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By Thomas Lane Carter

THE history of mining in South Africa differs somewhat from that of other countries in the part taken by the aborigines in the development ?of the mineral deposits. The Spaniards in America, and the fortune-seekers of Australia and New Zealand, found large numbers of natives in these new countries, but the inhabitants did not become willing or efficient workers ill the mines which the white men started. The Kaffirs of South. Africa have not shown the same antipathy to labor, nor do they show any signs of dying out in the presence of the white man's civilization. They are a virile race, and so far the vices of civilization have not killed. them. While it is true that the brain and skill necessary for the exploitation of the mineral resources of this sub-continent-have been supplied by the white race, it is also a fact that most of the rough labor in the development of the mining industry of South Africa has been done by the Kaffirs. The Kaffir tribes differ greatly in their mental and physical capabilities. Compare, for instance, a Zulu of Natal with a Bechuana, or a Xosa of Cape Colony with some of the degenerate tribes of Central or East Africa, and you will find that they have little in common, save that their skin is black and that they do not believe in clothes. As a general rule, the tribe's in the milder, healthier climates are far superior, both in mind and body, to the Kaffirs brought up in the hot malarial sections of Central Africa; and it naturally follows that the black men from the temperate zones of the country, are much finer workmen than the degenerates from less favorable sections: It is universal in South Africa to speak. of the .Kaffirs as " boys." No matter if he is 90 years old, the Kaffir is always a " boy," and in this paper the word " boy " is synonymous with Kaffir.

Nov 1, 1908

By A. C. Johnson

The Bureau of Mines explored the Three Kids deposit in 1941 as part of a strategic minerals program. Earlier mining and exploration had established the presence of a substantial tonnage of medium-grade wad ore, and drilling and sampling by the Bureau of Mines, in collaboration with the Federal Geological Survey, indicated an additional tonnage such that development and exploitation became more clearly feasible. Private interests, with Government support, undertook to produce metallurgical-grade manganese. The present paper describes the Bureau of Mines exploration and subsequent development. Manganese in the Three Kids area is found in one of the lower members of the Muddy Creek formation in a bed of fine sandstone and silt, which outcrops around the north edge of the River Mountains and generally dips 20° to 40° away from the hills. There is considerable variation in the thickness and grade of the ore. The ore is light weight, having a density of 1.2 to 2.

Jan 1, 1956

Fresh coal refuse was sampled at 21 US mines. Five of the sites were drilled, sampled and tested more extensively. Field tests included Standard Penetration tests, and in-situ density determinations. Laboratory testing included specific gravity, gradation, maximum, and minimum density tests, as well as 9-inch) drained triaxial tests, 9 and 10-inch, permeability tests, slake-durability tests, and accelerated slaking tests. Some refuse sites had significantly lower shear strengths and permeabilities in old, slaked or weathered material than in fresh refuse. Testing did not show useful correlations between strength and permeability changes and other material properties which could serve as "predictors". Testing of refuse under "accelerated slaking" conditions showed promise as a comparative tool and as a potential means of preparing artificially aged samples for evaluations of long-term behavior. The state-of-the-art in slaking research, and the implications of slaking on coal refuse disposal, and on practical methods of managing slaking, were also studied.

Jan 1, 1981

By Donald B. Lindsay

This report presents the findings of an investigation into the characteristics of a number of techniques for cleaning ambient air with special emphasis on their applicability to the removal of the short-lived radioactive decay products of 222-radon, the so-called " radon daughters" that have been identified with the induction of lung cancer in underground uranium miners. The purpose of the study was to review the requirements for control of radon daughter concentrations in mine air, and to examine all techniques whose feasibility has been demonstrated in principle and which in our judgment would be capable of meeting those requirements. The study has included a review of all pertinent literature, both technical and proprietary, on the subject of the control of miner exposure to the radon daughters and in the area of potentially applicable air cleaning technology. Information about the nature of the problem and about the experience of the uranium mining industry in applying air cleaning methods to its solution was obtained by visiting mines where such methods are in use, and by written correspondence and telephone conversations with other industry sources. Information on performance characteristics and costs of applicable air cleaning methods and equipment was obtained from the experience of our own engineering staff and by visits, interviews, and correspondence with manufacturers of industrial air cleaning equipment.

