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By H. E. Powell

Because of increasing consumption of high-and super-duty refractories, the Bureau is studying the feasibility of beneficiating submarginal and marginal clays. Diverse mineral dressing tests were used to beneficiate samples from the east-central Missouri fire clay district. Standard ASTM tests were used to determine refractory properties of both crude and beneficiated clay samples. Marginal and submarginal clays containing impurities were effectively beneficiated by both wet-cyclone and wet-table treatment, but the wet-cyclone treatment was cheaper. Ion-exchange resins in the hydrogen form will probably prove more effective in removing potassium, the only alkali in Missouri fire clays to be a problem. Resins with greater cross linkage are more effective than resins with less. Roasting the crude clays before removing alkalis by chemical leaching was ineffective. By applying ultrasonic energy at a frequency of 10 to 25 kilocycles to aqueous suspensions of the clays, subsequent ion-exchange extraction of potassium was slightly improved. Higher frequency ranges did not help.

Jan 1, 1963

By Henry Rawdon

ONE of the most vital problems in the manufacture of steel at present is the occurrence of the defects that have been popularly termed "snow flakes," "flakes," or "scabs." Particularly is this the problem of many manufacturers who during the past 2 yr. have undertaken large-scale production for the first time. A study of the microstructure of such defective material throws considerable light upon the nature of these defects and is essential before measures may be taken for the elimination of the defects. Flakes do not appear to be found in the plain carbon steels; they have been found, however, in abundance in some of the simple alloy steels that are being used in such vast quantities; viz., nickel steel of the approximate composition, 0.40 carbon and 3.5 per cent. nickel, and in the chrome-nickel type. The present article summarizes the characteristic features of defective steel of the flaky type as they have been found by laboratory study of numerous specimens, and it aims to show the conditions within the metal that are favorable to the occurrence of this type of defect without entering into the details of mill practice (size of ingot, design of molds, rate of cooling, distribution of cooling stresses, etc.), all of which conditions appear to play a role in the production of these defects.

Jan 2, 1919

The relative contents of Au in a series of groundwaters from water bores and exploration drillholes, located near Au mineralisation at Stawell, Ararat, Clunes and Ballarat in central Victoria, were found to be clear indicators of relative proximity to mineralisation in each region. In the same series, waters with anomalous concentrations of As distinguished Au mineralisation in bedrock from secondary palaeochannel or deep lead Au. In some groundwaters, acid pH values, high sulphate relative to other anions and detectable concentrations of reduced Fe reflected sulphide minerals associated with bedrock Au deposits. Close to some ore zones, locally anomalous groundwater concentrations of Mn reflected the Fe carbonates that accompany Au in these zones. In addition, elevated concentrations of other elements provided geochemical signatures for the aquifer lithologies associated with Au mineralisation. Of the lithological indicators Co and Ni, U and F, Rb and Cs, Mo and Li respectively reflected the mafic, felsic, potassic rich and quartz zones, principally in the Stawell mine area and to a lesser extent those at Clunes and Ballarat. Mineral stability diagrams, based on groundwater activities of K', Mgt and H`, demonstrated that a series of ore-zone groundwaters follow a trend that conforms with a biotite to sericite to kaolinite alteration sequence in aquifer mineralogy. This is a good illustration of how present day groundwaters under surface conditions can reflect the underlying mineral sequences that accompany these Au deposits. These observations around mine areas suggested that groundwater chemistry could provide a rapid and cost effective method of assessing prospectivity for An of extensive areas in central Victoria. To test this, regional sampling and analysis of 355 bore waters was carried out in a region where potential An bearing rocks are covered by Mesozoic and Cainozoic sediments and volcanics. Contoured elemental abundances and distribution from this program indicated five zones in which groundwaters had elevated Au and despite the cover, appeared to reflect variations in the underlying Palaeozoic rocks. Three of the Au zones could be in terrain affected by extensions or intersections of faults, a feature in common with the established Au deposits in central Victoria. Reflections of concealed Palaeozoic rocks included a possible zone of concealed Cambrian greenstones that coincides with three of the Au zones. It was concluded that each of the An zones represents a groundwater Au focus that warrants follow-up exploration.

