Search Documents

By M. T. G. Davis, J. V. Cleasby, H. J. Wright

Mining practice in the Kimberley Division of De Beers Consolidated Mines Limited by J. V. CLEASBY. B.Sc.. A.R.S.M. (Fellow). H. J. WRIGHT. B.Se.. M.Sc.. (Fellow). And M. T. G. DAVIES. B.Sc. (Visitor) T his paper highlights the changes that are taking place at De Beers Consolidated Mines Limited in mining methods, mechanization, and employment practices. De Beers has four underground mines in Kimberley itself (Dutoitspan, Bultfontein, De Beers, and Wesselton), and two open-cast mines outside Kimberley (Finsch and Koffiefontein). Emphasis is placed on the new method envisaged for Koffiefontein when it becomes an underground mine. The paper also includes notes on chemical drilling and on winding practices.

Jan 12, 1975

Continuing a tradition of excellence established in 1937 when a group of editors under the chairmanship of Samuel H. Dolbear produced the first edition, the fourth edition of Industrial Minerals and Rocks just published by SME-AIME with the support of the Seeley W. Mudd Memorial Fund offers a treasure of information for geologists, mining engineers, marketing people, executives, chemists, chemical engineers, educators, engineering students, government officials - and, indeed, anyone whose work is directly or indirectly related to industrial minerals. This fourth edition is the end result of several years of effort by 86 authors and 11 editors, under the guidance of Editor-in-Chief Stanley J. Lefond.

Jan 12, 1975

By M. B. Algeo

Discussion of the above paper M. B. ALGEO The management and staff of Buffelsfontein Gold Mining Company Limited are to be congratulated on the excellent performances described in the paper presented by Mr Christos. In this day and age, with the current economic and labour situation, the mining industry is being constantly pressed to increase the productivity of ever-diminishing quanta of resources. Stress in rock The ISRM Symposium, 1976 is to be held in Sydney from 9th to 13th August, 1976. It is being organized by The Australian Geo. mechanics Society as a regional symposium of the International Society for Rock Mechanics. Thermal analysis The First European Symposium on Thermal Analysis will be held at the University of Salford on 20th to 24th September, 1976.

Jan 12, 1975

Termination of membership In accordance with By-Law 7.6.1. of the Constitution of the Institute, the names of the undermentioned members have been removed from the membership register. Colloquium and General Meeting A General Meeting and Colloquium on 'Heavy-medium separation and ore sorting' was held on 18th September, 1974, at 09h15, in Kelvin House, Johannesburg.

Jan 12, 1975

By Ta M. Li

US mine-related fatalities were reduced by 10.3% at metal and nonmetal operations in 1974, according to a report by the Secretary of the Interior to Congress concerning the administration of Public Law 89-577. While there was no significant change in the overall injury experience, the 157 fatalities were the lowest recorded in the mining industry since federal mine inspections began under the Act in 1970. The report attributes this reduction to the "improvement in the quality and increased size of the inspection force as well as the continuing emphasis on mine safety conditions and practices." The year 1974 represents the first full calendar year in which the Mining Enforcement and Safety Administration (MESA) had responsibility for administration of the Federal Metal and Nonmetallic Mine Safety Act, and the Federal Coal Mine Health and Safety Act of 1969. Prior to MESA's establishment in 1973, these functions were delegated to the US Bureau of Mines. Research activities in health and safety were continued by the Bureau in 1974.

