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By John F. Gartner

"New terrain maps provide information on the ground conditions in northern Ontario. This information has a relevance to mineral exploration because it assists the user in determining ground conditions prior to entering the area. The prospector, geologist, geophysicist and geochemist can then plan for the optimum use of exploration techniques best suited for theseground conditions.These terrain maps are the result of the Northern Ontario Engineering Geology Terrain Study-a program carried out by five consultants under contract to the Ontario Geological Survey of the Ministry of Natural Resources. The area mapped is 370,000 km2 and more than 100 basic data maps at a1:100,000 scale will be published.An unique terrain legend was derived to facilitate the mapping and it allows the derivation of specific user information. Examples of some of these uses are described. Introduction""Where did all the boulders come from Charlie?"", asked the student, as the prospector and his young assistant clambered through the bush. "" Why son, they were brought down here by the glacier"", the prospector replied. ""But where is the glacier now Charlie? "", persisted the young man. ""Gone back up north for more boulders son!""An old story, but one that illustrates the importance of overburden to the prospector. The use of overburden as a prospecting technique is not new. In fact, the principles have been known in the western world for at least 235 years (Shilts 1976). More recently, Dreimanis's classic work on boulder tracing (1957) and Lee's work (1971) emphasize the role of glacial geology in prospecting. In addition, papers by Smee and Sinha (1979), Averill (1978), Bereton (1978), and Gleeson and Hornbrook (1974) all describe the importance of drift in mineral exploration programs. The discovery of the copper deposit in the northern Ontario township of Currie (Thompson, 1979) is attributed in part to till prospecting methods. So the significance of the overburden is firmly established, both in the literature and in the minds of today's prospectors, geologists, geophysicists and geochemists."

Jan 1, 1981

By B. Hohenstein, B. McBain, B. de Jong

"The automated fire assay system (Fast In-line Fire Assay or FIFA) has not found acceptance in the Au mining industry as the lower measurable limit of 0.20 ppm did not allow Au tailings to be measured with confidence. The development of arrested cupellation has overcome this hurdle which was a limiting factor in the FIFA 1 process. In the new automated fire assay process, automated sample preparation, fluxing, fusion and separation of a Pb button are essentially similar to the FIFA 1 process, albeit with some improvements. However, the game-changer is the development and incorporation of arrested cupellation into the automated system, now called FIFA 2. The purpose of arrested cupellation is to reduce the 50 g Pb button to a 5 g Pb button by partial cupellation in a specially developed arrested cupellation system thereby concentrating the Au in the Pb by a factor of 10 and in so doing moving them into higher concentration ranges in the mini-button where they can be read on the spark spectrometer. Results show that concentrations down to 0.02 ppm Au in geological materials can now be determined using arrested cupellation in the FIFA 2 process, an order of magnitude improvement over FIFA 1.INTRODUCTION Traditional fire assay for Au has remained virtually unchanged for 3000 years. It has survived for so long because it is accurate, has relatively low detection limits and is relatively inexpensive. However, it is labour intensive, has a long turn-around time (typically at least 7 hours), is environmentally unfriendly and exposes assay operators to potentially unsafe conditions (toxic fumes, toxic dust and extreme heat from furnaces). The NiS collection method is not as effective for the assay of Au as it is for the PGEs. A rapid, accurate, cost-effective method for the determination of Au and the Platinum Group Elements (PGEs) in geological materials would be a tremendous benefit to mining companies. Many of these objectives have been met by the FIFA 1 (Fast In-line Fire Assay) developed some 15 years ago in which automated methods have replaced the manual procedures which are part and parcel of conventional fire assay. However, concentrations below 0.2 ppm have been very difficult to achieve with sufficient reliability."

