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By T. T. Chen

Raw anode slimes consisting primarily of PbSO4, AgCuSe, Cu3Se2, Cu2-x Se, Cu2O, CuSO4.5H2O, Sn arsenate and Sb-Bi-As oxide are batch-leached with electrolyte-O2 to dissolve Cu. During this process, Cu2O and CuSO4.5H2O are solubilized and the Cu in the selenides is leached with the formation of Ag2Se and Se. A small amount of Cu remains in the Ag2Se, Sn arsenate and Sb-Bi-As oxide. The decopperized slimes are repulped in Na2CO3 solution to convert most of the PbSO4 to NaPb2(CO3)2(OH). The Sn arsenate and Sb-Bi-As oxide partly react, but the Ag2Se is not significantly affected by the Na2CO3 solution. The NaPb2(CO3)2(OH) intermediate phase is dissolved in acetic acid to leave a final product consisting of Ag2Se, Se, Sn arsenate and Sb-Bi-As oxide, together with small amounts of PbSO4, NaPb2(CO3)2(OH) and various gangue constituents.

Jan 1, 1993

By Š. Šachlová, T. Lokajícek, M. Petružálek, T. Svitek, A. Štastná

During the past 20 years, alkali silicate reaction (ASR) as a cause of concrete deterioration has been studied by a wide range of experimental methods such as microstructural and macrostructural analysis, bulk chemical analysis, X-ray and neutron diffraction analysis, etc. All of these data are compared with expansion values of mortar bars (following ASTM standard C 1260). Recent studies indicate the useful application of non-destructive methods with the aim of better reflecting mechanical properties and the degree of deterioration of real concrete. Ultrasonic testing methods (including ultrasonic pulse velocity UPV) are widely used to determine material mechanical properties and the changes induced by a variety of mechanical or chemical processes. However, only a few laboratory studies of ASR focused on ultrasonic testing of mortar bars. Due to this fact, a heating chamber was designed and constructed to enable ultrasonic sounding of mortar bar specimens while stored in accelerating solution. Regular ultrasonic sounding of mortar bars reveals significant dependence of ultrasonic data such as longitudinal P-wave velocity, signal energy, signal amplitude and signal frequency on mortar bar storage time. Ultrasonic data were subjected to time domain as well as frequency domain analysis. Different storage conditions were used to determine the effect of ASR on ultrasonic parameters. Mortar bars, prepared in the same manner with one type of aggregate, were stored in cold or warm water or in an accelerating warm medium. Ultrasonic data accurately reflects the differences in hardening and deterioration of tested mortar bars due to different storage conditions. Ultrasonic results showed very good correlation with the results of ASTM standard expansion tests and much higher sensitivity to ASR-induced concrete deterioration. Expansion tests showed 1% measured length differences in comparison with up to 80% resolution of ultrasonic data. The ultrasonic testing proved to be a suitable laboratory method for investigating ASR-related processes and could lead to an improvement of standard testing procedures.

Jan 1, 2015

By J. Visman

"The Compound Water Cyclone is a concentrator for the wet processing, in bulk, of finely divided materials such as slack coal, fine ores and mineral sands. It was originally developed by the Fuels and Mining Practice Division of the Mines Branch, Department of Mmes and Technical Surveys, Ottawa, for the cleaning of friable slack coals and slurries.Since its introduction in the coal industry in 1962, its application to other materials has also been studied, with special emphasis on simplicity of operation and low over-all cost per ton of finished product .In this paper, a description is given of commercial two-stage units presently available for the processing of granular materials, including wastes a1:1d other low-grade products. A pneumatic control system is used for operating the cyclone under back pressure .and for automatic cut-point adjustment. An account is given of results obtained on coal mineral sands and ores in the Wes tern Regional Laboratory of the Department of Mines and Technical Surveys. Results of several industrial applications are discussed."

Jan 1, 1966

By William P. Shinn

Jan 1, 1881

By Erle C. Donaldson

The pendant drop interfacial tensiometer is being used to study interfacial phenomena that influence the production of crude oil. A description of the instrument showing the modification of the cell and cell holder is presented. The modified cell and cell holder allow formation of a precise and reproducible drop size, and the image of the drop is easily alined and focused. Interfacial tension measurements and observations of film formation can be conducted at various temperatures with the jacketed cell.

