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By G. Ergin

The interactions taking place between Al-Mg alloys and the bed media during aluminum filtration are not yet well understood. These interactions were studied using the infiltration technique. The reaction interface was analyzed using different techniques such as SEM and TEM. Only spinel formation was observed at the interface regardless of the type of alumina and contact time. This paper discusses the results of the study.

Jan 1, 2004

By Andrew J. Freyman, Graham T. Armstrong

"In September, 1968, a survey of operating mines in the Yukon and the Northwest Territories was undertaken to determine the role of Indigenes (Indian, Metis, Eskimo) on the mines, and the attitude of mine management to these employees. The operating mines in the Territories had (at that date) a total employment of 2,002 men, of which 91 (4.5 per cent) were Indigenes. Indigenes make up 45 per cent of the Territorial population (18 per cent in the Yukon and 63 percent in the Northwest Territories). The paper documents some of the problems associated with indigenous employment in mines. A study was undertaken to determine the role of Indigenes (Indians, Metis, Eskimos) in operating mines in the Yukon and in the North-west Territories. In addition to the mines north of the 60th parallel, the experience of several other Canadian mines was examined. The general picture obtained is considered to be representative of the Canadian mining industry."

Jan 1, 1969

By Don H. Baker

THE need for new or improved refractory materials has caused metal phosphides to be given renewed scrutiny. Some metal phosphides show high-temperature inertness, are exceptionally hard, and exhibit a marked resistance to chemical attack. Various metal phosphides have been prepared for study by direct combination of the elements,'-' by reaction of metal or metal compounds with phosphine or phosphorus trichloride,'"' by thermal decomposition of a metallic phosphate or phosphite,"-'8 and by molten salt electrolysis.19 Electrolytic preparation of phosphides of titanium, manganese, and chromium from their oxides is reported in this paper. An externally heated 3-in.-ID by 6-in.-deep graphite cell, that served as the anode as well as a container for the electrolyte, was used in these investigations, and a suspended, centrally positioned graphite rod served as the cathode. A closely fitting silicon carbide furnace liner minimized atmospheric oxidation of the crucible. Electrolyses were performed for predetermined periods and current settings. Preliminary research had indicated the more efficient current and potential settings that could be used. Upon completion of the deposition period, the deposit was hot-stripped from the cathode. The mass of crystalline deposit, plus occluded and adhering salt, was crushed to minus 10 mesh and hot-leached in dilute hydrochloric acid. The leached crystalline material was water-washed, dried, and sampled for analysis. Products were identified by X-ray diffraction and standard analytical procedures. Electrochemical studies were initiated to establish the optimum conditions necessary to produce manganese phosphide (MnP), titanium phosphide (Tip), and chromium phosphide (CrP). Among the factors studied were the operating temperature, the imposed current, and the electrolyte system. If the temperature, or imposed current, was too high, deposition of phosphorus resulted, and if either were too low, partially reduced lower oxides were deposited. The operating conditions established for repetitive high-quality production of metal phosphides of the MP structure are presented in Table I. The metal phosphide crystals varied in size, but all had a definite metallic appearance. Typical are the crystals of CrP shown in Fig. 1. Evaluation data and analysis of the crystals are presented in Table 11. Efforts to measure resistivity of these three compounds over the temperature ranges of 250o to 400°K were hampered by the small physical size of the crys-

Jan 1, 1968

By O. A. Bascur

An expert process operation advisor system can increase plant efficiency, even in a complex, natural environment where not all elements of the production process can be measured directly. This system, develaped and tested in a Frasch process sulphur mine, monitors key process variables with extended qualitative pattern processing and provides on-line advise to the operators of sulphur production wells. An expert system framework captured common sense rules generated from years of experience obtained in the operation of a sulphur well monitoring system. The existent operating procedures were enhanced by process analysis using a qualitative modeling approach which provided extended rules for on-line classification of a well operational status and an expert alarm system. The methodology for development and implementation of the process advisor is presented in this report. Qualitative process modeling, statistical process control and heuristics were incorpomted into the process advisor resulting in a more efficient use of heat, an extended well operational life and the resulting cost savings. The computer process advisor also allowed the operator to concentrate his attention on the weak wells or wells in trouble. A process management system improved plant operation by automatically storing well data into a commercial database for operator validation. The enhanced relational data base system provided valuable and timely information for planning and decision making. The synergistic combination of on-line process analysis tools, expert control systems and database technology is shown to facilitate the flow of materials, energy and infomation in a modern plant.

