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By C. A. Pickles, K. Mackowiak, D. Gajonera

"Shake-flask oxidation tests were performed on Red Dog mine waste to study the initial dissolution behaviours of lead, zinc, and iron. The conditions for accelerated acid generation in terms of Eh and pH were determined. Each mineral behaved distinctly, with galena dissolving first, followed by sphalerite, then pyrite, although there was some overlap in behaviour. Iron was not detected in solution until approximately day 40 and was present at low concentrations. The experimental conditions and the theoretical model results indicated the formation of iron oxyhydroxides at low weathering times and jarosite at longer times.RÉSUMÉ Des tests d’oxydation par agitation en flacon ont été effectués sur les déchets miniers de l’exploitation Red Dog afin d’étudier les comportements initiaux de dissolution du plomb, du zinc et du fer. Les conditions entraînant la production accélérée d’acide en termes d’eH (potentiel d’oxydoréduction) et de pH (potentiel d’hydrogène) ont été déterminées. Chaque minerai se comportait différemment ; la galène a été la première à se dissoudre, suivie de la sphalérite, puis de la pyrite, mais un certain chevauchement des comportements a été observé. La présence de fer en solution n’a été détectée qu’après environ 40 jours et ce, à de faibles concentrations. Les conditions expérimentales et les résultats du modèle théorique signalaient la formation d’oxyde-hydroxyde de fer sur de courtes périodes d’altération atmosphérique, et de jarosite sur des périodes plus longues."

Jan 1, 2017

By Ellis Thomson

The microscope is now used extensively not only in the examination of solid ore but also in the determination of fragmental mill products. It has therefore become a matter of paramount importance to be able to mount and polish fragmental as well as solid specimens in the easiest and most efficient way, so that the minerals present may be readily determined. In the case of the solid ore the ordinary mount of plasticine set on a glass or metal slide serves for most practical purposes. An improvement on this is furnished by the small brass container inside of which the specimen is mounted in a cementing medium of sealing wax. The latter is the method in use at Harvard University. It has the advantage of uniform height, thus obviating the necessity of a slide of any sort. It is also easily catalogued as the brass holder may be stamped with a convenient series of letters and numbers that will serve as a label. Other advantages of this type are the ease with which any particular part of the section may be re-located, the excellent storing facilities afforded by mounts of uniform size, and the possibility of polishing ten or a dozen sections at the same time by means of a holder which is placed over the polishing wheel, is geared with it, but revolves the opposite way.

Jan 1, 1926

By A. Longval, Q. Jiao, T. Shannon

In 2000, Xstrata Zinc (former Falconbridge Ltd.) Brunswick Smelter commissioned a modified lead blast furnace. Since then, efforts have been made to improve its operation in order to achieve optimal operation in terms of coke consumption, lead loss to slag, and improved environmental and hygiene conditions. This paper will review the important step changes in operational philosophy, undertaken since 2004, for the control of the blast rate, oxygen enrichment in blast, slag chemistry and charge level. Furthermore, a review of the improvements made in secondary materials consumed at the blast furnace will be made. This paper will also discuss the significant reduction of the frequency of accretion removal as a result of improved furnace operation.

Jan 1, 2008

By C. Joulian, A. G. Guézennec, A. Chmielarz, Y. Ménard, M. Hanke, P. d’Hugues

"The copper concentrate used in this study is produced by flotation of a black shale organic rich ore. This resource is a carbonate-rich, polymineral concentrate. In the last 5-6 years, ore characteristics changed and the concentrate grades degraded. This study evaluated bioleaching of the concentrate in stirred tank reactors as an alternative to the pyrometallurgical technology that is currently applied, and which may no longer be feasible in future given the concentrate chemistry.The first part of the study focused on testing non-traditional operating conditions during continuous bioleaching experiments: high solids concentration (> 20% solids), reduced agitation and aeration rates. For the same residence time, bioleaching performance at high solids loading (25%) was the same as that reached during previous bioleaching experiments at 15% solids. No mixing or microbial issues were encountered. The bacterial consortium used in the experiments demonstrated a high copper tolerance.The second part of the study was devoted to technology development for metal recovery from copper bearing solutions obtained during bioleaching experiments. Due to the high copper concentration of the leachate, solvent extraction prior to electrowinning was not necessary. After iron removal, high quality copper cathodes (morphology and composition) were obtained from the PLS by electrowinning."