Jan 1, 1997

By C. B. Manula, R. L. Sanford, R. A. Rivell

PART I. DATA INPUT FOR THE OPERATING PROTOTYPE [To run the Rail Haulage Model independent of the Production Sub-system, remove the production data from card type four through the blank card following END DATA on page B18 and change the fourth data element under ADDITIONAL DATA from 1 To 0.]

Jan 1, 1974

By Larry Howe

Second, or retreat mhng with Mobile Roof Supports (MRS) has now been part of coal mining in the United States for a decade Their utilization has evolved into mining applications which vary in seam heights from 38 inches to 170 inches, and overburden depths from outcrop to beyond 1200 feet This paper will detail the pillaring plans, lift sequences, and mnchky utilized in these operations and the rational for the plans A comparison of the current productivities achieved will be outlined

Jan 1, 1998

By C. C. McDermond, Others, B. N. Zavoico

Production of crude oil in Venezuela for the year 1937 was 186,653,-916 bbl., as compared with 155,228,982 bbl. produced in 1936, an increase of almost 31,500,000 bbl. The oil-field strike, which started on Dec. 14, 1936, lasted until Jan. 25, 1937, when a total of 10,000,000 bbl. of production was estimated to have been lost (5,750,000 bbl. in 1936 and the remainder in 1937). Of the total of 186,653,916 bbl. produced in 1937, the Lagunillas field contributed 45.6 per cent, a drop of approximately 10 per cent under 1936 figures; Tia Juana, 14.3 per cent; Quiriquire field, 14.0 per cent; La Rosa area, 13.3 per cent and the Mene Grande field, 7.6 per cent, these being the five leading contributors of the year's production. Detailed production figures by fields and by companies are shown on Table 1. Of the total production of Venezuela the following four major companies accounted for the greater proportion: Standard of Venezuela and Lago Petroleum Corporation together, 48.3 per cent; Shell, 37.4 per cent and Venezuela Gulf, 14.0 per cent. At the end of the year, 2491 wells were producing, of which number 1291 wells were pumpers, or about 52 per cent. Production The accompanying statistics of production record of Venezuela oil fields from its inception to Dec. 31, 1937, shown on Table 2, indicates that the cumulative production reached 1,503,283,228 bbl. In order of importance, Lagunillas leads all the fields, having accounted for about 50 per cent of Venezuelan production, followed by La Rosa area, which produced about 21 per cent; Mene Grande, which produced about 13 per cent, and Quiriquire, which produced 6.5 per cent. Table 3 shows the age of each field. Mene Grande is the oldest, having produced for 24 years; Tarra is next, 21 1/2 years old, and El Mene third, 171/2 years. The gravity of the crude from the various fields, also shown on Table 3, remained unchanged, the only addition being the new Tia Juana field, which averages 15.6' A.P.I. Table 4 shows the method of production by fields as of Jan. 1, 1938; at the end of the year 2491 wells were producing, compared with 2005 wells producing at the beginning of 1937, or an increase of 486 wells. The completions for the year reached 512. Of the 2491 wells producing crude oil, 1291 wells, or approximately 52 per cent, were pumping, 925 (approximately 37 per cent) were flowing naturally and 275 (11 per cent) were on

Jan 1, 1938

By James Wm. White

Computer based dispatching in open pit truck haulage operations yields many benefits of current interest to mine management. The key tangible benefit is a substantial productivity increase with a given fleet of equipment or, alternately, a significant reduction in equipment required to meet production quotas. Other tangible benefits, depending on the operation, include minimizing rehandle, meeting several blending constraints simultaneously and ensuring a target plant feed rate. Intangible benefits include production forecasting, performance comparisons of trucks or shovels of different manufacture and extensive on-line report generation. Recent advances in mini and micro computer hardware and software and solid state electronics permit design and implementation of system features not feasible even a few years ago. Here we discuss many of these recent developments with emphasis on system aspects and dispatching algorithms.

