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By E. J. Roberts

Hydrometallurgical operations and many processes in the chemical industry require the separation of dissolved material from solids. One of the decisions which has to be made in designing a plant for such an operation is how this separation shall be accomplished. It is the purpose of this paper to set forth the general principles involved in such separations in order that the optimum flowsheet and equipment may be selected. Countercurrent Decantation with thickeners, or C.C.D. as it is generally known, is, of course, only one way of separating dissolved material from undis-solved. Other unit operations such as Countercurrent Filtration (C.C.F.) and Countercurrent Classification (C.C.C.) are widely used. The same principles may also be applied to centrifugally assisted decantation, as with nozzle or solid bowl type centrifugals, and to separations using screens, either gravity or centrifugal type. Another form of countercurrent washing applicable to granular materials is practiced in continuous ion exchange operations. All of these operations depend on two basic principles, or combinations of these principles. In C.C.D. type operations the solids are concentrated into the smallest possible volume of liquor in each step and the resulting pulp then mixed with a more dilute liquor and recon cen trated, the liquors separated from the more dilute stages being advanced to dilute the more concentrated liquor in a previous solids concentrate, as is shown in Fig. I. This will be termed the solids concentration-solution dilution principle, or, for short, solution dilution. countercurrent decantation- type circuits. The second principle used in washing solubles from solids is that of solids concentration-solution displacement. Here the solids are restrained from movement while wash solution is forced through the interstices in a counter-current fashion, as in Fig. 2. In the simplest application of this principle, once the "cake" has been formed, it is not disturbed until the operation is completed. In continuous filters, the cake is merely moved under the successive washes and the displaced filtrates removed as in Fig. 4. Often, however, after one or two displacement washes, a repulping step is introduced, the cake reformed and washed again. This procedure brings the solution dilution principle into play as well as the solution displacement principle. Merely thickening ahead of filtration, which is often operationally advantageous, does not hybridize he circuit. It still can be a pure solution displacement operation from the washing

Jan 1, 1961

By João Carlos Jânio Gigolotti

O avanço tecnológico tem gerado demanda crescente por materiais que possam ser utilizados em alta temperatura e ambientes oxidantes, o que inclui ligas intermetálicas MR–Si–B (MR = metal refratário) com estruturas multifásicas. Assim, este trabalho teve por objetivo estudar a microdureza de ligas do sistema Hf–Si–B na seção isotérmica a 1600ºC, na região rica em Hf. Ligas Hf–Si–B foram fundidas com lâminas de Hf (min. 99,8%), Si (min. 99,998%) e B (min. 99,5%), em forno a arco e tratadas termicamente a 1600 ºC em atmosfera de argônio. As relações de fases nessas ligas foram identificadas por difração de raios-X e por contraste, em imagens obtidas via microscopia eletrônica de varredura no modo elétrons retroespalhados. As ligas tiveram sua dureza medida pelo método Vickers (microdureza) com cargas de 0,05 kgf e 0,2 kgf e tempo de aplicação de 20 s. Os resultados, obtidos da média aritmética das medições realizadas nas regiões heterogêneas de cada liga, mostraram uma dureza média de 11,08 GPa, com pequeno coeficiente de variação de 3,8%. Os boretos HfB2 (19,34 GPa) e HfB (11,76 GPa) apresentaram dureza mais elevada que os silicetos Hf2Si (8,57 GPa), Hf5Si3 (9,63 GPa), Hf3Si2 (11,66 GPa), Hf5Si4 (10,00 GPa), HfSi (10,02 GPa) e HfSi2 (8,61 GPa).

Aug 17, 2017

By F. De Lucio

Para la aplicación de la instalación de un sistema de relleno hidráulico es necesario evaluar las funciones que el relleno debe contener y determinar si el material a usar cumpla con las funciones especificadas. En ese sentido, el objetivo del texto presenta una interpretación científica sobre tal método para especificar las funciones que el relleno deba cumplir y la metodología experimental adecuada que evalúe cuantitativamente a un relleno hidráulico.. Asimismo, se describen sus propiedades estructurales como la densidad relativa, reducción de volumen y estabilidad de tajeos contínuos, así como los métodos indirectos para inferir dichas propiedades y las posibles consecuencias secundarias que pueda generar el empleo de relleno hidráulico.

