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By Ludwig Strah

"The paper outlines the history of rubber mill liners beginning with the awarding of the first North American patent rights in 1923. It includes the early-day applications and installations of the 1920s and 1930s through to their present-day application. Over-all rubber mill liner design is discussed in relation to present day installations employing rubber mill liners in various grinding applications. A brief overview is given of a manufacturer's procedures to produce rubber mill liners.IntroductionIn early 1910, it became apparent that the productive life of the silver mines in Cobalt, Ontario, could be substantially prolonged by mining lower-grade ores.The mining of lower-grade ores required the establishment of treatment facilities which initially employed jaw crushers, stamp mills, jigs and concentrating tables. The recovery of silver in other than a coarse metallic form required the additional step which was introduced at that time: the cyanidation of silver concentrates from the tables. The resultant requirement for increased and improved recovery led to the introduction of grinding mills, i.e. tube mills.Shortly after the introduction of the tube mills to the Nipissing Mine's mill in 1914, the idea of using rubber as a mill liner material was spawned. However, no action was taken due to the advent of World War I. It is interesting to note that the idea of rubber mill liners emanated from having used pieces of solid rubber tire as an emergency repair on a set of liners when a liner had broken and no immediately available spare was on site.The credit for this ingenuity and subsequent application for a patent on rubber mill liners falls to James John Denny, the mill superintendent, and Rolla Barnum Watson, the general manager of Coniagas Mines Limited. The patent application was formally made on December 3, 1921. The U.S. Patent Office issued Patent No. 1,470,597 on October 16, 1923."

Jan 1, 1982

By Zhang Wei

"Pulang Copper Mine is located in Shangri-La county, Diqing Prefecture, Yunnan Province, with currently defined copper reserve of 4.8 million tonnes of copper metal and an average grade of 0.34% Cu. The mineralized zone in a dome shape is 2,300 m long, 600–800 m wide, and 1,000 m high. At present, the project is at a construction phase, with a first-stage mining and processing capacity of 12.5 million tonnes of ore per year. Ore haulage is planned via a drift and ore pass development system. The cavability of mineralized rock is classified into three types (II, III, IV), with type III accounting for more than 98% of the total reserves. The cavability of the orebody is generally considered to be good and block caving mining method is planned. Semi-autogenous grinding and ball milling are adopted for the mineral processing. The tailing dam construction method is a center-line method.INTRODUCTIONAs the China's largest underground nonferrous mine, Pulang Copper Mine is located in the northeast of Shangri-La County, Diqing Prefecture, Yunnan Province, China. It is 62 km northeast of Shangri-La city. Shangri-La County is a Tibetan-dominated, multiple-ethnic region, with a population of approximately 163,000 in 2009. The county is rich in mineral and water resources, thriving with tourism. Its economy is also dominated by agriculture. To date, the defined copper reserves at the Pulang Copper Mine is 4.8 million tonnes of copper metal at an average grade of 0.34% Cu. In addition, it contains a gold reserve of 145 tonnes, a silver reserve of 2,754 tonnes, a molybdenum reserve of 0.19 million tonnes, and a sulphur reserve of 10.5 million tonnes. The first-stage mining and processing capacity is planned at 12.5 million tonnes of ore per year. When it ramps up to this production rate, the mine will produce copper concentrate containing 50,000 tonnes of copper and molybdenum concentrate containing 968 tonnes of molybdenum. A drift and ore pass system is planned for ore haulage and mining method is a block caving method. Semi-autogenous grinding and ball milling are considered for mineral processing. A center line dam is adopted for the tailing dam construction (Feng, 2010; Feng, Li, & Wang, 2011; China Enfi Engineering Corporation, 2014)."