Jan 1, 1983

Level measurement of underground orepasses is important. Orepasses are not only utilised to funnel ore to the shaft skip loading station but also as silos for storing of ore in order to smooth out ore flow in a shaft system. Safety and operational efficiency are also improved as proper orepass level measurement could prevent overfilling of tipping areas. A study was therefore commenced to determine alternative technologies available as well as identifying practical installations across the Anglo American plc Group. From an instrumentation perspective an orepass system is an extremely difficult environment to take measurements in. Factors like dust, vapour, interference, bridging, wear and physical installation have to be taken into account. The study discusses time-of-flight (ultrasonics, radar and laser) measurement techniques followed by other possible solutions. These solutions included strain gauge measurement, the æjumping monkeyÆ technique, radiotomography, fibre optics and very long baseline interferometry (VLBI). Finally, various South African suppliers have been approached in order to determine instrumentation that is available for orepass level measurement in the marketplace. These recommendations were verified, where possible, by visiting the claimed installations.

Jan 1, 2005

By L. Hartsell Cash

INTRODUCTION Created in 1944 to help rebuild those economies, principally in Europe, which were seriously damaged or destroyed during the Second World War, the World Bank--or to use its correct name, the International Bank for Reconstruction and Development-began its operational phase by making a loan to the Government of France to accomplish two tasks: (i) to import coal for space heating purposes; and (ii) to buy new machinery and equipment to help rehabilitate its coal mines. Once the thrust of reconstruction in postwar Europe was largely accomplished, the World Bank Group (for today the World Bank has three separate lending windows) turned to mobilizing funds to improve living standards in developing countries, which remains its primary goal today. Over this period of time, the World Bank Group has continued to assist the world mining industry in various ways and, since 1955 the World Bank Group has financed mining or mineral processing projects with loans/credits totalling $1.5 billion. The World Bank Group consists of two institutions--the World Bank itself and the International Finance Corporation (IFC), which was founded as a separate institution in 1956 and three separate lending windows--the World Bank, the International Development Association (IDA), and IFC. The World Bank loans are provided at commercially-related interest rates but have grace periods usually of up to 3 to 5 years and repayment periods ranging from around 15 to 20 years. Since the World Bank raises its operating funds on the international capital markets in varying currencies and in varying interest rates, it relends a basket of currencies at floating interest rates which are fixed every six months to reflect the Bank's own borrowing cost. At the present time, the interest rate is just below 10% per year and in addition, a one-time front-end fee of 1/4 of 1% is charged. Also, a commitment fee of 3/4% per year is charged on the undisbursed amount of the loan itself. For loans to industrial and mining projects, it is normal to charge an additional guarantee fee of 1 to 1.5% in addition to the annual interest rate. This guarantee fee is payable to the government of the country in which the project is carried out since, by its charter, the World Bank is required to have the guarantee of the host government for each loan made in a specific country. By far the greatest source of lending funds within the World Bank Group is that of the World Bank itself and for the fiscal year ending June 30, 1984, the World Bank approved loans totalling $12 billion. The second lending window within the World Bank Group is IDA which performs the same functions as the Bank itself and has the same staff. Nevertheless, its loans (called credits) are made on much softer terms and are made to the poorest nations only. IDA funds are subscribed by the wealthier countries, usually as grants, and these are relent as credits to those countries with the lowest per capita income. IDA credits are made for 50 year periods, including 10 years of grace, to the government itself. The credits are interest free, but there is a service charge of 3/4% per year on the amount withdrawn and outstanding to defray the administrative costs of IDA. Credits approved during fiscal 1984 totalled $3.5 billion. The third lending window is IFC. While IFC is a separate corporation and operates quite separately from the World Bank and has its own staff and regulations, it works very closely with the World Bank on its overall approach to the mining sector and to a particular country. IFC's mission is essentially to supply venture capital and to stimulate development of the local private sector in capital markets as well as to promote the international flow of private capital to developing countries. Unlike the World Bank and IDA, the IFC does not lend directly to governments

