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By H. A. Pearse

The history of the flotation process, as applied to the practical field of ore dressing, dates back somewhat less than twenty years; yet this fact may be overlooked in view of the present universal dependence on this process in the concentration of almost all classes of ore. It is therefore interesting to recall that Britannia was the scene of some of the earliest experiments with flotation on a commercial scale. In 1911, sixteen years ago, an Elmore vacuum machine was operated for several months with encouraging results. In 1913, some time before flotation was very generally adopted elsewhere, a Minerals Separation plant, capable of treating 600 tons daily, was operating successfully at Britannia. Considering how little was known of the theory and practice of flotation at that time, the recovery was remarkably good, but it was not until the present mill was completed in 1923 that any attempt was made to raise the concentrate grade by differential flotation, or, in other words, to float the chalcopyrite while rejecting the then worthless pyrite with the tailings. The first ore passed through the present concentrator in March, 1923. As originally designed, the rated capacity was for 2,000-2,500 tons, but this has been increased year by year, until at the present time 4,000 tons daily can be treated economically. During the first few months of operation the concentrate grade averaged only 10-11 per cent Cu, but by the end of 1923 this had been raised to over 20 per cent, due to the elimination of the pyrite by differential flotation. In 1923 the tailings averaged approximately 0.25 per cent Cu, but also in the matter of recovery a considerable improvement has been effected, for during the year 1926 an average tailing of 0.15 per cent Cu was maintained.

Jan 1, 1927

By Mehmet Guney

This article is based on a detailed heat investigation conducted at the Rokana Division of Nchanga Consolidated Copper Mines Limited while both authors were employed in Zambia. Mindola Mine is one of the three underground mines comprising the Rokana Division on the Copperbelt of Zambia, producing about 270,000 tons of ore per month at 1.9% Cu and 0.14% Co. The total volume of air being circulated by means of five primary fan installations slightly exceeds 1,000 m3/sec at standard density. Sectional bulk cooling is practised where air cooling coils are installed at primary splits some considerable distance from the stoping operations. Total capacity of the refrigeration complex is 10,500 kw (3,500 R. tons), of which about 7,000 kw is available as effective cooling power after losses, but the heat removed from the coifs is about 3,500 kw with 61% over-all plant performance. An extension program is planned for a further five production levels with the re-deepening of a sub-vertical shaft. Thermal heat will become a major problem at increased depth associated with higher rock temperature, higher thermal conductivity of the rock groups encountered and fissure water flowing into working areas through the strata with increased rock temperature. This paper describes the ventilation and refrigeration practices in Mindola Mine, with special reference to future thermal heat problems. These are discussed with a view to mining at depth.

Jan 1, 1979

By J. A. Brusset

THE Greenhill mine of West Canadian Collieries, Limited, is situated at Blairmore, Alberta, and produces 2,500 tons per day of bituminous coal. On Monday, October 25th, 1943, smoke was discovered by a party of firebosses on their regular weekly inspection of air-ways. Probably the fire had been smouldering for several days but, as it had started on the outcrop at the top of an old raise filled with dirt, only a small quantity of smoke could filter through, and the plume of mist that crowns the fan at that season had prevented the fan-man from noticing it. This raise is only about 200 feet from the fan, and is 70 feet long between the fan-drift and the outcrop. It was impossible to prove the origin of the fire, as it had probably started several days before it was discovered, but it is possible that a careless smoker may have thrown a match into the opening at the outcrop, and that the old, dry timber had caught fire. The airways are in No. 2 seam, a bituminous seam 18 to 25 feet thick surmounted by shales and sandstones. Only 45 feet vertically above it is No. 1 seam, 12 feet thick, overlain by a strong conglomerate. In that vicinity, No. 1 seam had been worked out about ten years ago and the strata between the two seams are undoubtedly fissured. The pitch of both seams is 43 degrees.