Jan 1, 1978

By Timothy Green

El presente texto explica la historia, características complejas que intervienen en el desarrollo, producción, comercialización del oro. De otro lado, como consecuencia de la abundancia de este metal, se produjeron las "fiebres del oro", originando migraciones de muchedumbres a territorios vírgenes que estimulaban el rápido crecimiento de ciudades y comunicaciones.

Nov 1, 1988

By Ajit Godbole, Ping Chang, Ramakrishna Morla, Purushotham Tukkaraja, Shivakumar Karekal

This paper presents the optimum auxiliary fan(s) location to control air recirculation in dead-end workings where dieselpowered vehicles operate. Investigations were conducted with various secondary fan locations from the dead-end crosscut with varying the intake air quantities using a 30 m3/ s capacity twin 75 kW auxiliary fan and 45 m3/ s capacity twin 110 kW auxiliary fan to control air recirculation and DPM. The results showed that if the drive intake airflow rate matches the fan capacity, air recirculation will occur even when the fan is located 10 m away from the crosscut entry. Results also showed that if the intake drive air quantity was greater than or equal to 150% of fan capacity, no recirculation was observed when the twin 75 kW fan location was at least 5 m and the twin 110 kW fan location was at least 10 m away from the dead-end crosscut access.

Oct 18, 2022

The Boliden Aitik concentrator in Sweden processes 2,000 tph of low grade copper ore. The plant consists of five grinding lines feeding four bulk flotation banks with a scavenger concentrate regrind mill, and a column cleaner circuit with a regrind mill. The authors installed a model-based expert, optimizing control system to maximize copper recovery in the bulk flotation circuit while maintaining an appropriate copper grade in the cleaner feed. The optimizing control system uses on-line assays and calculates and implements set points for cell pulp levels, air rates and reagent addition rates. It combines the power of a dynamic population balance model which estimates mineral liberation in each stream, an optimizer which computes appropriate set points and a rule-based module which implements the strategy. The benefits have been evaluated over three months. The model-based expert, optimizing control system generates a measurable increase in copper recovery, around 0.5 per cent and an optimized bulk concentrate grade. The need to maintain the optimizing control system and other practical aspects are discussed.

Jan 1, 1998

By V. F. Parry, W. S. Landers, John B. Goodman

"INTRODUCTION The object of this investigation was to demonstrate a satisfactory method of storing slack subbituminous coal in open pits in a manner,that would minimize the cause of the physical deterioration and would have a practical application.The storage of coal by industrial plants is to their advantage, since an adequate operating supplying of fuel is available at all times as insurance against transportation delays, shortages, and strikes. Furthermore, it is possible to participate in low seasonal freight rates and mine costs by permitting the railroads to utilize idle equipment and by taking advantage of the off-peak production at the mines. For a number of years, one of the larger beet-sugar companies operating in the Rocky Mountain region has taken advantage of the lower prices and seasonal production of subbituminous slack coal during the summer months and purchased a large proportion of its requirements for the annual winter campaign. This company, operating sugar-refining plants in the 1943 campaign, used 256,613 tons of subbituminous coal. Of this quantity, 166,636 tons was purchased during the off-peak season and stored for use during the winter. It is the practice of this concern to place coal purchased through the months of January to October in underwater storage for use in the beet-sugar campaign, which lasts from October to as late as, January. The beet-sugar refining ""campaign"" period starts immediately after the beginning of the beet harvest and lasts 60 to 70 days."

