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By M Watson, A V. Engelbrecht, E Murray-Hayden

Whereas mine reconciliation is a well-established month-end process for most modern mining operations, the resource sector has yet to endorse uniform reporting factors against which model accuracy and metal recovery can be formally assessed. Logically, any comprehensive reconciliation framework should facilitate comparison between period reserve, mine and mill and production figures. Historically, Parker’s F Series ratios (Parker, 2012) are often used in some form by mine operators, although they are rarely shared externally, as formal definitions have yet to be accepted. This paper presents a structural extension to the reconciliation process, wherein resource ratios (R Series factors) are used to quantify the long-term impact of the information effect, together with dilution and ore loss. A case study from the El Limón Guajes (ELG) Mine Complex in Mexico is used to demonstrate how an R Factor Series can be implemented to facilitate operation optimisation, over and above conventional F Series reconciliation treatments. This approach is applicable to any mining operation.

Mar 22, 2022

The nickel operations at Kambalda consist of mining thin massive to disseminated Ni sulphide orebodies from 10 individual mines of variable grade.Daily sampling involves visual estimation of the grade of working faces based on geological parameters. This system of grade estimation is used as a guide for daily grade control only.Nickel metal allocation is based on an external sampling system. As all ore sources are blended at the primary crusher, only one calculated mill head grade is available. Therefore all sources are sampled prior to crushing. This system historically consisted of mechanically grab sampling ore from trucks as they passed over a weighbridge on arrival at the concentrator. Currently the system involves diverting one out of every ten trucks to its mine sample stockpile, which is crushed through the primary, secondary and tertiary crushing system fortnightly. The individual mine grades are re-combined to create a total sample grade. This is reconciled against the calculated mill head grade. The reconciliation factor is applied uniformly to all individual mine sample grades to calculate mill reconciled mine grades.

Jan 1, 1990

By H. García

El yacimiento minero de Yauricocha cuenta con un área de exploraciones donde se ha encontrado material de afloramiento con terrones de oro y concentraciones de plata. Con la finalidad de seleccionar una alternativa que beneficie el tratamiento de estos minerales, se inició un programa experimental que evalúa el proceso de lixiviación en pilas a nivel piloto. En este sentido, el presente texto analiza la correlación de parámetros existente entre las diferentes escalas de experimentación que van desde el nivel de laboratorio hasta el pilotaje, a fin de plantear formulaciones matemáticas que faciliten el escalamiento de data y racionalizen mejor el proceso de lixiviación en pilas.

Aug 26, 1988

By H. O. McDonald

The Bureau of Mines reviewed the chemical vapor deposition (CVD) literature of the group IVB, VB, and VIR elements. This review was utilized in the Bureau's research to provide erosion-, abrasion-, and corrosion-resistant coatings for valve components used in coal gasification units. This report attempts to bring together the many CVD references that have been published since 1966. Each of the group IVB, VB, and VLB metal coatings were reviewed, and some of their preparation methods, uses, and properties are given. A total of 160 references were found for the nine elements. Isotope separation, stronger steels, solar absorbers, alloys, superconductors, optical fibers, and coatings to increase the life of materials are some of the new uses for CVD.

Jan 1, 1979

By Jr. Gabler

Because of concern over the availability and reliability of an uninterrupted supply of manganese and other materials, the U.S. Congress requested that the U.S. Bureau of Mines (USBM) study the /low of strategic and critical materials in the economy to delineate and quantify the production areas where metal values are lost. As a result, the USBM developed a generic computerized commodity flow model that is readily amenable to updating. The original model developed for cobalt, with slight modifications, was used to track the flow of manganese. This report follows the flow of manganese through its metallurgical and chemical applications and highlights areas where significant losses occur owing to downgrading, export, or disposal. The study indicates that materials containing 695,000 short tons (st) of manganese were consumed domestically in 1990. Scrap recovery specifically for manganese recycling was insignificant. However, considerable manganese was recycled through processing operations as a minor component of ferrous and nonferrous scrap and steel slag. The major loss category is manganese lost in steel processing, 323,156 st or 46 pet of the 1990 apparent consumption. Most of this loss reports to steelmaking slags. Recovery from slags is technically feasible, but is not economically feasible.