Jan 1, 2016

By Poul Hansen

"In mid-1986, a world-class mining enterprise was created in Highland Valley, British Columbia, bringing together the copper mining operations of Lomex and Cominco . In 1988, Highmont joined the new partnership.Highland Valley Copper is the largest copper mine in North America in terms of both tonnage mined and tonnage milled, and it is one of the largest in the world. Due to its relatively low ore grade its production of copper in concentrate ranks about ninth in the Western World.The current eighteen year mine plan is based on ore reserves of 761 million tonnes. The daily milling rate is 133 000 tonnes. At the end of mine life, a total area of approximately 6500 hectares will have been disturbed. At this time, vegetation has been established on about 600 hectares and while work will be done during the operating years, it will not be until the end of mine life, about 2008, that the last half of the land can be reclaimed and revegetated.Once final reclamation has been accomplished, Highland Valley Copper will have completed its "" temporary use of the land"". In the meantime, about 1250people have had employment for about 50 000 man years, at wages ranking among the best in Canada.IntroductionTo provide and sustain our way of life, we need steel, copper, aluminum, zinc and many other minerals.To sustain mining, we must have adequate ore reserves and replacement of reserves as they are mined. Each year the search becomes more difficult as more of the Earth's surface is investigated and depo sits are mined. This calls for aggressive and sustained efforts.In British Columbia, past and present mining activities have disturbed less than one-tenth of one per cent of the land.With today’s technology, mining operations can be substantially reclaimed and thus complete the cycle of ""A Temporary Use of the Land""."

Jan 1, 1992

By Stephen Mcgibbon, Tim Twomey

"Abstract - The High-grade Zone (HGZ) was discovered 5000 ft (1520 m) below surface in the hangingwall of the existing orebody, 46 years after the Red Lake mine first went into production. The very rich ore of the HGZ is characterized by a remarkably abundant distribution of visible native gold. The location of this discovery challenged conventional wisdom at the time and its genesis has yet to be fully understood. Textural observations of ore within carbonate veins as well as crosscutting relationships suggest peak-metamorphic emplacement for at least some of the gold. Post-lamprophyre dike remobilization of gold is locally observed in the HGZ. Structure and dilatancy were the key elements for localizing ore at the Red Lake mine. Ore occurs where a fault trend intersected folded ultramafic volcanic rock that created a semi-permeable cap-rock to ore fluids ascending the "feeder" structure. This was enhanced by strong competency contrasts between the eastern ultramafic rocks, felsic volcanic rocks west of the HGZ, and the mafic volcanic host to ore - an exceptional environment for the development of protracted dilatant fluid pathways for gold deposition.Development in the HGZ began in February 2000 and reached commercial production on January 1, 2001 at a capital cost of US $53 million. December 2001 reserves are 1.9 million short tons (1.73 Mt) at an average cut and diluted grade of 2.05 ounces per ton gold (70.5 g/t) containing 3.8 million ounces of gold. The extremely rich ore presented a unique challenge in grade estimation for the Geology Department at the mine. The historic cutting factor was replaced by a statistical method as more data were collected from mining and mill reconciliation. The mine produced 503 000 ounces of gold in 2001. Exploration at the mine is targeting HGZ-type ore formation within basalts associated with the intersections of fluid pathways and folded ultramafic rocks, as well as other targets."

Jan 1, 2001

By Sean Dessureault

Technological Revolution ?Information age ? brought about by: ?Low-cost processing, storage, information sharing ?Shared & integrated data ? Increasingly more sensors & data sources From data collection to data use ??Data mining??analyzing the huge volumes of data ?Key example used in MBAs: ?Wal-mart, Google Explosion of data, trickle of information ?Paralysis of action Outline Trying to provoke- What drives innovation now? ?Challenges in mining Data Action Approach ?Examples from research & consulting upon request Conclusions ?Unaddressed challenges (Research Opportunities)

May 1, 2006

By K. M. Sarkar

"In many plant trial s(1,2) it has been proven that very small amounts (10 to 20 ppm) of uranium dissolved in mine water can be effectively recovered by the use of ion exchange resins and this uranium recovery has many advantages. In this paper an economic analysis at different levels of uranium contamination and at different market prices of uranium are described.For this study an operating mine-mill complex with a sulphuric acid leach circuit, followed by solvent extraction (SX) process, is considered, where contaminated mine water is available in excess of process requirements. lt is further assumed that the sulphuric acid eluant containing uranium would be mixed with the mill pregnant liquor stream that proceeds to the SX plant for final uranium recovery.Recovery by Ion ExchangeMine water, in this study, is defined as the water coming from the underground mine, or mine pits, and the run-off water from stockpiles, mine shops, crushing plant , washdown areas, etc.In nature, uranium mainly occurs in two stages; reduced (tetravalent) and oxidized (hexavalent) . The oxidation of sulphides present in the orebody often causes the presence of S04- and acidity in mine water, and this acidic water readily dissolves U+6 part of the depo sit. The react ion between hexavalent uranium, which is dissolved in water as U02+ 2 cation and S04 producing uranyl sulph ate as,"