Nov 20, 1972

By Tim Peterson

Factors Controlling Stability Stability of slopes in soft rock, waste dumps or soils is governed by three factors: ?Slope configuration ?Groundwater ?Shear strength

Jan 1, 2004

By J Parr, P Ashworth, S Johns, C Yeats, A Littleboy

The ocean floor is increasingly being discussed in terms of its resource potential. New discoveries, improved knowledge and access to unexplored areas of the deep sea and continental shelf are some factors contributing to a renewed interest in the seafloor exploration and mining industry. The industry has been referred to as the ænext minerals frontierÆ. To date, much of the research has focused on proving economic and technical viability of the industry, with environmental issues addressed locally. However, there is limited research internationally, and none known in Australia that considers the social viability of the industry, addressing issues such as regulatory contexts, international precedence and public acceptability. Does the nascent seafloor exploration and mining industry have a social license to operate? Does it have support amongst the wider community? If not, why not? The Wealth from Oceans National Research Flagship explored these questions by scoping the social issues that would surround an expansion. Two desktop studies provide insight into the current level of activity in seafloor exploration and mining, recent developments and the regulatory regimes on which the industry is based. One study focused on the situation in Australia, while the other was internationally focused. A series of workshops were held with key stakeholders from government agencies, industry and other interested parties, such as environmental groups and the fisheries industry. These workshops identified and explored the different stakeholdersÆ perceptions of the benefits, concerns, opportunities and key questions associated with an expansion of the seafloor mining industry. The desktop studies revealed that Australia is one of only a few countries with legislation specific to seafloor exploration and mining. Nevertheless, barriers to licence approval exist because of lack of precedent in applying this legislation. Consequently, the decision process can be vulnerable to political issues and subjective judgements. The outcomes from the stakeholder workshops suggest this inconsistency may be influenced by the high levels of concern and uncertainty over environmental impacts. Uncertainty over environmental impacts can influence the acceptability of an environmental impact assessment (EIA) and also mean the perception of risk is variable. Overall, this research suggests that the future of the seafloor exploration and mining industry will be highly dependent on AustraliaÆs ability to:improve the knowledge-base underpinning the regulatory regime,generate open and transparent communications between stakeholders, andimprove the understanding of policy and regulatory processes.

Jan 1, 2008

By K. Soldenhoff, M. Fainerman-Melnikova

The use of strong base resins for uranium recovery is severely affected by the presence of chloride ions in solution. In areas where high-quality process water is not readily available, the use of saline water would extend the potential application for ion exchange in uranium processing. This study presents measurements of uranium uptake, using a wide range of commercially available weak base anionic exchangers, from solutions with chloride concentrations ranging from 2.5 to 22 g/L Cl. Out of 14 weak base anionic resins tested, 3 were identified that were not severely impacted by the presence of chloride and significantly outperformed a gel strong base resin typically used for uranium recovery in high-chloride environments. The uranium loading was sufficiently high for the consideration of development of the application of uranium recovery from uranium ores leached with seawater.

Jan 1, 2012

By William F. Hahn

This project focused effort on three separate areas: demonstration of a low seam longwall illumination system, design of illumination systems for low coal auger miners, and an assessment of machine lighting systems for machinery used to mine low seam coal. Results indicated illumination systems can be purchased by the mine operators of low coal seams. These systems can be supplied with the equipment as a factory integrated system or can be retrofitted to the machine or longwall equipment.

Jan 1, 1982

By Warren L. J, Horsley R. R, Meagher L

Mineral concentrators often use process water that is very saline and/or hard. In this paper the effect of increasing concentrations of sodium chloride and calcium chloride on the rheological properties of 70 wt% quartz suspensions (d5o - 10.6 ¦m) is reported. The apparent viscosity at 100 s t in 5 mol dm -3 sodium chloride solutions (approx. 300,000 ppm) was nearly 500 times the viscosity of water without salt or particles present. Part of the increase in viscosity is caused by aggregation (coagulation) of the suspension.