Jan 1, 2017

By D. S. Flett, A. V. Tolstov, M. A. Mulagaleeva, N. V. Gudkova, A. M. Zhizhaev, V. I. Kuzmin, Institute of Chemistry and Chemical Technology SB RAS, O. A. Logutenko, V. N. Kuzmina

The complex niobium-rare earth pyrochlore-monazite-crandallite ores of the Tomtor deposit, located in the Siberian Arctic, should be considered as a new type of rare metal materials. The major valuable components of the ore are niobium, rare earth elements, yttrium, and scandium; associated components are titanium, vanadium, aluminum, and phosphorus. Because of the irregular distribution of the rare earth metals and niobium according to grain-size, the extremely finely dispersed nature of the minerals and their close interpenetration to each other, ore processing by gravitation and flotation is not successful. The processes studied for the treatment of the Tomtor ores use direct alkaline-acid leaching to open the ore. A problem in the first stage of alkaline leaching is the high aluminum content, which decreases the activity of sodium hydroxide and alkaline-earth metals, which are bound to phosphorus. Ore processing using alkaline-nitrate and alkaline-chloride leaching was proposed and investigated. The first variant was used to obtain rare earth and scandium materials and a niobium-titanium concentrate, which can be a stock material for processors who use chlorination for the processing of ores and concentrates. The second variant is a complex advanced ore processing scheme with electrochemical regeneration of the waste chloride solutions obtaining sodium hydroxide, hydrochloric acid, and chloridizing agents. Moreover trisodium phosphate is used for purification of the waste mother liquors from metal cations. The complex salt, NaAlCl4, is proposed as the chloridizing agent for the decomposition of the niobium-titanium concentrate.

Jan 1, 2016

By R. Clarkson

"Free gold particles occur in many base metal and precious metal mines throughout the world. Due to the high density and malleability of gold, large circulating loads of free gold particles can build up over time in grinding circuits. This gold is often deposited in unintended traps throughout the mineral processing system.These unidentified free gold deposits represent a serious security risk as well as an inaccessible inventory of gold. Deposits of free gold particles often remain undetected by mine management until they are accidentally discovered while repairing mill equipment.Nuclear tracers have been used to determine the free gold recovery efficiency of gravity recovery equipment, drills, and sampling equipment (Clarkson, 1994, 1995; Walsh and Rao, 1986; Walsh and Kelly, 1992). In November, 1993, the author inspected the grinding circuit at La Mine Doyon in Rouyn-Noranda, Quebec and made recommendations to recover coarse gold and to eliminate gold traps from the circuit. In 1995, the author salted mineral processing circuits with radioactive gold particles. The gamma and X-ray radiation from gold’s nuclear isotope (Au198) were detected through steel, in pipes, and in moving equipment using scintillometers. The radiotracers proved to be a safe, rapid and accurate method of identifying gold traps and improving security.Nuclear TracersWhen particles of gold are placed in a nuclear reactor, some of the gold atoms (Au197) absorb another neutron in their nucleus to form gold’s radioactive isotope (Au198). In the process of radioactive decay, this isotope emits high energy gamma rays and X-rays which are easily detected (even through steel) with scintillometers.Radioactive gold (Au198) has a very short halflife of 2.7 days. At the relatively low activity levels used for tracing, the particles remain detectable with a small hand-held scintillometer for about 10 to 14 days. After 14 days the irradiated gold is close to background levels and within two months it is essentially non-radioactive. The radiation has no effect on the recovery characteristics of the gold particles. The gold radiotracers are very safe due to their very low level of radiation, short half-life, and their inherent physical and chemical stability. However, the use and possession of even mildly irradiated gold is strictly licensed and regulated."

Jan 1, 1997

By T. McCallum, B. Wellbrook, T. Ratnaweera

Leaching of copper (Cu) concentrates produces elevated concentrations of Cu and acid, which makes solvent extraction (SX) processing more challenging. Maintaining extraction targets can be more difficult with higher pregnant leach solution (PLS) grades, and variability of PLS Cu and acid can lead to increased chemical iron transfer. Diluting concentrate leach feeds with an existing heap leach inventory makes SX processing easier. However, considerations about how much to dilute and where to distribute the flow into the SX configuration must be carefully evaluated, given their impact on metallurgical performance. In this paper, characteristics of a concentrate leach feed are discussed, along with considerations for processing by SX. Also reviewed are pilot plant results of concentrate leach distribution into SX and plans for commercial testing. INTRODUCTION Hydrometallurgical processing of copper concentrates continues to gain interest from the industry. Treatment by smelting and electrorefining continues to dominate, accounting for ~80% of global copper production, but is faced with its own challenges (Li et al, 2017). The case for increased hydrometallurgical processing has been discussed as high grade ore deposits are diminishing, capital costs for smelting are high, and the environmental aspects present challenges for sustainable practice. The hydromet copper industry is also turning a corner as easily leachable copper oxide deposits are depleting, and excess SX-EW capacity exists in certain regions. The transition to hydrometallurgical processing of copper concentrates will take a bit of effort as leaching of copper sulfides is difficult and byproduct credits must be considered. Various POX leaching processes have been studied and proposed to the industry as viable practices. Of the many processes, commercial use has been practiced with the Mount Gordon Copper Process, total and partial pressure oxidation by Freeport-McMoRan at their Bagdad and Morenci, Arizona complexes, the Sepon Copper Process in Laos, and the bioleach BIOCOP™ process in Chile (Dreisinger, 2016).