Jan 1, 1990

By Frank Palkovits

All technologies move through a cycle from infancy to maturity. Thickened tailings have moved into the young adulthood phase of its development. Many mining companies like the idea of reducing their water-taking and water disposal issues. This limits the risks associated with traditional surface water-covered tailings facilities and the reduced dilution possible through underground disposal of thickened or paste tailings. Just as home theater systems advertised as ?plug and play? are rarely quite that straightforward, implementing and improving a thickened-tailings system has its challenges. However, the technology has also developed in recent years so it is more accessible. Some success factors have emerged because of the new technologies. Is thickened tailings the right solution? The first step in success with thickened tailings should be whether it is, in fact, the right solution for a particular mine. And, if so, what type of thickening is best. The answer depends on several factors, including: ? Grain size: The grain size that is optimal for maximizing mill recovery is some-times not suitable for thickening. Other mineralogical factors, such as mica content, may also influence whether the tailings are suitable. ? Water issues: Available water does not always have the purity necessary for the process. Another issue to consider is that if water is in short supply, as is increasingly often the case, thickening may be a way to reduce the need to both take and dispose of water.

Jan 1, 2008

By G. J. Hundman

Control of respirable dust produced by auger type continuous mining machines is normally attempted by water sprays from fixed nozzles mounted on the frame of the machine. In tests conducted under this contract, a 'wet auger' system was used, where the spray nozzles were mounted on the rotating auger itself. The tests were conducted at the Hunter mine of Smith and Stover Coal Company using a Jeffrey 1.00L auger miner. Operating the mining machine in the wet auger mode, it was found to produce 47 pct less respirable dust than when the fixed conventional sprays were used. On section dust levels were reduced too 3.5 mg/m3 which is equivalent to approximately 2.0 mg/m3 for a full shift portal to portal sample. The major difficulty that had to be overcome was the development of a simple reliable water transfer mechanism to get the water into the rotating augers. This was successfully achieved by the development of a water-through-the-shaft water system. This system can be retrofitted to existing machines and is available in kit form.

Jan 1, 1977

Jan 1, 1884

By Vernon F. Swanson

Several laboratory flotation tests were conducted by the Bureau of Mines on a sample of unweathered diorite from the B. F. Camden property, Amherst County, Va. Results showed that an ilmenite concentrate analyzing 45.5 percent Ti02 (titania), 0.07 percent P205 (phosphorus pentoxide), and 2.21 percent Si02 (silicon dioxide) could be produced from a feed containing 7.72 percent Ti02 and 3.94 percent P205. Ti02 recovery in the concentrate was 47.6 percent in a batch test. The weathered saprolite material overlying the diorite required scrubbing and desliming to remove argillaceous material and preliminary flotation of apatite followed by flotation of ilmenite. The resulting concentrate analyzed 47.3 percent Ti02, 0.19 percent P205, and 0.99 percent Si02 from a starting feed of 8.99 percent Ti02 and 3.37 percent P205; TiO2 recovery was 54.5 percent.

Jan 1, 1963

By AIME AIME

A FALL meeting that should have repercussions both in the "Transactions" and MINING AND METALLURGY was that of the Industrial Minerals Division (Nonmetallics) at Wilmington, Oct. 21-23; headquarters, Du Pont Hotel. The sixteen technical papers and two addresses were substantial and interesting. Moreover, in every instance but one, the author made the presentation, and the one exception must have been next of kin because the ensuing discussion indicated his command of the subject. The meeting schedule clicked at every turn, thanks to Dr. Gillson, chairman of the local committee, and even the four field trips adhered to the time table. The program pre-empted morning, noon, afternoon and night two general luncheons, two dinners, and an evening technical session reminding one of the Annual Meeting. Only the registration was disappointing - about 80.