Jan 1, 1995

By D.W. Gentry

1. Book reviews Mine investment analysis, by D.W. Gentry and T.J. O'Neil. Society of Mining Engineers (Caler No. D, Litleton, CO 80127, U.S.A.). US$50.Finance for the mineral industry, by C.R. Tinsley, M.E. Emerson, and W.D. Eppler. Society of Mining Engineers (Caler No. D, Litleton, CO 80127, U.S.A.). US$50. 2. Mintek reports The folowing reports are available from the Council for Mineral Technology, Private Bag X3015, Randburg, 2125 South Africa. They are free of charge to South African addressees, but there is a handling charge of US$25 per copy for reports sent to overseas destinations. Report M291D Removal of pebbles and pre-crushing of selected feed material in autogenous milling, by D.I. Hoyer. First issued Nov. 1986, reissued Apr. 1988. 16 pp Report M350 A survey of miling and mil-lining practice on South African gold mines, by M.S. Powel. Jun. 1988. 30 pp Report M356 The distribution of cobalt in mineral constituents of the Merensky Reef and UG-2 Chromitite Layer of the Bushveld Complex, by G. Smits. Jut. 1988. 13 pp Report M359 The development of a mobile laboratory for the monitoring of gold and cyanide in alkaline cyanide solutions, by R.V.D. Robert, C. Pohlandt-Watson, H.J. du Plessis, and G.D. Marshal. Aug. 1988. 17 pp. Productivity and technology The Metalurgical Society and Geselschaft Deutscher Metalhuten-und-Bergleute are sponsoring the Symposium on Productivity and Technology in the Metalurgical Industries, which is to be held in Cologne, West Germany, from 17th to 22nd September, 1989.Non-ferrous smelting Commemorating a centenary of lead smelting and refining at Port Pirie, the Conference on Non-ferous smelting wil be held at Port Pirie from 17th to 20thSeptember, 1989. International trade fairs From 20th to 26th May, 1989,4 major international trade fairs wil be held in Disseldorf, West Germany.

Jan 1, 1988

In August, 1975, North Broken Hill Limited announced that an intersection of 37.3 m of high grade lead-silver-zinc mineralisation, assaying 26.2 per cent Pb, 495 g/tonne Ag and 21.2 per cent Zn had been obtained at its Mine at Broken Hill, 520 m north-east of its No. 3 Shaft and slightly below the No. 36 level (1581 m). Subsequent drilling confirmed the presence of the extension of the Broken Hill Orebody on the north-western side of the Globe Vauxhall Retrograde Shear Zone and defined 1.8 million tonnes of high grade mineralisation. The area containing this mineralisation was subsequently named the Fitzpatrick Area in tribute to the late Mr. W.E. Fitzpatrick a former Member of the the Board and Manager of the Ccnpany's Broken Hill operations. This paper describes in brief the exploration programme leading up to the discovery, the general geology of the area and the proposed future exploration progranme for further extensions of the orebody within the mining leases of North Broken Hill Limited.

Jan 1, 1983

By Tristan Worsey, Nathan Rouse, Daykin Schnell

The authors were retained by a proposed underground metals mine operation to evaluate the potential blast vibration amplitudes that could be generated at surface structures above the proposed mine. Literature reviews of published blasting documentation gave little information, data, or models on surface blast vibrations produced by underground mines. At the client’s request, the authors contacted a number of underground mining operations to evaluate interest in sharing blast vibration data with the authors so that the authors could develop an underground-to-surface blast vibration regression equation.

Feb 1, 2020

By W. W. Adams

"Although rock-dust is an effective and generally recognized preventive of wide-spread explosions in bituminous-coal mines and although in explosions many lives have been saved by its use that almost certainly would have been lost otherwise, yet more than two thirds of the yearly production of bituminous coal from underground mines in the United States is still being obtained from mines that do not use rock-dust, and more than two thirds of all men that work underground in bituminous mines are employed in nonrock-dusted mines. These facts are revealed by a statistical survey of all mines in the United States that were in operation during 1930, 1931, and 1932. The survey was conducted by the Demographical Division of the Health and Safety Branch of the United States Bureau of Mines and was based upon reports from operating companies received in connection with the Bureau's annual statistical surveys of accidents in the mining industry.In 1932, the latest year for which complete figures are available, rock-dust was used, to some extent at least, in 393 bituminous-coal mines whose total production of coal during the year was 83,632,327 tons, or 30.6 percent of the entire output of bituminous coal from all mines in the United States not including opencut mines. The number of men employed underground at mines that used rock-dust was 25.7 percent of the total number employed underground at all bituminous mines, and the number of man-hours worked at these mines was 27.1 percent of the total number of man-hours worked underground at all bituminous mines during the year."

