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By David Morrison

Our present longwall problems in Cape Breton can be grouped under five main classifications. These are: (1) Roof control on the face and on the main roadways leading thereto. (2) Transportation of coal along face and levels. (3) Mechanical loading at the face. (4) Safe method of conducting and applying power at the working faces. (5) Dust nuisance. The usual layout for longwall operation in Cape Breton is to have three, and sometimes four, faces in line with each other, the length of face being from 400 feet to 500 feet (see Figure 1), and producing between 425 and 500 tons per face. Each wall is serviced by a well constructed roadway for transportation of coal, men, and materials, and is operated as an independent unit. Each wall works under a regular cycle of operations: first, cutting and boring; second, drawing hardwood chocks, building midwalls, and shifting panlines; and third, loading. The present method of roof control and operation of longwall faces has developed through trial and error since the commencement of longwall miring in Cape Breton. The basic method of roof control in all longwalls in Cape Breton is: rigid support of the roof in the immediate vicinity of the working faces by hardwood blocks, as shown in Figure 2, accompanied by a cushion support furnished by continuous midwalls, 12 feet wide, constructed of stone obtained from the waste and spaced at 50-foot centres. These midwalls are kept forward to within 4 feet to 10 feet of the working face and allow a gradual subsidence of overhead strata, thus preventing any sudden break at the working face.

Jan 1, 1947

By R. G. McDonald

"High iron solution concentrations often result in the formation of basic ferric sulfate during the high temperature oxidation of sulfidic materials such as base metal and refractory gold concentrates. Consequently, the “Hot Cure Process” followed by limestone neutralization is required to facilitate subsequent processing and/or disposal of the leach residue. The present paper discusses strategies that can be employed to influence the composition and nature of the high-iron content leach residues produced during pressure leaching.INTRODUCTION Control of iron deportment in hydrometallurgical processing remains a key challenge for a range of reasons. Strategies generally relate to the control of conditions under which iron is optimally rejected (Demopoulos, 2009). Supersaturation provides the driving force for crystallization and this can be controlled by a number of factors that include (1) pH and/or Eh control, (2) the presence of matrix anions and impurities, (3) dilution, (4) complexation and dissociation and (5) manipulation of the rate at which the metal to be precipitated is released to solution. Each of these factors is impacted by temperature. Good control of crystallization is essential to the control of precipitate properties such as the degree of crystallinity, stability, particle size and quality which covers both the extent of impurity uptake and suitability of the precipitate for waste disposal. The quality and properties of iron precipitates in turn can impact downstream processing. It is the aim of this paper to discuss the generation of iron-containing residues produced during the pressure oxidation of sulfidic ores and concentrates and how the nature of these can be controlled to potentially facilitate further processing. A brief overview of several related topics will now be given and include, where relevant, discussion of work undertaken in our laboratories. In addition, brief discussions of selected process options that enable good control of iron rejection will be provided."

Jan 1, 2016

By Gerhard W. Heinrich, Gerald V. Schroeder, Daniel A. Murphy, Daniel F. Suarez, Jamie B. Beauchamp

"Washwater 'Finger' sprays were installed and tested in the copper/nickel separation circuit at Strathcona Mill to improve flotation capacities and related metallurgical performances. The new spray design features submerged sideways introduction of wash water into the flotation froth through nozzles at the end of vertical pipes which are suspended from a header above the froth. This maximizes the effective cross sectional area of flotation vessels while maintaining effective froth cleaning and a desirably high density of the concentrate slurry. The plant tests gave increases of copper concentrate production rates of 17% to 20% for conventional cells and 16% to 20% in column flotation at target grades of 29% to 30% copper and of less than 0.5% nickel. Basic considerations and concepts of tests and evaluation procedures are described.IntroductionMeeting flotation concentrate grade targets at maximum production rates and recoveries is a challenge all too familiar to operators of base metal ore concentrators. Frothwashing is an option to improve grade/recovery performance by minimizing entrainment of impurities into the concentrate, which is commonly known since the sixties (Kaya & Laplante, 1989). It has been recommended for the flotation of sulphides and industrial minerals alike (Kaya & Laplante, 1989; Miller, 1969; Heinrich, 1989) and has found its ultimate application in flotation columns (Finch & Dobby, 1990). The washwater addition in a flotation column is most evenly distributed over the column's cross-sectional area thus ensuring almost complete displacement of feed water from the froth by a countercurrent washwater flow -provided, a positive bias is maintained. Therefore, flotation columns are ideal for cleaning flotation. However, there is usually less room for boosting the concentrate production capacity by increasing airflow or slurry level then with conventional cells because of the smaller cross-sectional area available."

