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By Dmitrievskaya TY, Cheremnykh PA, Kuftinova IV, Yaremenko VN

The comprehensive processing of raw materials and the tendency to waste-free production require the combination of various methods of concentrating mineral resources. Magnetic separation, an ecologically clean method of concentration, is one step in the technological cycle of ore processing, and cleaning and classifying of raw materials. Separators with superconducting magnetic systems cooled by liquid helium are the novel equipment for practical concentration. Recently, high-gradient (HGMS) and open-gradient (OGMS) magnetic separators using the effect of superconductivity have appeared. The separators of the first type are expedient in the head-end of the technological cycle, as they are most efficient for processing of particles 100 ¦m and greater in size. In this case the main task is to obtain pure tailings with a minimum amount of the useful component. This method allows the essential reduction in the cost of the subsequent crushing and grinding, because only the magnetic concentrate is directed to further processing. The separators of the VGMS type are used more efficiently in the final stages of the concentration cycle to condition the end product. The present work is devoted to the theoretical and experimental investigation of the motion of weakly magnetic particles in the working chamber of superconducting separators of the open-gradient magnetic separator (OGMS) and HGMS types. The flat OGMS is equipped by a magnetic system with NbTi racetracks cooled by liquid helium. The chamber is divided into zones by partitions parallel to the plane of the magnetic system. It is shown how, depending on the number of the zones and their depths, the extraction function of the OGMS varies and the transition from the OGMS to the HGMS occurs. The particles 2 mm and less in size are considered. The extraction parameter distribution of the particles was measured for a multicomponent weakly magnetic ore. It was experimentally shown that xD2 is the extraction parameter for the particles in the OGMS on condition that (p-po)D /l8/tl/g

Jan 1, 1993

By K Dudley, D Readett

The design of entrainment control processes in copper SX plants has been studied by use of models based on achievable plant performance. A number of alternatives have been assessed for their suitability in minimising the transfer of deleterious species from PLS into the electrolyte. The position of the wash (scrub) stage in the circuit, either before or after the loaded organic tank, has been the subject of considerable debate. The modelling shows that at ænormalÆ entrainment levels, the performance of the circuits are very similar. However at high entrainment levels the selection of the wash after the loaded organic storage has significantly lower transfer of contaminants. When considering the inclusion of a loaded organic coalescer the results of the modelling again show that the best circuit has the loaded organic storage/coalescer before the wash stage. The overall control of EW contaminants includes both a wash stage and an EW bleed flow. The total water use for these two flows is shown to go through an absolute minimum. The minimum flow rate is not greatly dependant on the total entrainment from the SX settlers. This can be a useful operating strategy if the quantity of high quality water for make up is limited by the capacity of the water treatment plant (eg RO). However the minimum cost option is to maximise the flow of water to the wash stage and minimise the EW bleed stream. The main driver for this is the cost of the cobalt sulphate contained in the electrolyte. Some results from the latest circuit modifications at the Nifty and Girilambone Copper Projects are presented to confirm the benefits of using both coalescing systems and a wash stage. The EW bleed has been reduced to a level that is less than the loss internally in the SX stage to stage entrainment. There has been an occasional need to add chloride to the EW to maintain sufficient concentration to act as a growth modifier.

Jan 1, 2002

The Hall-Heroult process is likely to be the dominant method of aluminium production for the remainder of the century. The characteristics of the operation of a modern smelter are described and attention drawn to their disabilities which are due chiefly to the small production capacity of individual cells.The principal components of the Hall-Heroult cell- the electrolyte, the anode and the cathodes are discussed in order to identify the problems of scale-up. The factors influencing current efficiency and energy consumption are analysed and lead to the conclusion that the greatest potential for energy saving lies in reducing the anode to cathode distance (ACD).The most promising direction for major change is in the application of a new titanium diboride-carbon composite for coating of the surface of the cathode carbon. It improves the wetting of the carbon by aluminium and should permit the use of sloping cathodes and anodes. The deep metal pad would thereby be eliminated and, in the absence of magnetic perturbations, the ACD could be substantially decreased.