Jan 1, 1945

By J. S. Edwards

The ISASMELT? process is recognized worldwide as a modem, flexible, environmentally-friendly and low capital cost smelting technology. Due to the inherent simplicity, and the advanced process control that has been developed, personnel become competent within weeks of being introduced to the ISASMELT? technology. This compares with the years required to become proficient with alternative technologies. Copper smelters in Australia, USA, India, China, Peru and Zambia have installed ISASMELT? technology under licence from Xstrata Technology. In the secondary copper business, plants in Belgium and Germany are processing copper and/or lead materials in ISASMELT? furnaces in a two stage process. In a single furnace smelting is followed by converting. Both plants have exceeded design capacities and are continuously improving their performance. The next evolutionary step for the technology is the implementation of the continuous copper converting process on a commercial scale. The present work describes the design status of the continuous converting process - ISACONVERT?.

Jan 1, 2007

By O. Hall

STOPING at Noranda" is a sequel to "Mining at Noranda". "Mining at Noranda", presented in 1937 (1), sketches Noranda's history, metallurgical problems, exploration, mining methods, mining details, pillar extraction, and costs. "Stoping at Noranda" deals in greater detail with our stoping, the use of sub-level drifts instead of benches, and the drilling out of the stopes with jointed rock drill steel and diamond drills. Sun-LEVEL DRIFT STOPING: Sub-level drift stoping is almost universal throughout the mine and is the standard sroping method in both sulphide ore and rhyolite flux ore. The features that have led to the adoption of this standard are: (1) Continuous symmetrical drilling in sub-level drifts with no delay for blasting. (2) Large-tonnage blasts Saturday night after the drillers have left. (3) Comparative freedom from gas and smoke during the working days. ( 4) The daily safety achieved by having all stope drilling done in drifts. (5) The safety and security achieved by drilling out stopes, floors, and pillars before there is any weighting or cracking.

Jan 1, 1939

The JKRBT (JK Rotary Breakage Tester) is a newly developed impact breakage testing device for rapid ore breakage characterisation, and has recently been commercialised after a three year comprehensive validation study, involving five major mining companies and six industrialised JKRBT units deployed worldwide. Comparisons of breakage mechanisms and characterisation data between the JKRBT and the Drop Weight Tester (DWT) indicate that, despite the differences in the breakage modes, the JKRBT can provide statistically similar A*b parameters, by using a data reduction procedure which takes into account the difference in the number of contact points, strain rate and potential for secondary breakage. Feedback from the validation sponsors has indicated higher productivity and better repeatability of the JKRBT compared with the DWT. This better precision, combined with the JKRBT?s wider particle size capability and wider specific energy range, provide a more powerful tool, ideally suited to rapid mapping of ore hardness in geometallurgical and comminution applications.

Jan 1, 2012

By S. N. Dixon

"Maximizing the value of each tonne of processed ore is the goal for all operations. Cyanidation processing of gold-copper ores has been challenging since its first use in 1889. The current practice treats a bleed or the total flow of mill solution to recover copper as copper sulfide (by sulfidization, acidification, recycling, and thickening), or to recover the cyanide (by acidification-volatilization neutralization). The process presented uses the adsorption of copper cyanide by carbon and the selective elution of copper from carbon to concentrate copper into a smaller stream. Copper contained in the smaller stream is precipitated as copper cyanide.RÉSUMÉ Toutes les exploitations ont pour objectif commun d’optimiser la valeur de chaque tonne de minerai traité. Depuis sa première utilisation en 1889, la méthode de traitement par cyanuration des minerais aurifère et cuprifère s’est révélée complexe. La pratique actuelle traite la saignée ou le débit total d’une solution de traitement du concentrateur pour récupérer le cuivre sous la forme de sulfure de cuivre (par sulfuration, acidification, recyclage et épaississement), ou pour récupérer le cyanure (par acidification, volatilisation et neutralisation). Le procédé présenté dans cet article utilise l’adsorption sur charbon actif de la solution de cyanure de cuivre et l’élution sélective du cuivre depuis le charbon pour concentrer le cuivre en un plus petit jet. Le cuivre contenu dans ce plus petit jet est précipité sous forme de cyanure de cuivre.INTRODUCTIONProcessing gold-copper ores by cyanidation has been a cost-control challenge since the cyanidation process was first used in 1889. Copper cyanide is stable only in the cuprous state, not the cupric. This factor results in the oxidation of a mole of cyanide per mole of nonchalcocite copper extracted. Each mole of copper extracted forms a cyanide complex with a minimum of 3 mol of cyanide. This cyanide-to-copper mole ratio is required to dissolve gold. The oxidation of cyanide and copper complexation with cyanide results in high cyanide consumption for copper-gold ores, which is a significant operating cost.One challenge in processing gold-copper ore is the cost of cyanide related to the extraction of copper. Processing 10,000 t/d of ore containing 1,000 mg/kg copper and 10% copper extraction yields 1,000 kg/d of copper. Currently, processes to remove copper from cyanide leach solution treat either the total flow of the barren or a bleed of the barren. The two processes used for copper-gold ores are sulfidization, acidification, recycling, and thickening (SART), which produces a copper sulfide product for sale; and acidification- volatilization-neutralization (AVR), which recovers the cyanide from a gas and produces a low–cyanide content solution. This low–cyanide content solution can be recycled to the process or might require additional treatment before being disposed from the operation."