Jan 1, 1994

By Anne-Laure Bonnet

Les connaissances acquises au cours des dernières décennies sur les gîtes de métaux de base et précieux intensément métamorphisés (p. ex. Vokes, 1991; Cornell et al., 1992; Zaleski et Peterson, 1995) ont permis d?élaborer des guides d?exploration pour de tels gisements dans les terrains de haut-grade métamorphique (Spry et Scott, 1986; Rubin et al., 1993; Hand et al., 1994; Spry, 2000; Spry et al., 2000). Un transfert de ces connaissances à la cartographie des vastes terrains gneissiques non différentiés de la province de Grenville permet d?affiner l?approche cartographique nécessaire pour reconnaître les systèmes hydrothermaux métamorphisés en terrains vierges et peu diagnostiques puis d?en discriminer les divers halos d?altération (Corriveau et al.,1996, 1997, 1998, 2003; Williamson et al., ce volume). Cette approche prend en compte les « empreintes métamorphiques » observées sur le terrain, telles que les variations des assemblages minéralogiques, du mode et de la composition des minéraux métamorphiques, pour reconnaître des roches présentant une composition inhabituelle caractéristiques de protolites altérés par hydrothermalisme. Ces empreintes citées cidessus sont facilement reconnaissables dans les terrains de haut-grade où la recristallisation induit un grossissement des grains qui permet de déterminer la nature et le mode des minéraux dès les levés de terrain. Cette approche raffine la compréhension des terrains de haut-grade métamorphique et illustre que leur complexité (i.e. polyphasage de la déformation et du métamorphisme) n?est pas forcément une limite à leur exploration. Elle a donc été utilisée systématiquement lors des levés de terrain réalisés dans le cadre d?un projet de l?Initiative géoscientifique ciblée de RNCan. La zone cartographiée se situe le long de la marge sudest du Groupe de Wakeham dans le secteur est de la Province de Grenville. Deux régions ont été plus particulièrement étudiées, celle du lac Musquaro (SNRC 12K10, 11 et 14) et la région côtière comprise entre Kégashka, La Romaine et Baie des Loups (SNRC 12K1, 2, 3 et 7) (fig. 1).

May 1, 2003

By R. W. Thompkins

"PREFACEThis paper will be published in three parts. Part 1, in this issue, will cover the occurrence of uranium, radiation from uranium ores, the uranium series, radioactive theory, radioactive equilibrium and application to the radon series, the working level, the theory of emanation and diffusion, transport by thermal diffusion of radon emanating from porous rocks, and definitions.Part 2, to appear in the October issue, will deal with radiation theory applied to uranium ores, other radon migration factors , fact ors affecting the radon gas release rate, measurement of radon gas emanation rates, the tunnel concept, variation of emanation rate with grade, and estimating radioactivity from grade analysis.The series will conclude with Part 3, in the November issue, which will discuss the techniques for controlling radiation and give some example calculations.1.0. Occurrence of Uranium1.0.1. Uranium is widely distributed in nature. Sedimentary rocks contain less than igneous or metamorphic rock s and as the outer 10 miles of the earth's crust is composed of 95 per cent igneous and 5 per cent sedimentary rock, it has been estimated that about 1.3 x 1014 tons of uranium exist in the earth's crust.1.0.2. It is not surprising, therefore, that radiation has existed naturally in the ear h ever since the beginning of time. It is found in such places as:(1) non-uranium mines;(2) houses not close to or connected to uranium mines;(3) ground-water tables supplying drinking water to large populations.1.0.3. All mines do not necessarily have abnormal radiation in them, but it is possible for many mines to have abnormal levels of radiation. Therefore, all underground mining operations should be tested for radiation."