Jan 12, 1975

O.F.S. Branch Minutes of the Committee Meeting held in the Committee Room at the St. Helena Club at 4.45 p.m. on Wednesday, 3rd September, 1975. Book reviews JONES, M. J. (ed.). Minerals and the environment. London, Institution of Mining and Metallurgy, 1975. Mining Companies of the world.. 1974/75. London, Mining Journal Books Ltd (15 Wilson Street), 1975. £12. 303 pp. NIM reports Report no. 483 Summary of the mineralogical investigation of pegmatites. (11th April, 1969; re-issued October 1975). Report no. 1697 A petrographic and mineralogical investigation of silica samples from the farm Elandskraal 470JQ, Rustenburg district. (24th Jan., 1975; reissued October 1975). Report no. 1761 The determination, by atomicabsorption spectrophotometry, of minor elements in anode sludges and residues. Report no. 1762 The determination, by instrumental neutron-activation analysis, of some elements in the NI M ROC standard reference materials. Report no. 1770 The spectrophotometric determination of vanadium in chromiumbearing materials. Foundry conference An international foundry confcrence, spomored and organized by South African Institute of Foundrymen, will be held in Johannesburg from 23rd to 27th February, 1976. The themes for each day are follows: Coordination chemistry A symposium on coordination chemistry in extractive metallurgy is to be held in Kelvin House, Johannesburg, on 18th and 19th March, 1976. Practical jet cutting The third international symposium on jet-cutting technology to be organized by BHRA Fluid Engineering will be held in Chicago from 11th to 13th May, 1976, in conjunction with the lIT Rese:uch Institute of Chicago. Hydraulic transport The fourth international conference on the hydraulic transport of solids in pipes (Hydrotransport 4) is being organized by BHRA Fluid Engineering.

Jan 12, 1975

By C. R. S. Needes, M. J. Nicol, G. T. W. Ormrod, N. P. Finkelstein

The industrial application of a dioxide electrode uranium by C. R. S. NEEDES, Ph.D. (London) (Visitor), M. J. NICOL, Ph.D. (Rand) (Visitor), N. P. FINKELSTEIN M.Sc. (Rhodes), Ph.D. (Liverpool) (Fellow), and G. T. W. ORMROD (Visitor) A correlation between the potential of a U02 electrode and the rate of recovery of uranium has been proved in laboratory and plant trials. When the recovery rates change because of variation in the concentrations of Fe(III), Fe(II), SO4 'and H+, a positive correlation is observed. However, an 2- increase in the concentration of phosphate in solution produces an increase in the U02 electrode potential but a decrease in the rate of leaching of U02. The correlation between the U02 electrode potential and the rate of leaching of U02 is then negative. It is concluded that, as a control device, the electrode cannot compete with the platinum electrode for use on certain plants. Nevertheless, the U02 electrode will act as a useful warning device if the total concentration of iron in solution decreases to below a level concomitant with the economic recovery of uranium. Furthermore, because of the positive correlation between the U02 electrode potential and the phosphte concentration, the electrode will also be of value in the detection of an increase in the phosphate level in solution. When it was incorporated in a suitable industrial probe, the electrode was found to be able to withstand the rigours of the leaching conditions in a large pilot-plant pachuca, and only failed after six weeks' operation.

Jan 11, 1975

By R. H. Steel

Ingot casting and wire drawing In Iron Age Southern Africa by R. H. STEEL (Visitor) This paper describes the experiments that were conducted in 1974/1975 on two related aspects of Iron Age copper technology in Southern Africa: ingot casting and wire drawing. Three types of ingot were successfully cast: the St Andrew's Cross ingot, the marale ingot, and the musuku. It is suggested that the 'studs' on the musuku are not the remains of broken-off rods as previously proposed by other investigators, but that the ridged pattern is an ornamental feature. Copper wire was successfully drawn with similar tools and according to the procedures described in the literature on African Iron Age wire drawing. It is concluded that these accounts are generally accurate and that the pre-European metal workers are worthy of respect for the results they achieved with primitive methods.