Jan 1, 2017

By Vladislava A. Ignatkina, Victor D. Samyguin

"Within the limits of two-phase approach, considering mass transfer with pulp and air streams was shown that each bubble appears to be an elementary carrier, transporting particles from the collection zone into the froth. The kinetics of flotation was described by the exponential equation in which first order flotation speed constant has to be replaced with two-phased coefficient of a mass transfer. Criteria of selectivity of two ore fractions separation, based on determination of optimum time at which maximum difference between extractions and components content in separated fractions were offered. An interrelation between optimum time of pulp residence in a flowing chamber of a flotation machine, time of bubbles mineralization and an optimum airflow has been ascertained. Cumulative criterion of mass transfer efficiency of flotation process has been ascertained to be a form of the spectrum and its position on axis of three-phase coefficient of a mass transfer.INTRODUCTIONRegularities of a mass transfer of three bearing streams: pulp stream, air stream and froth stream underlie theory of mineral complexes flotation (Samygin, Filippov, & Shekhirev, 2003)However, only description of mass transfer in pulp stream by means of kinetic equations that were simple and convenient for practical use, has gained a full distribution (Tykhonov, 2009;Rubinstein&Filippov, 1980; Saleh, 2010).Within the limits of a single-phase approach, the role of gas stream in increase of speed and selectivity of flotation, was associated with an improvement of hydrodynamic mode. An influence of particles and bubbles sizes (Rubinstein&Filippov, 1980; Rubinstein&Samygin, 1998, Samygin et al., 2003; Dai, Fornasiero,& Ralston, 2000), of pulpflow and airflow (Finch& Dobby, 1990) and turbulent energy intensity (Shubert, 1979; Massinaei, 2007) on the flotation process has been studied. It was stated that flotation selectivity is increasing by means of gradual airflow increase from first to final cameras of the impeller flotation machine (Aslan&Boz,2010; Finch, 2011) and by means of using a multizone flotation machine (Samyguin, Filippov, Matinin, Lekhatinov, &Tertyshnikov, 2013)."

Jan 1, 2016

By G. S. Hume

FOR MANY YEARS Canada lived in the hope of attaining a substantial production of petroleum and natural gas that, to geologists familiar with the sedimentary basins of this country, seemed an entirely reasonable expectation. There have been surges of exploration activity stimulated by oil and gas discoveries and development such as occurred in Turner Valley. However, it was not until the Leduc field in Alberta was found in 1947, and the significance of that discovery was realized, that the search became really intensive and continuons. Expansion now has become a matter-of-fact attitude based on results which would have been considered impossible of achievement a few years ago.