Jan 1, 1985

By I. J. Jansen

Successful soil construction involves preparation of an adequate base, selection of high quality soil materials, and placement of those materials by means which will establish a continuous macropore network and modest to low soil strength. Where such has been accomplished, experiments reveal row crop productivity on reclaimed land which is very competitive with that on undisturbed land. Inferior productivity and sensitivity to drought stress are experienced where the soils are excessively compacted during construction. Some deep tillage practices have been quite successful in improving the compacted soils, but it is preferable to avoid compaction as the soil materials are handled.

Jan 1, 1987

By M. Kawahara, H. Sunayama

Oxidation rates of the cubic specimens, which were prepared by cutting the shaped magnesia-carbon bricks, were measured continuously with a thermo balance in the temperature range from 1273 to 1 823 K in N2-02 and Ar-02 mixed gas with 2.1 x 104 and 3.7x 102 Pa of oxygen partial pressure respectively. The effect of the graphite content, the maximum grain size of magnesia clinker and the oxygen concentration in the atmospheric gas on the oxidation rate for the MgO-C refractory has been investigated. The value of effective diffusion coefficient of O2, which diffuses through the porous decarburized layer, decreased with the decreasing of the porosity and the oxygen concentration in the external gas phase. It was speculated that the dense layer formed easily due to the high tortuosity of pores and the low recession speed of the carbon interface in the MgO-C bricks.

Jan 1, 2004

By Kung-Lee Wang, Brian W. Mackenzie, Warren E. Morrison, DeVerle P. Harris, George F. Sharrard

The term "mineral economics" is applied to a wide range of activities in the mineral industries. Earlier chapters have described the application of economic concepts to the mineral industries-supply, demand, conservation, tariffs, etc. The solution of mineral economics problems is often assisted by the application of quantitative methods. The purpose of this chapter is to describe a number of quantitative methods-econometric, operations research, and management science techniques-which find application in the analysis of mineral economics problems. These methods include input-output analysis, trend analysis, forecasting techniques, simulation, multivariate statistical analysis, mathematical programming, and market research techniques. The purpose of this introductory section is to provide a mineral economics framework for the application of these methods. Mineral economics is a subdivision of economics that is justified by a sufficient number of economic problems in the mineral industry requiring special experience and an unusual combination of skills. These problems are concerned with the conversion of minerals as geologic resources to minerals as economic goods. The mineral conversion process is outlined in Fig. 8.A.1. The physical occurrence of mineral deposits in nature and the market demand for mineral products in the economy provide the basic stimuli. The conversion process embodies a number of sequential stages-exploration, the development of mineral deposits, and mineral processing facilities and, consequently, productive activity to supply market demand. Changes in demand and the depletion of deposits illustrate the dynamics of the process. Mineral economics applies economic con-

Jan 1, 1976

By Iga Trisnawati, Fitria Puspita, Himawan Tri Bayu Murti Petrus, Gyan Prameswara, Idi Amin, Andi Nurfaadhilah Ulfah

Laterite ores, rich in essential metals like nickel, iron and cobalt, are a crucial resource for modern technology. However, the extraction of nickel from laterite ores is a complex process due to their intricate mineral compositions and low nickel concentrations. This paper presents the results of a study to understand the leaching behavior of preroasted laterite ore and the impact of roasting on leaching kinetics. The ore was subjected to roasting at 280 and 610 °C for a duration of three hours, followed by leaching in sulfuric acid (H2SO4) under atmospheric conditions. The results show that preroasting the ore at 610 °C significantly improved the recovery of nickel during leaching, with recovery rate of up to 93 percent, and the leaching process of the preroasted ore was primarily controlled by diffusion through the ash layer. The activation energy values were found to be 20.97 kJ/mol for the ore roasted at 280 °C, and 18.97 kJ/mol for the ore roasted at 610°C. These findings suggest that preroasting can enhance the leaching performance of laterite ore, potentially paving the way for more efficient and sustainable nickel extraction processes.