Jan 1, 2014

By T. W. Bingay

The production of both lead and zinc in Canada has steadily increased during recent years until today Canada ranks among the world's leading producers of both of these metals. The high prices which they have commanded have led to an energetic search for new deposits and also to an investigation of abandoned properties which, under the present conditions of better prices and more efficient methods of treatment, offer chances of commercial success. It is confidently expected that during the next few years success in both these lines of activity will further increase Canada's lead and zinc output, giving her a still higher ranking among the world's producers. In 1926, approximately 140,000 tons of metallic lead was produced from ores mined in Canada, and of this, 125,000 tons was refined in Canada at Tadanac, B.C. During the same year the production of metallic zinc from Canadian ores amounted to 68,000 tons, of which 62,000 tons was refined at Tadanac. History Of Lead and Zinc in Canada The production of lead in Canada is much older than that of zinc. The chief source has always been the interior of British Columbia. As earl y as the 'eighteen twenties', Indians and Hudson's Bay Company's trappers had discovered an outcrop of lead ore on the site of the present Blue Bell mine on the east shore of Kootenay lake, but it was not until1865 that active prospecting for lode deposits began. In the early nineties the activity of the silver-lead-zinc region of the Slocan reached its culmination and a steady production has been maintained down to the present time. Up to the end of 1924 the Slocan area produced over 38 million ounces of silver, nearly 300 million pounds of lead, and almost 122 million pounds of zinc.

Jan 1, 1927

By Jing Li, Weiqiang Lai, Joe Zhou, Jiezhen Ma, Shuibo Chen, Ashele Copper Company, Feng Gao, Guofu Feng

"Copper-zinc ores often contain gold and silver, which can be recovered into copper concentrate by flotation as by-product. The challenges for operations that produce copper, zinc, gold and silver are the separation of copper and zinc and the low grade of precious metals. Ashele copper-zinc ore in north China contains 2.38% Cu, 0.69% Zn, 0.21 g/t Au and 18.10 g/t Ag and the plant produces copper and zinc concentrates, with gold and silver being recovered into copper concentrate. Copper occurs mainly as chalcopyrite and Zn occurs as sphalerite. Copper is well recovered with a recovery of over 94%. However, the recovery of Zn is substantially low (around 50%) due to fine grain size of sphalerite. In addition, gold recovery is much lower than expected and only 33% of gold in the flotation feed was recovered. The grade of gold in copper concentrate is also lower than the required payable grade (1.0 g/t). To determine the cause for lower Zn and Au recoveries, a plant survey program was conducted on the operation. The information acquired shows that the loss of Zn was mainly in the copper concentrates (accounting for approximately 38% of the head assay); of which, 24% was liberated, 8.5% was associated with chalcopyrite and 4.6% was associated with pyrite, indicating that the separation of copper and zinc was the main cause for the Zn loss, with liberation being the second cause for Zn loss. Future effort in improving Zn recovery should be focused on the separation of zinc from copper. Gold in the ore occurs as both microscopic gold and submicroscopic gold, accounting for 36% and 64% of the head assay, respectively. Microscopic gold occurs mainly as native gold and electrum; it is relatively coarse with a grain size of 10 to 240 µm and a large portion can be recovered by gravity. Submicroscopic gold was mainly carried by pyrite (accounting for 38%), and to a less extent, by tennantite (15%) and chalcopyrite (10%). Gold in sphalerite is nominal (1%). It is suggested that more coarse gold and tennantite be recovered and a gold recovery increase can then be achieved to obtain a copper concentrate with over 1.0 g/t Au through flowsheet optimization. Gravity concentration should be investigated and may be worth added into the existing flowsheet to maximum the gold recovery and grade.INTRODUCTIONCopper-zinc ores containing gold and silver is a subtype of polymetallic sulphide ores. Unlike porphyry copper sulphide ores and iron-oxide copper-gold ores, this type of ores often contains substantial amounts of zinc and lead. Polymetallic sulphide ores are mainly distributed in Canada, such as at the LaRonde and Horne deposits. Other examples include Mt. Morgan in Australia and Boliden in Sweden. Globally, production and reserves from gold-rich VMS deposits account for 1370 t gold. This is equivalent to 1% of the world production and reserves, whereas the Canadian total for gold-rich VMS deposits is 870 t, representing close to 10 % of Canadian production and reserves (Gosselin & Dube, 2005a, 2005b). Flotation is the principal process for processing the copper-zinc sulphides ores, for subsequent smelting, roasting, or hydrometallurgical treatment. Oxidized copper-zinc ores can also be processed using leaching technology. For example, at LaRonde operation (a Cu-Zn-Pb ore containing 3-4 g/t Au and 60-100 g/t Ag) the flowsheet consists mainly of a copper flotation circuit and a zinc flotation circuit followed by a cyanidation process of flotation tails. The precious metals are recovered with copper concentrate, zinc concentrate and cyanidation of zinc tails via Merrill Crowe precipitation (Zhou et al., 2005)."