Jan 1, 1987

IT is generally accepted that for transport of coal underground from different collecting stations, the system of endless rope haulage with remote control is not only one of the safest and most economIcal, but is also one of the most'efficlent in dealing with output.When the coal measures lie in regular planes, the work of laying down such a haulage presents no difficulties. When, however, the dip of the measures is Irregular, or dislocated by faulting, the management is faced with the problem of constructing vertical curves of such a radius that the sag of the rope will correspond with the road bed, and thus obviate the danger of the rope rising and throwing the skips off the track.The direction of the main roads for haulage purposes being ascertained from the plan of the royalty to be worked, the faults or dislocations in the seam are determined for these roads with the greatest possible accuracy by means of bore holes from the surface.From the data thus obtained the haulage road can generally be so graded that the rope will keep on the floor during haulage operations, although the grades may in places be synclinal.The writer confesses that he knows of no accurate formula for calculating the sag of the rope under varying tensions and so determining the safe radius of the curve, and he had to depend upon past experiences under somewhat sImilar conditions.The accompanying sections illustrate a case where the writer has recently installed an endless rope underground approximately 5000 ft. in length, from the foot of a tunnel in which an endless rope delivers the output to the screening plant, and having to negotiate, first a 400-ft. downthrow fault, and later a 32 ft. upthrow.

Jan 1, 1927

By Baird G. R, Jurak R. N

In this study Dynamic Finite Element Modelling is used to investigate the distribution of peak particle accelerations (PPA) induced in a rock mass by a vertical decked column of explosives. The rock mass is assumed to be viscoelastic. The influence of the delay time between decking charges, the viscosity attenuation (quality factor Q), the decking configuration, and the velocity of detonation (VOD) on PPAs is examined. The results of this paper are relevant to fragmentation since the nature of the fragmentation is related to the stress magnitude and hence the PPAs. It was found that increasing the VOD, and increasing Q increases the PPAs in the neighbourhood of the blasthole. However, the VOD and rock quality factor Q have little influence upon the distribution of PPA. It was also found that an even distribution of PPAs, at a fixed distance from the blasthole, could only be obtained by increasing the ratio of charge length to stemming length. The study showed that the amplitudes and distribution of PPA surrounding the blasthole was approximately independent of the delay time between the decked charges. The modelling also shows that the particle accelerations at locations below the bottom of the charge are relatively small and so the model predicts no substantial damage below the bottom of the charge after blasting.

Jan 1, 1995

By Stevenson I, Dickinson W, Taylor R. N

Despite flash smelting's widespread use little is known about the actual processes taking place in flash furnace shafts and comparatively few reports of sampling campaigns have appeared in the published literature. his paper reviews the previous reports of the use of horizontal trough samplers and analyses their expected collection efficiency. In the light of the deficiencies revealed by this analysis an isokinetic sampler was produced and a vertical sampling technique was also developed to obtain samples from directly below the burners in the shaft of the flash furnace at the Kalgoorlie nickel smelter. Comparison of the sizing of the samples obtained with the horizontal trough and isokinetic samplers confirmed the theoretical analyses and showed that the trough samplers were not collecting the fine particles. Besides providing data to validate mathematical models of the burners and shaft, chemical analyses of the shaft samples showed that the coal in the charge was reacting preferentially and that the plume of at least one of the burners was being deflected from its axial position. In the region directly below the burner there was evidence that the disperser on the burner was imparting more momentum to the coarser particles and that these were concentrating in the outer regions of the particle plumes issuing from the burners.

Jan 1, 1992

By M Andrew, D McTiffen, M Adams

A major Ventilation Upgrade Project commenced at the Fosterville Gold Mine (FGM) in 2017 to service the ongoing ventilation requirements of the underground mining operation. The project consists of three large diameter ventilation raises totalling 1100 metres, and new axial primary ventilation fans to upgrade the mine ventilation system. With a mining depth of 1200 metres and a thermal gradient of approximately 2.7 °C per 100 metres of depth, the completion of the Ventilation Upgrade Project is key to the ongoing success at FGM. The Ventilation Upgrade Project will allow continued mining, including high-grade gold deposits, lower in the mine where heat is increasing. Figure 1 below illustrates the underground workings at FGM, and provides a general view of the ventilation upgrade works to establish the new exhaust system from the lower workings to surface. Whilst raisebore pilot drilling the H4760 Return Air Rise (RAR) from surface to 395 metres, the raisebore drill string became stuck in the raisebore pilot hole at approximately 300 metres down hole, presenting a significant technical problem and delays to the project. This Case Study provides an overview of the recovery process undertaken at FGM including the recovery of the stuck drill string. The value of the stuck in-hole equipment, the investment in the shaft site preparation, the collar stabilisation, the underground development to the base of the ventilation raise, the surface footprint prepared for the Primary Fans construction and the limited available space on the site were all motivations to recover the raisebore drill sting and ultimately recover the ventilation raise location. More importantly, the long lead-time required should a new shaft location be the final solution, and the delay this would incur to the ventilation upgrade was unacceptable. Recovery of the drill string was not possible using the capability of the Contractor’s Raise Drill. An alternative method for freeing the drill string was required. A significant amount of engagement with industry was undertaken to seek out potential solutions and draw from the experience of others. All methodologies available were considered and assessed. Ultimately, after several attempts at freeing the raisebore drill string using various methodologies, Adams Drillers and Clear Cut Interventions were engaged to provide a turnkey recovery solution.