Nov 1, 1934

By Pradip

Bastnaesite, a rare-earth fluocarbonate, was separated from associated calcite and barite gangue minerals in the Mountain Pass, CA rare-earth ore beneficiation plant by froth flotation using fatty acids (tall oil) collector, lignin sulfonate depressant and soda ash modifier after high-temperature (steam) conditioning with reagents. Starting with a feed grade of 7.6% REO, concentrates having a grade of 65% REO can be produced at a recovery of around 80%. A detailed investigation consisting of Hallimond tube microflotation experiments, bench-scale tests with a laboratory Denver flotation cell, and predesigned plant campaigns was made to delineate the underlying surface chemistry involved in this separation and to develop an alternate reagent scheme to enhance the selectivity of separation for this ore. Our results clearly demonstrate the superiority of alkyl hydroxamates to the conventional fatty acid collectors that were being used in the plant. Our study also indicates the possibility of achieving the desired selectivity with alkyl hydroxamates even at room temperature, thus obviating the need for steam conditioning. A critical review of the literature on rare-earth mineral flotation suggests the possibility of designing a more selective reagent combination for the beneficiation of Mountain Pass rare-earth ore, using a methodology based on ab initio molecular modeling computations.

By P. B. Queneau

An operating problem encountered at the Moa Bay operation in Cuba, where nickeliferous laterite ore is processed by sulfuric acid pressure leaching, is the formation of alunite and hematite deposits on the autoclave walls. The AMPX Extractive Research & Development, Inc., metallurgical laboratory (Golden, Colorado) has made substantial improvements in the Moa Bay process in the areas of metal recovery, energy consumption, and feed versatility. One of the advantages of AMAX's process is its ability to treat substantial portions of nickel- and magnesium-rich serpentine while maintaining acid utilization efficiency. The process minimizes scale formation by combining staged acid addition with vigorous agitation and 270°C operation, but does not eliminate scaling. This paper describes how advantage can be taken of MgSO4?XH20 precipitation both to inhibit alunite scaling and to disperse hematite scale within the MgSO4?XH20 matrix. Cooling the autoclave from its 270°C operating temperature down to 180°C takes advantage of the reverse solubility of magnesium sulfate. The magnesium dissolves, liberating entrained hematite, thus providing a means for control of autoclave scale with minimum process disruption.

Jan 1, 1984

By H. Kenworthy

Laboratory experiments were conducted on several materials to determine their suitability for the production of mineral wool. By blending raw charges in the proper proportions and in some instances by adding lime, acceptable wools were made from samples originating in Alaska, Florida, Texas, and Virginia. It was shown that satisfactory wools can be produced from many kinds of raw materials if the ratios of acidic and basic constituents are properly maintained. INTRODUCTION The Federal Bureau of Mines has facilities at the Mississippi Valley Experiment Station, Rolla, Mo., for examining and testing mineral-wool raw materials. Samples are evaluated through small-scale wool-blowing experiments, aided by petrographic, chemical, and physical analyses of the raw materials and finished wools. When enough experimental data have been accumulated they are made public through Government reports and periodicals. This report of investigations follows that published in 19513/ and presents test data on samples received and examined since 1951.

Jan 1, 1956

By K. J. Miller

A two-stage froth flotation technique was developed in the laboratory to separate fine-size pyrite from coal. The process consists of the initial flotation of a 15-percent solids coal slurry with a minimum of frother; the coarse, free pyrite and other refuse are removed in the tailings. The froth product from this first stage is then repulped and treated with a coal depressant, a pyrite promoter, and a frother to float the remaining fine-size pyrite or pyrite attached to coal particles. With the two-stage process, the pyritic sulfur content of a Lower Freeport bed coal sample was reduced from 1.78 percent to 0.75 percent in the first stage, and from 0.75 percent to 0.27 percent in the second stage with good clean coal recovery.