Jan 1, 2016

By D. KEYS, D. E. Gemmell

The portion of the earth's surface covered by peatlands has been conservatively estimated at over 420 million ha (Kivinen and Pakarinen 1980). It is estimated that there are about 170 million ha of peatland in Canada. New Brunswick contains about 140,000 ha. Harvesting of peat for horticultural purposes has been carried out in New Brunsiwck since 1942. This industry, and the potential for using peat for energy purposes, indicated the need for an accurate assessment of the resource. In 1975, therefore, the New Brunswick Department of Natural Resources began a detailed peatland inventory. Assistance from the Canada Department of Regional Economic Expansion permitted acceleration of this program and field work was completed in 1982. Information gathered by the program will form the basis for a management plan for future use of the resource.

Jan 1, 1984

By A. D. Misener

Introduction Temperature gradients have been determined for numerous locations in the Canadian Shield in connection with mining operations (1, 2, 12, 13, 14, 15). As part of a programme of geophysical studies of this region, some of these gradients were re-determined by the writer at locations where other thermal properties, specific heat, thermal conductivity, radioactivity, etc., were also to be measured. The ultimate object was to determine the heat flow to the surface at these locations. It was felt that the practice of determining heat flow from the temperatures and conductivities obtained in a single vertical bore hole (3, 4, 5, 6, 7, 8, 9) might give results which were appreciably divergent from the average for a considerable area. Particularly, it was thought that temperature gradients, whether obtained in a single vertical hole or from a number of random locations at various depths in a mine, might be subject to local variations and anomalies serious enough to render unsure any discussions based on them. The procedure followed in this investigation was to select a location where mine workings extended to considerable depth over a reasonably wide area. At selected depths below surface, horizontal drill holes extending into regions of undisturbed rock were located and resistance thermometers were inserted into these holes far enough to record the true rock temperature. An attempt was made to obtain a sufficient number of readings at or near any one level to give a representative coverage of the area selected. This ideal could not always be attained, but the large number of readings obtained for each are a does give a reasonably representative picture of the temperature conditions. These readings required much rime and movement of men and equipment underground . They could not have been obtained without the wholehearted co-operation of the management and considerable assistance from the personnel of the mines concerned.

Jan 1, 1949

By V I. McCallum

In 1954, Falconbridge Nickel Mines Limited began the program of deepening the Falconbridge mine workings for 2,000 feet below the bottom, or 4025, level in order to provide twelve new levels for production. Involved in this program were a production-sized internal shaft, .crushing, pumping and hoisting installations, the integration of the new shaft operations with those of existing shafts, and considerations of ventilation requirements and ground support at depth. This paper describes the major items of equipment, and the depth development of No. 9 shaft as a whole, and also emphasize the planning phases of the program. The factors involved and reasons for the equipment and layouts chosen are given. Introduction and History THIS paper describes the planning and development of that portion of the Falconbridge mine between the 4025 and 6050 mining levels. This mine, the oldest of several being operated by Falcon-bridge Nickel Mines Limited in the Sudbury district, has been a continuous producer for over thirty years.

Jan 1, 1964

By L. R. Hougen

The Falconbridge Matte Leach Process yields high-purity nickel chloride by selectively dissolving nickel from copper-nickel converter matte with hydrochloric acid , purifying the solution by solvent extraction and crystallizing NiCl2 4H2O by further acidifying the purified leach liquor. In the Kristiansand Matte Leach Plant, a granular oxide is produced by high-temperature hydrolysis of the nickel chloride for subsequent reduction to a high-purity granular metal product, designated NICKEL 98. This paper describes the investigation of on alternate route to processing nickel chloride in which high-quality cathode nickel is produced by electrowinning from all- chloride electrolyte. The investigation was made in a pilot circuit containing two production-size electrowinning tanks operated in conjunction with the commercial-scale leach plant.

Jan 1, 1977

By L. Li, K. Jiang

China is the world largest producer and consumer of zinc. Beijing General Research Institute of Mining and Metallurgy (BGRIMM) is one of major research and engineering institutes for nonferrous metallurgy in China. This paper (presentation) introduces the development of China’s zinc smelting industry, key production processes and main producers. The process research and development are reviewed as well as BGRIMM’s R&D activities in the last decade. China's refined zinc production was 4,829kt in 2012, accounting for 38.6% of world production. Primary production was 4,722kt. There are around 150 refined zinc producers in China. The traditional fluid bed roasting - leaching jarosite is still a dominant process for primary production and its production accounts for about 60% of country's total production. However, the direct leaching process is gaining market share. Seven direct leaching plants with 330kt/a capacity, including autoclave leaching and the Outotec direct leaching, have been put into production by June 2013. Five autoclave leaching projects with 590kt/a capacity are in the pipe line and are expected to be commissioned in 2014 and 2015. To cut the production cost and improve smelter economics, process research to optimize the production flow sheet, to improve the iron removal and to enhance the recovery of co-existed rare metals were carried out. The development trends of China’s zinc smelting industry from the view of cutting production cost, improving energy efficiency, increasing comprehensive utilization are discussed accordingly.