Mar 15, 2021

By Dawes S

Efficient roof control in colliery operation is a factor that must be maintained for· the maximum reQovery and economic extraction of the mineral. It must be carefully considered in each of the following stages in the life of a mine.1. The primary development and the first working of the mine.2. The maintenance of access roads, intake and return airways.3. The extraction of pillars.FACTORS IN ROOF CONTROLThe main objects of roof control are: The support of the roof in working places, the relief of roof pressure from the workings during pillar extraction, and in some instances the prevention of subsidence of the surface.The support of the roof during development operations and first working, and the subsequent maintenance of these is influenced by:-1. The depth of the seam below the surface.2. The thickness of the seam.3. The dip of the seam.4. The condition of the roof and floor.5. The method of extraction-mechanical or by hand.6. The method of. working-Iongwall or bord and pillar.7. The availability of material.As a general rule, the pressure exerted by the superincumbent strata may be taken as one pound per square inch for each foot of cover, and the crushing strength of coal as 1,500 to 2,000 lb. per square inch; this, of course, varies, but from these figures it may be assumed that seams below 2,000ft. in depth are liable to crush. If any part of the seam is removed, added weight is thrown onto the remaining coal. It is therefpre essential that for effective working this extra weight must be removed or supported as soon as possible.The outstanding principle in the support of mining excavations is to ensure that the supports are set as soon as possible after the natural support has been removed.Where a system of bord and pillar is applied, the early setting of supports reduces the extent to which the roof bends, thereby reducing the liability to ·tension fractures at the centre of the road.

Jan 1, 1947

MR. E. J. HORWOOD wrote: In view of the difficulty of obtaining accurate results when using plumb lines in shafts, owing to the effect of currents of air, the writer, over M years ago, devised a method of transferring oearings from the surface to, the underground workings independently of plumb lines.An attachment was procured for the theodolite consisting of a 45° prism enabling a view of a fine line stretched across the shaft at the surface to be observed from the bottom of the shaft. The instrument was set up in such a position that.a view of the portion of the surface line could be obtained as close as possible to the shaft timbers.By candle light signals an assistant at the surface moved his line so that the portion close to the side or end of the shaft coincided with the cross wires of the theodolite. The theodolite was then swung to enable the crosswires to traverse the surface line. It was a simple matter to transfer the bearing of the surface line to points in the drive extending from the shaft. Similarly the relation of the bearing of the surface line to the shaft, with which a connection was intended, was easily obtained.The success of this method was demonstrated at Broken Hill in making connections many hundreds of feet from the shafts from which these were driven.

Jan 1, 1940

In this paper presented are the criteria used when assessing the harmfulness of shocks affecting the buildings. Those criteria are based on the value of speed or accelerations of building vibrations. Presented is the scale of harmfulness of vibrations of Langefors and Kihlstrom, Bureau of Mines, and SWD contained in the Polish Norm PN-85/B-02170. The parameters of the mining shocks measured by the Lubin coal mine station were compared with the parameters calculated as per the correlations (regression curves). The average acceleration calculated from the correlations for eight measurements is only two per cent higher than the actual one. But the average frequency of vibrations calculated from the correlations for eight measurements is as much as 2.22 times lower than the actual one. In order to analyse whether that takes place in the whole range of the energy of shocks compared were the results of calculations from the correlations for various magnitudes of shocks and various distances from their epicentre with the results of the measurements. From that it follows that only for the shocks of the highest energies the lowering of the frequency of vibrations by two times causes movement from the higher zone of harmfulness to the lower one (for example from the IV to III). In the one-family houses in Lubin there were the damages that are characteristic for not only for the III but also for the IV sphere of harmfulness as per the SWD scale. That should be explained via further research and maybe it would be feasible to draw out a new correlation to determine the frequencies only for high values of energy of shocks and determine the preciseness of the acceleration and frequency correlations used presently.