Jan 1, 1982

By A. R. Laplante

"In this paper, the performance of the Knelson Concentrator and of the batch and continuous Falcon Concentrators are compared. The units are based on different operating principles, and as such they perform quite differently. The Knelson yields very high free gold recoveries over a wide size range of both the recovered and rejected species. It is ineffective in recovering very fine ( <15 µm) or flaky gold, as encountered in flotation feeds, concentrates or tails. It is the: preferred unit for gold recovery from grinding circuits. The batch Falcon is effective in the fine range, typically less than 37 µm for gold. Its recovery zone is quickly saturated when there is significant heavies in the feed. It works best as a pre-concentration unit. The continuous Falcon is a versatile unit which is capable of recovering fine heavies (density down to 5 g/cm3 ), especially from coarser gangue. INTRODUCTIONThe purpose of this presentation is to describe the mode of operation of two Canadian centrifugal concentrators, the Knelson and Falcon. It is hoped that it will prove informative to prospective users in the selection, testing and optimization for applications of either machine. The work is based on testwork both in Canadian mills and at McGill. I am indebted to many colleagues at these locations. Appropriate references will be made to articles further describing the work, either already in the open literature or in preparation.Although this work is meant to be more practical than scholarly, it is appropriate to begin by considering how the two units achieve selective recovery. This will become useful in establishing a suitable testing methodology, which will then be described, and interpreting typical results. In the last section I will attempt to define appropriate applications for the two units. This is a thankless task, as I am likely to miss some applications or to make projections based on partial results, as much of the work is still in progress. In deference to the reader and both manufacturers, areas where reasonable doubt still remains will be identified."

Jan 1, 1993

By Andrew Hickinbotham

"A water well represents not only a significant investment but also is a key to making a living or sustaining a reasonable lifestyle. This naturally makes the water well a precious possession that needsto be protected.This paper describes the challenges that TransAlta Utilities Corporation faced and how it responded to the concern of residents that open pit coal mining would affect their water well supplies.BackgroundWells have a certain mystique. Tum on the silver tap and water flows at your command without you knowing how it got there and whether it will continue to flow.Each well is different and has a story to tell. Some wells have a lot of history and are described fondly and with pride (""Grandad built this place 50 years ago and she hasn&apos;t failed us yet""). Some are passed on from father to son, some are part of the pride of good farming, some wells are famous for tapping that huge underground stream or have been mysteriously witched or have been part of a rip-off by an unscrupulous well driller. Some have to be babied so that the cows can be watered, the children can have showers and the dishes can be done. All wells represent a significant $5,000 to $10,000 investment and is a key to making a living or sustaining a reasonable lifestyle.Most wells continue to provide water faithfully - until there is a problem. For those people living next to a mine, there is the additional concern that mining has or will affect their water well supplies. Water well problems reported to the mining company have to be dealt with promptly and responsibly. The mining company&apos;s groundwater specialist must gain the trust and confidence of well owners living in the area ."

Jan 1, 1992

By A. Probst, J. A. Finch

"Solids concentration (% solids) profiles and the clear liquid/slurry interface level (mudline) were determined from conductivity measurements in thickeners at Falconbridge' s Strathcona mill (Ni concentrate and non-mag thickeners) and Kidd Creek Division (Cu, Zn concentrates and final tails in the concentrator and thickeners in the Zn plant).The conductivity measurement system consisted of a probe 1.5 m in length with 24 electrode cells, a 24-channel relay, a conductivity meter and a computer. A conductivity profile is collected which locates the mud-line by the sharp change in conductivity. The conductivity measurements are readily converted to solids concentration profiles without need for calibration.The results from the conductivity measurements were compared with those from pressure profiles and direct measurements on local samples obtained using a modified Noranda sampler.It is concluded that the conductivity technique is applicable to locate the mud-line and to estimate the solids concentration profiles in thickeners. This on-line information could improve the operational efficiency of industrial thickeners.INTRODUCTIONAn automated, on-line technique for detecting the clear liquid/slurry interface (or mudline) and the variation in solids concentration with depth would enhance thickener operation and control. In some processes such enhanced control offers significant benefits. For example, in hydrometallurgical operations solid/liquid separation is often the process limiting step. Water treatment plants are increasingly expected to operate remotely and reliable sensing is vital.Current attempts to detect the mud-line include reflection of some signal (e.g. sonar), floats (Dahlstrom, 1985) and measurement of pressure (Rosenblum, 1991), and in one case, natural radioactivity of the solids (Johnston and Simic, 1991). A recent commercial development uses reflection from a vertical array of optical transmitters/sensors, which also gives local solids concentration (BTG Inc., 1991)."