Jan 1, 1943

By J. P. Ramsey

This is a description of the efforts of a research project intended to demonstrate methods of alleviating pollution from coal mine refuse piles and slurry lagoons. These are mainly derelict barren sites. Some are burning and some are vulnerable to wind erosion which causes air pollution. Some occupy valuable land near metropolitan areas. They are an integral part of the landscape of the Appalachian and Midwestern Coal Fields. They are important in the light of growing civic awareness of the great general problem of waste disposal and environmental improvement. In the V-shaped valleys of the Pocahontas Region, they continue to be piled higher and higher. In flatter topography, they tend to form broad, flat ridges. Some contain more metal forms than others and some have a minimum of metal, but weather to a fine talc, which chokes streams with a fine particle suspension. Most are burning or have burned, but burning or weathering, most all are sources of pollution to the atmosphere and to adjacent waterways. This demonstration project is being carried out at an abandoned mine near the town of Du Quoin in southern Illinois. It is jointly sponsored by the Truax-Traer Division of Consolidation Coal Company and by the Federal Water Pollution Control Administration of the Department of the Interior. The site area is a refuse pile and slurry lagoon, each of fifty acres. It is hoped that basic data from this study will be generally applicable to other sites and will provide a basis for rational and efficient engineering design of future reclamation projects. Most refuse piles have extremely long term capabilities to produce highly potent acidogenic oxidation products typifying the more serious aspects of acid mine drainage contamination. Numerous sites remain where the abandoned mine no longer discharges acid waters, but its associated refuse pile continues to generate significant quantities of acid and other oxidation products even after many years.

Jan 1, 1969

By C Fricke, R Wood, P Velletri

"In a climate characterised by an ever increasing focus on cost reduction and maximising the utilisation of existing assets and infrastructure, understanding the uncertainty associated with alternative investment and operational choices becomes paramount to minimising the risk of making an ineffective decision. To assist in this process, TSG Consulting has developed an analytic framework to capture the underlying complexity of a mineral supply chain, and then quantify the impact of the uncertainty associated with the key drivers of business productivity. The technical basis of this approach follows three distinct steps: analyse the current system and identify the major factors that drive value build detailed models that can measure the response of the system to potential changes in the factors identified quantify the sensitivity of financial and capacity forecasts to these factors.Each of the above steps draws on a different area from the field of applied analytics, namely: data analytics dynamic modelling and designed experimentation meta-modelling and optimisation.Following the three-step approach described above ensures a rigorous modelling and analysis process is executed to support strategic mine planning decisions. The approach is equally applicable to the analysis of fully integrated system supply chains (pit-to-port), the evaluation of incremental capital investments to targeted areas of a supply chain, or when considering revisions to the operating philosophy of a system in the short term. The basis of each of the three analytic steps is explored in detail in this paper. The result is the definition of a structured mechanism for a business to actively manage risk and drive productivity as a component of the strategic mine planning process.CITATION:Fricke, C, Velletri, P and Wood, R, 2014. Enhancing risk management in strategic mine planning through uncertainty analysis, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 275–280 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By Dan Nower

Machinery Health Monitoring of Shovels MINExpo 2012: Caterpillar announced the largest Electric Rope Shovel, capable of 120 short tons The next day, JoyGlobal (P&H Mining) ?one-upped? CAT, introduced a shovel capable of 135 short tons Large Concern: breakdown (unplanned outages) of one machine will be more disruptive to production

May 1, 2013

By Jun Li

Rate processes of silver cyanidation were studied with the objective of understanding the reaction mechanism. The research was divided into three sections: anodic dissolution of silver in cyanide solutions, cathodic reduction of oxygen on silver surfaces and the direct leaching of silver in oxygenated cyanide solutions. The charge transfer steps plus the diffusion of reactants from bulk solutions to the silver surface were identified as rate-limiting and the rates of both anodic and cathodic reactions can be calculated using the Butler-Volmer equation and Fick's first law. Based on mixed potential theory and the results of electrochemical studies, a comparison of the rate obtained from direct leaching with that predicted from the calculation is made. Calculated results agree well with the experimental data.