Aug 1, 1946

By J. A. Herbst

A state of the art computer simulation package, named UTAH-MODSIM is being developed. This package can run on a mainframe (eg. UNIVAC) as well as on a microcomputer (eg. IBM/PC with at least 512 kBytes of core memory). Friendliness was the major concern in developing this software. The user simply generates a complete flowsheet by presenting the flowsheet on a graphics terminal. This flowsheet defines the circuit to be simulated. With the minimum required data, the user can obtain a complete mass and water balances within a few minutes. Moreover, this package will provide scale-up and capital cost information of specified equipment relevant to design. In order to illustrate the utility of this software, three design examples are given. They are: a) A typical multistage crushing plant. b) A reverse closed grinding circuit comparing one stage with two stage classification. c) A standard closed grinding circuit suitable to liberate a specified fraction of chalcopyrite from a copper ore.

Jan 1, 1986

By Breno Totti Maia, Rubia Teodoro Silva, Daniel A. G. de Carvalho, Aline Lima da Silva, Gilvan Nascimento de Souza

Para a maior eficiência na técnica conhecida como Slag Splashing, empregada com fins de manutenção e reparo de refratários de convertedor LD, a escória deve apresentar características apropriadas em termos de viscosidade e fração de sólidos. No presente trabalho, desenvolveu-se uma metodologia híbrida, combinando a utilização de padrões para a caracterização visual de escórias na planta, baseada em critérios de atribuição de notas, com a simulação termodinâmica usando o software FactSage para determinação das fases presentes na escória, quantificação de fração de sólidos e cálculo da viscosidade efetiva. A metodologia proposta permite identificar os quadrantes ideais de viscosidade efetiva, fração de sólidos e teor de ferro total, de modo que se possa garantir escórias com notas altas, apresentando qualidade apropriada para o processo. Os resultados indicam que as escórias com nota 3 (ótima) são obtidas nas seguintes condições: temperatura de fim de sopro de 1690-1720ºC, viscosidade efetiva na faixa de 0,070-0,650 Pa.s, fração de sólidos de 13-22%, teor de ferro total na escória de 14-17,5%..

Oct 1, 2019

By Eugene McAuliffe

In the year 1581, the counselors of King Philip of Spain suggested to that monarch that a canal across the Isthmus of Darien would open the west coast of the South American continent to Spanish miners and explorers, enlarging and expanding the flow of precious metals then just beginning to trickle across the path cut by Spanish Conquistadors, from old Panama to Puerto Bello on the east coast. The King sent out a party of surveyors and explorers under the command of a young engineer, Savadaerro, who returned after two years, reporting upon a location for a canal which was virtually adopted by the French engineers employed by De Lesseps, who in 1877 commenced the work of constructing the Panama Canal-296 years after Sava- daerro's first survey was begun. The suggestion for an Isthmian canal, made to the king at a time when Spain was a proud, virile nation and when that country was contending with England in the fields of discovery and conquest, represents a measure of vision that has never failed to intrigue the imagination. That the young Spanish engineer recommended an undertaking so gigantic in conception that it took three and one-third centuries for its completion from the time it was first visioned matters little. In the day of Philip of Spain,

Jan 1, 1932

By Oliver Bowles

"Underground operation.In its broader sense the term ""mining"" is applied to all processes whereby raw materials are taken from the earth to be used as sources of mineral products. In a more restricted sense ""mining"" is applied to underground operations as contrasted with open pit work designated as quarrying. The tern is used in the restricted tense in this paper; for it relates to the exploitation of limestone deposits by modern methods of underground operation rather than by open pit methods.Present tendency toward miningIt may seem to some readers that a paper on mining limestone will find little general interest among lime plant operators, for only a limited number of them have yet resorted to this means of procuring raw materials. It is noteworthy, however, that a growing tendency exists toward underground operation, for one by one quarry owners are faced with increasing difficulties in open pit operation. It seems desirable, therefore, for operators to keep closely in touch with this gradual change in process, to inquire into the underlying causes, to compare costs, and to study the effects of the change in method on subsequent steps in calcining the stone to produce lime."

