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By M. S. Badollet, N. W. Edgerton

"A study of the physical properties of long grades of asbestos fibers imported into the United States during the past eight years has disclosed information that will contribute materially to effective selection and use of fibers for electrical products. The study embraced fiber lengths, volume resistivity under three different conditions, total iron by chemical analysis, magnetic rating, conductivity of an aqueous ex-tract and its sodium chloride equivalent.The fibers examined included chrysotiles from Rhodesia, British Columbia, and Barberton area; marlime from Bechuanaland and Province of Quebec; amosite and crocidolites from Africa and Australia; and anthophyllites from Mozambique and from Georgia in the United States. Volume resistivity values provide a relative basis for estimating the electrical performance of end products; magnetic rating -an estimate of the quantity of iron compounds present in excess of those in the asbestos structure; conductivity of an aqueous extract; and an estimate of the ionizable impurities in fibers.Tests of these factors yield in-formation, not heretofore generally known, which may serve as a guide in the evaluation of asbestos fibers for electrical products."

Jan 1, 1960

By N. Samman, S. N. Lau

"A series of new, grease-based, solvent free open gear lubricants were developed to meet the demanding service requirements of mining equipment. The use of these products has resulted in better performance under conditions of temperature extremes and in terms of longer component lives. They have gained widespread acceptance within the mining communities for such applications as the lubrication of mining shovels, draglines and ball mills.These products are WHMIS non-controlled and are environmentally acceptable. The benefits and advantages of using this type of product to lubricate mining equipment as well as the field evaluation and experience will be discussed."

Jan 1, 2002

By F. W. Gray

A GEOLOGICAL study seeking to determine, for economic purposes, the value of the Sydney coalfield as a source of coal supply. Limitations of the coalfield come under two main heads: (a) Areal extent of the undersea coalfield. (b) The distance from shore at which coal can be mined at a cost of production permitting its profitable sale. Conclusions reached are that the areal extent of seams below the Phalen seam is of. small economic importance, and that non-persistence of these seams in full thickness and quality in the undersea extension of the coalfield will put an end to profitable mining before any limitations connected with distance from the shore-line become operative. With respect to the Phalen seam, non-persistence or deterioration of the seam will become effective in the western part of the coalfield, and less certainly in the eastern part of the coalfield, before operation of limitations by distance from shore. In the central portion of the coalfield, the seam probably persists in commercially workable thickness and quality to beyond the limit of mining set by distance from the shore-line. With respect to the seams above the Phalen seam between the Mountain fault on the extreme western boundary of the coalfield and the assumed termination of the deposition area on the eastern extremity of the field near South Head of Morien, there appear to be only such limitations as arise from engineering approach, distance from shore, sufficiency of strata cover between the sea-floor and the upper coal seams, and quality of the coal (with certain reservations as to the continuity of the upper seams under Sydney harbour and in the Sydney Mines-Little Bras d'Or district). Some of these seams have fragmentary land outcroppings from which their persistence seaward is assumed, and there may be other and still higher seams in the strata column which are entirely submarine.

Jan 1, 1941

By S. P. Lowe

Introduction In the following pages a general description is presented of the concentrator and cyanide plant of the Hudson Bay Mining and Smelting Company, Limited, at Flin Flon, Manitoba, together with some account of the steps which have led to the adoption of the present practice. For an account of the preliminary test-work and pilot-mill operation, the reader is referred to a recent paper by R. E. Phelan on the History of Flin Flon Mine up to Construction (1). Additional notes may be found in a paper which the writer presented at the Annual Meeting of the Institute in 1930 (2). The first ore was crushed in the present plant on July 1st, 1930, and the first ball-mill was started one month later, on August 1st. Since that time, production has been continuous with the exception of one month lost during a strike in the summer of 1934. There have been no major changes in equipment or methods of treatment since the present plant was built, but many minor changes have contributed to the improvement in results obtained and to the increase in capacity to the large tonnage now being milled. The accompanying flow-sheets indicate the equipment used in the several plants, with the average life and repair cost. As originally built, the concentrator was to treat 3,000 tons per day, but the capacity has been increased to 4,400 tons. The methods adopted to make possible this increase in tonnage will be referred to below. It was the intention to produce two classes of ore: (1) a heavy sulphide, and (2) a disseminated ore. The mill was consequently divided into two sections, each adapted for most efficient treatment of one particular type of ore. However, it was soon found that it would be impossible to mine the two classes of ore separately, so it was decided to treat open-pit ore, which varies greatly in character, in the sulphide section, and underground ore, which is fairly constant, in the disseminated section. This segregation is still maintained.

