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By J Zhou, D M. Hunter, S M. Iveson, K P. Galvin

The REFLUX Classifier is used to perform particle separations on the basis of density utilising a set of parallel inclined channels positioned above a vertical fluidised section. In continuous mode, feed enters part way up the vertical section, while fluidisation water is introduced from below. Lower density particles are conveyed upwards and collected in an overflow stream, while high density particles segregate onto the inclined surfaces, settle to the base of the system and empty via an underflow stream. Pressure transducers are used to measure the suspension density in the vertical section. This suspension density is maintained by a pneumatically controlled underflow valve to maintain a target suspension density or ‘set point’.Previously, Galvin et al (2010) demonstrated the significant improvement achieved via a new laminar-shear separation mechanism, achieved by utilising closely spaced inclined channels in the REFLUX Classifier. For the separation of low-density coal particles from mineral matter, a channel spacing of 6 mm proved effective; however, for the separation of gangue minerals from much higher density minerals such as iron ore, the shear-induced lift needs to be even higher. In this paper, we examine the influence of two different channel widths on the continuous processing of an industrial iron ore feed in the REFLUX Classifier. It was found that when moving from 6.0 mm to 3.0 mm channels, the ability of the system to reject coarser gangue material and retain finer high density material across a particle size range from 0.125 to 1.0 mm was increased, resulting in a higher grade product.CITATION:Hunter, D M, Zhou, J, Iveson, S M and Galvin, K P, 2017. Influence of shear rate on separation of iron ore fines using the REFLUXTM Classifier, in Proceedings Iron Ore 2017, pp 205–210 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By S. Vivek

An atomic force microscope (AFM) was used to measure the surface forces between silica surfaces immersed in solutions of hydrolysable cations and/or sodium oleate. Hydrophobic forces were observed at the pH range where the concentration of the singly-charged hydroxo-complexes (CaOH+ or MgOH+) in solution is the highest. In the absence of oleate, the adsorption of the hydroxo-complexes was indicated by the disappearance of the repulsive hydration force. These results suggest that the hydrolysable cations adsorb on silica as singly-charged hydroxo-complexes. Based on the results obtained in the present work, a model for the adsorption of hydrolysable cations has been developed.

Jan 1, 2009

By Cecil Q. Cupps

Results are presented of a comprehensive study of the characteristics of the original oil in the Weber sandstone reservoir, Rangely oil field, Colorado. Through the medium of subsurface sampling, adequately representative samples of the original reservoir oil were obtained from many parts of the reservoir over a period of 5 years concurrent with active development of the reservoir. Data of differential gas liberation, pressure-viscosity, and. pressure-volume-temperature relationships are shown for 12 subsurface oil samples. Data also are given of reservoir pressure and. temperature, composition of liberated or solution Gas, composition of 22 produced-gas samples, and Hempel analyses of crude-oil samples from 18 wells. The characteristics or physical properties of the 12 subsurface oil samples, as determined by laboratory analyses, were correlated with elevation of the top of the Weber sandstone. These relationships of oil characteristics to elevation in the reservoir show that only the oil in contact with the initial gas cap was gas-saturated at the existing pressure and temperature. The characteristics of the original reservoir oil were marked by an appreciable decrease of saturation pressure and solution gas-oil ratio and increase of viscosity and density with depth below the gas-oil contact. The composition of solution gas and of' produced was also was found to vary with elevation of the oil in the reservoir.

Jan 1, 1951

By Mohsen Amir-Rahmat

The ore of Sarcheshmeh copper deposit that has been located in the south ?east of Iran, contains four type of rock that they have their specific hardness and strength according to their alteration type and mineralization. Blasting of these various types of mine rocks prepares various types of size for the product of mine as the feed of concentration. Along the crushing of this feed a few factors effect on the efficiency of the crushing unit. The aim of this project has been the consideration of the effect of ore size on the efficiency of crushing unit. For this investigation along the year 2000 A.D., six sample from feed and six sample from product of crushing unit have been prepared. The results of the screen analyze of these samples has shown that the size of feed has been lesser than the primary plan and the size rate of the product has been bigger than the primary plan. Also in this research the effect of feed size on the quality of product size has been considered.

