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By Alexander L. Peyton

The Magruder and Chambers copper deposits in the Little River gold district, on the border line of Lincoln and Wilkes Counties, Georgia, have been known for a number of years (fig. 1). The Magruder deposit was first opened as a gold mine but has produced mostly copper and load. Records show that about 50 cars of concentrates were shipped from this property. No record of any production at the Chambers deposit is available. The Bureau of Mines, in its program of investigation of strategic minerals deposits, diamond drilled 10 holes, totaling 3,784 feet, on the two properties between December 3, 1948, and June 23, 1949. Eighty-eight core samples were analyzed, and the analyses and drill-hole data are presented in this report.

Jan 1, 1950

By J. A. Fulton, A. B. Foote

Gold was discovered in the Sierra Nevada by J. W. Marshall on Jan. 2, 1848. The town of Grass Valley soon sprang up and contained several stores in 1849; but the population of the town has always reflected the fluctuations in quartz mining. Gold-bearing quartz was found on Gold Hill in September 1850, and in the next two years most of the quartz-bearing veins in the vicinity were located. At first, the quartz was crushed in mortars with spring poles; the IIuff Co. took out $20,000 in this manner during the winter and spring of 1851. The first mill was put up in January, 1851. In 1866, there were in Grass Valley 248 stamps, crushing 71,420 tons of ore with an average yield of $30 to $35; in Nevada City, there were 142 stamps, crushing 14,200 tons, with an average value of $25. Rut in 1918, only two properties in this region, the Empire and the Korth Star, were producing Since then, there has been a revival of mining in the district and the following properties are being opened up: The Golden Center. Grass Valley Gold Mines Co.. Idaho-Maryland Mines Co., while the Su1tana is kept unmatered and work is going on in a half dozen mall propertics Mining Claims At the first meeting of miners in Grass Valley, Jan. 13. 1851, a plot :30 by 40 ft. was allowed for a claim, the boundaries in all cases being perpendicular. In 1852, the quartz miners in Nevada County deeided that "each prospector shall hereafter be entitled to 100 ft. on a quartz ledge or vein and the discoverer shall be allowed 100 ft. additional. Fach claim shall include all the dips, angles, and variations of the vcin." This rule was in force until replaced by the Federal mining laws of 1872; these allowed quartz claims to be 1500 ft along the vein, with all the dips, spurs, and angles, and to have a width of 600 ft. The holdings of the principal companies consist of these early patented mining claims; standard claims, as authorized by the Act of 1872, both patented and unpatented; agricultural tracts, both patented and

Jan 1, 1927

By M. du Plessis, J. P. Gouvea

Mesh based areal support is commonly applied in South-African deep-level gold mines. It forms part of an integrated support system that can cater for both rockfall and rockburst incidents. The application has been successfully applied over many years. Operations have different geotechnical conditions and practical considerations, which has led to the development of various types of mesh and integrated mesh-based support systems (i.e. meshing and lacing versus welded or chain-link mesh sheets). Typically rolls or sheets of mesh is pinned with rockbolts to the surface of an exposed excavation. Applications vary from hangingwall coverage in a conventional stope gully to complete excavation coverage in footwall drives of conventional mines or on-reef drives in massive mechanised mines. It is however critical to understand the behaviour of the rockmass and apply suitable support systems.

Apr 26, 2022

By O. E. Humeniuk, A. I. A. Salama, M. W. Mikhail

"The Western Research Centre (WRC) of CANMET operate a unique pilot plant facility where ongoing R&D on coal preparation and mineral processing is conducted. The pilot plant carries out two functions: coal preparation processing using state-of-the art technology and coal-liquid mixture preparation with intensive cleaning circuits that can also be used for mineral processing. In total, the pilot plant includes more than 30 different flowsheet options. The facility is dedicated to small and fine coal, and designed to be flexible and versatile.This paper describes the use of a pilot-scale facility as a research tool for process control development, fine coal beneficiation, development of coal-liquid fuels technologies, development of process models and testing and evaluation of new developments. The pilot plant is used to assist in resource development by evaluating and optimizing flowsheet selection, and producing sufficient samples for utilization tests. The facility is also an important tool for evaluating and testing samples from troublesome circuits of operating plants to find means to optimize and improve recovery, particularly of fines circuits.Detailed examples are given to demonstrate the role of a pilot scale facility in coal preparation R&D, coal industry development and optimization of coal processing operations. These examples include the development of heavy-medium cyclone computer control system, detailed evaluation of beneficiation of a coal deposit with high clay content, development of column flotation, and its role in fine cleaning circuits and treatment of ultra-fines in relation to intensive cleaning, the importance of testing coals in different processes, and cleaning processes influence on coking quality and other utilization applications. The potential of the facility for helping the mineral industry is also described."