Jan 1, 1935

By O. Peters, D. Lascelles, R. Caldwell

Ageing tests on a crushed Cu-porphyry ore were conducted to assess the impact of sample oxidation on flotation performance. The objective of the testwork was to simulate ageing of ore that would be blasted through block caving but not milled for possibly several months. Ageing was performed in specially designed columns, using site and deionised water to keep the samples moist over the entire ageing period. Samples from each ageing interval (0, 0.5, 1, 2, 4, and 8 months) were examined for physical and metallurgical changes resulting from the ageing process through chemical analyses, size analyses, and batch flotation tests.

Jan 1, 2009

By J. W. Meier, J. O. Edwards, R. C. Bell

"IntroductionTHE DIE CASTING industry .as we know it today is the direct result of the invention and development of die casting machines during the nineteenth century and of reliable alloys in the twentieth. The early machines were designed to cast low melting point metals such as lead .and tin, and their alloys.It was inevitable that, as these die castings were put into service, the demand should arise for stronger materials. Zinc alloys, often containing lead, tin, copper, and aluminum as major constituents, were relatively easy to cast and stronger than the lead and tin alloys. However, it became apparent after a number of years that these zinc alloys tended to become brittle, distort, and corrode, particularly if kept in warm, humid atmospheres. Thus, considerable quantities of zinc-base .alloys were in use before the trouble was realized and effective measures could .be taken to determine the cause of the instability.The deleterious effect of certain metallic impurities on the properties of zinc •die casting .alloys has now been known for about thirty years. Brauer .and Peirce, and, later, other research workers of the New Jersey Zinc Company such as Anderson and Werley, discovered the pronouned effect of lead, cadmium, and tin on the stability of zinc-alloys."

Jan 1, 1952

By Fred G. Hewett

The Cassiar orebody is located in a sill-like serpentinite body intrusive into the Devonian-Mississippian sedimentary rocks of northern British Columbia. Subsequent intrusion of the Cassiar batholith formed the McDame synclinorium and produced chrysotile asbestos. Present information indicates an orebody of approximately 16,277,000 tons amenable to open-pit mining, but continued diamond drilling will be needed to accurately define total tonnage and grade. A program has been developed at the mine to provide the required information on a daily basis, and work is continuing on more effective dollar-value prediction methods.

Jan 1, 1978

By Franz Simon

Conventional fine gold electrolytes for barrel applications working electrolytically actually permit significant precious metal savings by corresponding optimizations but the most gold is still deposited on areas of the components where it is not absolutely essential for the desired bonding and soldering applications, i.e. in high current density areas. Therefore an electrolyte working electrolessly has been developed which inevitably leads to a much more uniform thickness distribution since in an electroless process there are no areas favoured by metal deposition and current distribution. The new electrolyte will be presented and its performance will be compared with conventional electrolytes as regards thickness distribution. The potential gold savings will be discussed.