May 1, 2003

By Angel Rafael Arce Chilque

Um estudo visando à caracterização metalográfica e metalúrgica foi realizado em um aço ARBL (alta resistência e baixa liga) tipo X80, soldado com o processo arame tubular (FCAW) robotizado, com três diferentes níveis de energia de soldagem. Para tal foram utilizadas técnicas de metalografia óptica e microdureza Vickers (Hv). Foram depositados cordões de solda em forma de camadas sobre chapas do aço X80, variando a energia de soldagem e sem pré-aquecimento, no estado como soldado. Os resultados mostram que a técnica de sobreposição utilizada, com baixa e média energia de soldagem, não foi suficientemente adequada para melhorar as propriedades metalúrgicas dos cordões depositados anteriormente, inclusive da ZTA do metal de base.Os cordões depositados com alta energia de soldagem promoveram crescimento do tamanho de grão da GGZTA do aço X80 com a consequente diminuição da resistência ao impacto.Este trabalho da subsídios para uma melhor compreensão das soldas multipasses.

Aug 16, 2017

Jan 1, 1959

By Douglas Bartley, Brian Wingfield, Robert McClure

Recent studies and limited tests indicate favorable results utilizing high accuracy electronic detonator technology over conventional non-electric pyrotechnic systems. This study discusses the application of this technology using the Daveytronic programmable system in an on-going production basis. The study quantifies the performance as it relates to fragmentation, excavation, vibration and productivity in an eastern U.S. aggregate mining operation.

Jan 1, 2001

By R. Tomás, J. B. Serón, M. Romana

The Slope Mass Rating (SMR; Romana, 1985) geomechanics classification was developed as a sequel of Bieniawski’s Rock Mass Rating (RMR) system, which was almost impossible to use in slopes due to the extreme range of the correction factors (up to 60 points of a maximum of 100) and to the lack of definition of them. A detailed quantitative definition of the correction factors is one of the advantages of SMR classification. During the last thirty years the use of SMR system has been extended to many countries from the five continents and, thus, it is time to review the most interesting developments. Both RMR and SMR are discrete classifications, depending on the values adopted by the variables that control the parameters. This can cause major changes in the parameters value due to small differences in the variables value, with changes in the final rock mass assigned quality. On the other hand, geomechanics quality indexes are extremely biased. To avoid this problem, some authors have proposed continuous functions for SMR. This classification has been also adapted for its application in heterogeneous and anisotropic rock masses, for high slopes, for is application trough stereographic projection and Geographical Information Systems, has been used as susceptibility rockfall parameters and has been included in the technical regulations of several countries. Additionally, some open access computer tools have been developed for the computation of SMR. Consequently, this paper reviews: 1) the most important modifications and adaptations of slope classifications which derive directly from SMR; 2) the use of SMR throughout the world; 3) many significant papers on slopes analysed with SMR all over the world; and 4) future trends in the use of SMR.

Jan 1, 2015

By Tiago de Souza, Caroline Gonçalves, Carlos Eduardo de Castro, Everton Dias

The Miraí plant from Votorantim Metais, has two screening stages to the bauxite classification after scrubbagem. The final product has hold the larger size of 0,84 millimeters (20 mesh). There are two sieves Haver & Boecker (model R-TE 3658 x 10972), which have four modules with cut size sieves of 10 mesh (1.70 millimeters) and ¼ inch (6.35 millimeters) on the primary screen, and 20 mesh (0.84 mm) on the secondary screen, all made of polyurethane. The actual configuration was established according to the empirical tests realized that aimed the increase material load on the secondary screening. However, having in mind the screening process improvement and use the fractions smaller than 0,84 mm, which have significant levels of Alumina and low reactive silica, was proposed a new test of change the sieves opening for 6 mesh in the primary screen and 28 mesh for the secondary sieve. The objective of this work was measure the ore alterations on the particle size distribution on the screening steps, increasing the plant weight and ratio recovery before and after the test.

Jan 1, 2014

Earnest Advocacy - A Key to Sustainable Minerals Industry Education - A Philippine Experience

Sep 13, 2010

By Tatsunori Matsumoto

In order to investigate the variation of the load-displacement relations of piles in a site, vertical load tests were carried out on 25 small diameter steel pipe piles. Out of 25 piles, 15 piles were close-ended pipe piles attached with a blade at the pile toe and 10 piles were open-ended pipe piles. To carry out these load tests in a short period, two types of rapid load test methods, Spring hammer load test and Falling mass load test, were employed. The load tests of all piles were completed in two days with 180 blows in total. In order to estimate a static load-displacement of a pile, non-linear damping method was used. It is shown from the test results that the performance of the pipe piles such as the ultimate pile resistance and the initial pile head stiffness is improved by re-driving.

Jan 1, 2006

By R. W. Smith, A. M. Raichur, M. Misra

Mycobacterium phlei has very good potential as a hematite flotation collector. The flotation recovery of hematite is dependent upon the solution pH and concentration of the microorganism. The critical pH for maximum recovery of hematite is around three, which corresponds to the point of zero charge of the microorganism. An excellent correlation between the flotation recovery and bacterial adhesion on hematite is observed. The adhesion of Mycobacterium phlei on hematite can be described by the potential energy of interaction calculations using an extended DLVO theory.