Jan 1, 1993

By James A. Deeks

"Motor failures and equipment bearing failures are responsible for reduced productivity.With the introduction of computers and data acquisition systems, users are now able to monitor, report and trend deteriorating conditions and take corrective action before a critical shutdown occurs.This paper discusses the monitoring and trend analysis of&apos; motors, and motor and equipment bearings. With today&apos;s digital electronics technology users are now able to monitor their equipment, detect deteriorating or abnormal conditions quickly, alarm the condition locally and or remotely, and decide if immediate corrective action is necessary or if it can be delayed until the end of a work Shift. All of this can be done long before any damage is done to the equipment.Monitoring Trend AnalysisIt is no longer necessary to compromise in selecting products, since state-of-the-art designs allow the adjustment in such small increments that the users are able to detect minute changes in a system&apos;s performance.Monitoring and trending of motors and equipment bearings is now available in economical packages which can be expanded as a system grows. Simply select the information you need, set the parameters, choose the scan time, and decide on the degree of reporting.Buffer storage of short-term monitoring of a number of analogue channels permit the user to view the recent history of motor data such as: motor average load, unbalance, motor current, ground fault, reserve thermal capacity, plus all of the settings of the protective device.A decision can be made to freeze the stored information after the motor stops or after the motor starts. Then the user is able to recall the conditions and diagnose the performance and the cause of the abnormal condition. Typical scan times range from ¼ second to 5 seconds ."

Jan 1, 1992

By D. Eriksen

Zero Emission Gas power, ZEG, is a novel concept where a high temperature solid oxide fuel cell (SOFC) is integrated with a reforming reactor producing hydrogen from natural gas through Sorption Enhanced Steam Methane Reforming (SESMR). The SOFC is used as a high temperature heat source for regeneration of the CO2-absorbent. Moreover, by using part of the produced hydrogen as fuel for the SOFC, the waste heat of the process is considerably reduced. Thus, the process has a very high thermal efficiency and produces both electricity and hydrogen from natural gas. In addition, a stream of pure CO2 is produced in the regeneration step and can be deposited or used commercially. Initial cost estimates indicate a cost of electricity and a cost of hydrogen well below today&apos;s prices. A small (1kWel + 1kW H2) demonstration set-up is under construction and experimental results and related research will be presented. This set-up comprises one 2.5kWth H2 SESMR-reactor (about 0.85 Nm3/h H2) operating batchwise with dolomite as the CO2-sorbent. The reactor developed is designed like a parallel plate heat exchanger where the mixture of sorbent and reforming catalyst is packed between the heat exchanging plates. The demonstration set-up includes a 1kW SOFC operating in a continuous mode. The set¬up will therefore demonstrate continuous simultaneous hydrogen- and electricity production, but cannot demonstrate simultanuous electricity- and CO2-production. The set?up is well equipped for on-line monitoring of gas composition, flows and temperatures. This important part of the demonstration set-up is developed and provided by Christian Michelsen Research (CMR). A minor part of the project is the development of a continuous circulating fluidized bed SESMR-reactor system and in another related project the focus is on the development of more suitable sorbents. In these two projects co-operation with University of British Columbia and Lousianna State University, respectively, is highly appreciated.