Jan 1, 1989

By F. E. Joyce

This paper describes the development of a process for producing manganese and iron pellet concentrates from low-grade manganiferous iron ores of the Cuyuna range by a two-stage sulfatization-reduction roast. First, the manganese minerals (7.5 percent manganese) were converted to water-soluble manganese sulfate by roasting in sulfur oxide gases at 700° C, then, the hematitic iron minerals (31 percent iron) in the hot sulfatized are were reduced to magnetite with simulated reformed natural gas in the temperature range of 350° to 425° C. Batch tests were made in a 3-inch-ID by 6-inch-long, gas-heated, stainless steel retort, and continuous countercurrent experiments were performed in a 2-inch-ID by 10-foot-long, electrically heated shaft furnace. Manganese sulfate was removed from the roasted product by leaching with water, and over 90 percent of the manganese was recovered in an oxide product (65 percent manganese) obtained by precipitation, drying, and thelmal decomposition of the sulfate. An iron oxide concentrate (60 percent iron) with an iron recovery of 75 percent was obtained from the water-insoluble residue by magnetic separation.

Jan 1, 1973

By W. H. Ode

In 1949 the Coal Committee of the Economic Commission for Europe, Geneva, Switzerland, established a Classification Working Party, to develop an international system for classifying coal. This project was necessitated by the increased trade in coal among various nations following World War II. Although national classification systems existed, they had been developed to cover the characteristics of domestic coals without reference to coals of other countries. Different terms for describing similar or identical coals in each nation caused confusion in evaluating coals shipped in international trade. Experts from Austria, Belgium, Bulgaria, Czechoslovakia, Denmark, the Federal Republic of Germany, France, Greece, Hungary, Italy, the Netherlands, Poland, Sweden, the Union of Soviet Socialist Republics, East Germany, the United Kingdom, the United States of America, and Yugoslavia participated in various stages of the classification work. Walter A. Selvig was appointed by the Bureau of Mines as the technical expert to represent the United States because of his experience in developing and standardizing methods of analyzing and classifying American coals. He served on the Classification Working Party until his retirement from the Bureau of Mines early in 1956. Extensive laboratory work was done in connection with the classification studies at the Pittsburgh Experiment Station of the Bureau of Mines.

Jan 1, 1958

IN previous discussions on the occurrence of gold in the Bendigo quartz reefs the opinion has been put forward that the gold shoots are primary concentrations in the quartz reefs during the period of vein-formation. The view has been based upon the constant features of the gold shoots in a large number of individual reefs, independent of their depth below the surface. These features include the mineral associations accompanying the gold, the appearance and association of the gold in the quartz, the similarity in all respects (excepting mineral content) between richly gold-bearing quartz and poor quartz, and the variations in mineral content in the reef apart from gold. The view has been supported by a relation of the gold shoots to faults, together with the dependence of the reefs on the existence of pre-mineral faulting. The secondary deposition of gold has only been observed in a few instances .associated with the younger monchiquite dykes, and is of no economic importance.

Jan 1, 1922

By Tom Pfitzer, Alice Correa, Meredith Hardwick

The past decade has brought significant changes in the use of risk-based criteria for safety within the U.S. Department of Defense. The Range Commanders Council (RCC) chartered a working group to develop and define risk acceptance criteria for protecting the general public and mission essential personnel from debris from launch ranges. This working group has continued to develop and update RCC Standard 321 as the needs of the ranges and range users have evolved. A revision to RCC Standard 321 is near finalization and will include casualty criteria, guidelines for assessing risks due to other flight hazards in addition to inert debris, and an overall risk management process for range safety. This paper reports on work in progress and includes several precedents which may prove important to the explosives safety community.

Jan 1, 2007

By Francis J. Kelly

This Bureau of Mines study was made to obtain and present facts concerning the production and marketing of rare-earth metals and thorium in the Central and Southern Rocky Mountains (Arizona, Colorado, New Mexico, Utah, and Wyoming, referred to in this report as the region) and to review the current demand for these elements in the United States. Little or no published information was available on the marketing practices for these commodities. As a result of many inquiries from industry, potential prospectors, and the general public, the various factors of resources, production (present and potential), marketing, and consumption have been investigated, and the results are set forth in this report. Material concerning occurrences and deposits is from published references detailed in the bibliography.

