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By G. W. Donaldson

Theoretical and engineering aspects of slimes-dam construction by G. W. DONALDSON, M.Sc. (Eng.)(U.C.T.), D.I.C. (Visitor) Tile paper reviews the recommendations made in 1959-60 as a result of research into slimes-dam construction and finds that these recommendations are still valid. The requirements for pollution control, vegetating, in situ leaching, and future development of slimes dams as building areas are considered as they affect the engineering aspects of slimes-dam construction, and it is found that these requirements can be met without any major changes to current recommended slimes-dam construction practice.

Jan 12, 1973

By R. E. Gundersen

I have to express my surprise and must send a note of warning concerning the use of polyurethane foam as described in a paper by R.N. Torbin and R.F. Kovar, entitled "Innovative Shaft Lining Method," published in your February 1989 edition. In September, 1986, 177 miners lost their lives when they were exposed to fumes downwind from a fire in a tunnel lined with polyurethane foam. Whilst polyurethane exhibits reasonable fire retardent properties in small-scale tests, mass use in a tubular configuration, exacerbated by the furnace effect of cross-radiation, can lead to a rapid, uncontrollable conflagration.

Jan 1, 1990

Executive Joseph L Gillson, Chairman, J W Woomer, Vice-Chatrman, John S Bell, Walter R Hibbard, Jr. R R McNaughton Finance John P Hammond, Chairman, James C Gray, J S Smart, Jr Investments Gall F Moulton, '63, Chairman, Andrew Fletcher, '62, John M Lovejoy, '61, George I Brigden, ex off as AIME Treasurer, John P Hammond, ex off as Chairman, AIME Finance Committee Award Committees Grouped together at end of list Cooperation with the Canadian Institute of Mining and Metallurgy and the Mining Society of Nova Scotia R R McNaughton, Chairman, C Gerow, Sherwin Kelly

Jan 1, 1960

By V. M. Lovell, N. P. Finkelstein

Fundamental studies of the flotation process: The work of the National I nstitute of Metallurgy N. P. Flnkelsteln and V. M. Love Presented at the Colloquim on Flotation, March 1972, and published in the Journal, July, 1972. AUTHORS' REPLY TO DISCUSSION In his contribution to our paper Dr Lloyd makes two criticisms: The first criticism, as we interpret it, is that the agglomerate flotation process that we described is not really necessary because previously described processes effect almost the same results or could be made to give the same results by including sufficient paraffin in the reagent combination.

It is with great pleasure that I accepted the invitation to make a closing address to this Congress particularly as it is here in Brisbane. The main duty of the International Mine Ventilation Congress Committee and in particular the chairman is to ensure that these conferences are held every four to five years in suitable locations. My main role over the last four years has been to promote holding this Congress in Australia and it was a great relief when the Queensland team and the Australasian Institute of Mining and Metallurgy accepted the challenge in November 1986.

Jan 1, 1988

In 1975 the US Bureau of Mines (BOM) under contract with the Bureau of Indian Affairs (BIA), began a systematic mineral resource evaluation of Indian reservations in the United States. The purpose of the BIA/BOM program was to stimulate economic development on Indian lands through exploration and mining ventures with the mining industry. Since that time, 109 phase I reports (literature studies) and nearly 45 phase II and phase III (field studies) reports have been written by the BOM. The various tribes in conjunction with the BIA have access to these reports for decision making regarding mineral resource development.

Jan 1, 1990

By M. S. Alam, Jae-Chun Lee, M. Tanaka, K. Koyama

Extensive research work is being carried out at AIST for developing energy saving green technology for base and precious metals recovery. In the present work, a new flowsheet is developed for copper recycling from waste electronic circuit board where copper was recovered by leaching followed by solution purification and direct electrowinning of Cu(I) from ammoniacal alkaline solution. In this new technology, power consumption in EW circuit was greatly reduced. This paper describes the overall process with an emphasis on different aspects of solution purification where impurities were selectively removed by cementation and solvent extraction techniques under nitrogen atmosphere.

Jan 1, 2004

Reynolds Jamaica Mines, Ltd., has received a $3+ million loan from ECA for the development of what are termed the largest bauxite deposits in the world in Jamaica, B.W.I. This amount is in addition to $11 million already provided. The new agreement calls for delivery of 750,000 tons a year beginning in early 1952. Inco has announced a new alloy containing 35 pet Ni which can be used for many purposes served by the old alloys which ran up to 70 pet Ni. The new alloy "Incoloy" is 35 pet Ni, 20 pet Cr, and the balance iron.