Jan 1, 1967

By W. V. McKnight

The paper discusses the equipment and methods used to establish some of the characteristics of a braking system. Some typical tests are described and an explanation of the approach used to derive information from the recorder charts is given.

Jan 1, 1966

By A. E. Wraith, J. Protheroe Jones, P. J. Mackey

The world’s first copper electrorefinery started production in 1869 at Burry Port in South Wales. Built within the Pembrey Copper Works which had commenced smelting operations in 1849, the new refinery was based on principles described in the British patents issued to J.B. Elkington in 1865 and 1869. Refining principles and practices pioneered there were key to the foundation of modern electro-refining practice in what is now a dominant international industry producing over 16 Mt of electrical grade copper annually. This paper explores the background to this pioneering application of the new, early 19th century, science of “electro-metallurgy” and examines its links to the contemporary decorative electro-plating industry and to the shortcomings of 19th century fire refining. The beginnings and early years of the Pembrey electrorefinery are briefly discussed in relation to the quality, applications and pyrometallurgy of copper at the time. More than a decade would elapse before the birth of the electrical age: the Pembrey refinery may be seen as one of its vital precursors. Note: This paper was originally published as part of the Copper 2013 proceedings (A.E. Wraith, P.J. Mackey and J. (formerly R.) Protheroe Jones, “Origins of Electrorefining: Birth of the Technology and the World’s First Commercial Electro-Refinery”, paper in Electrorefining, Vol. V, Book 2, (Eds. R. Abel and C. Delgado), Cu 2013 International Conference, pp. 19-33, IIMCh, Santiago, Chile, 2013). It is reproduced here together with a new Appendix and supporting references that lists the year of commencement of the first electrolytic copper refinery by country, 1869 to 1956. It all, the year of the first electrolytic copper refinery established for 15 countries is included. These 15 countries now produce more that 70% of world refined copper (for 2018). INTRODUCTION In the 1840s, the new science of ‘electro-metallurgy’, a term coined by Smee in 1841 (Smee, 1841), was being adapted to the decorative electro-deposition of silver in a thin, bright adherent coating that was evidently equal in appearance to traditional silverware (Williams, 1976). Chief among innovative manufacturers of decorative objects who took up the new art of silver electro-plating was the acclaimed firm of G.R. Elkington and Co. of Birmingham, England. The company, which vigorously developed all aspects of electro-metallurgy for the decorative trade, entered the field of ‘electrotyping’, a technique in which the surface features of a mould are copied on an electro-deposited copper layer which, when stripped off, can be used to reproduce an imprint of the mould. In essence, it is a form of casting by electrodeposition, invented in 1837 independently by Jacobi in Russia (Pavlova, 1968) and Spencer in England (Wyatt, 1851).

Jan 1, 2019

By J. E. Tobey

THERE are a lot of good things about this great industry of ours. Let us stop commiserating and consider some of the things that are right in this business. Coal is number one in the basic material industries. Our civilization owes more to it than to any other basic commodity. We are literally immersed in the benefactions of coal. In cur man-made world it is indispensable and we are constantly surrounded by objects, materials, and services which owe their existence to coal. Practically all the important materials, such as iron, steel, brick, cement, lime, rubber, glass, cotton, and wood have felt its magic touch.

Jan 1, 1939

The SFR system utilizes a skimmer or extractor placed at or near the slurry-froth interface where there is a higher concentration of valuable mineral particles. With assistance of hydrocyclones, it is possible to classify the extracted particles into coarse and fine particle streams, that can be handled separately. It also allows the coarser solids to be separated from entrained low-value fines. The first test results with the SFR system significantly improved both coarse and fine particle recovery in a flotation cell. The SFR system was tested in the flotation circuit at a copper-moly concentrator, and the results show that the use of the skimmer has huge potential to increase the froth recovery (Rf) of both molybdenum and copper.

Jan 1, 2012

By J. W. Eckerd, W. S. Sanner, P. L. Woolf, R. E. McKeever

The Bureau of Mines experimental blast furnace was operated successfully with anthracite metallurgical briquets . Tuyère pressures were higher and more erratic than for operations using coke , and furnace " hangs " occurred more frequently . Higher hot - blast temperatures were required to maintain the quality of the metal . By using higher hot blast temperatures , the fuel and production rates and slag volumes were comparable to those obtained for all - coke operation . The anthracite metallurgical briquets exhibited excellent mechanical strength and descended through the shaft of the furnace with little breakage or reduction in size .