Jan 1, 1962

The problem of ventilating an advancing drive which finally reached 5,550 ft from the fresh air base in rock with virgin temperature of 83°F was solved economically by the use of two 15 h.p. electric fans forcing ventilating air through 281/2 in. dia. fiexible polythene tubing of wall thickness 0·010 in. The saving in cost over conventional metal duct was estimated to be £3· 24 per ft of drive.INTRODUCTIONAs described by Dutton (1965) and Newton (1965) the existing 1,480' ft level drive at the South Mine, Broken Hill, was extended in two stages. The first extension was 3,790 ft, the face then being 4,790 ft from the fresh air inlet. Later, after a vertical ventilation connection was made 1,000 ft back from the face, the drive was extended a further 4,550 ft. The rate of face advance in both stages was about 15 ft per day (3 shifts of 5 ft), 5 days per week. Drive size was 8 ft by 9 ft 6 in. high.The Mines Inspection Act of New South Wales requires 6 hr shifts (instead of the normal 7 in Broken Hill) to be worked if the wet bulb temperature exceeds 80°F. Virgin rock temperature on the 1,480 ft level was 83°F. Inlet air temperature varied with seasons from 58 to 72,oF wet bulb.To adequately ventilate the face, a flow of air of about 11,000 c.f.m. was thought to be necessary.Re-entry time was about 75 min, being governed by the 7 hr length of shift (3 shifts per day) and travelling time.Blasting was permitted only at the end of the shift, in accordance with local industrial restrictions.

Jan 1, 1965

In choosing such a threadbare subject for a paper I fear that I may in some measure be taxing your patience, yet as upon the accuracy with which the work is done depends the result of conclusions drawn as to whether a property will be profitable to work or otherwise. The subject cannot be too well threshed out, and I trust that upon certain points that have come within my own experience I may be able to give 'hints that will prevent others from making mistakes. First as to alluvial. Gold is often found from the grass roots down, often ill particular horizontal bands in the wash, but more generally concentrated either on a true or false bottom. When sampling dry ground for proposed hydraulicing I have obtained accurate results only by taking the whole of the dirt from measured shafts, stacking it as it was lifted on a tarpaulin, and putting the whole quantity through a carefully constructed box. In wet ground careful borings will in most cases give fairly correct results, but where it is possible to sink shafts, that should be done, as a guide is then also obtained as to the nature of the wash, whether it is bouldery, cemented, or free. Sampling in a face is a more difficult work in many respects than in new ground, as so many elements enter into action to spoil accurate sampling. Of course the great thing to avoid is sampling in any place where either natural or artificial concentration has taken place, and very much has to be left to circumstance and the sampler's own judgment. In passing I may mention that I have on several occasions seen diggers deceive themselves in wet ground where they were sinking and coping as best they might with water. They would take a dish of dirt from the bottom of their hole, pan it off, and take the result as a fair yield, and on the strength of it perhaps spend a lot of time and money in tail races and whereas in their sample there had been a process of concentration carried on, the movement and working in the water had caused the gold to work down, and anything like accurate estimations by the method pursued were out of the question.

By Habib Zughbi, Paul Zulli

"A key step towards sustainability in iron and steelmaking is to optimise the use of raw materials and energy consumption, and consequently minimise CO2 emissions. Models based on a Process Integration (PI) approach play a key role in evaluating various scenarios and the impact of introducing changes in raw materials and operational conditions on the overall energy consumption and CO2 emissions. BlueScope uses a PI based comprehensive model for its Port Kembla Steelworks (PKSW), called the Integrated Steelworks Energy and Emissions Model (ISEEM). ISEEM is tightly coupled to the configuration of PKSW. It is based on mass and energy balances as well as thermodynamic relationships. ISEEM is a steady-state model and is used to predict overall and detailed unit-by-unit energy consumptions and CO2 emissions. It is also used for plant-based scenario modelling. This paper investigates the impact of major changes to PKSW configuration, including the shutting down of a blast furnace and cokemaking battery, on the energy consumption and CO2 emissions of the plant. It discusses some of the issues involved in updating the model and some identified opportunities."