Jan 1, 1957

?Introduction to the Delphi Group ?Why is carbon important to your organization ?Key elements of a carbon management strategy ?Inventory ?Risk & opportunity scan ?Mitigation options and financial mechanisms ?Identify targets and develop policy ?Communication and improvement ?Manage for success

May 1, 2009

By Haofeng Xie, Lijun Peng, Xujun Mi, Xue Feng, Xiangqian Yin, Zhen Yang, Guojie Huang

The Cu/Al composite wires have been widely used in cable industry. Especially in the development of aerospace, the light weight character of wires is particularly important. The wires are fabricated by a drawing process and heat treatment. Mechanical and electrical properties are measured and analyzed. The bending behavior is studied by scanning electron microscope. INTRODUCTION Cu/Al composite is a typical bimetallic composite that has been used in plenty of fields such as automobile and aerospace. The composite has the advantages of excellent conductivity as well as low weight, which cannot be obtained from single copper or aluminum. Industrial products of Cu/Al composite include Cu/Al composite joints (Uscinowicz, R., 2013), Cu/Al bimetallic sheets (Li, X. et al., 2011), Cu/Al flat bar (Wu, Y. & Liu, X. & Xie, J., 2014) and CCA wires (Ahmed N., 1978). CCA wires refer to the composite wires that copper layer concentrically coated on the surface of aluminum core conductor, implementing solid combination of two metals on the interface and forming an integral. At present, the aircraft cable generally use copper or copper alloy conductor, which makes the wire in the aircraft occupy a considerable proportion due to the large density of copper. Therefore, the use of Cu/Al composite wires instead of copper wires for weight loss, is of great significance to the development of aerospace technology industry. Heat treatment is an indispensable procedure to improve plasticity during cold working process, which is of great importance to preparation of wires (Wang, Q. et al., 2008). During the heat treatment, the Intermetallic Compounds (IMCs) are inevitable formed at the contact area of Cu/Al due to the occurrence of diffusion (Lee, S. et al., 2012). According to the results of former researchers, kinds of IMCs were discovered. Antoine Gueydan (2014) identified the formation of three IMCs (Al2Cu, AlCu, and Al4Cu9) at the interface between copper and aluminum after thermal aging. IMCs have a significant effect to the properties of Cu/Al wires. Bending performance is a vital property for the actual application of wires. The brittle IMCs may create a stress concentration that can cause crack initiation during bending process. This work focus on the mechanical properties of Cu/Al composite wires after heat treatment. The effect of various annealing condition on mechanical and electrical properties are studied, in order to find the appropriate annealing conditions, which produce optimal combination properties of Cu/Al clad composite wires. Bending fracture of composite wires is discussed by morphology observation.

Jan 1, 2019

By W. T. Robson

ONE of the problems encountered in any mine is the effect of increasing pressure manifested by increasing depth. Although the depth at which excessive pressure assumes serious proportion, and the manner in which it appears in underground workings, are influenced by a variety of factors, nevertheless the difficulty is present in all mines and its gravity increases with increasing depth. In the Kirkland Lake camp, as far back as seven years ago, mining had proceeded to depths sufficient to result in the formation of pressure great enough to cause violent disruption of masses of rock. It is proposed in this paper to deal with the effect of pressure caused by mining as observed at Lake Shore Mines, and to describe some of the methods which have been adopted to counteract it. There are many contributing factors in a study of the problem, and results vary widely in individual mines and in different localities. One feature common to all, however, is that there is ground subsidence, evidenced either by a gradual settling accompanied by crushing and shearing of the ore and wall-rocks, or the disruption of the ground surrounding the periphery of an excavation may take place suddenly, attended by more or less violent shattering of the rocks. Such violent failure of a mass of rock has been designated by the term rock-burst. The history of rock-bursts extends over a great number of years. They have occurred in some form or other in practically ali places where mining operations, at all but very shallow depths, have been carried out. Since the theoretical aspects of the subject have been dealt 'with at great length by capable and experienced writers (1), the present paper will give only a brief résumé of the theories propounded by those engaged in deep mining operations in various parts of the world.

Jan 1, 1940

By John B. Hodgeson

AMMONIA is an essential constituent in the production of the ammonium-sulphate and ammonium-phosohate soil fertilizers manufactured by the Consolidated Mining and Smelting Company of Canada, Limited. The fertilizer plant, built in 1930 at Warfield, near Trail, provides a means of utilizing the large amount of sulphuric acid produced from the sulphur dioxide which is removed from the smelter smoke. The plant has an avail-able source of cheap power which makes the production of fertilizer economically possible. The fundamental operations involved in the production of ammonia at the Warfield plant are, first, the manufacture of hydrogen by the electrolytic dissociation of water; next, the recovery of nitrogen by the fractional distillation of liquid air; and finally, the combination of hydrogen and nitrogen in proper proportions and under suitable conditions to form ammonia.