Jan 1, 2019

By B. Dubreuil, J. -M. Lalancette, D. Lemieux, C. Chouinard

The extraction of gold and silver has been examined via the use of mixed halogens: chlorine and bromine. The reaction was performed in a brine of sodium chloride with a small amount of sodium bromide at 40-50°C, in an atmosphere of chlorine, at atmospheric pressure. The process takes advantage of the very high reactivity of bromine towards gold, while the higher oxidation capacity of chlorine leads to gold chloride as end product with recycling of bromine. Fast reaction rates are observed along with gold recovery at the level of 95%. Chlorine-consuming common elements are removed prior to chlorination.

Jan 1, 2011

By J. Font

The RAF or copper fire refining process at the Caletones smelter of CodelcoChile consists of several pyrorefining stages that successively lowers the levels of S, Fe, Pb, As, Sb, Te, Se and to some extent 0 in the copper melt, allowing the production of high quality fire-refined copper of 99.93 % purity (RAF copper). This chemical feature of the RAF copper is only achieved by quite long processing times, and a considerable consumption of fluxes and fuels in the RAF vessels. The main goal of this study was to improve the RAF process performance by thermodynamic considerations and industrial scale tests, i.e., an in situ approach for the process as featured by intensive sampling, characterization and subsequent modifications. Thus, both theoretical and industrial data were derived, and based on kinetic and thermodynamic evaluations, a higher operational standard was achieved for the RAF process. These new operational practices allowed enhancing the overall economic of the RAF process, by reducing the time and operational costs, and consequently increasing the availability of the vessels.

Jan 1, 2007

By Jun Deng

The aim of this paper is to study the scientificity and reliability of three coal gas indices used to predict coal fire disasters, namely Graham?s ratio, CO/CO2 ratio, Litton ratio and their different characteristics and service conditions. Data from a programmed temperature experiment were applied to check their veracity and accuracy. Each index performed well in detecting the level of a fire. We conclude that it is better to redefine the definition through experimentation before applying a given index. Integrated analysis of the results can provide reliable reference data for predicting spontaneous combustion of coal.

Aug 1, 2013

By C. O. Stee

IN the October, 1936, issue of the Canadian Mining Journal there was published a series of very comprehensive and exccellently illustrated papers by Mr. C. O. Stee and members of his staff dealing with Siscoe operations and ore-bodies. These were, in the order in which they appeared: Geology of Siscoe Gold Mine, by O. L. BACKMAN Diesel Power at Siscoe Gold Mines, Ltd., by C. O. STEE andE. A. BLOMQUIST Mining at Siscoe, by L. T. POSTLE and W. F. Engineering and Surveying, Siscoe Milling Practice, Research and Testing Laboratory, Assaying of Mill Tails and Solutions, BROWN(6) by P. A. TEEPLE (7) by L. E. DJINGHEUZTAN by L. RIVETT (8) by G. IRWIN (9) The Editor of the Canadian Mining Journal cordially assented to our suggestion that these papers be reviewed at the 1937 Annual General Meeting of the Institute, and the authors very kindly accepted our invitation to present such reviews . Of these courtesies, full acknowledgment is here accorded. To our readers, we commend the original papers in the Canadian Mining Journal. The summaries presented at the meeting follow. EDITOR. THE GEOGLY OF THE SISCOE MINE The Siscoe gold deposits lie in and near a stock of granodiorite, related to the Bourlamaque batholith, which has intruded highly folded Keewatin volcanic rocks .. The volcanic rocks lie to the north of a belt of Timiskaming sediments.