Jan 1, 1984

By S. E. Malouf, W. Thorpe

"The Chibougamau Explorers property comprises 35 claims or 1,726 acres in La Dauversiere and Rohault Townships along the west shore of Norhart Lake. The property is serviced by a twelve-mile all-weather high-way leaving the main St. Felicien-Chibougamau highway at mileage 121. This road junction will be a railway siding on the C.N.R. St. Felicien-Chibougamau branch line in early 1957. The property lies 30 miles due south from the town of Chibougamau. The mine-sponsored Chibougamau Explorers town has a population of 250 with 28 residences and a well equipped recreation centre.The original showing was found by Rider Storn, a prospector financed by Val d'Or interests during the 1950 field season. This showing did not stand up to detailed prospecting but it did lead to the discovery of the main zone by A. Oakley during the following winter.The company was incorporated in I 950 under the presidency of E. Ayrhart. Financing following the initial drilling involved an increase of capitalization from 3 to 5 million shares and the advent of financing and management control by Anacon Lead Mines Limited.Exploration and development to Jan. I, 1956, has included 42,331 feet of surface diamond drilling; 31,363 feet of underground drilling; a 3-compartment shaft to 1,245 feet, with 8 levels at 150-foot intervals; and I 1,054 feet of drifts, crosscuts, and raises. Ore reserves to the 900-foot level, proven and partly developed, total 546,725 tons averaging 0·30 ounces gold and 0·93 per cent copper. A mill with capacity of 500 to 750 tons will be installed by January 1956.GeologyThe Chibougamau Explorers property lies along the belt of Keewatin volcanics striking through Bachelor Lake, Opawica Lake, Doda Lake, Coapatina, Norhart Lake, and Rohault Lake, where it is in close proximity to the paragneisses of the Grenville series. The boundary of the paragneisses, a gradational contact, lies within a mile of the Chibougamau Explorers shaft collar."

Jan 1, 1949

By H. M. Giegerich

"INTRODUCTIONThe Red Dog Project in Alaska is being developed by Cominco Alaska, a subsidiary of Corninco Ltd. of Canada, and the Nana Regional Corporation, one of the 12 native corporations created by the Alaska Native Claims Settlement Act of1971.The State of Alaska is also a very key part of the project through its financing of the transportation system for Red Dog. Red Dog will be the third, and largest, of Cominco's Arctic mining developments in the past thirteen years, after the Black Angel Mine in Greenland, which started up in 1973, and the Polaris Mine in the Canadian Arctic, which began production six years ago in 1982.Red Dog is one of the world's great mineral deposits, with a unique combination of large size, high-grade, and a waste-to- ore ratio less than I: I, which will make it the world's largest, and one of the lowest cost zinc producers, when at full production. The present mineral reserve is estimated to be 85 million tons , at a grade of 17.1010 zinc, 5% lead, and 2.4 ounces per ton of silver. Based on the current production forecast, this will give a mine life of almost 50 years, and the deposit is still open in two directions, although the structure is becoming thinner at depth. As well, there is a satellite zone about one mile south of the main deposit which could contain up to another 8 million tons of mineral at Red Dog grades or better. This is not presently included in the reserve due to potential processing difficulties.In relation to other zinc deposits, Red Dog is the second largest ever discovered, smaller than the original Broken Hill deposit in Australia, but larger than Cominco's own Sullivan Mine in British Columbia, which is number three. It is quite possible that, when the area is adequately explored, Red Dog will be number one."

Jan 1, 1989

"The Society for Mining, Metallurgy, and Exploration (SME) Inc. developed a guide of minimum standards for reporting exploration results, mineral resources, and mineral reserves for the purpose of informing the general public. The SME Guide has been adopted by the Society.History1. In 1988, at the request of members of the Society for Mining, Metallurgy, and Exploration (SME), Inc., the President of SME formed Working Party #79, Ore Reserve Definition, with the mission to develop guidelines for the public reporting of exploration results, resources, and reserves. A Subcommittee was appointed by the Working Party to draft these guidelines and submit recommendations to SME. The Subcommittee's recommendations were published by SME in the April 1991 issue of ""Mining Engineering"", and as a document entitled ""A Guide for Reporting Exploration Information, Resources, and Reserves"" (the SME Guide) in January 1992. Work continued on an ad-hoc basis until 1996, when Working Party #79 was renamed the SME Resources and Reserves Committee and became a standing committee.In 1994, the Council of Mining and Metallurgical Institutions (CMMI) started a concerted international effort to create a set of international definitions for reporting mineral resources and mineral reserves. An ad-hoc International Definitions Group was formed, with representatives from mining and metallurgical institutions from the United States (SME), Australia (AusIMM), Canada (CIM), the United Kingdom (IMM) and South Africa (SAIMM). A major breakthrough came on October 18, 1997 when the CMMI International Definitions Group met in Denver, Colorado and reached a provisional agreement (the Denver Accord) on definitions of mineral resources and mineral reserves. Concurrently, and since 1992, the United Nations Economic Commission for Europe (UN-ECE) was developing an international framework classification for mineral resources and mineral reserves. Starting in October 1998, joint meetings were held in Geneva between the CMMI International Definitions Group and the UN-ECE Task Force, resulting in agreement to incorporate the CMMI definitions into the UN framework classification."