Jan 1, 1994

By John Craw

This paper has formulated the methods, both medical and engineering, for the control of pneumokoniosis in the haematite-mining industry in West Cumberland, but this is only part of a general service to improve the lot of the worker in these mines, to make him a better and happier workman, and to permit him to enjoy his work and leisure in comfort and good health. This organization has now been functioning for more than ten years and the results are indeed heartening, but it is only as a result of constant vigilance from the mining and medical point of view that such a plan can operate efficiently. The human element and its full understanding is by no means the least of the problems.

Jan 1, 1947

By M. J. Collins

"Autoclaves were first used in the metallurgical industry in 1893 to recover alumina from bauxite. In the 1940s and 1950s, several high temperature and pressure processes were invented in the laboratory of Professor Frank Forward at The University of British Columbia, in parallel with advances in equipment and processes by the Chemical Construction Corporation. Sherritt Gordon Mines Limited enlisted these groups to help develop the nickel sulfide ammonia leach process that was commercialized in 1954. Autoclave processes that have since been commercialized include high-pressure acid leaching of laterites, zinc pressure leaching, and pressure oxidation of refractory gold feedstocks. RÉSUMÉ En 1893, l’industrie métallurgique est la première à utiliser les autoclaves pour l’extraction de l’alumine dans la bauxite. Dans les années 1940 et 1950, plusieurs procédés à haute température et à haute pression sont inventés dans le laboratoire du Pr Frank Forward de l’université de la Colombie-Britannique (UBC) ; parallèlement, la Chemical Construction Corporation fait de grands progrès en matière d’équipement et de procédés. Sherritt Gordon Mines Limited fait appel à ces groupes pour qu’ils aident la société à développer le procédé de lixiviation du sulfure de nickel dans de l’ammoniaque, commercialisé en 1954. Les procédés de lixiviation en autoclave commercialisés depuis incluent notamment la lixiviation acide à haute pression de latérites, la lixiviation sous pression du zinc et l’oxydation sous pression des matières premières de l’or réfractaire.INTRODUCTION Autoclaves are chemical reactors that are built to contain processes taking place at elevated pressure. They are used in metallurgical refineries throughout the world to take advantage of the increased reaction kinetics and different reaction products that can be obtained in aqueous systems above the boiling temperature at atmospheric pressure. The word autoclave comes from the French “auto” and the Latin “clavis” and literally means self-locking—that is, the core distinguishing feature of an autoclave is that it includes a means for pressure regulation (e.g., a pressure relief valve). Denis Papin (Figure 1a), one of the inventors of the steam engine, was the first to make use of a safety valve to control steam pressure. He is credited with inventing the autoclave in 1679. Papin’s “digester” (Figure 1b) was a type of pressure cooker that was originally used to liquefy bones. Most commercial autoclaves are horizontal, multicompartment vessels with mechanical agitation, as shown in Figure 2a; however, the steam-agitated Pachuca vessels used to leach laterite ore in Moa, Cuba (Figure 2b), are also classified as autoclaves according to the self-locking definition provided above."

Jan 1, 2018

By G. W. Jones

"INTRODUCTION As part of its work in promoting safety, the Bureau of Mines is investigating various means of eliminating or mitigating the explosion hazards of combustible gases encountered in mining and industry. Information has been obtained and a procedure developed whereby the explosibility of many complex gaseous mixtures may be calculated in a rather simple manner without the necessity of performing laborious laboratory experiments. An earlier publication 3/ described the method of determining by calculation the limits of inflammability of gaseous mixtures, including methane, hydrogen, carbon monoxide, nitrogen, carbon dioxide, and oxygen. The information published in the above report permitted calculation of the limits of inflamnability of such gases as are liberated by mine fires, gases from explosives, automobile exhaust gases, gases present after mine explosions, blast-furnace gas, and other gases of similar type.Gases liberated in certain potash mines in the western part of the United States sometimes contain ethane, in addition to the gases named. An investigation was made to obtain data from which the limits of inflammability of such gaseous mixtures could be determined by calculation. 4/Similar data have been Published covering all types of natural gases containing wide ranges of concentration of nitrogen and carbon dioxide.5/"