Jan 1, 1937

By H. Weissenbaeck, B. Nowak, M. Oesterreicher, R. Stastny

The producers of certain metals like nickel and cobalt increasingly face a shortage of easy-to-mine and easy-to-process ore bodies. Their focus is shifting towards alternative raw materials which in turn demand new, different extraction techniques. One potential route for processing a ferrous ore with a non-ferrous target metal is atmospheric leaching with hydrochloric acid followed by purification of the pregnant leach solution (PLS). For the separation of iron from the PLS, and, in turn, the extraction of the non-ferrous compounds, the following flow sheet is proposed. Pre-concentration of the PLS, oxidation of ferrous (if present) to ferric chloride, hydrolysis of ferric chloride leading to the precipitation of hematite and the evaporation of hydrochloric acid, followed by crystallization of non-hydrolysable metal chlorides by means of sparging hydrogen chloride into the solution. Hydrogen chloride required in the latter step is produced internally by super-azeotropic distillation of regenerated hydrochloric acid. The liquid filtrate from the crystallization step is recycled to hydrolysis. Depending on the specific composition of the PLS, the hematite produced contains only traces of other impurities, whereas the crystallized mix of non-hydrolysable metal chlorides – containing also the target metal in enriched form – contains ferric chloride only in an amount referring to the filter cake moisture. These crystals can then undergo further hydrometallurgical separation and extraction processes. As an example, this flow sheet is proposed for treating nickel laterite ores. Experiments related to the demonstration of crucial assumptions in the flow sheet are presented. Based on those experiments a mass and energy balance of the flow sheet was calculated and is presented here together with a table of the major consumables in order to provide a basis for an operating cost estimate and other process economics.

Jan 1, 2016

By Rita Aiello, Stan Mack, Peter Werth, Joseph McCarney, Jozef Stachulak

"Johnson Matthey has developed the first diesel particulate filter (DPF) for underground mining that controls particulate matter (PM) at the same time as maintaining emissions of NO2 at or below engine baseline levels. DPF technology is critical for controlling PM which is classified as a carcinogen, but passively regenerating systems rely on the use of oxidation catalysts that can potentially increase NO2 emissions. This paper reviews the development of low-NO2 PM control technology and the results from testing this technology underground on diesel mining equipment. KEYWORDS Decomposition catalyst, Diesel particulate filter (DPF), Diesel particulate matter, Mining Continuously Regenerating Trap (CRT®), NO2, SCR INTRODUCTION The introduction of diesel particulate filter (DPF) technology on heavy duty diesel (HDD) engines has been an important step towards addressing the clean air and health concerns for mining companies. Control of diesel particulate matter (PM) emitted from diesel engines is already being implemented for on- and off-road vehicles, and similar legislation is being prepared for mining equipment. In addition to PM, the diesel emission control strategies (DECS) also reduce carbon monoxide (CO) and hydrocarbons (HC). Some DECS control oxides of nitrogen, or NOx, which is composed of NO and NO2. Johnson Matthey has led the development of emission control technologies for diesel engines for almost 30 years. Over the last ten years alone JM has supplied over 3 million Continuously Regenerating Trap (CRT®) DPF systems for on-road vehicles, and over 200,000 systems for off-road vehicles. The patented CRT technology combines a diesel oxidation catalyst (DOC) with a DPF to effectively trap harmful PM from diesel exhaust, while removing CO and HC. The DOC converts part of the engine NOx to NO2, which reacts with the trapped soot to regenerate the filter. As engines become more fuel efficient, less waste heat enters the exhaust. This can be a disadvantage for after-treatment systems as it leads to lower catalyst operating temperatures. The CRT system regenerates passively, without addition of heat, at temperatures that are typical of diesel engine exhaust. JM recently launched the Mining CRT system which integrates CRT technology with NO2 abatement to reduce PM and tailpipe NO2 from underground diesel mining equipment. This is the first technology proven to control both PM and NO2 emissions for a cleaner, healthier working environment. The Mining CRT is also cost-effective compared to other technologies."