Jan 1, 2003

By Stavros A. Argyropoulos, Radhakrishna Valiveti, Bernard Closset

"The use of microprocessors in metallurgy is currently increasing at a very fast rate. A large number of companies are offering systems ""off the shelf"" which are aimed at the data acquisition and process control market. There are two main drawbacks to these systems: first, they are usually quite expensive, and second, they are not completely compatible with the target metallurgical application. An alternative is to develop a microcomputer-based system "" in lab "".A dedicated microcomputer system has proved to be very useful in many metallurgical research applications(1,2)). However, in this system the analog input signals had to be transferred over long distances , and significant noise was introduced despite the use of shielded cables. In order to overcome this problem a network of low pass-filter s was designed and built. The usage of the abovementioned system brought the need to digitize the analog signals in-situ and transfer the digital signals, which are much less susceptible to noise over very long distances. This distinctly different design philosophy has become a reality with the evolution of microprocessor technology over the last few years. This design philosophy is utilized in this development."

Jan 1, 1984

By Charle Lawrence, Murray E. Blanchard

"A significant addition to Canada's commodity export transportation capabilities is being built by Ridley Terminals Inc. on Ridley Island in the Port of Prince Rupert on British Columbia's north coast.Site preparation began in early 1982. By the end of 1983 the terminal will be receiving coal from two major new mines being developed in B. C.'s massive $2.5 billion northeast coal development.The RTI terminal will have initial capacity to transfer 12 million tonnes of coal a year from railcars to storage and to ships. Capacity will be doubled to 24 million tonnes as market opportunities are developed.The challenge of building this $220-million facility in less than 24 months, the benefits Canada has received from the work the project is generating, and the long-term faith in Canada that this project represents, are all part of the excitement which surrounds the Ridley Terminal and northeast coal developments.RIDLEY TERMINALS INC. (RTI) is building a very significant addition to Canada's commodity export transportation capabilities. The facility, on Ridley Island at Prince Rupert, on the north coast of British Columbia, is a key link in British Columbia's northeast coal development which in itself is a massive undertaking involving investment of some $2.5 billion. The entire project is making a substantial contribution to Canada's economy at a time when such contributions are sorely needed.The development is creating employment, not only in British Columbia where its various parts are being created by mining companies, railways and others, but also across the country where suppliers are manufacturing a wide variety of good s and equipment for the development's participants.The RTI terminal is no exception. It is a critical cog in this mega project's large transportation system and its construction is contributing substantially to job creation and to other economic activity, in the Prince Rupert area and in many other parts of British Columbia and the rest of Canada."

Jan 1, 1983

By F. Cheuk, E. Krause, V. G. Papangelakis, G. A. Moldoveanu, S. Abendschein

Systematic studies have been conducted at the University of Toronto in order to evaluate lanthanide extraction from clay minerals from different geographical regions. It was found that rare earth elements (REE) are easily recovered into an aqueous solution via an ion exchange mechanism by leaching with electrolyte solutions containing monovalent cations under ambient conditions. In this study we assessed extraction levels of individual REEs as a function of initial clay composition and leaching conditions. It was found that, in spite of variations in clay origin, all clays consistently reached peak REE extraction levels with fast kinetics. However, terminal extractions were clay-specific. The feasibility of using seawater as a leaching solution and potential synergies with ammonium sulphate as a lixiviant was also investigated. Seawater was found to be inferior to using ammonium sulphate, and provided no observable synergy in leaching performance when used together. The aqueous phase trapped in leached clays was shown to contain significant amounts of REE, as demonstrated in clay washing tests. Techniques to improve the REE concentration in leachate through process variations were investigated. However, it was found that most techniques capable of increasing REE concentrations in the resultant leachate also resulted in reduced REE extraction.