Jan 1, 2003

THE exceptional rainfall characteristic of the West Coast of Tasmania, in conjunction with the rugged topography of the district, has always suggested the utilization of water-power, and from the earliest days of the Mount Lyell Company theeventual installation of a hydro-electric power scheme, making use of some near-lying lake, has constantly been kept in view. At the period of the inception of the company, however, the time was not ripe for such an undertaking, and it is only oflate that the various important considerations involved have sanctioned incun;ing the heavy expenditure necessary, with the positive assurance of permanently reaping the benefits expected. The West Coast of Tasmania contains many lakes of varioussites; situated at high levels, and, although the catchments of these lakes are not very extensive, still, the excessive rainfall is so constant over long periods that its regularity may be relied on as offsetting the limited catchments. The explanation of the abnormal rainfall is simply the circumstance that the West Coast Range forms the first high land barrier which is met by the moisture-laden westerly and north-westerly winds blowing off the Southern Ocean. By the time the clouds strike the mountains they ride very low, consequently the elevation of the range, the peaks of which do not exceed 3000 to 4000 ft. above the sea, is sufficient to cause a copious precipitation. Lake Margaret, which is situated five miles north of the reduction works, was first recognized as a possible source of waterpower by Mr. Hugh Ohrisp, a surveyor, who visited it about 1893-4. Earlyl in 1895, while the preliminary work on the erection of the first furnaces of the Mount Lyell Co.'s reduction...

Jan 1, 1915

By P Moser, P Schimek, F Ouchterlony

This paper summarises the findings of 27 model-scale bench blasts in magnetic mortar, which were conducted from 2011 to 2014 at the blasting site of the Montanuniversitaet Leoben.The aim of the study was the investigation of the influence of blasthole delay times in small-scale bench blasts on the face characteristics and cracking damage created in the surrounding rock, which affects the fragmentation in subsequent rows.The test specimens or blocks, which were produced out of magnetite concrete, were roughly 1:100 in scale to normal bench blasts. The confinement of the testing blocks at the sides and back ensured the similarity to normal bench blasts with regard to the wave transmission into the surrounding rock. The specimen contained three or four rows with five blastholes each and were shot row by row, with virgin (undamaged) material in row 1 and increasingly damaged or preconditioned material in the following rows.The tested delay times varied between 0, 28, 73 and 140 µs, which corresponds to 0, 0.4, 1.0 and 2.0 ms/m of burden.The evaluation of the material properties showed that the use of magnetite concrete eliminated the inhomogeneous behaviour of rock, but some unexpected differences of the individual production cycles were still detected.The characteristics of the bench after each blast was evaluated along three horizontal lines out of a 3D model of the bench face. The tested delay time sequences of the virgin (first row) and single preconditioned blasts (second row) produced more overbreak for longer delays, while the third-row shots resulted in a smoothened surface independent of the chosen delay.The introduced damage after every blast was evaluated by an observation of irregularities on the newly blasted bench face. The visible cracks at the top of the testing blocks were documented and divided into several crack families according to their angle, length and origin. The remaining block was broken out of the blasting site after blasting, cut into several horizontal and vertical slices and dye penetrant spray was used to visualise the cracks created. Some of the detected crack families showed an influence of the delay time. The calculated mean crack density and mean crack intersection density showed that longer delays resulted in a higher degree of damage.The fragmentation results were well reproduced by the basic three-parameter Swebrec function. The observed improvement of fragmentation in the second- and third-row blasts was linked to the preconditioning of the burden for the following row while blasting the actual row. With the exception of the simultaneously initiated blastholes, the blasts showed coarser fragmentation for the shortest delays, while the longest delays generated the finest fragmentation.CITATION:Schimek, P, Ouchterlony, F and Moser, P, 2015. Influence of blasthole delay times on fragmentation as well as characteristics of and blast damage behind a remaining bench face through model-scale blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 257–266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