Oct 1, 2003

By Y. Nara, N. Aramaki, M. Maruyama

Evaluation of three dimensionally non-uniform strain distribution in rocks under various conditions such as in water or under freeze-thaw cycles is of significant importance to understand their complex deformations and fracturing mechanisms. For this purpose, we developed an image analysis method which can evaluate or “measure” the three dimensional (3-D) strain distribution in rocks. The proposed method utilizes the 3-D images of rock under initial and deformed configurations, which are obtained by some imaging techniques such as X-ray computed tomography (X-rayCT). In the proposed method, the obtained 3-D images are divided into multiple sub-regions of interest. For each sub-region, the strain is evaluated utilizing 3-D affine transform with unknown coefficients to be determined. In the first step, 3-D voxel level displacements at multiple representative points in each sub-region are computed by 3- D digital volume correlation technique between the comparison images and the initial-guess of the transform coefficients are obtained. In the second step, referring to the initial-guess of unknown transform coefficient, they were optimized in sub-voxel level by finding optimum digital volume correlation between the comparison images, which can evaluate the transform coefficients with higher precision. From the calculated transform coefficients, the strain was directly obtained through the spatial derivative of displacement based on affine transform. In this paper, along with the description of the proposed method, the evaluation of deformation in a lignite specimen due to immersion in water was presented as an application example. As the 3-D imaging technique, micro-focus X-rayCT was applied. The result showed that the induced dilatational strain field due to the initiation and extension of cracks in the specimen was clearly captured. Therefore, authors believe that the proposed method can be applicable to various problems in rock mechanics.

Jan 1, 2015

By T. H. Etsell, P. Kerr

Over the past 50 years, there have been a number of geological, mineralogical and metallurgical studies carried out on the Clear Hills ironstone deposits in northern Alberta, Canada. Due to the low grade and complex mineralogy, previous metallurgical studies have achieved limited success. After rejecting some of the more ‘conventional’ techniques for iron ore beneficiation, the authors chose to investigate the grain enlargement/iron segregation process for the beneficiation of the Clear Hills ironstone. The segregation reactions for iron have not been explored in as much detail as they have for copper and nickel. Iron segregation roasting involves the addition of a carbonaceous reductant and a chloride transport agent to an iron oxide ore, and heating the mixture to an appropriate temperature. The benefit of this process is that it allows ores in which the value minerals are intimately associated with gangue minerals to be processed in circumstances where conventional iron ore processing techniques are not suitable or capable of upgrading the material. As iron is one of the few elements that can be transported through this process, a clean high purity metallic concentrate can be achieved.Through the use of crucible testing followed by Davis tube magnetic separation, scanning electron microscopy, X-ray diffraction and atomic absorption spectroscopy analysis, characterization of the reaction products has been made with an improved understanding of the reaction mechanism.

Jan 1, 2015

By E. Onal, C. Craddock, A. Chapman, M. R. Endsley

ABSTRACT Mining equipment operators must interpret and respond to complex information delivered by technology-centric rather than user-centric systems. The ability to achieve high situation awareness (SA) in the face of this data overload is a key challenge to effective decision-making and information exploitation. Incidents attributed to human error that compromise safety and result in loss of revenue, or even life, are often the result of system designs that overload human cognitive capabilities. This paper defines SA as it relates to the operation of mining equipment and describes the design and preliminary evaluation of a new electric shovel operator user interfa