Jan 1, 2014

By M. Korchynsky

"The key words which characterize vanadium are: unlimited availability, versatility of applications and price stability. The supply of vanadium is assured by diversified sources, distributed all over the globe. The inexhaustible raw materials base is complemented by a strong vanadium industry. Both the fully integrated vanadium producers and converters of vanadium oxide or vanadium-containing slags or residues guarantee an adequate supply, commensurate with the steady growing demand.The major share of the world's vanadium output is being consumed by the steel industry. As an additive to steel, the versatility of vanadium is particularly impressive. A few hundreds of one per cent of vanadium convert plain carbon steel into high-strength, low-alloy steel with more than double strength. On the other extreme, high-speed steels made via the powder metallurgy route show superior performance with vanadium additions as high as 6 or 8 percent. Vanadium is used as a cost-effective alloying addition in steels for high-temperature service, fully alloyed heat-treatable steels, new dual-phase steels for automotive components, rail steels, etc., to mention only a few applications. Vanadium is also an established essential addition for titanium alloys. The chemical industry is relying on vanadium compounds as important catalysts.In spite of a wide diversity of applications and continual growth in consumption, vanadium has exhibited, over the past several decades, a remarkable price stability, free of conjunctural fluctuations. Because of its availability and versatility, it will continue to be one of the key metallic elements for future technologies.Key Features of VanadiumIn attempting to single out the key features of the metallic element vanadium, three descriptive characteristics come to mind: availability, versatility and price stability."

Jan 1, 1982

By I. J. Burgess, B. C. Barlow

"The electrodissolution of nickel pellets with different controlled electrical variables was investigated in an effort to mitigate plating residue in Watts bath based electroplating cells. During galvanostatic dissolution at 0.4 A dm-2, the anode potential was seen to oscillate between passive and pitting potentials. In-situ microscopy and ex-situ characterization has shown that lacy-pit formation and large, partially perforated, pit covers form during the potential decay from pitting potentials. In general, covered pitting at low current density shows increased plating residue. Using potential pulses is one way to maintain greater control over surface pitting by creating a higher density of pit nuclei while at the same time controlling their growth. Pits generated from a series potential pulses were examined ex situ for a range of pulse times and stages of pit growth were identified. An alternative method of anode dissolution was devised using potential pulses and duty cycles that allowed average current densities comparable to industrial plating conditions to be achieved. By restricting the time at pitting potentials to 0.05 s, plating residue was reduced more than six-fold in comparison to an equivalent galvanostatic experiment run at a comparable current density.INTRODUCTIONIn typical galvanostatic (direct current) nickel electroplating cells employing soluble anodes, some amount of plating residue is produced which consists of metallic nickel and impurities that detach from the bulk in the form of small fines. Significant buildup of residue requires plating operations be halted and the anode assembly cleaned of residue before operation can resume. While variables in the refining process have been shown to affect plating residue, more precise control of electrochemical variables may provide an attractive route to mitigation of residue."

Jan 1, 2016

By G. S. Cole

By 2025, the U.S. automotive industry will have to average 54.5 mpg (4.3l/100km) Corporate Average Fuel Economy (CAFÉ). While new/improved powertrain technology (turbocharging, electrification, diesels, transmissions and stop/start) will be critical, it is estimated that 25-40% of the new CAFÉ standards will require significant mass reduction, and lightweight structural materials will be required. This presentation examines vehicle mass reduction based on new developments in manufacturing automotive structures and components using light metals (aluminum and magnesium), conventional heavy metals (iron and steel), polymers, and carbon-fiber reinforced polymer composites. Components that used to be sand cast or pressure die cast provided minimal fatigue strength and ductility. But greater mass reduction uses more light metals in structural applications. They require eliminating porosity and inclusions to improve ductility and fatigue strength. Improved casting processing, with vacuum die casting, counter pressure and squeeze casting, and new forging and extrusion applications are being developed for this purpose. New grades of ultra-high strength steels can be made thinner, and save over 1/3 the mass vs conventional mild steels. But more complex and expensive processing, such as hot stamping and in-mold quenching, is required. Most engine block structures have migrated from grey cast iron to aluminum over the past 40 years. But compacted graphite cast iron has higher strength at high combustion temperatures and pressures so that high powered engines can be smaller and even lighter than aluminum. Assembling a range of lightweight materials into vehicle structures requires specialized assembly techniques, including sophisticated structural adhesives that can mitigate vehicles’ unique corrosion environment. The presentation will conclude with discussing lightweighting strategies of Asian, American and, European marques and the materials, component designs and assembly techniques used to achieve 2025 CAFÉ.