Jan 1, 2015

By A J. H Newell

The background and the basis for conducting a Technical Due Diligence are discussed as well as the source information, typical studies and potential limitations. Typical short comings including ‘show-stoppers’ are presented for the metallurgical area, with examples. Issues found in other areas such as geology, mining, infrastructure and financial evaluations are briefly reviewed, highlighting the input and interaction required by metallurgists with these disciplines. A checklist is provided as a guide to maximise the success of a Due Diligence as well as a check on the quality of a Feasibility Study.CITATION:Newell, A J H, 2015. Fatal flaws in technical due diligences, in Proceedings MetPlant 2015, pp 61–77 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By D. Settles, R. Rose, P. L. Dunn

"A new mineral sands operation is being developed in Georgia by Southern Ionics, Inc. (SII). Prevailing mineralogy and certain design constraints required detailed testing and circuit analysis to create a robust separation processes. The floating wet concentrator plant (WCP) and mineral separation plant (MSP) flow sheets were designed based on historical testing information and recent SII test campaigns on various composite feed samples. The flow sheets were finalized through rigorous process and orebody sequence modeling.The process uses traditional physical separation equipment; however a new MT spiral, the MG12, was selected for use on board the WCP for roughing duty. The MG12 spiral is a two-stage, twelve-turn spiral that has been proven to achieve very high recoveries of heavy minerals. The floating plant includes feed desliming operations, a central MT surge bin for optimum spiral circuit feed control and ancillary operations for concentrate and tailings handling. Scrubbed heavy mineral concentrate (HMC) is then transported to the MSP for concentration of the titanium and zirconium bearing mineral fractions.The testing, flowsheet development, and plant design will be described and explained, and a brief summary of the current project status will be given.IntroductionSouthern Ionics Inc. (SII) is a privately held chemical manufacturing company, founded in 1980 by Milton Sundbeck. SII focuses primarily on the sale of specialty and intermediate inorganic chemicals. Core markets include cement and refinery catalysts, molecular sieves, zeolites, pulp and paper, pharmaceuticals, TiO2 and water treatment. SII is built on the four cornerstones of service, quality, technology and delivery with all SII facilities ISO certified and key products used in potable water treatment certified to NSF standards. SII owns and operates its own transportation fleet and is focused on being a low cost producer, committed to safety and the environment."

Jan 1, 2015

By James R. Kerr

Although metallurgical benefits of processing metals in a vacuum or reduced atmosphere have been realized for a hundred years, the problem of creating a vacuum in the range from 10-0 to 10-4 mm. of mercury in a moderately sized furnace chamber has been difficult to solve. The demand for these and lower pressures, with the advent of World War II, for separating the fission-able uranium isotope from its stable twin by the electromagnetic process, gave impetus to developing pumps capable of delivering extremely low pressures. With the release of data by the Atomic Energy Commission on methods of securing high vacuum in large equipment, steel companies took the initiative, and the growth of the vacuum-melting industry was assured. Vacuum-induction melting of steel in the United States began on a small scale in early 1945 and in 10 years grew to 60,000 pounds per month or 720,000 pounds per year. The years following 1954 showed tremendous expansion, culminating in 1958 in a capacity of more than 36 million pounds.

Jan 1, 1962

By Wilson Bardales

El presente trabajo describe la experiencia de la Gestión de la Calidad en la Cía. Minera Poderosa S.A., específicamente en el rol que desempeñan los Círculos de Mejoramiento Continuo (CMC´s) como un vehículo efectivo para alcanzar los objetivos de la empresa. Los CMC´s están integrados por trabajadores de un mismo proceso, a quienes se capacita en el manejo de herramientas, técnicas y metodologías de la calidad, con la finalidad de realizar mejoras en los procesos. En ese sentido, en la compañía minera La Poderosa, la administración es participativa y el directorio difunde las políticas, para lograr la rentabilidad de la empresa. Así también, los mandos medios definen los objetivos y estrategias, desplegándola en cascada a la supervisión y estos a su vez, al personal de línea. Este concatenamiento de responsabilidades y la participación de los CMC´s aseguran el alineamiento y control de la gestión.

Sep 12, 2005