The timber township of Powelltown, Victoria lies N.E. of Yarra Junction, 60 miles east of Melbourne and in the site of the mill of the Victorian Hardwood Company Proprietary Ltd.A lift gauge railway owned by the company connects Yarra Junction on the Warburton line, with the township through two or three smaller mill centres on the way.The company has been operating for some 12 years. In the divide, about four miles from Powelltown, between the Little Yarra and Latrobe rivers, cutting was continued with material being handled by winch and double incline haulage over the divide. A small bush locomotive dealt with the traffic between the divide and the cutting site.In order to reduce costs, which were heavy at the haulage, the company decided to make a continuous railway from Powelltown to the bush by means of a tunnel through the divide.Hand bore holes were put down on the proposed line of tunnel and showed that the divide at this point consisted of decomposed depth of about 100 ft. towards the eastern or Latrobe side - and that the undecomposed granite summit lay to the west of the surface summit.The bores also served to locate the underground water line, this was afterwards found to rise and fall with wet and weather.To avoid tunnelling in hard and heavy water, the grading of the was laid out with the summit of the hard granite the point in the line.

Jan 1, 1925

The most critical step in the development of any mining project is the completion of a feasibility study. The feasibility study has one primary goal; to demonstrate that the project is economically viable if it is designed, constructed and operated in accordance with the concepts set forth in the study. Starting from a mineral resource data base, the feasibility study will define the ore reserves, the mining methods, the mineral processing concepts and the scale of the project. The disciplined activity of developing a feasibility study leads the proponent to examine every aspect of the project, many of which might otherwise be ignored. All technical concepts will be established and the corporate philosophy with respect to organisational structure, social and environmental responsibility, infrastructure contributions and financing will be determined. All the major decisions about how the project will be developed are made during the feasibility study. The success of the project will then depend upon the assumptions and decisions in the feasibility study and the ability and empowerment of the development team.

Jan 1, 1997

In terms of tunnelling the mining industry is generally thought of as the crude cousin of the civil construction industry. Mining has tended to concentrate on speed and flexibility rather than the high standards required in civil tunnelling. Historically this difference has been based on the belief that such high standards were not required by the mining industry, they would slow down the development of the project and as a result increase the costs and extend the time period between start up and a positive cashflow.For civil works the construction of a tunnel is the project, for mining the construction of declines, crosscuts and drives are merely the means of accessing the orebody so that the real work can begin û MINING. Extraction of ore is the core business of most mining companies û it is what pays the bills.Though most mining companies have the equipment, the people, the knowledge and the ability to excavate tunnels, in the past mining companies did not appear to put the same energy into their tunnelling operations as they put into improving their ore extraction operations. In the past decade this appears to have changed, many mining companies now realise how important the correct excavation of a decline is to the success of the overall mining operation. They began to recognise that there were cost benefits to be gained in using the correct development techniques without overly sacrificing the benefits of speed and flexibility.This recognition also coincided with the growth of underground contractors whose predominant work was primary development (declines and ore access crosscuts and drives). The contractors again had the same knowledge, the same people, and similar equipment but their focus was different from that of the mining company û the contractors were focused on the development of the mine, the excavation of declines, crosscuts and drives. These deliverables were the contractorsÆ core business û itÆs what paid the bills.

Jan 1, 1999

The Sto Tomas II orebody of Philex Mining Corporation is a porphyry copper deposit located at Padcal, Tuba, Benguet, Philippines. It was mined through open pit method for the first two years starting 1958 and subsequently through underground method using the Block Cave System. The slusher type of draw was employed at the upper levels of the orebody from mid-year of 1959 up to 1994 and then shifted to LHD as the ore became more competent at the lower levels. Application of rock mechanics played a vital role during the conceptualisation of the LHD method of draw, the first of its kind in the Philippines. Rock mechanics is a combined responsibility of the geology and the mine engineering staffs, with the geology providing the vital information to the mine engineering to include in the mine planning the following:the general geology of the orebody; the ground characterisation through rockmass classification; determination of the cavability of the ore column (this includes our experience on airblasts which occurred during the early stage of our last slusher blocks); undercutting sequence; fragmentation of the rockmass in the ore column; drawzone spacing; proper draw control procedure; lay-out of openings; and the design of ground supports based on the rockmass condition. For the proper interpretation of the rockmass that would cater to the diverse mining situations, Philex adopted the modified geomechanics rockmass classification (Mining Rockmass Rating, MRMR) as this system is recognised and used by most of the block cave mine worldwide. This paper aims to discuss and present the role of rock mechanics in the analysis and determination of geomechanical issues encountered in Philex mechanised block cave operation.