Jan 1, 2016

By J. Etcheverry, E. Seguel, R. Díaz, F. Parada, R. Parra, E. Balladares

A thermodynamic and kinetic model is proposed to explain the formation of bornite, chalcopyrite and magnetite during partial roasting of enargite-containing copper concentrates. The proposed mechanism involves solid-solid-gas and solid-gas reactions between chalcocite, pyrrhotite, gaseous sulfur and oxygen. The formation of bornite could be explained by a two-step reaction: the first one involving the formation of chalcopyrite by a reaction between Cu2S, FeS and gaseous sulfur, followed by a second step in which the newly formed chalcopyrite reacts with additional chalcocite to form bornite. Although thermodynamically the direct formation of bornite is more favorable than that of chalcopyrite, the lower diffusion kinetics of bornite formation could explain the preferential formation of chalcopyrite. If the reaction occurs with stoichiometric chalcocite and pyrrhotite in the presence of gaseous sulfur to form chalcopyrite, no bornite is formed, while for the stoichiometric reaction between chalcopyrite and chalcocite in the absence of sulfur, only bornite is formed. For the formation of magnetite and chalcopyrite the mechanism could involve the partial reaction of chalcocite and pyrrhotite in the presence of oxygen. The proposed model is thermodynamically consistent with the experimental results obtained in laboratory and pilot plant. INTRODUCTION The processing of high-arsenic copper concentrates with over 0.7 wt.-% arsenic by conventional smelting-converting normally require an additional arsenic removal step to reduce arsenic content to levels below 0.2–0.3%. One of these high-arsenic copper concentrates is the one produced by the Ministro Hales Division (DMH) of CODELCO, which has the typical chemical composition shown in Table 1. Enargite (Cu3AsS4), chalcocite (Cu2S) and pyrite (FeS2) are the main mineralogical species present in these concentrates, with over 75 wt.-%, as shown in Table 2. Partial or “neutral” roasting of these concentrates under controlled temperature and partial oxygen pressure conditions at 923–993K (650–720ºC) can remove up to 95% of the arsenic as As2S3 (As4S6), which has a high vapor pressure under these conditions, leaving a calcine with low residual arsenic. In copper concentrates, arsenic is present generally as enargite and arsenopyrite. This compounds as well as others such as pyrite and covelite, decompose readily above 770 K (500ºC), releasing, in addition to gaseous arsenic trisulfide, gaseous sulfur which by oxidizing to SO2 generates most of the heat required by the process.

Jan 1, 2019

By E. Bratygin, G. Gazaleeva

"The article describes the analysis of methods and criteria of selectivity of optimal ore preparation schemes. Traditional criteria based on study of physical-mechanical properties of ores give the comparison of obtained figures with a reference standard or statistic data and the selection of the ore preparation scheme is made on a basis of a similar scheme from the existing production.Further on estimation is given to different criteria of the crushing selectivity, the new criterion is offered, the definition of which is done by results of an optical microscopy– the estimation of a valuable mineral release degree. The final estimation of the crushing process selectivity L? is performed by a calculation of a ratio of the valuable mineral free grains quantity in a desired size grade of a crushed material to the valuable mineral free grains quantity in a desired size grade of a raw product.Besides, optimality assessment of using the specific crushing unit is preliminary performed according to a maximum crushing degree of a material, however, the priority is given to the maximum selectivity criterion. The check of the proposed criterion was done when comparing the crushing of niobium bearing ores of the Vishnevogorskoye deposit in cone inertial and centrifugal impact crushers. Different operation modes of crushers were also checked. The comparison of the crushing selectivity criterion L? showed that the centrifugal impact crusher (CC) has the value of the selectivity criterion lower than the cone inertial crusher (CIC). For the crusher CC the criterion L? is 0.82 – 0.87 units, whereas for the crusher CIC – 1.43-1.755 units. The best crushing mode for the crusher CIC-300? is as follows: turning angle of debalance is 120°, peripheral speed of a cone rotation – 1,420 rpm, specific energy consumption – 6.99 kW?t/t.INTRODUCTIONIt has been shown that the most efficient techniques of mineral raw materials disintegration are selective crushing enabling to produce liberation of particles at maximum use of destruction techniques by borders of minerals cleavage. These days, such techniques are usually called special disintegration techniques (Jankovic & Valery, 2015), and they are used in 3–4 crushing stages. The selection of optimal crushing techniques is performed based on the following main parameters:- degrees of crushing, calculated based on granulometric features of raw and crushed products;- selectivity criterion defined according to useful mineral release and slime ability degree; and- traditional criteria (Gazaleeva et al., 2015) of choice based on study of physical-mechanicalproperties of ores gives the comparison of obtained figures with a reference standard or statistic data and the selection of the ore preparation scheme is made on a basis of a similar scheme from the existing production."