Jan 1, 2013

By C. H. Buck, A. J. Taylor

"In 2015 Vale’s Clarabelle Mill began the process change to enable a higher degree of Cu separation. The flowsheet modification was part of a complete divisional flowsheet change being implemented in Vale’s Sudbury Operations. This paper will centre on some of the Operational Readiness (OR) work, culminating in the commissioning of the circuit in March 2017. The emphasis will be on the implementation of an integrated test plan to prepare for the process flow change through the mill.BackgroundClarabelle Mill (CBM) began making a saleable Cu concentrate in 2006 with the installation of the Cu separation circuit. Typical separation rate was 35-40% of Cu in feed reporting to Cu concentrate based on a target Ni concentrate Cu:Ni target of 0.7-0.8. The remainder of the recovered Cu (55-60%) reported to Ni concentrate and was smelted through the Copper Cliff Smelter.In 2013 a capital project, Surface Facility Upgrade (SFU), was implemented to focus on matching the surface plants capacities with the future mine plan to maximize revenues. This was to be achieved by redistributing the metal flow, specifically Cu, through CBM to increase metal unit content through the Smelter. The amount of redistribution of Cu was determined to be based on maintaining a stable Cu to Ni ratio (Cu:Ni) in the Ni concentrate.The change in Cu:Ni ratio in the Ni concentrate would affect the Sudbury divisional flowsheet, and required process changes across the all of the surface plants. The detail that surrounds the flowsheet changes as a whole will not be discussed, but the outcome of the decisions plays a large role in the operational readiness interactions between the mill, its suppliers and its downstream customers."

Jan 1, 2018

By M. F. Almeida

"Due to the randomness of all factors influencing the sintering operation, a two-stepped procedure is proposed to find the best way of using stocked fines at a plant producing Fe-Mn alloys for the steelmaking industry. The approach is based on the following: (1) predict the result of the sintering operation by establishing the best multilinear regression model using some of the characteristics of the loaded material; and (2) find the best solution under a minimizing cost criteria by solving a linear optimization problem using the regression equation plus constraints on the feed and product. IntroductionSome tests carried out using 20% to 30% of sinter in the material loaded into a 60 000 KVA Tysland-Hole electric furnace producing Fe-Mn alloys for the steelmaking industry indicated: (1) a meaningful decrease in the off-gas temperature and, consequently, a better energy use due to the material higher porosity; (2) more uniform heat distribution as a consequence of the electrode reaction zone enlargement; (3) an improved furnace control resulting in a smoother operation; and (4) a decrease in gas production facilitating the off-gas treatment. For some years, this plant used only the coarse fraction of the Mn ores, thus stocking all the received and own-generated fine particles. In view of the mentioned results, a strategy for increasing the use of stocked fines was formulated, including a step where it was necessary to decide which components and respective quantities should be used in the blends to be sintered (Almeida, 1984).It is well known that several factors affect productivity and energy consumption in sinter production, also influencing the product quality. Raw materials characteristics, namely chemical and size composition, affect permeability to gases and may or may not allow a deeper bed. In general, finer ores decrease permeability, increasing electricity consumption by fans, but due to their higher specific surface area, react more completely with other components in the mixture. For coke granulometry, a compromise must be obtained in order not to burn it too quickly nor to widen the flame front, therefore decreasing productivity. Decreasing coke in the blend also acts in sinter bonding, decreasing its consistency and increasing crushing and return fines. Moisture addition also influences components mixing, pre-agglomeration, bed permeability and, consequently, sintering productivity. Therefore, optimum conditions must be established for both a given sintering plant and the components in the feed (Dawson, 1993)."

Jan 1, 1998

By A. Motamedi

Indoor localization has gained importance as it has the potential to improve various processes related to the lifecycle management of facilities and to deliver personalized and location-based services. Radio Frequency Identification (RFID) based systems, on the other hand, have been widely used in different applications in construction and maintenance. This paper investigates the usage of RFID technology for indoor localization of RFID equipped movable assets during the operation phase of facilities. The location-related data on RFID tags attached to fixed assets are extracted from a Building Information Model (BIM) and can provide context-aware information inside the building which can improve Facilities Management (FM) processes. The paper proposes a new approach to use received signals from available reference tags in the building attached to fixed assets to locate movable assets. The approach uses signal pattern matching and clustering algorithms for localization. As a result, a user equipped with an RFID reader is able to estimate the location of target assets, without having access to any Real- Time Location System (RTLS) infrastructure. A case study is performed to demonstrate the feasibility of proposed methods.