Jan 1, 1964

By Susana Caballero, Lourdes Yurramendi

Air Pollution Control (APC) ashes from Municipal Solid Waste Incineration (MSWI) plants need to be treated prior to landfilling due mainly to their heavy metals content. This research evaluates the capacity of the APC residues to sequester carbon dioxide, while the ash becomes stabilized for storage. It has the benefit of using two wastes, with no addition of any raw material. APC samples from different MSWI plants were treated by gas/solid accelerated carbonation at different temperatures and carbon dioxide concentrations to evaluate the residue behaviour to the process. The extent of carbonation was evaluated by means of weight gain upon carbonation and by the measurement of the final carbonate content. The APC residues were analyzed before and after the treatment in order to know their composition and their leaching behaviour according to the criteria for the acceptance of wastes at landfills established by the European Council Decision 2003/33/EC.

Jan 1, 2008

By Carlos Maurício F. Vieira, Giulio R. Altoé, Maria Carolina A. Teles, Sergio N. Monteiro, Maycon A. Gomes, Frederico M. Margem, Gabriel O. Glória

Due to growing concern about the ambient impacts, the society is demanding for materials that are environmentally friendly. The lignocellulosic fibers, like PALF fibers, appears like an option to replace the synthetic ones in composites with polimerics matrices. Besides the environmental advantages, the lignocellulosic fibers have economical and some properties advantages like the low density in comparison with the synthetic fibers. Nowadays the lignocellulosic are used in industries, like the automobile and aerospace. This objective of this study was to analyze the absorbed impact energy of the composites reinforced with PALF fibers. The fibers were incorporated into the polyester matrix with volume fraction from 0 to 30%. The results showed increase in the absorbed impact energy with the increase of the percentage of fiber incorporated. The fracture surface of the specimens were analyzed by SEM (scanning eléctron microscope) and indicates that the PALF fibers act as reinforcement for the polyester matrix.

Mar 1, 2017

By V. K. Chandaliya

N-Methyl-2-pyrollidone (NMP) has already been proven a good solvent for extraction of coal. It is believed that organic components of coal are likely to be dissolved with the solvolytic power of NMP. During dissolution process, original coal also gets disintegrated and thus helps in further extraction. Coal extraction highly depends on temperature, coal to solvent ratio, N-Methyl-2-pyrollidone (NMP) to Ethylenediamine (EDA) ratio and the size of coal particles. The process has been established in the laboratory. There is no reference available beyond lab scale. In present study, we are running a bench scale plant with 40 kg/batch capacity. Design of experiment was done in such a way that the optimum zone of the process gets evaluated for clean coal having low ash with high yield. Bench scale plant trial was conducted based on optimum zone developed during design of experiments (DOE). From the DOE analysis it was observed that feed size and coal to solvent ratio are important parameters for this process. Total 27 experiments (four factors with 3 level of variation) were designed through Box-Behnken model. It was observed that -0.5 mm feed size of coal, 150 °C extraction temperature, 17:1 NMP to EDA ratio, 1:9 coal to solvent ratio was optimum conditions. The results obtained at optimum conditions are 50% clean coal yield with 5% ash.

Sep 1, 2012

By R. E. Robinson

A novel variation of the GYPCIX process for the treatment of the acid mine effluent water from Grootvlei is described, in which a number of valuable by products can be obtained and the product water can be used for a variety of different purposes. A conceptual case study is presented in which the important cost parameters are described and certain critical path activities are indicated in order to derive a Return on Investment evaluation according to methods previously published. The study indicates that the treatment costs can be dramatically reduced, provided that proper utilization of the by products is taken into account. There are many possible uses for the water. However, by far the most advantageous contribution to the RDP and the best return on capital is derived if the water is used to establish small-lot farming activities providing work opportunities for thousands of people and contributing several hundred million Rands to the GDP. Vastly improved social conditions will be generated in an area of Gauteng that is in danger of rapid deterioration and a contribution will be made to maintaining mining activities in this area. The environmental impact is positive.