Jan 1, 1992

By S. A. Abdel Sabour

Strategic decisions in the mining industry are made under multiple technical and market uncertainties. Therefore, to reach the best possible decision, based on information available, it is necessary to integrate uncertainty about the input variables and model financial risk of the project?s merit measures. However, this provides few useful insights to decision-makers unless accompanied by modelling management responses to uncertainty resolutions. It is widely acknowledged that conventional decision-support methods based on static, no-change, discounted cash flow (DCF) techniques such as net present value (NPV) and internal rate of return (IRR) tend to provide inaccurate value estimates. This could mislead the strategic decision-making process and result in significant value losses. This paper aims to model financial risk related to uncertainty about market variables such as metal prices and foreign exchange rates. Other sources of risk that are related, for example, to geology and production costs are not considered in this work. The article outlines a flexible financial model that integrates uncertainty about market variables and management flexibility to react to uncertainty resolutions into mine project valuation using a real-options valuation technique based on Monte Carlo simulation. Significance of information generated from this simulation-based flexible valuation model to the strategic decision-making process is tested using an illustrative case study of a Canadian mining project. The project is a typical multi-metal, open pit mine that produces copper and gold. In this case, there are three uncertain market variables, which are: copper and gold prices and US$/CAN$ exchange rate. Financial valuations are carried out using both the conventional static DCF method and a flexible real-options model. In the flexible model, management flexibility to decide whether to go ahead with the next expansion or terminate production operations is integrated. Results show how the flexible financial model can enhance the decision-making process.

Jan 1, 2009

By J. M. Pugliese

The Bureau of Mines, in support of its overall goal of helping to meet future U.S. demand for minerals, undertook this study to aid the quarry entrepreneur and/or operator in developing quarries near urban areas. In response to increased environmental concerns, the quarry operator often must take steps beyond those required in the last decade toward gaining permits for quarrying near metropolitan areas. Following the steps suggested in this report should increase the chances to obtain the permits to open and develop a quarry. Each task and question in the general plan flow diagrams are described in detail, with the flow diagrams aimed at the goal of acquiring the necessary permits. The appendixes include (1) types of projects for which Environmental Impact Statements (EIS's) may be prepared and Federal agencies responsible for preparing them, (2) State contacts for information regarding environmental impact assessment requirements and mining and mineral land reclamation laws, (3) a checklist of environmental inventory factors, (4) a tabulation of different regulations that affect mining in Michigan and the number of townships and counties that have each of the listed regulations, and (5) environmental logic associated with site selection. A central recommendation is that the quarry entrepreneur and/or operator coordinate plans at the beginning with local government officials (such as township supervisors and/or city and county planning board members), State and Federal officials, and public groups that will be affected.

Jan 1, 1979

IN accordance with a programme arranged by a committee of the Institute, consisting of Mr. William P. Shinn, of St. Louis, chairman, and Mr. Joseph D. Weeks, of Pittsburgh, secretary, the member's of the Institute, with their ladies and invited guests, assembled in Chicago on Sunday morning, August 22d. A special train, provided by the Chicago and Northwestern Railway,. left Chicago on Monday morning at 7.50 o'clock, and conveyed the party to Marquette, arriving at 9 o'clock P.M. Here the steamer Northern Queen, which had been chartered by the committee for the accommodation of the Institute, was in waiting, and the members and ladies at once took up their quarters on the boat. EXCURSIONS IN THE MARQUETTE IRON REGION. Local Committee. EXECUTIVE. -J. C. Morse, chairman; C. Y. Osburn, secretary ; D. F. Wadsworth, treasurer; C. H. Hall, H. Merry. RECEPTION.-S. P. Ely, J. P. Pendill, E. Breitung, W. F. Swift, A. P. Swineford, J. C. Fowle, C. G. Griffey. TRANSPORTATION.-Samuel Schoch, D. Morgan, D. H.. Merritt, J. Pickands. FINANCE.-Peter White, A. W. Maitland, W D. Rees, E. R. Hall. EXCURSIONS.-W. E. Dickinson, H. A. Burt, A.. Kidder, C. E. Wright. REFRESHMENTS.-J. Q. Adams, H. H. Stafford, Joseph Kirkpatrick, D. H. Bacon. On Tuesday the iron mines in the vicinity of Negaunee and Ishpeming were visited, transportation being provided by special trains on the Marquette, Houghton and Ontonagon Railroad. In the morning the McComber, South Jackson, and Jackson mines were inspected, and in the afternoon the Cleveland, New York, Lake Superior, and Barnum mines. Dinner was provided at Negaunee, and gracefully served by, the ladies of the town. In the evening the first session of the Institute was held in the saloon of the steamer. The President, William P. Shinn, of St. Louis, congratulated the Institute on the happy consummation of the wishes of its members to have a meeting on Lake Superior. After tedious and baffling negotiations arrangements had been com-