Jan 1, 1938

By Xiong Tong, Jiushuai Deng, Yingbo Mao, Lingyun Huang

Ammonium carbamate has been used as a reagent for the leaching of copper from the copper oxide ore found in the Honghe state, Yunnan province, China. In order to find the optimal conditions for the leaching of copper from this copper oxide ore,the effects of several processing parameters, including the concentration, time, temperature, particle size and stirring intensity have been investigated. The results of these optimization experiments showed that the leaching rate of copper reached up to 72.76% under the following conditions: liquid-to-solid ratio of 10:1, ammonium carbamate concentration of 2.5mol/L, leaching temperature of 45 °C, stirring speed of 300rpm, a reaction time of 1.5 h and 85% by weight thereof passes through a sieve having 0.074 mm.

Jan 1, 2015

By A. D. McKay

Uranium exploration expenditure in Australia reached a record level of A$220.5 million in 2008, which has subsequently declined to A$185.2 million for the year ended 30 June 2009. Recent discoveries include: Ranger 3 Deeps east of Ranger open pit (Northern Territory), Pepegoona and Yadglin sandstone hosted deposits (South Australia), and Thunderball project (Northern Territory). Australia?s Reasonably Assured Resources recoverable at costs of <US$80/kg U at June 2009 are estimated to be 1,210,000 t U, 4% higher than the estimate for December 2008. The main additions were in the south eastern portion of the Olympic Dam orebody. The Olympic Dam Expansion is based on a large open pit and will increase output to an annual capacity of 19,000 t U3O8; 750,000 t copper; 800,000 ounces gold. The Four Mile in situ recovery project was approved in July 2009. An ion exchange facility is to be constructed at Four Mile and uranium-bearing resins will be transported to the Beverley plant to recover the uranium. Recent developments at Ranger mine, and Honeymoon, Oban and Yeelirrie projects are discussed.

Aug 1, 2010

By J. M. Wolverton

CONSIDERABLE interest has always been taken in Safety-First and First Aid at the Sullivan mine. Even during the early days of development, Safety-First committees periodically held meetings, while lectures in first aid were given to any employees interested in the work. In 1929, a Safety Department was organized, and all accident-prevention and first-aid work was put in charge of a full-time Safety Engineer. An extensive programme has gradually been developed, the value of which can best be indicated by the reduction of the accident rate from 18.4 shifts lost per 1,000 shifts worked for non-fatal accidents and two fatalities for 1927, to 3.24 shifts lost per 1,000 shifts worked and no fatalities for 1936. SUPERVISION All work connected with accident prevention or first aid is under the jurisdiction of a central committee, known as the Accident Prevention Committee, which meets regularly once a month. It consists of all superintendents, department heads, foremen, and shift bosses, and is presided over by the Safety Engineer. At these meetings, the accident records of the previous month are reviewed and all accidents carefully analyzed and discussed. All proposed changes in the safety rules or in the accident tprevention programme are taken up and passed upon. Complaints or suggestions from the Safety-First Committee and the Employees Co-operative Committee, dealing with safety, are discussed and passed upon or a subcommittee is appointed to investigate and take any action found advisable. The question of underground ventilation and dust control, which recently has become a very important problem, always receives considerable attention.