Jan 1, 1998

By Frank J. Foster

This Paper will deal with Bucketwheel Suction Dredging and its particular relationship to mining applications. There will be comparisons with other methods of suction dredging and descriptions of two recent bucketwheel installations in the mining area. The Directory of World Dredging Fleets published in the `larch 1984 edition of World Dredging magazine shows that there are about 1.000 conventional Cutterhead Dredges listed throughout the world with 289 in the United States. There are 242 Bucketline Dredges listed throughout the world of which only 6 are in the United States. These figures are not completely accurate because several units are known to the author that are not on the list and, of course, there may be others.

Jan 1, 1984

By C. B. Manula

Languages such as SIMSCRIPT and GASP have reduced the programming skills required to build simulation models, but not to a level where these can be used by a busy engineer or manager unless he has extensive programming experience. In an attempt to make simulation a more readily available tool, Sanford (1969) structured a generalized materials handling model (UGMHS)* for underground coal mining. The majority of materials handling systems consist of a set of moves and a set of pieces of equipment required to execute the moves. UGMHS gives a technique for describing and classifying the elements in these sets and then a technique for simulating the interactions of these elements as the materials handling system operates. To apply the model, the user simply furnishes data parameters and a fixed set of orders to the computer for his own problem. This new philosophy of dynamic simulation as applied by UGMHS was demonstrated in the paper by Sanford and Manula (1973). A dynamic model of underground coal mining was presented for the purposes of systems design and selection of equipment for a completely new operation and the analysis of existing ones for possible alterations, additions, and general improvements. The main differences between this application and its predecessors is the ability to transport material from multiple mine faces to multiple mine destinations and the ready adaptability to a wide variety of mine layouts. The second difference that characterizes the model is the deterministic simulation of equipment moves according to their mechanical capabilities and the physical profile of the mining scheme. Here, the computer generates performance data in the absence of time studies to compare equipment rather than operator performance.

Jan 1, 1974

Jan 1, 1997

By James W. Reil

A test series of small, precisely-controlled and thoroughly-monitored production blasts was conducted at two quarries. In each series, all variables except delay were kept constant, as much as practically possible. The first aim of the study was to determine the effect of local geology on ground vibration. The second aim was to test several hypotheses relating the effect of millisecond delay intervals to fragmentation and ground vibration. A resonant frequency of ground vibration was shown to be related to the thickness of the overburden, in accord with a model proposed by Gupta (1961). Since the overburden geology creating this resonant vibration cannot usually be changed, two methods were tested to choose delays such that blast vibrations would destructively interfere. These were shown to be effective in modifying both the peak particle velocity and response spectra of ground vibration. The delay interval chosen also affects fragmentation, primarily in massive rock, with an optimum relief between holes of 2 ms/ft. Strain gage records indicate a possible mechanism consistent with this information.

Jan 1, 1985

By Jae-Chun Lee

One of the main advantages of the supported liquid membrane(SLM) would be that different kinds of ions can be extracted selectively or simultaneously from multi-component solutions by parallel treatments with multi-SLM units. This distinctive feature of the SLM extraction is originated from its non-dispersive contacting operation between organic and aqueous phases. In this study, simultaneous and selective extractions of zinc and copper ions from their mixed solutions have been demonstrated using two parallel modules of SLMs. PC88A and LIX84 were used as the extractants for zinc and copper, respectively, and the Hoechst Celanese hollow fiber modules(Liqui-Cel Lab Module) as the supporters. The performance of the simultaneous system was compared with those of the system in which the extraction of each component was achieved by individual runs

Jan 1, 1998

By Junzo Hino

Most of the waste that contains a small portion of copper is landfilled. The recycling process of copper from the waste, such as shredder residue, should be developed in order to save mineral resources and prevent environmental pollution. Shredder residue, generated from disposed automobiles and electric appliances, consists of many types of plastics, glasses and metals. The combustion heat of plastics is efficiently used for smelting in the recycling process that consists of melting and reduction. Because the waste contains numerous components the knowledge of the distribution behaviors of the main components is necessary to develop the recycling process. The distribution behaviors in the recycling process are evaluated by using the thermodynamic calculation program, HSC Chemistry. The calculation results are compared with the practical operation data of the recycling process and discussed.

Jan 1, 2003