Jan 1, 1992

By Clarence Merritt

STAINLESS iron, as mild stainless steel is usually called, an alloy ranging from 11.50 to 15.00 per cent chromium with carbon under 0.12 per cent, has been considered to be not appreciably affected in respect to corrosion resistance by heat treatment. This metal, while one of the most widely used of the "straight" chromium stainless alloys, has failed in many applications because of insufficient information regarding heat treatment. These failures have been attributed to many possible causes from an inherent lack of resistance to corrosion and misapplication to mysterious electrolytic effects or comparatively minute non-metallic inclusions. Many uses for a steel with such excellent physical properties is are latent in this alloy have been lost on account of corrosion failures which could have been avoided by applying proper heat treatment. The alloy has not received the recognition or attention it should because of the fact that' the details of its metallurgical behavior were not thoroughly understood. Response to heat treatment of the steel is well known as regards tensile properties, 1,2 but its application has been for improvement in tensile characteristics or on account of machining considerations rather than for corrosion prevention. The potential user of this steel has not been clearly advised in papers, either technical or commercial, that have been written about it in the last 10 years or more, of particular features that are of prime importance in developing the excellent properties of this metal. The data to be presented in this paper are concerned mainly with the effect of heat treatment on the corrosion resistance, but a study has also been made of the concurrent microstructural changes and an explanation developed for the phenomena revealed, as well as a correlation to the other physical properties-hardness, tensile characteristics and impact strength. Stainless steel, largely used for cutlery purposes, an alloy of approximately 13.00 per cent Cr with 0.30 per cent C, must be hardened and the surface prepared by polishing or pickling for best resistance to staining and corrosion.3 Monypenny reports that a loss of hardness is

Jan 1, 1932

By R. G. Bowman

Discussions of processes for the manufacture of white lead generally open with the statement that white lead is the oldest chemical pigment known to man. This fact is of more than historical interest; in the light of the present extensive use of white lead, it indicates that the compound possesses characteristics that make it unique among white pigments, and superior to all in its particular field. A greater variety of processes have been proposed for manufacturing white lend than for any other one chemical compound. Only a few of these processes have come into commercial use, however, and a large part of the present production here and abroad is made by the process used in ancient times. The outstanding disadvantages of the old process are that it is slow and laborious, affords no control of the product, and yields at best an impure material lacking in uniformity. Improved processes, sometimes classed all together as "quick processes," have had as their main object the shortening of the time required. Most of them accomplish this and some have yielded a superior product as well, but only two or three are now in use commercially. For centuries the manufacture and mixing of paints have been treated as an art, and the practice has been much influenced by tradition and precedent. There is a reluctance to abandon old materials for this purpose, and as few new uses for white lead have been developed, the adoption of the quick processes has been slow. The electrolytic production of white lead is not new, a large number of processes and forms of apparatus have been proposed and patented within the past 25 years, all directed toward the production of white lead, wholly or in part, by electrolysis. One or two of these processes were tried commercially but proved unsuccessful. Process The Sperry process, used by the Anaconda Lead Products Co., is the invention of Elmer A. Sperry, and was worked out to a commercial basis at the East Chicago plant. It resembles, in a general way, earlier methods, but embodies the features that make it possible to operate

Jan 1, 1926

By Han Xing, Cui Jianzhong, Qin Ke, Shao Bo, Zhang Haitao

In this paper, a new approach that uses hot-top DC casting process to producing multi-alloy ingots is present. The different type and size of composite and coated ingots (4045/3004/4045 three-layer composite ingots with section 630mm by 1500mm and 4045/3003 coasted ingot with F140mm/F110mm in diameter) are cast by this approach. The macro-morphologies and microstructures of the composite ingots, the temperature distribution and the element distribution in the interface zone were investigated, also and the interface bonding strength was measured. Results show that the solid supporting layer formed on the cooling plates plays a key role in the casting process of composite ingots. The solid supporting layer can prevent the blending of two melts by resisting the impact of alloy melt, which ensures the stable casting process and casting high quality composite ingots, because the contact height is increased using hot-top DC casting. In addition, fabrication and properties of 4045/3004/4045 three-layer composite ingots with section 630mm by 1500mm are reported in detail.

Jan 1, 2015

By R. S. Bradley

WHAT are known as insulating firebrick are lightweight firebrick with low thermal conductivity designed primarily for use in direct contact with furnace gases. These are a recent development in the refractories industry, and are really an outgrowth of the type of insulating brick suitable for use behind refractory walls developed by the insulation manufacturers. To differentiate between these two types of brick, the manufacturers have recently agreed upon the use of the term "Insulating Firebrick" to apply to the type of brick suited for use in direct contact with furnace gases, and the term "Insulating Brick" for the type suitable for use behind refractory walls. Insulation was applied to steam pipes as far back as 1900. This was a low-temperature insulation, the most common type being magnesia blocks. The next development was applying insulation to the outside of furnace walls, a service which necessitated an insulating material of higher temperature resistance. Natural diatomaceous earth, both in the powdered and brick form, was used; this was efficient and is still used extensively for backing up refractory walls where the inner surface temperature of the insulation does not exceed 1600° F.