Jan 1, 1972

By F. K. McKean

Abstract A discussion of the difficulties involved in the production of a clean molybdenite concentrate introduces the paper. There is a brief description of the various methods for producing molybdenite that will fit marketing specifications, and it is shown how these methods are nor suited to the milling of ores containing small quantities of bismuth and copper. A process that was developed in the ore testing laboratories of the Bureau of Mines at Ottawa for the La Corne mill of the Molybdenite Corporation of Canada is described in derail and some results from pilot plant operation of this milling scheme are tabulated. A description of the La Corne mill, where the writer supervised the introduction of the process on a commercial scale, adds to the interest of the paper. In conclusion, there is a review of the conditions necessary for proper operation of the flowsheet. An attempt is made to show how the process might be satisfactory in other problems similar to that at the La Corne mill. Introduction The production of a molybdenite concentrate, free from impurities and high in grade, has been a difficult task when milling some types of ore. Whereas ordinary flotation techniques will produce acceptable concentrates of the baser sulphides, in many cases they will not serve in the treatment of molybdenite, for this mineral must be of optimum grade and purity to bring the best prices, or to find a market at all . Faced with the necessity of meeting stringent specifications, the mill operator has been forced to employ expensive processing methods, and to be satisfied with low recoveries, in order to make grade with his product. The most objectionable and common impurities found with molybdenite are: (a) gangue minerals and iron sulphides, which lower the grade; and (b) copper, bismuth, or antimony, which are deleterious in the final uses of the molybdenite products. It is difficult, and sometimes impossible, to market a concentrate with over 0.5 per cent of any of the latter impurities, or with a grade much below 90 per cent MoS2. Various methods, which have been highly successful in specific applications, have been developed to meet the problem of producing a suitable concentrate. All of them, however, have certain defects precluding their use when treating ores of a nature different from the one for which they ? were designed. The writer has developed a process for molybdenite ores having an objectionable impurity content. A description of the procedure involved, and of the La Corne mill of the Molybdenite Corporation of Canada, where the process has been adopted, should be of interest to flotation operators.

Jan 1, 1947

By Selwyn G. Blaylock

There is no more important problem today than industrial relationship, and probably none that is receiving more thought. But in these days of Epie and Utopia, one has to be rather careful in speaking on this subject. Consequently, for fear that my plea for taking the working man into the family might be misconstrued, by some, as a step towards communism or socialism, I would like to say at the outset that I believe that, so long as we have human individualism, human ambitions, human hopes and fears, straight socialism is as far off as the Millennium. The same applies to communism, which only differs from socialism in that the communist realizes that his ideals can only be attained by massacring millions and destroying all that we hold sacred. Each still looks to Russia for inspiration and guidance, totally disregarding the Soviet swing-back to individual contract work and differential wage scales. They seem to be oblivious of the tyranny and repression in the present Russian system, and get very restless when reminded of it. In spite of the fact that the standard of living in civilized countries has improved tremendously and is still improving, we find that, every seven or eight years, production in many lines has outstripped consumption, and we have had panics or depressions of greater or less magnitude, accompanied by extensive unemployment. It is evident to every thinking person that there must be no little inefficiency in the control of industry. For four long years, governments and industrialists have striven to find the key to solve the present problem. Many countries are getting back to a position approaching normal-Canada probably more so than most. None, however, can feel assured that they have actually cured the situation. All kinds of schemes have been developed; tariff barriers have sprung up over-night where none existed before; currencies have been inflated to gain added security in the home markets and to try to gain advantage in export trade; and each country watches the movements of the others with fear and mistrust. I am not prepared to formulate a full solution of our troubles, but I hope to be able to demonstrate the feasibility and wisdom of the type of industrial relationship I advocate, and also that it may be a large, and possibly an essential, step towards the solution of our difficulties.

Jan 1, 1935

By Alexandre Keunecke Hardt

Nesse trabalho são abordadas as características de um barramento de serviços de manufatura, um software que promove a integração dos diferentes sistemas presentes no ambiente de TI industrial com o nível corporativo. O cenário atual de crescente competitividade e dinamismo da indústria siderúrgica e de mineração apresenta uma tendência cada vez mais forte de aumento da eficiência operacional. Isso demanda a gestão de ambientes de TI cada vez mais complexos que incluem desde sistemas especialistas a sistemas legados de fusões e aquisições. A integração dessas aplicações com os sistemas corporativos (ERP) resultam em um ambiente com intensas trocas de informações em que a operação se torna dependente do funcionamento sincronizado dessas comunicações. Este trabalho tem como objetivo discutir uma solução de arquitetura de integração manufaturacorporativa por meio de um barramento de serviços e apresentar um estudo de caso.