Jan 1, 1881

By Jos. R. Guiteras

This paper describes the operations of the St. Joe Mining & Milling Co. in Boulder County, Colo., as of June 1936. Later a brief visit was made to the mine in September 1936; information obtained at that time has also been recorded. The company operates a gold mine, the Grand Republic, in the Sugar Loaf mining district; a 100-ton flotation mill in Lefthand Canyon near Gold Hill; and a custom sampling punt, the Boulder Ore Sampling Works, at Boulder, Colo.

Jan 1, 1937

Stringent environmental benchmarks imposed by governments and successful legal challenges in the country of origin have changed the risk profile for all mining companies over recent years. In developing countries, however, where high government standards may not always be in place, direct community action has often made worthless substantial investments in otherwise viable mining operations. Real limitations are therefore imposed from these risks on all areas of mining activity, wherever they may be. Thus, the bar has been raised for all companies developing or operating mines. This paper argues real financial and global industry reputation benefits accrue when all known environmental risks, where practical, are managed. In response, among major international mining companies, as the industry moves towards greater global consolidation, senior management teams have increasingly adopted corporate governance standards including æTriple Bottom LineÆ (shareholder/government/community) sustainability reporting. Sustainability reporting is encouraged by improved international stockholder and financial investor perceptions by contributing to lowered social, community and geopolitical risk which lowers the cost of access to funds as well as improving staff morale and productivity. New mines must not only be primarily financially viable but must operate throughout in a sustainable way. Case studies of some recent mining operations, who have not foreseen or proactively managed major environmental risks, demonstrate the dire financial and personal implications for managers, directors and shareholders from not identifying and managing these environmental risks. Merely having a corporate policy statement on environmental standards or high level Government approvals process for a mining activity does not preclude mining operations from the risk of direct action by local populations or future adverse legal implications from risks which were perhaps identified but not mitigated effectively. Methods and processes for the identification and active management of environmental risks in the global arena are discussed to add a practical element to sustainability, based on the authors recent strategy development processes with governments and major mining houses such as BHPBillition, Rio and Xstrata. Emphasis is placed on proactive, innovative yet practical solutions which, where possible, show positive contributions firstly to the financial bottom line but also the community at large.

Jan 1, 2003

By Ahmad Ghahreman, James McNeice

Separation of rare earth elements (REE) is often achieved by acid leaching of mineral concentrates followed by subsequent solvent extraction (SX), to purify individual rare earth metals (REM). Cerium, the most abundant REE, is usually the largest component of these ores. Demand for less prevalent REE, such as praseodymium and dysprosium; have led to a market saturation and price collapse of cerium. One method of improving the economics of REE separation is to remove cerium from solution prior to SX. This is accomplished via the oxidation of cerium (III) to cerium (IV), which precipitates as cerium hydroxides. This study probes the efficacy of four oxidants; hydrogen peroxide, sodium hypochlorite, potassium permanganate, and Caro’s Acid with the goal of improving cerium removal whilst minimizing REE and reagent losses. The effect of oxidant type and dosage, pH, cerium concentration, and temperature on the kinetics of the process will be discussed.