Aug 1, 2013

By N Robb

This paper gives an account of the laboratory testing, plant testing and final inclusion of the two-stage sulphuric acid leaching process in the Milliken mill. Operational results for September, 1962, are presented, showing a uranium extraction of 95.5 per cent, with a saving of some 16 lbs. of 100 per cent H~S04 and some 9 lbs. of lime per ton milled. Methods for effecting further improvements in the process are indicated. HISTORY P RIOR to the incorporation of two-stage leaching, the process for the treatment of uranium ores at Milliken consisted of a single-stage sulphuric acid leach, followed by a solution recovery step involving washing in thickeners and two-stage filtration. The thickener overflow solution was subsequently concentrated and purified by ion exchange, and the uranium was recovered, by two-stage precipitation, as ammonium diuranate. Figure I illustrates this flowsheet. For satisfactory extraction of uranium from the. Milliken ore, a high residual acidity, of the order of 40 grams per litre of free acid in the discharge solution, must be

Jan 1, 1963

By R. L. Stanton

"The present contribution is complementary with a preceding one on the field association of the conform-able ""pyritic"" deposits. It considers the more important features of their mineralogical constitution and their microtextures, re-examines the present interpretations of these, and of-fer-some alternative explanations. The term ""pyritic"" for these de-posits is m many cases a misnomer, as two quite distinct ore types are inuolve. One is a banded pyritic sphalerite-galena-chalcopyrite ore (for which the term '•pyritic"" is in-deed quite suitable), while the other is non-banded and is composed essentially of pyrrhotite and chalcopyrite. In addition to these constitutional differences, each is distinctive in general appearance and texture. The occurrence of two such consistent but clearly distinguishable ore types is attributed -rather than to difference in source material and pressure-temperature conditions of deposition -to the contribution of similar source material to dissimilarly oxygenated environments of sedimentation. Textures in the banded ores generally thought to be indicative of replacement or of high-temperature exsolution are explained by slow, law-temperature segregation in situ during compaction, folding, and regional metamorphism."

Jan 1, 1960

By D. Pacey

"This paper reviews the installation, start-up, and operation of a comprehensive monitoring and targeting management technique in which all plant utilities (i.e., electricity, natural gas, compressed air, and water) are managed as controllable resources in the same way that raw materials, mined ore, personnel and capital are managed.The essential elements of monitoring and targeting (M&T) include:•gathering in a systematic, disciplined way the utility information by energy account centres;•closely monitoring the utilities used in each centre and comparing them with production on a common time base (e.g., kWh/ton per day);•bench marking and target setting to pro-vide attainable energy reduction goals which can be further refined as they are achieved; and•establishing an implementation plant that may provide efficiency enhancing benefits to various operating areas within the plant.The M&T system will reduce utility consumption per unit of production on a continuing basis.This would translate into sustained operating cost and waste. M&T will also provide better information for assessing the plant operation and progressively implementing further enhancements."

Jan 1, 1997

By H. Wotruba, L. von Ketelhodt, M. Kowalzcyk, M. Robben

ABSTRACT Decreasing reserves, water shortages, increasing energy costs, and environmental and social constraints are challenges to the gold mining industry that must be met with innovative machines and methods. This paper introduces the principles of sensor-based sorting and installations that demonstrate the technical and financial viability of the method. The scenarios discussed highlight the potential and advantages of this dry processing technology that requires little infrastructure. Case studies are presented for different ore types using optical- and X-ray transmission–based sorting. Current research is discussed in terms of the potential of near-infrared spectroscopy and X-ray fluorescence sorting for gold applications.

Jan 1, 2013

By J Zhou

Based on the mineralogical characteristics and mineral processing techniques required, gold ores can be classified into 12 types, including gold placers, quartz vein-lode ores, oxidized ores, silver-rich ores, iron oxide copper gold ores, porphyry copper gold ores, iron sulphide ores, arsenic sulphide ores, antimony sulphide ores, bismuth sulphide ores, telluride ores and carbonaceous sulphide ores. The bulk mineralogy and gold deportment of each ore type is different and may have a significant impact on ore processing and metal extraction. This paper summarizes the bulk mineralogy and gold deportment in some major types of gold ores and discusses the potential impact of gold deportment on gold metallurgy.