Jan 1, 2019

By G. Macfarlane

"In 1985, a crushing plant, located in the feed preparation area of Kidd Creek's copper smelter, was modified. The plant, which originally had treated only copper-bearing materials for the smeller, at a rate of 10 tonnes per hour, was expanded to 40 tonnes per hour capacity and modified to treat silica ores to meet the smelter’s flux requirement and also gold ores from the company's Hoyle Pond property. In the storage area adjacent to the crushing plant a 300 tonne per day gold mill was constructed.This paper outlines the construction and first year of operation of the crushing plant and gold mill with emphasis placed on the capital and operating advantages to be gained by utilizing an existing metallurgical infrastructure.IntroductionThe Kidd Creek Mines Ltd. copper-zinc-silver orebody is located 24 km north of Timmins, in Northern Ontario . Mining of this massive sulphide de posit commenced in 1966 and, in the ensuing years, a concentrator and zinc plant were constructed at the metallurgical complex, approximately 17 km by rail from the mine site . At this same site, in 1981, a copper smelter and refinery were commissioned. The smelter which utilizes the Mitsubishi smelting process for the continuous production of blister copper from copper concentrate, has been comprehensively described in previous papers.At the time of the smelter construction, a small (10 tonnes per hour) crushing plant was installed in the smelter's feed preparation area. This plant was used to treat the copper-bearing revert material produced by the smelter, and, apart from periods when slags and matte were produced through furnace drainage at the end of each operating campaign, it was generally under-utilized. This fact, together with the requirement to devise a more cost effective method of providing silica flux for the smelting operation, was the basic rationale for modifying and expanding and crushing plan t. At the same time, development at Kidd's Hoyle Pond orebody had progressed to such a stage that a gold mill of 300 tonnes per day was warranted."

Jan 1, 1988

By A. G. Lylie

Introduction At the Britannia Mining and Smelting Company's mill, the equivalent of 2,500 to 2,800 pounds of copper sulphate crystals per day is made from copper which is precipitated from the mine-water. This copper sulphate is used in the mill for the recovery of sphalerite by2 flotation. From 1932 until 1936 it was produced by exposing the precipitate to air for thirty days and then dissolving the oxidized copper with dilute sulphuric acid. In 1936, the flotation of sphalerite was discontinued and, when it was resumed in 1947, steps were taken to try to improve the former method. The present paper outlines the way in which this was done, and describes the plant and procedure by which copper sulphate is now being made, and by means of which an appreciable saving is being effected. Aboratory Tests The previous work had established that the precipitate, which consists mainly of metallic copper, must be oxidized before the copper would dissolve in dilute sulphuric acid. Various methods for oxidizing it were tried but in the early laboratory work the only suitable one found was to heat the precipitate to 600°C. and hold it at this temperature for two hours. When this was done, approximately 90 per cent of the copper became soluble in .acid. This percentage was considered satisfactory for practical purposes, but the cost of roasting was prohibitive because only a small amount of roasted precipitate was required each day.

