieved.

Jan 1, 2007

By S. M. Runke

An earlier Bureau of Mines report4/ reviewed and summarized all reports of investigations dealing with the coarse grained pegmatites of the Black Hills of South Dakota to dune 1951. It was proposed, and the hope was expressed in this report, that future progress in the development of the technology of the mining and beneficiation of the pegmatite deposits would be rapid enough to make it possible to issue annual progress reports. Although notable progress has been made in the treatment of pegmatite material, it has not been rapid enough to justify annual reports

Jan 1, 1954

By Roger J. Higgins

Papua New Guinea is a country on the cusp of development, struggling to find a balance between the demands of national and regional growth, landowner expectations and the maintenance of cultural identity. Ok Tedi Mining Limited is the single largest contributor to PNG?s economy, representing about 10 percent of the country?s GDP. OTML is demonstrating that business and country risk can be managed through effective, respectful partnerships with local communities. OTML?s relationships with the communities of PNG?s Western Province are multifaceted. Communities have borne the brunt of the mine?s environmental impact, yet have benefited enormously from the development that the mine has brought. Importantly, the PNG economy is now the ultimate beneficiary of more than four-fifths of the dividends from the mine, the majority of which are held in trust for long-term sustainable development projects. The paper describes how OTML works with the Western Province communities to create a secure operating environment that recognizes the people?s aspirations for development and self-determination.

May 1, 2002

The Mine Safety and Health Administration (MSHA) defines an independent contractor as any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine. Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Jan 1, 2008

By Jr. Holmes

"The Riley tungsten property of the Northern Nevada Mining Co. was examined by the Bureau of Mines in August 1943, and from February 22 to August 22, 1945, the property was explored by the Bureau.Riley mine, which comprises 60 acres, is in sec. 9, T. 38 N., R. 42 E., Mount Diablo base and meridian, in the Potosi Mining District, on the east slope of the Osgood Range in eastern Humboldt County, Nevada. J. S. Riley is president of Northern Nevada Mining Co., the general offices of which are at 29 East First Street, Reno, Nev.Winnemucca, Nev., 42 miles southwest of the mine and on the main line of the Southern Pacific and Western Pacific Railroads and U. S. Highway 40, is the nearest supply center. The post office for the Potosi district is 15 miles south at Red House, Nev., a station on the Southern Pacific and Western Pacific Railroads. A good dirt road, which leaves U. S Highway 40 about 15 miles east of Winnemucca, extends northeast to the property.Tungsten occurs as scheelite in a characteristic Nevada contact-metamorphic tactite deposit between limestone and granodiorite Fifteen diamond-drill holes were completed for a total length of 2,630 feet.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources, to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.Special acknowledgment is made to A. C. Johnson, chief, :Reno Division, Mining Branch; E. O. Binyon, mining engineer, Reno Division; S. F. Clabaugh and S. Warren Hobbs of the Federal Geological Survey, who made available the un¬published Geological Survey report ""Tungsten Deposits of Osgood Range, Humboldt County, Nevada;"" and S. P. Zimmerley, chief, Salt Lake City Division, Metallurgical Branch, Salt Lake City, Utah.The Riley tungsten property comprises 60 acres of patented land owned by the Northern Nevada Mining Co. of Reno,,a partnership comprising J. E. Riley, H. H. Luce, Phyllis Riley, Beatrice Knight, Gene Crosby, and M. R. Wilson.The property is part of a federal land grant to the Southern Pacific Railroad, from which it was acquired by Tom Dernan many years ago. Two short adits and several shallow pits were excavated in a search for silver ore, but no record of precious metal production exists."

Sep 1, 1946

By G. S. Knoke

This report presents the results of a demonstration of the technical, economic, and environmental feasibility of hydraulic borehole mining of shallow oil sands. Borehole mining offers a method for extracting the oil sands with minimal disturbance to environmental quality because (1) no overburden is removed, (2) no waste rock piles are required, (3) the tailings can be backfilled into the borehole cavity, (4) the ground water quality should be undisturbed, (5) a closed-loop water system can be employed so that no surface streams are polluted, and (6) surface subsidence can be minimized by backfilling the mined cavities. This project consisted of two concurrent tasks: mining operations and environmental monitoring. To generate the environmental impact, nearly 1000 tons of oil sands were mined from two boreholes. Water quality and ground subsidence were monitored. No significant changes occurred in the chemical composition of the process water, indicating that the borehole mining process does not dissolve the mined material. The average subsidence in the immediate vicinity of the boreholes was about 1/2 inch, although some points were noted to be slightly elevated. In general, the amount of subsidence increased with time and decreased with distance from the bore-hole. A mining cost analysis was used to project an estimated cost for production mining of about $38 per barrel of oil.

Jan 1, 1980

By Scott Turner

The present rapid growth of coal stripping in the United States is a curious reversal of the tendency of mining to proceed from outcrop to depth. A combination of technical and economic factors bas stimulated the use of stripping methods until today many million tons of coal We being recovered by open cuts from sites that an earlier generation of engineers would have passed by as not commercially mineable or, if workable at all, only by underground methods. The total quantity of bituminous coal and lignite mined in the United States by stripping in 1928, the latest year for which detailed figures are available, was 19,789,000 short tons. Of this, 71,000 tons came from small workings not equipped with power shovels and 587,000 tons from properties in which stripping and underground work were carried on at the same mine; but as neither of these types is representative of modern stripping practice, they will be omitted in the discussion that follows. The total from strip pits proper in 1928 was 19,131,000 tons, produced by 176 pits employing 385 steam or electric shovels.3 Figures by States are given in Table 1. Detailed statistics will be found in Economics of Strip Coal Mining; a study by O. E. Kiessling, to be published by the United States Bureau of Mines.

Jan 1, 1930

By M. F. Boos

The Portland beryl-mica district, Middlesex County, Conn., comprises three deposits investigated by the Bureau of Mines in 1943. The Gotta-Walden deposit is in a pegmatite dike 4 to 20 feet thick, which cuts gneiss and schist. In general, the hanging wall is rich in mica and beryl with some feldspar, quartz, and garnet. The central core is usually high in quartz and feldspar, with relatively little mica and beryl. The footwall comprises quartz and feldspar, with varying amounts of mica and some beryl. The beryl crystals range in color from green to almost golden and have a maximum diameter of inches. Results of surface trenches indicate a beryl content of 0.81 percent for the pegmatite. A small production of beryl, feldspar, and scrap mica has been made from the deposit.

Jan 1, 1949