Mar 1, 1924

By F. Navarro, F. Soto, G. Díaz, E. Jélvez, G. Morales, N. Morales

The increasing availability of tools on the web provides a great opportunity for the research community to boost investigation by accessing computational resources from all over the world. For example, data analytics libraries implemented in languages like Python can be accessed through many open and commercial platforms, therefore providing researchers with a common set of tools or shared datasets. Unfortunately, that is not the case with research in resource assessment and mine planning, where the most standardised tools are commercial applications designed to work on the desktop, but there are not many standard platforms for research. As a result, researchers from different groups often need to start from scratch in order to develop their work, and rarely share implementations details. Similarly, apart from a few publicly available examples, there is a lack of common datasets that are validated and can be used to compare results between different approaches. In this paper, we introduce a platform that provides tools for resource assessment and mine planning, which can be accessed remotely utilising Jupyter Notebooks. In its current version, the platform provides (i) definition and implementation of basic structures for managing samples and models (loading, saving, adding or removing columns, etc.), (ii) definition of experimental and modelled variograms for spatial continuity analysis, (iii) definition of standard interpolation methods in resource evaluation (inverse distance and kriging), (iv) definition of standard problems in mine planning (ultimate pit and precedence constrained production scheduling), (v) generation of 2D standard graphs like grade distribution, conditional means, tonnage-grade, and production plans (vi) a set of datasets, which can be used for case studies, and (vii) a set of notebooks with examples and documentation. In this paper, we introduce the platform and show some examples that illustrate some of the possibilities that it has for research and education in the area of resource assessment and mine planning.

Sep 1, 2021

By Rudy E. Barrientos Ontón

El presente texto describe los datos geopolíticos, reforma económica y poltíca nacional de competencia y regulación minera de uno de los principales líderes en la industria minera, Australia. Dicho país es similar al Perú -en tanto alberga recursos naturales como minerales e hidrocarburos, cuyos ingresos, producto de la extracción, son fuente para la realización de actividades conducentes al desarrollo sostenible.

Sep 1, 2014

By W. W. Krech, T. E. Perkins

As fractures are propagated through rocks, energy is absorbed near the extending crack tip. Apparent surface energies for several rocks have been measured by cleavage under dynamic con-ditions. At nominal crack velocities from 0.5 to 500 in (min, measurements showed that fractures propagated in discrete jumps. Calculated surface energies and moduli were relatively insensitive to nominal rate of cleavage. in another set of experiments, rocks were cleaved under high confining stresses. The rocks were submerged in low leak-off fluids which formed a filter cake on the freshly cleaved surfaces (similar to the hydraulic lracturing process). Apparent surface energies were increased substantially as the surrounding fluid pressure was increased. Moduli in bending increased significantly upon application of the first 1,000 psi but were insensitive to stress level at greater pressures. INTRODUCTION For almost 20 years, hydraulic fracturing processes have been utilized effectively to stimulate oil and gas wells. During this period, some process improvements have resulted from studies of fracture orientation, mechanics of fracturing, areas generated, conductivities of cracks, etc. Yet many questions remain concerning the conditions and pressures needed during fracture propagation. In this paper we will report additional studies of the mechanics of fracture extension. It was shown previously3 that large rock samples could be cleaved under controlled conditions so as to measure the apparent surface energy (that amount of energy absorbed per unit area of new surface created). In this paper we consider the effects of two additional factors on surface energies, viz.: (1) effect of cleavage rate and (2) effect of confining stress level. THEORY Cleavage experiments were conducted on rock samples similar to that illustrated in Fig. 1. Blocks of rock several inches wide, 2- to 3-in. thick, and up to 3 ft in length were grooved longitudinally with shallow guide slots. A crack was initiated and allowed to extend along the web as the top of the rock specimen was pulled (or pushed) apart. Auxiliary equipment permits the measurement of (1) force applied at the top, (2) separation at the top and (3) crack length. (Further experimental details will be given in the next section.) The rock beams created by the crack are considered ton be cantilever beams. The deflection (or separation of the rock beams) at any point is calculated 4,5 by the beam Eq. 1.

Jan 1, 1967

By Jos. R. Guiteras

This paper has been written to describe briefly the mining and milling of gold and silver ores in the Black Canyon and neighboring mining districts in Yavapai County, Ariz. The description of present operations is the result of a 10-day visit to the region by the writer in March 1936. Acknowledgments The author is indebted to earlier writers on the geology and mining in this regions and to the mine managers and their staffs, whose courteous cooperation has made possible the assembling' of material for this paper. Individual acknowledgments are made in the text.