Jan 1, 1937

By R. M. Foley, Hidesaburo Kurushima

About 25 pct of all Japanese pyrite comes from the Yanahara mine on Honchu Island. For the past 40 years lack of an economical recovery process forced the operator, Dowa Mining Co., to sell the pyrite for its contained sulfur only, leaving 7 million tons of high grade iron ore waste. Introduction of the Dorrco FluoSolids roasting system enabled the company to make use of its iron sulfides and also to find a market for the mine's considerable pyrrhotite production. The success of this project is of great importance to Japan's economy since it points the way toward material increase in her natural resources. Prior to use of the present process, no practical method was available for commercial exploitation of known large tonnages of pyrrhotite, while the copper content of the even larger deposits of pyrite made the roasted residue unacceptable for the iron and steel industry. In Europe, large amounts of copper-bearing pyrite cinder are given a chloridizing roast for separation of the copper and iron but this treatment is not economical in Japan where salt is imported from as far away as Egypt.

Jan 10, 1958

By Z. Y. Ma, M. D. Liu, Z. Z. Liu, J. K. Zhou

"An optimization method of microwave assisted leaching of copper anode slime was proposed based on Taguchi method. The results showed that the solid-liquid ratio was the most important factor affecting SNR(signal noise ratio) of the copper, tellurium and selenium leaching efficiencies, and its contributions to the copper, tellurium and selenium leaching efficiencies were 58.34%, 55.54% and 60.74%, respectively. Solid-liquid ratio was a significant factor to SNR(copper, tellurium and selenium). Reaction period was a less significant factor to SNR(copper and tellurium) and concentration of sulphuric acid was a less significant factor to SNR(selenium) while microwave power was an non-significant factor, its contributions to the copper, tellurium and selenium efficiencies were 3.22%, 11.73% and 12.73%, respectively. The optimized parameters of the microwave assisted leaching of copper were as follow: microwave power of 500 W, reaction period of 10 min, solid-liquid ratio of 0.10 g·mL-1 and H2SO4 concentration of 1.0 mol·L-1. The optimized parameters of the microwave assisted leaching of tellurium and selenium were as follow: microwave power of 800 W, reaction period of 15 min, solid-liquid ratio of 0.10 g·mL-1 and H2SO4 concentration of 1.0 mol·L-1. The validation experiments under the optimized conditions has been carried out, the copper, tellurium and selenium leaching efficiencies were 98.66%, 84.32% and 64.54%, respectively. INTRODUCTION As important valuable by-products, copper anode slimes are collected from the bottom of the electrolytic bath in the electrolytic copper refining process(Kilic, 2013). The value of the anode slime is determined by the content of rare metals and precious metals(Liu, 2014). Generally, pretreatment of copper anode slime is the first stage of the whole process. The aim of the pretreatment process is to remove Cu, Te and Se etc and enrich the valuable metals. The methods of pretreatment process can be differentiated into: pyrometallurgical processing and hydrometallurgical processing(Amer, 2003). The hydrometallurgical processes are more promising compared to pyrometallurgical processes in terms of cost effectiveness, low energy consumption and environmental concerns(Ranjbar, 2014). However, the disadvantages of the hydrometallurgy process are evident, such as lengthy processing times and low efficiency. Therefore, it is necessary to develop a highly efficient and environmentally friendly pretreatment method."

Jan 1, 2018

By J. A. Eisele

There is currently much interest in how extraction of gold and silver from ores with acidic thiourea solution compares with extraction using alkaline cyanide solution. Agitation leaching tests were performed by the Bureau of Mines on 14 precious metal ores using sodium cyanide (?NaCN) and thiourea [(NH2)2CS) as extractants. The objective was to compare the results of the two extractants. NaCN was used at a concentration of 2 g/L with and without H202 as an oxidant. (NH2)2CS was used at concentrations of 2 and 20 gjL, and the solution potential was controlled at 390 to 420 mV standard hydrogen electrode (Eh) with Fe2(S04)3. With both reagents a.t 2 g/L extractant levels, NaCN extracted more gold and silver than (NH2liCS from all of the ores. At 20 g/L (NH2)2CS compared with 2 g/L NaCN, (NH2)2CS extracted more gold than NaCN from two ores, the same amount from one ore, and more silver from one ore. NaCN extracted more gold than (NH2 )2CS from 10 ores and more silver from 4 ores.

Jan 1, 1989