Dec 1, 1944

By H. Verakis, M. J. Sapko

The Pittsburgh Research Laboratory (PRL)1 of the National Institute for Occupational Safety and Health (NIOSH) in collaboration with the Mine Safety and Health Administration (MSHA) Technical Support Center has devised a prototype hand-held instrument which can provide a direct assessment of the potential explosibility of a coal and rock dust mixture. Current Federal regulations require that rock dust be applied in all underground areas of a coal mine to mitigate the propagation of a coal dust explosion. To determine compliance with the Federal regulation, mine inspectors collect dust samples from sections of underground coal mines for an MSHA laboratory analysis of incombustible content. However, the laboratory analysis may not be completed for more than a week or two, during which time the mine area from which samples are taken may be inadequately protected. The operation of the Coal Dust Explosibility Meter (CDEM) is based on the difference in optical reflectance between light rock dust and dark coal dust. For a given coal volatility, the optical reflectance of such mixtures is relatively constant at the limit of explosibility, independent of the coal dust particle size. The CDEM is not intended to replace the current MSHA laboratory analysis of coal mine dust samples for incombustible content, but to serve as a supplemental device for enhancing mine safety through improved rock dusting practices.

Jan 1, 2006

According to the data provided by the most recent European Survey on Working Conditions, roughly 25 per cent of the European working population is exposed to mechanical vibrations for no less than one quarter of the work shift duration, while around ten per cent are exposed for the entire work shift. The occupational exposure to whole-body vibration (WBV), in particular, represents a major health risk in mining, quarrying and civil excavation activities. In accordance with European Directive 2002/44/EC, the latest version of the Italian law on physical risks has recently confirmed the possibility of using relevant literature data on vibration magnitude in order to evaluate personal occupational exposure (vibration database or data provided by the manufacturer). Still the alternative option, based on field measurements, represents the most appropriated method of risk assessment, as it accounts for the actual operating condition at the workplace; actual operator and vehicle under investigation and specific working cycle. The article discusses the vibration measurements taken on a number of heavy machinery (excavators, loaders, trucks, dumpers, etc) employed for talc extraction in a mine located in Sardinia and the resulting personal exposure for the drivers. The assessment was carried out in accordance with the specifications of ISO 2631-1 and EN 14253.

Dec 6, 2010

By Donald M. Liddell

ALTHOUGH the midday lunches of business associations have been re-echoing the phrases that re- search would lead us out of the depression and that the last place to economize is on research, nevertheless most executives apparently concluded that it was their neighbor who ought not to economize in research, and that in their own plants what had been discovered in 1929-30 was sufficient to lead them out of the wilderness. At any rate, I have discovered much less that seems worth noting, and compared with 1931, the report volume of the committee members is off about 40 per cent, and compared with 1929, about 80 per cent. Evidently there is some hookup with the +tee1 industry as to output, and the Report Reading Committee should investigate this and the relative use of commas and periods.

Jan 1, 1933

By Iann Bouchard

Introduction à l?abrasion et l?érosion Avec le temps, tout solide va éroder et user les métaux les plus durs; de plus, la Corrosion va aussi laisser une couche mince et faible d?oxydation qui sera rayée du substrat. Solutions et guide de sélection Les polymères de Henkel Loctite® peuvent: ? Réduire l?abrasion par glissement ? Protège contre les agents corrosifs ? Prévenir la cavitation ? Augmenter l?efficacité ? Réduire la turbulence ? Résister aux hautes températures?

Feb 1, 2008

By AIME AIME

THE following paragraphs, constituting the concluding portion of the Annual Report of the Council for 1903, have been withheld from publication until now, in order to make them as accurate and complete as possible. They will be published in Volume XXXV. of the Transactions in their proper place at the end of the said Annual Report. Franklin Ballou was born in Pittsburg, Pa., May 29, 1845. He was the son of an old resident, Arthur Ballou, a manufacturer and wholesale dealer in vinegar. In early youth Franklin attended the Western University of Pittsburg, but left school at the age of 16 to become book-keeper for his father, upon whose retirement from business, in 1868, he associated himself with Walter C. Childs, of Pittsburg, in the manufac¬ture of furnace-grates and asbestos-cement for blast-furnaces. This firm was known as W. C. Childs & Co., and did a success¬ful business for several years. In 1869 Mr. Ballou married Miss May S. Wilson, daughter of Judge Wilson, of Lewistown, Pa. In 1876 he spent several months traveling in the West and studying the mining industry, which greatly interested him. In consequence of this journey, he wound up his business in Pittsburg and removed in 1877 to Georgetown, Colo., where for several years he conducted a sampling-works, and built up an extensive business as an agent for the sale of ores, besides engaging to some extent in mining enterprises. , It is said that he controlled at one time about one-eighth of the output of the Leadville mines. In the early 80's, he became Vice-President and General Manager of the Bimetallic Smelter at Leadville, of which Mr. David H. Moflat was the principal owner. This was practically the first successful demonstration of pyritic smelting in Colorado. Upon the sale of the works in 1897 to the American Smelting and Refining Co., Mr. Ballou retired

Jan 1, 1905