Jan 1, 1936

By P. Yant, R. R. Sayers, R. D. Lieitch

"PURPOSE OF INVESTIGATIONOf more than 300 bituminous mines examined by Crichton 5 and his assistants in connection with litigation in Indian Creek Valley, Payette County, Pa., only four were found to have alkaline water. That work and many observations from of the authors have shown the general prevalence or acid drainage from bituminous coal mines. In connection with investigations pertinent to coal-mine drainage that are being conducted by the United States Bureau of Mines, it was noted with considerable interest therefore, that a mine in the Thick Freeport bed about 20 miles north of Pittsburgh had no acid water in the workings, As it was thought that this condition might be common to all mines,this condition in this bed most of them were visited, samples of the outflow and from different parts of the mine inside were examined, and such general information as was available was gathered.ACKNOWLEDGMENTSThe authors acknowledge with thanks the courteous assistance of mine officials in connection with collecting the data for this paper, and of the analytical and coal laboratories of the Bureau of Mines for analyses."

Nov 1, 1932

By Zoë Mullard

The introduction of Web 2.0 platforms (also referred to as social media), with their architectures of participation, has ushered in a new era of technological interaction and information exchange that is changing the nature of corporate-community communications. Web 2.0 platforms give users the ability to generate data collaboratively, meaning that more stakeholders maintain the expectation of being able to contribute to online dialogue. In light of these changes, it is important for business to consider how social media can be used strategically to enhance stakeholder relationships and increase business efficiencies. This article provides three case studies of how different stakeholders in the mining industry are strategically using Web 2.0 platforms to communicate with target audiences. The case studies are based on the experience of respondents and from website observations, which were undertaken as part of a thesis research project by the first author (Mullard, 2010), focusing on the application of social media in the mining industry.

Jan 1, 2011

By Hengwei Yan, Zhanwei Liu, Wenhui Ma, Ping Xiong

The sulfur in high-sulfur bauxite not only pollutes the environment but also harms alumina production. This study investigated the removal of sulfur from high-sulfur bauxite by adding Zn or ZnO during the Bayer process. The results showed that the different valence sulfur (S2−, S2O3 2−, SO3 2−, and SO4 2−) in sodium aluminate solution can be effectively removed by adding Zn during the digestion process. Adding ZnO removes the S2− in liquor, but the other sulfur compounds (S2O3 2−, SO3 2−, and SO4 2−) are not affected. The mechanism of sulfur removal has been elucidated, where the S2O3 2−, SO3 2−, and SO4 2− are first reduced to S2−, and after adding Zn, the S2− enters into red mud in the form of ZnS. The ZnO then reacts with S2− to generate the ZnS that enters into red mud. Thus, this is a new and effective method of sulfur removal by adding Zn during the digestion process. The results shed light on the removal of sulfur from high-sulfur bauxite during alumina production.

Jun 24, 2020

By Euclid P. Worden

INTRODUCTION Today, conventional raise boring is an accepted method of development in underground mines and on major construction projects. Over the years that this technique, and its associated machines and tools, have been under development, many articles have been written on the subject. To a great extent, these papers have reported operating results of one or more specific projects or have been generalized reviews of state-of-the-art machines and tools. This paper is intended as a review of the technique from an operational standpoint. Conventional raise boring, as opposed to the related variants box hole drilling and underground blast hole drilling, is a two step process consisting of the pilot hole drilling and reaming cycles. This author has covered the subject of pilot hole drilling in another article (1) . A good review of the current machines and equipment has been presented by Monroe (2) and an overall review of this entire technology was published by E&MJ (3) and Mining Journal, April, 1983 (4) . The subject of the reaming cycle is presented here together with some of the technical aspects of how the drilling tools are intended to be used. OPERATIONS Bit Change After the pilot bit has broken through at the end of the pilot hole cycle, a changeover takes place at both the machine and

Jan 1, 1985