Mar 1, 2018

By Dennis Hoffmann

"Abstract - Banded iron formation rocks associated with massive sulfide lenses in the Broken Hill Pb-Zn-Cu-Ag deposit in the Namaqualand Metamorphic Complex, South Africa , were investigated with respect to the geochemistry of manganiferous silicate-rich bands. Two common varieties of these are: amphibole- and garnet-rich iron formation bands. The results reveal that the former are enriched in Fe, Mg, Cu, Co and S. The garnet-rich bands are enriched in Mn, Ca, P, Pb and Ba with significant detrital contamination of Ti, Al, Zr, Cr, Y, V, Ni and Nd.The silicate-rich bands have compositions, in terms of, Si/Al, Si/Fe, Fe/Mn, La/Ce and Co/Zn, comparable to submarine chemical sediments which precipitated from hydrothermal fluids. The garnet­ and amphibole-rich bands are interpreted as ""evolved"" and ""immature"" hydrothermal sediments, respectively. The latter resulted from rapid precipitation after exhalation, whereas the former had a longer residence within sea water. The silicate-rich bands both exhibit increasing Mn/(Mn+ Fe) fractions, which are consistent with a variation expected from proximal to distal depositional settings. The prevalence of garnet-rich bands over amphibole-rich bands is interpreted as the result of injection of hydrothermal fluids from a single vent situated along the northwest margin of the Broken Hill deposit."

Jan 1, 1994

By Richard J. Stoehr

In his time on earth, man has mined about 93.3 kt (3 billion oz) of gold. About one-half of this has been produced in the past 35 years. Roughly one-third of this gold is held as reserve in Central Banks. One-third held is in personal reserves. And one-third is held as jewelry or other fabricated products. The world per capita availability of mined gold is increasing. There are many forces shaping gold's future. Gold currently has a favorable exchange ratio. This is encouraging many new gold mining developments. Production is increasing and new recovery techniques are surfacing. The use of gold in the financial markets is increasing in some unique ways. And gold is again fulfilling its role as a universal money, making its future predictable. Gold Today Man is currently mining gold at the rate of about 1.4 kt/a (44 million oz per year). This adds about 1.5% of newly mined gold to the total supply each year. This production plays a small role in the pricing mechanisms since much of the 93.3 kt (3 billion oz) mined is available to the market in some form. The 31.1 kt (1 billion oz) held by central and international banking

Jan 11, 1984

By G. L. Hopps

Various chemicals, including compounds of copper and lead, were added to a mixture of No. 2 and No. 6 fuel oils that was fired in an experimental furnace. Tests were made to determine (1) the effectiveness of these chemicals in removing soot deposits on probes devised to simulate heat-transfer surfaces in boilers and (2) the effectiveness of the chemicals in preventing the deposition of soot on the probe surface. Test conditions were regulated so that the temperature of the products of combustion adjacent to the probes was in the range of 625° to 700° F. The clean-metal temperatures of the air-cooled probes were comparable with the water-tube temperatures in boilers operated at 40 to 100 p.s,i.g. The dosages of the fuel oil additives used in these tests were generally larger than those usually recommended for most proprietary compounds.

Jan 1, 1962

By W. Drummond

The cooling of smelter gases by air dilution, adiabatic evaporative cooling and indirect heat exchange is discussed with reference to the process, to the subsequent cleaning of the gas. and to the use of the heat extracted from the gas. The method of reducing the effect of acidic sulphide formation on the corrosive properties of the gas and the dust and the development of surface cleaning mechanisms?are discussed. The development of indirect recuperators using air, water or steam cooling, made possible by the control of surface fouling is traced. The application of the modern Waste Heat Boiler to the new sulphide smelting processes is discussed with respect to the natural and forced circulation concepts. Case histories are presented to illustrate mistakes made with respect to designs produced without recourse to sensitivity analysis and without an appreciation of "worst process? conditions".

Jan 1, 1992

By W. Drummond

The cooling of smelter gases by air dilution, adiabatic evaporative cooling and indirect heat exchange is discussed with reference to the ,process, to the subsequent cleaning of the gas and to the use of the heat extracted from the gas. The method of reducing the effect of acidic ,sulphide formation on the corrosive properties of the gas and the dust and the development of surface cleaning mechanisms are discussed. The development of indirect recuperators using air, water or steam cooling, made 'possible by the control of surface fouling is traced. The application of the modern Waste Heat Boiler to the new sulphide smelting processes is discussed with respect to the natural and forced circulation concepts. Case histories are presented to illustrate mistakes made with respect to designs produced without recourse to sensitivity analysis and without an appreciation of "worst process conditions".