Jan 1, 1951

By M. B. Kime, A. T. Kaniki

"Grinding tests were conducted on an oxidized copper-cobalt ore using a pear-shaped ball mill. Twelve mono-sized ore fractions were prepared and wet ground batchwise. The mill was run for 0.5 to 30 min intervals. The shortest interval provided data more closely related to the breakage function (B) because less secondary breakage was hypothesized. Some selection function (S) and B parameters were determined. Remaining parameters were estimated using a population balance model simulator. To evaluate the kinetics model, an unsized ore sample was also milled. Predicted and measured particle size distributions (PSDs) agreed well, suggesting that S and B parameters can be used for continuous operation mass balances.RÉSUMÉ Des essais de broyage ont été menés sur un minerai oxydé de cuivre-cobalt à l’aide d’un broyeur à boulets piriforme. Douze fractions de minerai de dimension unique ont été préparés et broyés en voie humide en lots. Le broyeur était mis en route à des intervalles de 0,5 à 30 minutes. L’intervalle le plus court fournissait des données plus étroitement liées à la fonction d’abattage (B) car d’après l’hypothèse avancée, le besoin d’abattage secondaire était moindre. Certains paramètres de la fonction de sélection (S) et de B ont été déterminés ; les paramètres restants ont été estimés à l’aide d’un simulateur de modèle d’équilibre de population. Pour évaluer le modèle de cinétique, un échantillon de minerai non calibré a également été broyé. Les compositions granulométriques (PSD, de l’anglais particle size distributions) prévues et mesurées correspondaient bien, ce qui laisse penser que l’on peut se servir des paramètres S et B dans le cadre d’équilibrages massiques en fonctionnement continu. INTRODUCTIONSize reduction of solids is a very energy intensive and highly inefficient process. It consumes approximately 5% of the electricity produced worldwide (Rhodes, 1998), and more than 50% of the total energy used in mineral processing plants (Walkiewicz, Lindroth, & Clark, 1996). An increase in grinding efficiency can therefore result in significant reductions in operating costs. This often amounts to determining the optimal design configurations for milling an ore sample in a laboratory mill under standard conditions. Prior to optimizing the milling stage, the requirements for downstream processing in terms of particle size distribution (PSD) need to be understood because low liberation and overgrinding will lead to future problems. Once this is done, it is also important to clearly understand the breakage properties of the ore. The kinetics of size reduction in tumbling mills are often determined using two probabilistic functions: selection and breakage (Austin & Luckie, 1972). Knowledge of the selection and breakage functions also enables the prediction of the PSD for a given ore sample."

Jan 1, 2017

By J. L. Huisman, G. Schouten

After pyrometallurgy and hydrometallurgy, bio(hydro)metallurgy is the latest development in the ongoing search for efficient and economic metal winning processes. In addition to bioleaching, other biotechnology-based applications are getting more and more accepted. In this paper a number of proven and commercial processes will be presented that can be applied for nickel and cobalt recovery and refining. These processes are based on the ability of biomass to convert the redox state of sulphur compounds under ambient conditions. They can be applied to recover sulphate from effluents or SOx from off gases and convert it to H2S or dissolved sulphide that can be reused in production or effluent treatment. Not only does this minimize the costs on resources but it also reduces waste production and improves the quality of discharges even to the point where reuse becomes feasible.

Jan 1, 2005

By K. C. Corin, Z. G. Song, J. G. Wiese

In the present investigation flotation was used as a diagnostic to understand the effects of changes to the media during the grinding stage. The observations from flotation for different media are discussed in terms of particle size distribution, water recovery, solid recovery and valuable mineral recovery. The chemical parameters; pH, redox potential (Eh) and dissolved oxygen (DO) levels were measured. A Base Metal Sulphide (BMS) ore was ground under media of different shapes and compositions to determine the effect of different rod/ball material on the flotation performance of the ore. For a given grind (D80 = 75 µm), media shape had no effect on flotation performance of a BMS ore. Different grinding media had significant effect on slurry chemical properties and flotation performance. Mild steel rods (RMMS) produced the highest solids recovery, nickel and pyrrhotite (Po) recovery, with the highest ethylenediaminetetraacetic acid (EDTA) extractable iron and the lowest DO level. Chrome steel balls and stainless steel rods produced the lowest metal recovery, EDTA extractable iron and the highest DO level. A complementary study was conducted to investigate the effect of using different grinding media compositions, viz, ceramic, forged steel, 15% chrome steel, stainless steel and a mixture of stainless steel and 15% chrome steel (50:50) balls were investigated using a Platinum Group Mineral (PGM), UG2 ore. Grinding products of five different media produced the same solids and water recovery, but the grades and recoveries of Platinum Group Elements (PGE) and chromite were different. Grinding products of ceramic media showed the best flotation performance, with the highest PGE recovery and the lowest Cr2O3 recovery. While grinding products of stainless steel balls (SS) produced the lowest PGE recovery and highest Cr2O3 grade and recovery in the concentrates.