Jan 1, 2005

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&apos;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&apos;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&apos;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&apos;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

By L. Sun

Recently, micro-tubular solid oxide fuel cells (SOFCs) have attracted the attention of many researchers because of their numerous advantages over larger tubular and planar SOFCs. These include excellent thermal shock properties giving rapid startup/shutdown capability, a high volumetric power density compared to larger tubular SOFCs, and reduced sealing problem compared to planar SOFCs. In order to screen cathode materials for micro-tubular SOFCs, the perovskite cathodes were deposited, using a variety of methods, on 10.5 mol % yttria-stabilized zirconia (YSZ) tubes. Their electrochemical properties were then evaluated by using electrochemical impedance spectroscopy and steady-state polarization methods, based on a three electrode configuration, and with the reference electrode position carefully optimized. The oxygen reduction reaction kinetics at the cathode/electrolyte half cell were then investigated in detail.

Jan 1, 2005

By J. Hoover

"IntroductionThis chapter will discuss the operational and maintenance aspects of a heavy media cyclone circuits as applied to coal processing and using magnetite as the media. It deals with heavy media bath separators in terms of types of media, equipment, circuits, media recovery, maintenance, and product handling. It will detail heavy media cyclone operation and supplement the previously described topics.The heavy media cyclone was first developed in the Netherlands by the Dutch State Mines in 1945. A cyclone plant was not built in North America until 1961. Traditionally, heavy media cyclones have been used to treat size fractions between 1lz in. (12 .6 mm) and 35 mesh (0.5 mm). High maintenance related to heavy media bath separators has recently prompted some plants to crush all raw coal to minus 2 in. for treatment in heavy media cyclones.The heavy media bath separators utilize only the force of gravity to make the separation between heavy and light particles. This requires lengthy retention time which can lower capacity and also is inefficient for finer particles. A heavy media cyclone utilizes centrifugal forces which are 20 to 200 times greater than the force of gravity. This means the separation between coal and the impurities occurs very quickly, therefore a low retention time is required allowing cyclones to have high tonnage capacities. Also these greater forces allow better separation for the finer particle sizes.Heavy media cyclones are now widely used to produce both metallurgical and thermal coal. Work is in progress to reduce magnetite consumption, extend wear life, increase tonnage capacity, improve separation efficiency and automatically control these cyclone circuits."

Jan 1, 1989

By D. R. Murray

"A promising long-term solution to uranium tailings reclamation has been the establishment of vegetation directly on the waste material. The soil profiles of areas vegetated for 0, 3, 8 and 10years are characterized as to the extent of soil development . The characteristics are compared with the visually interpreted soil profile. Organic matter content is presently the best analytical judge of soil development. Vegetation procedures have produced a build-up of organic matter in the top 10cm of tailings where natural microbial populations flourish. The CN ratio is high and the profile depth shallow, suggesting the need for additional fertilizer applications.IntroductionThe reduction of surface erosion and improved aesthetics of uranium tailings has been accomplished by the establishment of a vegetative cover. In 1971 research concentrated on developing methods of plant establishment at minimal cost and soil amendments on uranium tailings in Elliot Lake , Ontario. One process of stabilization used on a large scale was direct seeding of grasses and legumes into the tailings which had received only limestone and fertilizer treatments. Fertilizer additions were made for varying lengths of time in subsequent years to maintain the established cover.Maintenance-free vegetation would be possible once a soil profile developed with sufficient nutrient recycle and plant regeneration capabilities(1). Tailings vegetated in 1971, 1973 and 1978 that had received either 3 or 5 years of maintenance fertilizers were examined for soil development profiles. The extent of soil development and the relative effect of time and fertilizer would provide direction on reaching the goal of a self-sustaining cover.This paper is an abridgment of Division Report MRP /MRL 81-126 of the same title(2)."