Jan 8, 1951

J. S. UNDER, Pittsburgh, Pa. (communication to the Secretary*).¬In discussing Mr. Wysor's paper, I said that we were investigating the deposits around furnaces working on certain ferro alloys. Since the meeting, we have made a number of investigations, and have found that the deposits in the second and third passes of the hot-blast stoves, and near the stack at the boilers of furnaces working on spiegel and ferromanganese, contain about 15 per cent. total potash, of which 10 per cent. is water-soluble. The potash occurs mostly as potassium sulphate, a very small amount being present as potassium carbonate.

Jan 6, 1917

Depending on material commodity market conditions, material contained in open pit waste disposals can hold potential value, Segregating subgrade material into separate disposals i.e. 'sub ore' stockpiles, affords open pit operators the opportunity to modify production strategies to reflect changes in market conditions. Discussion of the concept of subore stockpiling is presented. A two-step mathematical model and a nonlinear programme are employed to answer questions such as, 'how can the value of sub-ore material be determined to distinguish sub-ore from true waste?' and 'when and at what rate should sub-ore be processed?'

Jan 1, 1988

By Bill Runner, James T. Ludwiczak

During the last few years, there has been a flood of local, state, and Federal government regulations concerning blasting. Many of the laws and regulations were written by individuals who know little about explosives, the purpose of blasting, or blasting vibration and damage. I feel that the special interest groups responsible for some of these regulations are not trying to regulate blasting, but to stop it completely by unreasonable, non-flexible, regulations. The most recent being the Office of Surface Mining regulations that are already spreading to the quarry industry and will, no doubt, spread to all blasting involving disturbance of the surface.

Jan 1, 1979

By R. C. Gifkins

The ideas expressed in this paper interest me very greatly, partly for their own sake and partly because they are very close to some speculation I have recently made concerning grain boundary diffusion. This is in a paper describing an extension to Mott's "island" theory of the grain boundary, to be published shortly.37 The facets or islands of good fit are identified in terms of specific crystallography, as in the model put forward by Brandon et al., and the bad fit between them is suggested to be interlinked "channels" of relaxed vacancies, associated with grain boundary ledges.

Jan 1, 1969

By Charles M. Brinckerhoff

When I first went to Arizona in 1925, mining was primarily an underground job. Ajo, Sacramento Hill in Bisbee and Jerome were the only open pit operations in the state. Thousands of men, however, were employed in underground mining at Morenci, Miami, Inspiration, Globe, Ray, Bisbee, and Superior. The grade of ore in the larger operations was about 1-1/2% copper while a few of the smaller ones mined ore better than 2% Cu. In Utah, the Bingham pit was doing well and growing; in Montana, the vein mines of Butte still yielded ore running 6% Cu.

Jan 3, 1972

To reduce operator exposure to noise from vibrating screens at coal preparation plants. Background Hearing loss is one of the most common occupational illnesses in the United States. In the U.S. mining industry, hearing loss is 2.5 to 3 times greater than what is expected for the average population that is not exposed to occupational noise. Furthermore, studies by the National Institute for Occupational Safety and Health (NIOSH) showed that by age 50, 90% of coal miners have a hearing impairment versus only 10% of the population that is not exposed to occupational noise. A NIOSH cross-sectional survey of coal preparation plants showed that 43.5% of employees were overexposed to noise. The study also found that vibrating screens were one of the top five loudest types of equipment at these plants?as well as the most numerous?making them a key noise source to address.

Nov 1, 2009

By Suprakash Gupta, Pawan Kumar Yadav, Deepak Kumar, Debasis Jana

Draglines are extensively used in Indian mines. A dragline has more than hundreds of components, and it is complex in design. This study involves the evaluation of the reliability of a draglines system using a Bayesian network (BN) model mapped from a fault tree. Based on the BN inference, the reliability estimation, the diagnosis, and the sensitivity analysis are performed. In this paper, the overall reliability of the dragline is estimated as well as the contribution of the subsystems or components in the overall reliability evaluation is presented. The results showed that the three subsystems of the dragline, namely, the dragging mechanism, electrical auxiliary subsystem, and swing mechanism, have the lowest reliability (82.17%, 87.98%, and 91.30%, respectively) after an hour of operation. The overall reliability at the first hour of machine operation is estimated to be 62.03%. The study may provide a reference for future work related to the dragline machine’s reliability design and maintenance.