Jan 1, 2016

By A. J. Williams

"IntroductionAN EXCELLENT paper entitled Potash Discoveries in Western Canada (l) was presented to the 1948 Annual Meeting of the C.l.M. by L. Heber Cole, of the Department of Mines and Resources, Ottawa. In the intervening three and a half years, the search for oil and gas in Saskatchewan has added considerably to the information available on the occurrence of potash. It is the purpose of this paper to summarize the additional data. For greater clarity, it may be useful, first, to recapitulate some of the highlights of Mr. Cole's paper.Underlying the western plains of Canada there is a large deposit of sodium chloride, believed to be of early Devonian age. Associated with the sodium chloride are certain potash salts, primarily 'sylvinite,' a mechanical mixture of sodium chloride (halite) and potassium chloride (sylvite) crystals. The potash salts, when present, are usually near the top of the salt formation, though in at least one well they were found near the central part of the deposit. Cole reported on some seven wells in Saskatchewan which had encountered appreciable amounts of potash; these were the Ogema, Radville, Davidson Nos. 1 and 2, Prairie Salt Nos. 1 and 2, and Verbata wells. Depth of potash from surface ranged from 7,653 feet in the Radville well to a minimum of 3,466 feet in the Verbata well. Such depths do not compare favourably with those at which the potash is found in mines in the United States, France, and Germany, where about 1,000 feet is the average. The greatest concentration of sylvite encountered was in the Verbata well, where a bed 11 feet thick carried the equivalent of 21.64 per cent K20."

Jan 1, 1952

By A. Khan, C. Ciriello, W. Oliveira

"The purpose of this paper is to demonstrate the value of Operational Readiness (OR) in the successful delivery of capital projects. OR can be captured using several technical and practical definitions:• To ensure that the capital project being delivered is capable of an effective start up, ramp-up as planned and a sustainable productive operation.• To function as intended when started, with the appropriate people able to run it.• To increase the value in delivering the product/service through established systems, processes and procedures, while simultaneously minimize risk to both the project and the business.Historically, mining and metallurgical capital projects concentrate efforts on cost and scheduling during the implementation and design phases. The completion and subsequent handover of the operational unit is the main objective.When reviewing the mining and metallurgical industry’s capital projects, it seems many poor results and errors in terms of project design and ramp-up are self-inflicted, with the project neglecting to account for key aspects of the future operational plant. Interestingly, if the problems for the future plant occur during project implementation, they can be prevented during the project phase. It is required to connect the operational knowledge with the project in order to ensure an effective start up and operation.The benefits of OR will be shown to be applicable not only to mining capital projects but also to sustaining and business transformation projects. The paper also includes industrial examples showing both proper and improper use of OR techniques.The paper will cover 3 main areas of Operational Readiness: the OR model, OR related risk elements (i.e., risks associated specifically with the improper execution of OR) and conclude with OR specific case studies."

Jan 1, 2016

By Lars A. Bergstrom

High-voltage direct -current transmission is a relatively new technology. The successful development and operation of AC/DC converters, capable of handling large power blocks, have made HVDC transmission generally accepted by utility engineer s and planners around the world. HVDC technology still has significant development potential and, as a result, it is expected that equipment costs will escalate at a substantially slower rate than those of conventional AC equipment. This development will also result in still more compact terminal stations. This paper reviews two modern HVDC installations. In Zaire in Africa. a 1700-km overhead DC line rated at 500 kv, will supply power to the copper mining district in the Shaba region. Another HVDC link connects Norway and Denmark through a submarine cable rated at 250 kv. This is the longest HVDC cable in the world, 127 km, and the water depth , maximum 530 m, is also much greater than for any previous similar cable. The reasons for selecting HVDC are discussed, and the design and layouts are presented.

Jan 1, 1978

By D. M. Maijer, S. L. Cockcroft, A. B. Phillion, P. Fan, C. Reilly, H. Khadivinassab

A combined experimental / numerical approach is proposed to investigate the bulk transfer of solute due to liquid metal feeding during shape casting of aluminum alloy A356 (Al-7Si-0.3Mg). A dumbbell-shaped experimental casting geometry has been developed, which promotes solute redistribution due to liquid metal feeding. The redistribution of solute in trial castings is evaluated based on the area fraction of eutectic phases. In the numerical model, silicon species segregation during solidification are calculated assuming the Scheil approximation, and are coupled with macro-scale solute transport due to Darcy flow in the mushy zone and feeding flow. The model has been implemented within the commercial CFD software, FLUENT, which simultaneously solves the thermal, fluid flow fields and species segregation on the macro-scale. The experimental and numerical results are compared and contrasted to examine the effects of liquid metal feeding in this casting.

Jan 1, 2014