Jan 1, 1984

By V. Bruned, K. Mohamed, A. Michaut

Orano Mining Somaïr uranium treatment plant (Niger) uses a pugging-curing process to leach uranium. Sulfuric acid, nitrates and water are added to the finely grinded ore in a rotary drum to leach uranium bearing minerals and solubilize uranyl sulfate ions. Reagents, sulfuric acid and nitrates, are the main OpEx of this process step. The economical optimization of their addition requires a thorough knowledge of the ore behavior in solution with these reagents. Orano Mining technical direction and Somaïr laboratories developed a model to predict the curing process uranium recovery surface with a limited number of parameters. Experimental laboratory work to fit the model needs to be done for each type of ore which can require a lot of metallurgical tests and would be time consuming. In order to optimize the required number of tests, an innovative experience plan was designed in parallel to the development of this model reducing the required number of tests to only eight. Once the parameters of the models are correctly fit, the comparison between the estimated values and the actual values for the uranium recovery is excellent (less than 0.5% error in average). Associated with an updated cost model of the curing process, this new recovery model helps the plant operator find the best set of reagents to maximize curing process profitability in the Somaïr plant day after day.

Jan 1, 2020

By P. R. A. Andrews

"Talc ore from Bakertalc, High water, Quebec analyzing about 60% talc, previously dry ground to about 95% minus 53 µm was beneficiated in an 11.4 kg/ h pilot-plant flotation circuit. A concentrate of 95.9% talc (necessary for paper-grade) was obtained at a recovery at 75.3% by employing 53 g/t of Dowfroth 250 collector at pH 9.2; further cleaning increased the grade to 97.2% talc at a recovery of 57.5%.Flotation of fresh ground 60% minus 44 µm ore at a feed rate of 18.6 kg/ h produced a grade of 96.4% talc with a recovery of 78.2%, using Aerofroth 70 collector a six carbon-branch chain alcohol, at pH 9.2.The similarity in the concentrate grade and recovery between pre-ground and fresh-ground ore indicated that it was not neces¬sary to grind to 95% minus 53/2m to achieve comparable selectivity. A grind of 60% minus 44 pm corresponds to 100% minus 300 µm.Flotation retention times obtained with fresh ground ore indicate 33 min. for combined rougher/scavenger, and 15 min. each for the first and second cleaners.Talc-magnesite flotation separation is explained in terms of physico-chemical forces, with reference to surface charge and adsorption mechanisms."

Jan 1, 1989

By Phillip J. Mackey, Susumu Okabe

Copper mining and smelting has been carried out in Japan for over 13 centuries and in fact stretching back into antiquity. In 1889, the first electrolytic copper refinery in Japan based on Elkington’s principles was started by Furukawa Mining at Honjyo in downtown Tokyo based on the multiple or parallel system. Within two decades, a number of other copper refineries had begun operation. Interestingly, but perhaps not surprising given Japan’s long history of copper production, this first refinery in Japan commenced just ten years after the first refinery in the USA (1879), and not long after the first plants in Europe. By 1935, as a result of growth in copper demand, there were six domestic copper electro-refineries in Japan with an installed capacity of 97,800 tonnes/a, while actual production was 71,200 tonnes/a. Since about 1932, the majority of these plants were based on the more common parallel or multiple system. In 1946, just after World War II, domestic production capacity had dropped considerably to 29,000 tonnes/a, however with reconstruction, capacity and production expanded rapidly, with production reaching 81,000 tonnes/a in 1955, 187,000 tonnes/a in 1960 and 307,000 tonnes/a in 1965. The introduction of the first refinery and the early ones that followed and subsequent developments are discussed in this paper. The major technical achievements during the high growth period from 1945 to 1963 included: the use of fire- refined anodes; the introduction of newly-developed rectifiers; the introduction of lead-lined or vinyl-lined concrete cells; improvements in the electrolyte heating system; application of improved anti-corrosion materials and the introduction of heat-insulating surface coverings. In 2018, Japan’s refined copper production totaled 1,595,000 tonnes of copper, with Japan ranking third in the world after China and Chile. INTRODUCTION In 2018, Japan’s refined copper production totalled 1,595,000 tonnes of copper and Japan ranked third in the world for refined copper after China and Chile (Wood Mackenzie, 2019). There are now eight copper refineries in Japan which provide Japan’s production of refined copper. These plants are listed in Table 1 (Wood Mackenzie, 2019), also showing the production trend since 2013; in general, production over this period has been relatively steady. The Toyo plant is now the 7th largest copper refinery in the world after several large plants as rated by capacity in China, Russia and India (ICSG, 2019).