Aug 1, 2024

By F. W. Maclennan

PAPERS by D. B. Scott, E. G. Deane, and J. H. Hensley, Jr.1 describe the succession of mining methods used in the Miami mine—squarelset system, shrinkage stoping, top-slicing method, and the undercut caving system which was then being used, and which embraced the use of finger raises. The last-named system worked well but when the rich ore was exhausted it became necessary to reduce costs so as to make available a low-grade ore containing an average of less than 0.9 per cent. total copper with less than 0.8 per cent. in sulfide form and with no precious-metal values. There was then developed for this low-grade ore the system of separate large block-caving stopes, in lateral dimensions 150 by 300 ft., or 150 by 150 ft., with intervals between stopes of the same size so that subsequently these pillars may be similarly mined. The results have been most favorable. Under the previous system the production of ore per man-shift for all underground labor was 8 tons. The present production per man-shift underground is 28 tons. In starting this work the problems were: 1. How the ground would cave above the stopes. 2. Whether in the first stopes caving would encroach on the pillars as laid out. 3. Whether in subsequent mining of the pillars waste filling would be drawn from the previously caved adjacent stopes. Fig. 1 is a small key plan for showing the location of cross-sections as well as of ore mined and the limit of the escarpment and limit of cracking on the surface caused by the caving of the capping overlying the ore

Jan 1, 1929

The population and the per capila consumption of mineral resources have both grown dramatically during the century past. It is argued that growth will continue through the century ahead but that the magnitudes of undiscovered resources are probably adequate to meet demands. The challenge that the mineral explorer of the future will face is finding deposits beneath several kilometres of barren rock.It is further argued that the principal challenge that society will face in the century ahead is the amelioration of environmental stress.

Jan 1, 1993

By Millard K. Shaler, Sydney H. Ball

During the past 50 years the attention of mining-men has been turned to Africa, and within the past decade prospecting-expeditions sent into Central Africa have resulted in the open-ing-up of several mines. Having recently spent two years in the Belgian Congo for the Societe Internationale Forestiere et Miniere du Congo, it is our purpose to outline briefly the mining-conditions in that part of Central Africa. Before it became, in 1908, a Belgian colony, this region was known as the Congo Free State. 11. Location and Area. The Belgian Congo lies in southwestern Central Africa, west of the continental divide, as illustrated in Fig. 1. It has a coastline of but 20 miles on the Atlantic, but widens rapidly eastward to points 5 north and 14 south of the equator. Its area is 908,000 sq. miles, which is almost one-quarter that of the United States and Alaska, or more than one and one-half times that of Alaska. Stated in other terms, its area is nearly one-third that of the United States, exclusive of Alaska and the insular possessions, or more than that of all the United States east of the Mississippi river. III. Topography and Drainage. From north to south, Africa is made up of three topographic elements: 1, the Atlas mountains, a highly-accentuated region

Jan 1, 1911

Australia is the Western world's largest producer of alumina, supplying one third of total needs. Western Australia's South-West has the greatest concentration of alumina production in the world, with a current annual production rate in the region of 6.8 million tonnes per annum, over 20 per cent of the total supplied to market economies. The value of this production in 1989-90 was 2.34 billion dollars, a very significant contribution to the economy of the State (1). This is despite the fact that the bauxite from the Darling Range is the lowest grade that has ever been commercially exploited, and despite the geographical isolation of the region. It is therefore of great importance to the National and State economies that this industry retain its competitive edge, particularly in the current times of economic downturn. One essential ingredient of this competetiveness is technology and innovation, which can be assured by the committment of the industry to an active program of Research and Development, with support from the public sector as Appropriate.