Jan 11, 1975

In 1974, iron pellet production in the Great Lakes region reached the 53-million-tpy level, accounting for more than 88% of the nation's pellet production. By 1978, pellet output from the Great Lakes district will climb to at least 78 million tpy. To achieve this 50% increase in output, the US iron and steel industry is investing at least $1.25 billion in new mines and pelletizing plants, mostly in Minnesota and Michigan. The biggest effort is concentrated in the Mesabi Range of Minnesota, the heart of the US steel industry's major iron ore source: here, plans for two new taconite plants-one by Hibbing Taconite Co., and the other by Inland Steel Mining Co.-and three major expansions of existing facilities are already under way to boost Minnesota's total iron pellet capacity from the current 41.2 million tpy to 65 million tpy by 1978. The facilities being expanded are those of US Steel Corp. (Minntac operations), Eveleth Taconite Co., and National Steel Pellet Co.

Jan 11, 1975

By H. M. Friede, R. H. Steel

Notes on Iron Age copper-smelting technology in the Transvaal by H. M. FRIEDE, Ph.D. and R. H. STEEL (Visitors) Earlier reports on Iron Age copper metallurgy and copper-smelting techniques in the Transvaal are surveyed, and a description and tentative classification of the copper furnaces are given. The analyses of furnace slags and sherds of glazed crucibles from archaeological sites of the Transvaal and the neighbouring Orange Free State pro. vide evidence of copper smelting there in Iron Age times. . An investigation conducted by the Department of Archaeology of the University ofthe Witwatersrand provided information on the details of furnace construction and smelting processes, on the composition of the materials used and produced, and on the making and handling of tools and accessories, such as bellows and tongs, needed by Iron Age smelters. Three models (the KaondejVenda furnace, the Rooiberg crucible furnace, and the Uitkomst furnace) were constructed and operated as a demonstration of Iron Age copper smelting as it was practised in the Transvaal.

Jan 11, 1975

By Alan K. Burton

The individuality of off-highway trucks is largely determined by a number of truck components that include beds, frames, and suspensions. With the exception of tires, these features are generally standard equipment and the mine operator gets "what comes with the truck." With the advent of larger trucks, more complicated haul profiles, and sophisticated production control systems, a new truck support-component industry is rapidly appearing. The impact of the new options for off-highway trucks can be significant in terms of future fleet performance. Innovations include "Mesabi" radiator cores that reportedly offer greater engine temperature control; load indicators that insure proper truck loading at the shovel; and digital communication systems that signal truck status in the haulage cycle. An understanding of tires, brakes, and newly introduced support components is necessary before an optimum choice of truck can be made

Jan 11, 1975

By D. W. Fuerstenau

The United States is rapidly approaching an acute shortage of minerals. According to some observers, this situation may even be more severe than the energy crisis because the US consumes nearly 30% of the world's mineral production. With the mounting competition for world mineral supplies, we can no longer take for granted that foreign mineral products will be available to the US as abundantly as in the past. In 1973, US consumption of mineral raw materials was $35 billion. Of this, $7 billion consisted of imports. Without a drastic reorientation towards the mining of domestic mineral resources, the 1973 $7 billion deficit might mushroom to $100 billion by the year 2000. Thus, a return to domestic sources of raw materials will become absolutely necessary-and will be bucking the trend of the past 25 years, characterized by capital investment for growth in multinational overseas mining operations.

Jan 11, 1975

By Eugene Guccione

The domestic iron and steel industry is a vital and major segment of the US economy. Including its employees in coal mining, iron ore mining, limestone quarrying, and related transportation, the industry directly provides jobs for approximately 750,000 people, has a $10 billion annual payroll, and indirectly supports a substantial volume of employment for the entire country. Because of its size and visibility, if nothing else, the US iron and steel industry has always been an easy target of attack and has often been subjected to a great deal of political sound and fury. Today, the industry has different troubles and is fighting for survival: it is faced with spiralling costs, inadequate earnings, labor unrest, foreign competition, government over-regulation, an acute shortage of investment capital, and an all-time high debt burden.