Jan 1, 2019

By L. C. Galloway, P. M. Tiley

"Some progress has already been made in defining the parameters which will determine the performance of a guidance system in a mine shaft. Very little information is available, however, to help designers or operators predict the effects of varying these parameters in new or existing installations.The experience we have gained from monitoring a variety of installations has led to the development of a model which simulates the motion of a conveyance as it moves through a mineshaft, restrained by fixed guides.This paper presents a general analysis of the performance of the guidance system used in several installations, as well as a detailed description of the problem encountered at one mine and the steps taken to solve it.IntroductionOur company has investigated in some depth the problems that arise in the guidance of mine hoist conveyances.We have a telemetering accelerometer which we obtained to test mine hoist brakes. Frequently, during brake tests, the mine owners request us to use this instrument to measure the lateral motion of the conveyance ""to check guide alignment"". We have made such tests in shafts that have guide s of different kinds, including wooden guides, steel rail s and tubular steel guides. From these tests, we have gained some valuable information about guidance systems.In a well-aligned guidance system that is designed within common and well-known practice, the conveyance will experience very little shock most of the time. However, on rare occasions, shocks up to .5 g will occur. That is, the conveyance exerts a force of up to half its loaded weight on the guide. If the guide slips or is damaged by this force, it will be misaligned for future trips and become the cause of future shocks. In time, the whole guidance system can become misaligned."

Jan 1, 1982

By L. C. Galloway, P. M. Tiley

"Some progress has already been made in defining the parameters which will determine the performance of a guidance system in a mine shaft. Very little information is available, however, to help designers or operators predict the effects of varying these parameters in new or existing installations.The experience we have gained from monitoring a variety of installations has led to the development of a model which simulates the motion of a conveyance as it moves through a mineshaft, restrained by fixed guides.This paper presents a general analysis of the performance of the guidance system used in several installations, as well as a detailed description of the problem encountered at one mine and the steps taken to solve it.IntroductionOur company has investigated in some depth the problems that arise in the guidance of mine hoist conveyances.We have a telemetering accelerometer which we obtained to test mine hoist brakes. Frequently, during brake tests, the mine owners request us to use this instrument to measure the lateral motion of the conveyance ""to check guide alignment"". We have made such tests in shafts that have guide s of different kinds, including wooden guides, steel rail s and tubular steel guides. From these tests, we have gained some valuable information about guidance systems.In a well-aligned guidance system that is designed within common and well-known practice, the conveyance will experience very little shock most of the time. However, on rare occasions, shocks up to .5 g will occur. That is, the conveyance exerts a force of up to half its loaded weight on the guide. If the guide slips or is damaged by this force, it will be misaligned for future trips and become the cause of future shocks. In time, the whole guidance system can become misaligned."

Jan 1, 1982

By R. K. Jonas

Many leading copper and other mineral processors have rapidly adopted advanced controls in last 5-10 years. Almost 600 multivariable predictive controls have been installed in mineral processing, and almost 50% of those are in copper concentrator plants. In most cases, mineral processors rely on 3rd party support to implement these advanced technologies. One challenge facing advanced control user is the selection providers and services for these technologies. The trend has been towards the use of multivariable predictive control and use of technology provider’s services. This paper will discuss status of advanced control, and the merging trends in the mining industry. A review will be presented of how advanced control is being applied in the mining industry over the last decade, and how user challenges are being overcome. Next the emerging uses of multivariable predictive control (such as multi/inter-unit optimization), focusing on the latest trends in concentrator plants. Finally, a review will be made of emerging technology advances in the that can be advantageous to mineral processors. INTRODUCTION Review of advanced control in mineral processing Advanced controls are serving an increasing role to improve processing plant operations and profitability. As advanced control is being installed into more mining processing plants such as copper concentrators, many of these plants are concerned about the selection technologies and vendors to support the installation and maintenance of these controls. In a study by Jonas and Craw (2011), they found that most new users have not had prior experience with advanced controls. It is the author’s experience of almost 30 years in advanced controls that most mineral processers considering advanced controls can benefit from better understanding of the technologies and their support requirements.

Jan 1, 2019