Jan 1, 1937

By Jaeheon Lee, Junmo Ahn, Doyun Shin

"Many alternative leaching systems including bacterial leaching have been introduced to avoid passivation on the surface of chalcopyrite and to increase the leaching efficiency of copper from chalcopyrite. Recently, glycine, one of the simplest amino acids, has been emerging as an efficient and environmental-friendly lixiviant to recover copper. In the present study, an alkaline glycine–peroxide lixiviant system was used to leach copper from chalcopyrite concentrate and the leaching mechanisms were also investigated by a suite of kinetic studies under different conditions. The chalcopyrite concentrate contains 28.8% copper with 30.8% sulfide sulfur. The effect of concentration of glycine and hydrogen peroxide of the leaching solution was investigated. Glycine concentration was varied from 0.5 to 1.0 M and the hydrogen peroxide concentration was changed between 3 to 5%. Leaching time and pulp density were also varied. Hydrogen peroxide is an oxidant of the system and the leaching efficiency with periodic additions of the peroxide was also studied. A mineralogical study was performed using XRD and SEM. To investigate the surface of the residue materials, XPS was used to see if any passivating layer was formed during the leaching. Detailed results from mineralogical, chemical, and metallurgical studies will be presented and discussed.INTRODUCTION The greatest global resource of copper is low-grade chalcopyrite and heap bioleaching may be the only economic option for its processing. However, formation of a passivating layer on the surface of chalcopyrite slows down the oxidation reaction and reduces the efficiency of the process."

Jan 1, 2017

By W. G. Hatch

Introduction In November, 1927, a paper was presented at the Annual Meeting of the British Columbia Division by H. A. Pearse(l), in which he described the milling practice at Britannia and set forth the metallurgical results which were being obtained at that time. In the intervening four years, various changes and additions have been made in equipment and practice, which have resulted in marked improvements in efficiency and costs. These changes and their effects are discussed in the present paper. During the past few years two major changes have been made in plant equipment. The first of these was the. elimination of an intermediate crushing stage by discarding two gyratory crushers in favour of two Symons cone crushers. The latter installation-now effects in one stage a greater reduction than was formerly accomplished in two, that is, by the gyratories together with a set of rolls. The second important change in equipment took place when the original M.S. flotation machines were replaced by six Forrester pneumatic machines, so that now the flotation department consists entirely of machines of this type. A number of minor changes and some further additions to equipment have also been effective in raising plant capacity and concentrate grade, while making noticeable reductions in tailing losses and costs of ore treatment.

Jan 1, 1932

By Enrique I. Acuña

Creighton Mine is part of the mining history of Sudbury with more than 100 years of operation. Currently the deeper levels of the mine are reaching the 8000 ft level without implementation of mechanical refrigeration system as a result of the use of the Natural Heat Exchange Area (NHEA) over the past decades. The NHEA of Creighton Mine is part of an old block caving area divided into 4 blocks of trenches that were used to extract the ore. Currently, it is used year round to condition the outside temperature before the airflow enters the fresh air system of the mine. As the mine is progressing deeper, underground temperatures in the lower levels are starting to approach the limit of Vale?s guidelines for working in heat. This paper presents the study developed to improve the management of the NHEA to obtain cooler temperatures at the intake of the ventilation system and outlines the impact to the mine in terms of the additional level(s) that could be operated underground without the use of mechanical refrigeration. This is another of the efforts currently under development for energy conservation and to reduce the capital and operational costs of Creighton Mine while extending the expected life of the mine.

Oct 1, 2010

By T. Prietl

Metallurgical vessel linings are multilayered, consisting of refractory bodies, insulation materials, joints, and additional space to control for thermal expansion. A unique biaxial hot testing press (BHTP) was installed at the RHI Refractories Technology Center Leoben, Austria to enable the three-dimensional behaviour of complex vessel lining segments to be investigated under simulated service conditions. Using the BHTP, the heat up and thermo-mechanical behaviour of magnesia chromite brick lining segments with and without mortar filled joints were examined. The results obtained during the initial heat up provided validation of CFD modelling of the lining system. In addition, after the heat up and under steady state conditions, the lining behaviour during deformation-controlled compression and relaxation was examined. These analyses generated important data regarding the stiffness, joint compressibility, and brick damage of the lining segments after cyclic loading and unloading as well as the benefits of using mortar joints in the lining. These investigations were performed in collaboration with the Christian Doppler Laboratory for Secondary Metallurgy of Nonferrous Metals, University of Leoben, Austria. The BHTP has been operational since November 2004 and is providing information regarding the thermo-mechanical behaviour of different lining segments.

Jan 1, 2007