Jan 1, 1992

By Dhananjaya Senapati, E. V. S. Uma Maheswar, C. R. Ray

Carbothermic process of Ferro Silicon production is primarily a slag-less process. However, slag formation is observed in the regular operation as experienced by almost all the Ferro Silicon Producers in different pro-portions. The problem of slagging in the furnaces may be due to: a)Variation in the input burden charge material quality b)Fluctuations in the Carbon balance and/or c)Fluctuations in the Electrode penetrations The problem will be more severe in nature with the increase of the size of the furnace. The operation performance of the furnace gets badly affected if the slag formed in the furnace is not removed from the bath in time and to the maximum extent possible. It is, therefore, very essential to know the characteristics of the slag formed in the Ferro Silicon Furnaces, besides eliminating the very cause of formation itself; and to find the routes of draining of the same from the furnace bath effectively. This paper envisages the effects of using the LIME STONE in the Ferro Silicon Burden in stabilizing the 48MVA Furnace for improved performance and better consistency. Quality fluctuations in the available Raw Materials are compared with that of the requirements for the Ferro Silicon production. The furnace operational data is compared for 12 months period each for the period corresponding to the before and after usage of lime stone in the burden and found encouraging results in the performance. Implications of use of Lime Stone in the burden on the quality of the output alloy are also studied.

Jan 1, 2007

This report is the 22d in a series summarizing Bureau of Mines research and technologic work on coal and related investigations.2 3/ A summary of work published during 1957 and of work in progress is presented. Details regarding the subjects treated in the publications may be found by referring to articles cited in the footnotes. The objective of the coal work of the Bureau of Mines is to obtain information that will lead to improved production and utilization of coal, thus conserving a most important national asset.4 5/ Though studies of mining methods and exploration of various coalfields ma; contribute directly to improved production, no less so does the work in health and safety. The many problems relating to chemical and physical properties of coal reflect the need for an understanding of these properties for the most effective use of coal in its various fields of application and for the development of new methods of processing coal. Studies of existing and proposed processes of combustion, carbonization, gasification and hydrogenation of coal are necessary for increased efficiency in its use. Engineering service provided by the Bureau is of direct value in the conservation program in preventing waste. Stations where the main coal activities of the Bureau are carried out are shown in the following list:

Jan 1, 1959

By M. E. Volin

The Ladd manganese deposits are in San Joaquin County, Calif., about 13 miles southwest of Tracy. The deposits are confined in two main areas of development, roughly about 1,700 feet apart horizontally, and known as the Ladd mine and Fabian mine, respectively. The deposits occur as interbedded lenses in the white cherts of the Franciscan formation. The ore minerals are bementite, rhodochrosite and psilomelane. As a part of the Bureau of Mines program of investigation and development of domestic mineral deposits, a development program was started. August 24, 1940, and completed on June 24, 1941. The Federal Geological Survey cooperated by mapping the geology and logging the drill cores. The program included road building, trenching, rehabilitating the mine workings, trenching underground excavation, sampling, and core drilling. The following pages mention the location, give a brief history, and note the physical features of +1-.1, district. Mine workings are sketched, the deposit is described and the plan of the project is noted. The work performed by the Bureau of Mines is explained in the concluding pages with a summary of the drill hole logs.

Jan 1, 1949

By Mary S. Esfandiary

This is a revision of a directory of coal research organizations throughout the world that was first published in 1961 as Bureau of Mines Information Circular 8008. Because of the wide acceptance of the first edition, a revision which would supply up-to-date information on coal research and which would facilitate communication among organizations of similar interest seemed important. This compilation includes the names and activities of organizations of various types-government, university, private, and industry. The areas of investigation that each organization is engaged in are indicated in broad terms: Analysis and constitution, mining and geology, preparation, briquetting, combustion, high- and low-temperature carbonization, gasification, conversion to solid and liquid fuels, and health and safety. Publications issued by and describing the work of each organization are cited; almost all of the organizations also publish results of their investigations in the technical press. Selected technical and trade publications that publish information on the science and technology of coal and are not published directly by any of the organizations listed are cited in the pages following the list of organizations in each country.

Jan 1, 1966

By J. Robert Van Peli

IT was a strange but highly fruitful marriage-that union of hardy explorers, seeking the rich treasures of copper in the Lake Superior wilderness, with Boston's aristocracy of brains, capital, and enterprise. This historic wedlock, which has continued happily to the present day, was the means by which the wealth of Lake Superior's copper was won for the use and benefit of an expanding America. One branch of this family tree, the western branch, begins with prehistoric Indian miners, embraces the early French explorers of the Upper Lakes, and finally includes the British and American pioneers who reduced the vague rumors of copper to known fact and actually began the mining of copper in the wilderness. The other branch, the New England line, begins

Jan 1, 1948