Aug 16, 2017

By Fred C. Wrobbel

Two counties in Illinois, Ope and Hardin, and three counties in Kentucky, Crittenden, Livingston and Caldwell comprise the entire Kentucky-Illinois fluorspar district. The output from these five counties, however, makes up over 60 percent of our domestic fluorspar production, amounting to some 175,000 tons of finished product in 1956, The area is rough and hilly. It is bisected by the Ohio River, and has numerous smaller rivers and creeks. Add to this a generous average annual rainfall, in excess of forty inches, and it is understandable that the-area-can boast of an ample water supply. An abundance of water, however, is unfortunately not always conducive to ideal mining conditions. The faulted structure of the area and the soluble Mississippian limestones make the subsurface sediments' willing hosts to the surface water. Limestone cavers and sinkhole topography also compound the occurrence of underground water. It is little wonder, then, that water frequently presents an economic problem in the area, particularly in vein-type mining.

Jan 1, 1958

By S. L. Crouch

The general term "coal mine burp" refers to the sudden and violent failure of in situ coal. Coal bumps occur in most countries where coal is worked by underground methods, and are related to both geological factors and mining tech¬niques. Although no single set of circumstances is solely responsible for causing coal bumps, it is generally agreed that at least one of five conditions is necessary in order for then to occur: 1,2,3,4 (1) the depth of cover exceeds 500-ft., (2) the overlying strata are relatively strong and stiff, (3) the coal is structurally strong, (4) the floor does not heave readily, and (5) the mining method produces high stresses over a large area of the seam. Except for the last, these conditions relate to geological factors that are impractical to control. Consequently, methods of controlling or minimizing the occurrence of coal bumps usually are concerned with mining techniques. Coal bumps have been successfully controlled by both longwall and 'yielding pillar' mining systems 4. The longwall system is particularly effective in controlling bumps, but does not eliminate them completely, especially in strong coal seams being worked at comparatively great depths, say in excess of 2000-ft.5. Under such conditions, auger drilling or water infusion often prove helpful 5,6. These techniques are used to destress or otherwise alter the mechanical properties of the coal in an attempt to shift the peak "abutment pressure" away from the immediate vicinity of the face. Under 'normal' conditions, however, it can be expected that the coal near the face will be crushed under the prevailing high stress conditions and that the peak abutment pressure will automatically be shifted into the solid coal. In this context, coal mine bumps can be characterized as unstable releases of energy associated with successive yielding of portions of the coal seam with progressive mining. Longwall and yielding pillar mining systems are effective in controlling coal bumps because they ordinarily do not allow the zone of peak abutment pressure to become 'surrounded' by destressed coal.

Jan 1, 1973

By Tyler Acorn, Tristan Worsey

A dozer operator at a surface gold mine accidentally drove a D10 off the side of a highwall. The blade of the dozer caught on the lip of a catch bench 60 ft. (18.3 m), down stopping its descent. The operator scrambled to safety in fear that the dozer would not hold.

Jan 1, 2014

By R. L. Godfrey

The Custom Coals advanced coal cleaning plant will be designed with a unique blending of existing and new processes to produce two types of compliance coals: Carefree Coal? and Self-Scrubbing Coal?. Carefree Coal will be produced by cleaning the coal in a proprietary dense media cyclone circuit utilizing fine magnetite to remove up to 90 percent of the pyritic sulfur and correspondingly greatly reduce the ash. While may utilities can achieve full S02 reduction compliance with Carefree Coal, others face higher sulfur reduction requirements due to the higher sulfur content of their existing fuel supplies. For these circumstances, a patented Self-Scrubbing Coal will be produced by taking Carefree Coal and pelletizing limestone-based additives with the finest fraction of the clean coal. These technologies will enable over 150 billion tons of non-compliance U.S. coal reserves to meet compliance requirements.

Jan 1, 1995