Jan 1, 1991

By P. Somasundaran, G. Anastassakis, Z. Pan, D. R. Nagaraj

Gums are often used as depressants for talceous gangue minerals in the flotation of nickel and platinum bearing ores. However, the mechanisms of gum adsorption on talc are not clearly established. In this work, adsorption of guar gum at the talc-solution interface is investigated using spectroscopic and allied techniques. Guar gum adsorption on talc is not affected significantly by changes in solution conditions such as pH and ionic strength. Electrokinetic studies showed that guar gum decreased the negative zeta potential of talc but did not reverse the charge. Fluorescence spectroscopy studies conducted to investigate the role of hydrophobic bonding using pyrene and dansyl probes showed no evidence of the formation of hydrophobic domains at talc-aqueous interface. Urea, a hydrogen bond breaker, reduced the adsorption of guar on talc to the same extent as that for guar/alumina system, in which hydrogen bond plays an important role. All of the above results suggest that one of the main driving forces for guar adsorption on talc is hydrogen bonding rather than electrostatic or hydrophobic force.

Jan 1, 2003

By Z. D. Hora

"There has been a number of new developments in British Columbia's industrial minerals field over the past few years. Several new industrial operations were started to diversify the line of British Columbia mineral production by magnesite, perlite and fuller's earth. Industry activities and geological projects have identified occurrences of rare earth minerals, niobium, kaoline, fireclay and zeolites. The Geological Survey Branch significantly improved its database on industrial minerals. New geological concepts based on recent work are opening a number of new opportunities f or further industrial minerals' exploration and development in British Columbia.IntroductionTraditionally, the value of industrial minerals produced in British Columbia in any given year comprises between 100/0and 15% of the combined value of minerals, coal, petroleum and natural gas. Over the years a wide variety of industrial minerals has been produced , often with different levels of marketings success. For some products, such as dimension stone and clay or shale products, initial strong demand gradually dissipated; for others such as asbestos and magnesite, new discoveries or new industrial activities created demand and new markets . In some cases, such as fluorite , talc, pyrophyllite and perlite, wider use has been prevented by small size, poor quality or remote location of the deposits. Also, British Columbia , with 2.6 million inhabitant s, provides only a limited market and the industry therefore has to look beyond provincial borders."

Jan 1, 1990

By Zay Jeffries

Page Introduction............................. 474 Nature of Experiments ........................ 476 Materials Used in Experiments..................... 476 Description of Samples........................ 476 Details of Tests and Apparatus .................... 486 Determination of Elongation...................... 488 Determination of Reduction of Area .................. 488 Results of Tests........................... 489 Quantity and Arrangement of Amorphous Phase............. 497 Properties of Amorphous and Crystalline Phases............. 501 Intercrystalline Fracture........................ 530 Trans-crystalline Fracture....................... 531 Rupture ............................... 535 Explanation of Beilby's Results..................... 536 Mechanical Properties of Copper Wires................. 537 Mechanical Properties of Tungsten Wires................ 542 Mechanical Properties of Iron Wire................... 546 Effect of Diameter of Wire on Mechanical Properties........... 554 General Considerations on Properties of Metals at Very Low Temperatures .. 556 General Considerations on Physical Properties of Complex Alloys...... 557 Summary.............................. 559 Discussion.............................. 562 Introduction DuRing the period 1914 to 1916. the writer observed many times that tungsten wire could be drawn hot until it became brittle but on cooling to room temperature it became ductile again. In searching the literature for parallel cases. it was found that Beilbyl had produced hard-drawn wires of gold. silver. and copper that showed less than 1 per cent.

Jan 1, 1919