Jan 1, 2011

By H. Huang, H. M. Chen, W. B. Xie

Cu-0.8Cr-0.1Zr alloy were prepared by atmospheric melting. the microstructure and properties of the CuCrZr alloy after first cold rolled, solid solution, second cold rolled and aging treatment were analyzed by using optical microscope, electrical conductivity analysis and Vickers hardness tester. The results show that with the increase of the first cold rolled deformation, the grain breakage becomes more serious, and the cold hardening becomes more obvious and the hardness increases. The conductivity and peak hardness of the first cold rolled (reduction of 30% and 60%) alloys after solution, secondary cold rolled and aging treatment reaches 81 %IACS and 187 HV, respectively. However, the conductivity in the CuCrZr alloy with a higher rolling degree (reduction of 90%) after solution, secondary cold rolling and aging treatment is significantly higher, and the conductivity and peak hardness is 85.8 %IACS and 178 HV, respectively. INTRODUCTION CuCrZr alloy has been widely used in domestic industry for its excellent comprehensive properties such as high strength and high conductivity, especially in the contact wire and lead frame of high-speed railway (Sun, Tao, & Lu, 2015; Mishnev, Shakhova, Belyakov, & Kaibyshev, 2015; Zhang et al., 2016; Fu et al., 2017). In recent years, a lot of research has been done on how to improve the strength and conductivity of CuCrZr alloy. However, the high strength and high conductivity of copper alloys are contradictory characteristics. On the one hand, the addition of alloying elements is conducive to solution strengthening and aging strengthening; on the other hand, too much alloying elements in copper alloys cause defects in the lattice of copper matrix, resulting in a serious decline in the conductivity of copper alloys (Martienssen & Walirmont, 2005). How to obtain high strength and high conductivity at the same time is the main problem. At present, the main research methods are adding microalloying elements, thermomechanical treatment and severe plastic deformation to study the electrical conductivity and mechanical properties of CuCrZr alloys. For example, Xie et al. (2011) added trace Ag to the Cu-0.26 wt%Cr-0.08 wt%Zr alloy, and the size of precipitated phase Cr and Cu4Zr became smaller and the mechanical properties of the alloy were improved. Su, Dong, Liu, Li, & Kang (2004) found that the addition of trace Mg in CuCrZr alloy inhibits the growth of precipitated phase and reduces the internal stress around the precipitated phase. At the same time, the size of precipitated phase becomes smaller and the peak aging strength of the alloy is improved. Pang et al. (2013) found that adding trace Ni and Si to the CuCrZr alloy could improve the peak hardness, softening resistance and precipitation morphology of the alloy. Experiments shows that the grain size was significantly refined by equal channel angular extrusion combined with aging treatment, while the strength of the alloy was increased, and the electrical conductivity of the alloy did not decrease (Vinogradov, Patlan, Suzuki, Kitagawa, & Kopylov, 2002; Saray, 2016); Kermajani, Raygan, Hanayi, & Ghaffari (2013) showed that the strength of CuCrZr alloy can be improved by rolling at 500 °C. After 150 minutes of aging treatment, the strength and conductivity of the material increased to 431 MPa and 81 %IACS, respectively. Takata, Ohtake, Kita, Kitagawa, and Tsuji (2009) noted that the strain hardening, uniform elongation and tensile strength of the nano-precipitates produced by the mechanical heat treatment process can be notable enhanced. The mechanical and electrical properties of CuCrZr alloy can be improved by combining large plastic deformation with aging treatment in the test process (Gao, Huttunen-Saarivirta, Tiainen, & Hemmila, 2003; Huang et al., 2003; Xia et al., 2012; Zel’dovich et al., 2014).

Jan 1, 2019