Jan 1, 2000

The problems arising in the excavation of hard rocks with the use of mechanical tools consist chiefly in a slow advance rate accompanied by an intensive wear due to the toughness and abrasiveness of the rock. In order to allow the further extension of mechanical excavation beyond the limits of the presently available technology, the assistance of waterjet aiming at improving the performance of the equipment while reducing the wear rate of the tools, has been recognised as one of the most interesting technical solutions. The paper illustrates the improvement of the performance of both disk cutters and picks obtained with the waterjet assistance at the Waterjet Laboratory of the University of Cagliari on a medium-hard rock.

Dec 6, 2010

By C X. Zhang, W K. Ru, S C. Hu

To study the creep properties and the energy evolution characteristics of the weakly cemented rock (WCR) in western China, the creep deformation damage law of weakly cemented mudstone (WCM) under graded loading and the energy evolution characteristics of each creep stage were analysed based on the triaxial graded loading creep test of WCR. The results showed that as the confining pressure increased, the creep failure strength of the WCM increased from 9.5 to 24.8 MPa, and the relative displacement of the mineral particles in the mudstone increased gradually, resulting in a reduction in the fracture angle from 79.7° to 58.3°. At the same stress level, the strain energy Ue, the total energy U, and the dissipation energy Ud all increased as the confining pressure increased, but the growth rates of U and Ud decreased gradually, while the growth rate of Ue remained high. At the end of the stable creep stage, Ue increased slowly with the confining pressure, while U and Ud increased rapidly with the confining pressure, and their growth rates were basically the same. At the end of the accelerated creep stage, the growth trends of these three energies were all positively correlated with the confining pressure, Ue was significantly lower than that at the end of the stable creep stage, and Ud and U were further increased. These results revealed the unique creep properties and energy evolution characteristics of the WCR, providing a theoretical basis for long-term stability control of roadways that are built with WCR.

Nov 29, 2022

By T C. Souza Pinto, M Safari, F S. Hoseinian, D Deglon, L Leal Filhoc

In this study, the effect of hydrodynamic parameters on the iron ore reverse was investigated in a mechanical flotation cell. The work carries out using the case study of Iron ore from Vale in Brazil. The influence of hydrodynamic factors such as froth height, impeller speed, superficial gas velocity and solids percentage were evaluated on the quartz flotation. The results showed that the hydrodynamic conditions have a great effect on the flotation performance, especially on the fine and coarse quartz. The size-by-size analysis of the froth products showed that froth height, impeller speed, superficial gas velocity and solids percentage have a significant effect on true flotation quartz particles. The increase in the froth height decreased the recovery of quartz particles. The increase in the impeller speed increases the recovery of quartz particles to an optimum. The increase in the superficial gas velocity improved the flotation of coarse quartz particles. The increase in the solids percentage increases the recovery of quartz particles.

Sep 18, 2023

By Tsuchida N

The history of world nickel production has been affected significantly by the supply and demand situation and fluctuation of LME price of nickel metal. In the beginning of the 1980s, the decline of price and demand lead to the withdrawal of un-competitive producers and the shrinkage of the production capacity. During the same period, Sumitomo Metal Mining maintained the production level with continuous improvement of the traditional matte electrorefining process. However, Sumitomo has recognised that the continuous improvement alone does not promise us the ability to catch up with rapid changes in the world. In the meantime, Sumitomo intensively researched chloride hydrometallurgy and has developed the chloride process for the nickel refining. This includes the solvent extraction and chloride electrowinning in the mixed sulphide process and the chlorine leach of the anode slime arising from matte electrorefining. In the late-1980s, Sumitomo Metal Mining decided to develop a new nickel refining technology based on chloride hydrometallurgy. The new process was designed from the comprehensive aspects involving safety and the environment. Construction of the plant for the matte chlorine leach electrowinning (MCLE) process was commenced in 1991. The MCLE plant with a capacity to 2000 tonnes per month has been commissioned at Niihama since 1992. The process has provided high productivity, overall good economics and high quality of electrolytic nickel produced. After the establishment of the process, Sumitomo has maintained continuous improvement of the new process and has attained the best practice of the work classification.

Jan 1, 1996