Jan 11, 1975

By Thomas M. Plouf

Flotation, as we know it today, is a physiochemical method of concentrating finely ground ores. The process involves chemical treatment of an ore pulp to create conditions favorable for the attachment of certain mineral particles to air bubbles which are carried to the surface of the ore pulp for removal. Frother reagents, combined with air and the agitation mechanism, produce the effective bubbles in a flotation cell. A method of analysis is presented to evaluate the effect of frother reductions and additions on a bank of flotation cells, and to economically determine if and to what extent frother reductions and additions are justified. Comparative evaluations of different frother systems, as well as the amount of frother used in a given flotation machine, cannot be made on the frother cost alone. An indepth study must be made to evaluate any given frother as applied to a particular ore body. The recovery of a given mineral is as dependent on the amount of frother as on the type of frother used. An actual case study follows in which the amount of frother required by two different flotation machines was used to make a decision as to which unit performed more efficiently based on costs. This same method may be used to evaluate new frothers as well as to determine if a larger frother addition is advisable.

Jan 11, 1975

By Christine Alexander

Twenty years ago, the northern Oquirrh Mountains overlooking Salt Lake City were bare. Heavy logging and overgrazing combined with erosion and uncontrolled forest fires had severely denuded the mountains by the turn of the century. As a final coup de grace, a copper smelter was built there in 1906, and for the next 50 years its sulfurous fumes killed off what little vegetation remained. In 1956, Paul Rokich, a biology student at the Univer¬sity of Utah, started to surreptitiously restore the mountains. For the next 17 years, Rokich devoted his spare time and money to replanting the Oquirrhs, with the result that several thousand acres of the mountains are green again, and animals have returned: deer, elk, and rabbits thrive among olive, maple, and fruit trees, wheat grass, and sunflowers.

Jan 10, 1975

The case for national research in mineral processing PRESIDENTIAL ADDRESS given by R. E. Robinson*, Ph.D., B.Sc. (Eng.) (Wits.) Some of you have only raised your eyebrows, some have made tactful comments, and a few of you have been fairly outspoken, but all of you in industry are concerned at the high level of State expenditure by bodies such as the National Institute for Metallurgy. The case for a national research organization in mineral processing is not clear-cut and in fairness I must present both cases - for and against. Competition for student members Each year the South African Institute of Mining and Metallurgy offers a prize (or prizes should the entries warrant it) of up to Rl00 for the best paper or dissertation on a topic appropriate to the interests of the Institute.