Jan 14, 2023

By Geraldo Lúcio de Faria

O sucesso do transporte ferroviário depende, entre outras coisas, da integridade física dos componentes metálicos empregados na via permanente. Um dos mais importantes é o trilho, pois falhas catastróficas deste componente podem gerar graves acidentes. No intuito de desenvolver aços com bom desempenho para esta aplicação, estudos têm sido desenvolvidos para se entender os efeitos de composição química e histórico de processamento termomecânico sobre a microestrutura e propriedades mecânicas dos aços. Neste contexto, este trabalho caracterizou microestruturalmente dois aços de aplicação ferroviária, sendo um Standard e um Premium. Amostras representativas destes aços foram submetidas a ensaios dilatométricos e a cinética de transformação de fases austenita-perlita foi investigada. Por meio dos resultados obtidos, foi possível concluir que o aço Premium estudado possui microestrutura mais refinada e que este efeito é devido, principalmente, à menor concentração de Mn em sua composição química. O menor teor de Mn facilita a nucleação de cementita eutetóide, possibilitando a formação de perlita em tempos mais curtos e temperaturas mais baixas do que no aço Standard. Isto possibilita que o aço Premium, em seu processo de fabricação, possa ser resfriado a taxas mais elevadas do que o Standard sem formação de martensita, justificando sua estrutura mais refinada.

Aug 17, 2017

By Alexandre de Freitas Gomes de Mendonça

A remoção de inclusões nos distribuidores de lingotamento contínuo tem sido investigada por meio de modelamentos físicos e matemáticos. Recentemente, a injeção de gás nos distribuidores tem sido considerada como uma alternativa para aprimorar a remoção de inclusões. Vários trabalhos vêm sendo desenvolvidos analisando os efeitos da injeção de gás e sua interação com as inclusões. No entanto, existe espaço para mais investigações envolvendo o efeito da vazão do gás e a localização do sistema de injeção de gás na eficiência de remoção de inclusões. No presente trabalho, foi usado um modelo físico construído em escala 1:3 de um distribuidor industrial de 40 toneladas de capacidade nominal, para analisar o efeito da injeção de gás. Os experimentos incluíram contagem on-line de partículas pela sonda APS III e análise de curvas DTR. O resultado mostrou que a injeção de gás é benéfica à remoção de inclusões e que a análise pura dos volumes característicos, calculados a partir das curvas DTR, não é suficiente para avaliar a eficiência de remoção.

Aug 17, 2017

By L. Zhou, L. Yuan, D. Bahrami

Underground mine fires remain a concern for mine operators, posing a health and safety risk to mineworkers. In the last decade, the number of mine fires has decreased significantly; however, dealing with an unknown fire in underground mines can be a challenging task, which could lead to a hazardous condition for miners during an evacuation and rescue operation. A timely detection of a mine fire and monitoring its characteristics, namely size and location, are of great importance in reducing the risk of mine fire injuries. A new improved fire location algorithm has been developed and integrated into an Atmospheric Monitoring System (AMS) program by researchers from the National Institute for Occupational Safety and Health (NIOSH). This paper describes the new fire location model and presents the results of verification fire tests conducted at the Safety Research Coal Mine (SRCM) facility of the Pittsburgh Mining Research Division (PMRD) using the collected AMS data. NIOSH is endeavoring to develop workplace solutions to improve detection of and reduce the risk of hazardous conditions in mines. The results demonstrate successful application of the improved fire location model and provide a useful tool for solving the problem of unknown fire location and reducing the risk of hazardous conditions.

Sep 29, 2020

By M. I. Kalashnikova, Y. M. Shneerson, M. V. Keskinova

Interaction between mattes having various compositions and solutions with a wide range of free acid and non-ferrous metals concentration have been studied in terms of chemistry, mechanism and kinetics. The solution acidity and oxidizers to reducers ratio in the matte-solution-gas phase system have been demonstrated to be the major factors determining the process behaviour. It was found that the types of copper and nickel secondary sulphides resulted from nonferrous metals precipitation from solution, depend on of the solution and initial matte composition. Based on these studies, technologies of matte leaching and nonferrous metal precipitation in the form of rich sulphide concentrates are developed.

Jan 1, 2004

By Johne Jesus Mol Peixoto

No reator RH, a otimização do fluxo recirculatório de aço entre a câmara de vácuo e a panela é a chave para promover as reações de refino. Neste trabalho, foram utilizados água e solução de cloreto de zinco (ZnCl2) como fluido similar ao aço para investigar a taxa de circulação no modelo a frio de um reator RH em escala 1:7,5. A taxa de circulação foi determinada utilizando o método de pontes de Strain Gages. A técnica PIV foi utilizada de modo a calibrar e validar os resultados. O aumento da vazão de gás de 30l/min para 120l/min resultou na elevação da taxa de circulação para ambos os fluidos. Cálculos preliminares demonstraram que há grande diferença nas condições de arraste de escória entre os sistemas água/óleo e ZnCl2/óleo.

Aug 17, 2017