Jan 1, 2016

By R. D. Studer

"The Snow Lake massive sulphide deposits are hosted by Aphebian volcanic rocks of the Flin Flon - Snow Lake greenstone belt, which in this area were deformed and metamorphosed to the amphibolite facies during the Hudsonian orogeny. All the known deposits occur in felsic rocks a short distance below the contact with an overlying mafic rock unit.The Stall Lake copper deposit occurs close to the top of an explosive felsic volcanic sequence. Rocks stratigraphically underlying the deposit have been hydrothermally altered by the mineralizing fluids. The sulphides were probably deposited from submarine volcanic vent(s) on the flanks of a felsic dome. The ore has been tightly folded, flattened and elongated parallel to the northerly trending lineation of the surrounding rocks during the several periods of deformation. Strike lengths of the lenses range from 60 to 300 feet and plunge-to-strike ratios are as much as 15:1.Ore lenses I to 4 typically consist of massive coarse-grained pyrrhotite, chalcopyrite and pyrite. A stratigraphically higher lens differs in that it contains fine-grained pyrite and chalcopyrite, with an increase in sphalerite toward its hanging wall. The No.4 orebody has a distinct footwall alteration zone characterized by brecciation and abundant chlorite-staurolite- garnet schist, with minor kyanite, anthophyllite, cordierite and anhydrite, as well as sulphide minerals. Chemically, the alteration zone is distinguished from the unaltered felsic rocks by Na20 depletion and Mg-Fe enrichment"

Jan 1, 1982

By Q. Han

Irradiation of high energy ultrasonic vibration in metals and alloys generates oscillating strain and stress fields in solids, and introduces nonlinear effects such as cavitation, acoustic streaming, and radiation pressure in molten materials. These nonlinear effects can be utilized to assist conventional material processing processes. This article describes recent research at Oak Ridge National Labs (ORNL) and Purdue University on using high intensity ultrasonic vibrations for degassing molten aluminum, processing particulate reinforced metal matrix composites, refining metals and alloys during solidification process, welding, and producing bulk nanostructures in solid metals and alloys.

Jan 1, 2014

By J. G. Bensley, K. S. Detheridge

"Many plants use computers for process control and most have computerized Management Information Systems but few have been able to have these systems interact with one another. Developing this system interaction is not a one-step process but requires careful planning and implementation. This paper describes two projects that were implemented to provide the bridge between the process control and management information systems of Cominco Limited. Both projects include the replacement of essentially process control systems installed in the late 1960s. These original systems provided an enhanced level of control in the form of Direct Digital Control (via computer/manual analogue control stations) and a management reporting capability of process data. The experience gained from the use of these systems over a period of fifteen years formed a basis for the evaluation and planning for the new systems. The new systems were commissioned in 1985 and 1986 and operating and further developments leading to a totally integrated process information and control system are underway. INTRODUCTIONThe concept of hierarchical control involves a control structure consisting of a number of defined levels. Each level performs a defined function with information consolidated and combined as it moves up through the hierarchical structure. The commonly accepted structure of a hierarchical control system echoes the structure of the plant which is being controlled. Referring to Figure 1:Level 0 - Sensors and ActuatorsSensors and actuators, such as thermocouples and flow control valves, interface directly to the process and are generally connected directly to the controllers or multiplexers at Level I.Level 1 - Regulatory ControlThis level provides basic PID control (proportional/integral/ derivative) typically using microprocessor based controllers and programmable controllers for digital control of motors and machines. Systems at this levelare usually segregated by plant unit, e.g, crushing, flotation, drying. Control is concentrated on achieving optimum conditions for a particular feed rate."

Jan 1, 1989