Jan 10, 1975

O.F.S. Branch Proceedings of the Annual General Meeting on Wednesday, 30th July, 1975 The Aromal General Meeting of the Branch was held at the St. Helena Club on Wednesday, 30th July, 1975 at 7.45 p.m. Mr D. A. Smith (Chairman) was in the Chair. There was also present: Professor R. P. Plewman, President of the S.A. Institute of Mining and Metallurgy. Conference on Vacuum Metallurgy The Fifth International Conference on Vacuum Metallurgy is to be held in Munich from 11th to 15th October, 1976. Excavation and tunnelling A conference on 'Rapid Excavation and Tunneling' is to be held in Las Vegas from 14th to 17th June, 1976. Book reviews Mine filling. Queensland (Australia), Mt. Isa Mines, Limited, ] 973. 293 pp. $A20,00 incl. postage. Young, R. S. Cheml:cal phase analysis. London, Charles Griffin, 1974. 126 pp. £4.50. NIM reports Report no. 1714 The efficiency of the fire-assay procedure with nickel sulphide as the collector in the determination of platinum,silver, gold, and iridium. Report no. 1721 A preliminary investigation into the mechanism of depression in the flotation of sulphide minerals at the Prieska Copper Mine. Report no. 1725 The determination of silica in fluorspar by 14 Me V neutron-activation analysis. Report no. 1736 The determination, by atomic- absorption spectrophotometry and liquid extraction, of antimony (parts per million) in ores and concentrates. Report no. 1741 South African costs of equipment for the metall'urgical industry(1975}. Report no. 1744 The refining of the platinum-group metals . Report no. 1746 The determination, by atomic-absorption spectrophotometry, of minor elements in zinc, lead, and copper sulphide concentrates. Report no. 1747 Magnetohydrostatic separation of gold from gravity concentrates. Report no. 1750 A review of the present and future development of sulphur production in South Africa. Report no. 1754 A new three-dimensional anodic electrode for reduced power consumption du,ring the electrowinning of metals. Report no. 139 A preliminary survey of goldrecovery problems arising in the production of pyrite. (9th Feb., 1967, re-issued Jun. 1975.) 16 pp. Report no. 140 A preliminary mineralogical investigation of pyrite from the K imberley and the Main Reefs, VogelstruisbuU Gold Mine. (13th Feb., 1967, re-issued Jut 1975.) 11 pp. Report no. 165 Gold recovery from pyrite flotation mill products by cyanidation. Progress made up to 1st May, 1967. (5th May, 1967, re-issued Jun. 1975.) 8 pp. Report no. 133 Gold recovery by cyanidation from mill products obtained after pyrite flotation. Progress made up to ht July, 1967. (18th Jul., 1967, reissued Jun. 1975.) 14 pp. Report no. 219 A review of some of the mineralogical factors influencing the flotation of pyrite. (29th Nov., 1967 reissued Jun. 1975.) 20 pp. Report no. 278 Gold recovery by cyanidation from mill products obtained after pyrite flotation. (24th Jan., 1968, re-issued Sep. 1975.) 51 pp. Report no. 306 The effect of preaeration on two samples of thickener under flow from the Venterspost Gold Mine. (30th Mar., 1968, re-issued Jul. 1975.) 14 pp. Report no. 317 Results of tests carried out at the Loraine Gold Mine during the period 5th to 7th February, 1968. (21st Mar., 1968, re-issued Jul. 1975.) 11 pp. Report no. 321 Aeration of ore from the Loraine Gold Mine before theaddition of cyanide.(17th Apr., 1968, reissued Jul. 1975.) 30 pp. Report no. 380 The effect of aeration, before cyanidation, of pulps of gold ores containing xanthate. (14th Aug., 1968, re-issued Jul. 1975.) 44 pp.

Jan 10, 1975

By Alan K. Burton

Along with tires and transmission systems, engines have been a limiting factor in the growth of large off- highway trucks. The problem, primarily, has been the development of reliable, high-performance engines that are not prohibitively heavy or expensive. For many years, horsepower to overall truck weight ratios have been in the vicinity of 300 lb per hp for rear dump units up to 50 tons capacity. This ratio is obviously very poor when compared to the much lighter and smaller highway trucks, which frequently have a performance ratio of 100 lb per hp. Unfortunately, the larger mining trucks have not been able to match even the 50-ton trucks, and in some cases, ratios have dropped as low as 450 lb per hp. This results in a performance of only 67% of that achieved by the older smaller trucks. Thus, the message is clear: what is needed is more horsepower and less weight.

Jan 10, 1975

By A. D. Rovig, T. J. Fisher

By converting its autogenous mills to steel ball mills at the C. E. Weed concentrator in Butte, Mont., The Anaconda Co. has achieved substantial increases in through- put tonnage, plus better recoveries as a result of the finer feed size to subsequent flotation operations. If steel grinding is so superior to autogenous grinding, why wasn't it chosen in the first place? Briefly, here's why:

Jan 10, 1975

By F. Milton Lewis, Roshan B. Bhappu

In Part I of this article, published in the September issue of MINING ENGINEERING, Edward S. Frohling and Robert M. McGeorge of Mountain States Mineral Enterprises, Inc., reviewed the general overall financial aspects and methods of raising the necessary capital for developing the mine. In Part 2 of this two-article series, we will present several case histories to show how realistic feasibility studies are used for evaluating the choices and options entailed in mining ventures. Basically, after a potential ore body has been discovered, and the necessary funds obtained for the development of the deposit, the next major problem is one of ascertaining what specifically is to be produced, and the costs of production. The profit potential of the mining venture can then be accurately assessed by the mine owner, operator, or loan officer.

Jan 10, 1975