Jan 1, 2014

By David R. Lentz

Abstract -At True Hill in southwestern New Brunswick, low-grade porphyry-style Bi-Sn-Mo greisen mineralization is associated with the cupola of an epizonal granite porphyry (granite) that also exhibits three episodes of brecciation. The first episode of brecciation is an in situ, 8 m to 10 m wide transitional zone of net-veined to coarse-grained "blocky" endogranitic mesobreccia that is chloritized and greisenized and hosts weak disseminated mineralization. ln a zone doser to the host rock­ granite contact, angular fine- to coarse-grained endogranitic mesobreccia with greisenized matrix is superimposed on the earlier transitional breccia. The latest episode is fault-controlled and consists of quartz- and chalcedony-hosted subangular to rounded fine-grained "pebble" mesobreccias that crosscut and brecciate the other breccia types, as well as the adjacent altered metasedimentary country rocks. The first two episodes of brecciation are magrnatic-hydrothermal in origin related to hydrofracturing of the granite carapace and are accompanied by greisenization and mineralization, whereas the post-mineralization, silica-hosted, "pebble" mesobreccias related to hydromagrnatic, low­ temperature fluid circulation and/or boiling along faults near the contact. These magmatic­ hydrothermal and hydromagmatic mesobreccias are similar to those associated with W-Mo-Bi porphyry-greisen mineralization at the Mount Pleasant deposit.

Jan 1, 1994

The primary steel industry of the Prairie Provinces consists essentially of three companies whose total annual melting capacity, as of January 1, 1963, was 333,000 net tons. These companies have steel rolling facilities. In addition, there are five other companies producing steel castings by melting scrap in electric furnaces which, with the plants having rolling facilities, gives a total annual furnace melting capacity of 380,000 tons. Since 1954, the annual production of steel ingots and castings has ranged from a low of 66,588 tons, in 1954, to a high of 211,138 tons in 1961. The present facilities on the Prairies for making steel ingots from scrap, and rolling them to produce light merchant mill products, appear to be sufficient for many years ahead. Steel scrap, as electric furnace feed to make steel ingots for the present line of products, will probably continue to be available at reasonable prices either on the Prairies or from the north-central United States. It is recognized, however, that residual elements in scrap may be-come of greater significance and necessitate more rigid control of scrap quality.

Jan 1, 1963

By T. A. Utigard, S. Pedler

Ilmenite from the Everett deposit in Quebec was characterized both chemically and mineralogically. The sample investigated contained the following main components: 40% Fe2O3, 21% TiO2 and 21% SiO2. The ilmenite grains contained about 20 to 25% hematite intergrown blades, with widths ranging from 2 to 30 \u03bcm. Crushing the sample to less than 0.85 mm led to significant liberation of the ilmenite from the gangue minerals. Gravity separation followed by magnetic separation of this size fraction led to a TiO2 concentrate grading of about 30% TiO2, with a recovery of 94%.

Jan 1, 2010

By Dharmendr Kumar, Pradip, Sivakumar Subramanian, Beena Rai, Venugopal Tammishetti

The separation efficiency in a mineral processing plant is generally assessed and reported in terms of elemental assays constituting the minerals of interest. However, different minerals comprising of same elements behave differently under similar process conditions. Thus, it is imperative to track the mineral composition thank elemental composition of different streams in a processing plant. The availability of automated mineral analyzers such as QEMSCAN and TESCAN in recent times has made it possible. However, due to the high cost and expertise required, their adaptation in day to day monitoring of operations is not yet a common place. X-ray diffraction (XRD) profile fitting (Rietveld Refinement) is another technique which can provide estimates of mineral proportions in a sample. The results of Rietveld Refinement however are affected by coating of fines on coarse particles, method of sample preparation, particle size distribution of sample, elemental substitution in mineral crystal lattice. In the present work, we propose a simple and efficient method for quantitative estimation of minerals in iron ores using elemental assays and thermo-gravimetry analysis data. The minerals (hematite, goethite, gibbsite, kaolin and quartz) are identified using powder XRD analysis. It is also observed that goethite contains Al substitution in the crystal lattice. The samples were analyzed for %Fe, %Al2O3 and %Silica using chemical analysis. The measured Loss on Ignition (LOI) in the sample is contributed from goethite, gibbsite and kaolinite phases. LOI from gibbsite and goethite occur in temperature range 250–350°C and LOI from kaolinite occur in temperature range 400–700°C. According, LOI are determined in two different temperature ranges that are 100–400°C and 400–850°C. We have used the data to successfully determine the mineral compositions of iron ore samples. We have also employed a data reconciliation algorithm on the calculated data for further improvement and consistency of our results. Our method is very convenient for quick estimation of mineral proportions in a sample. The proposed method can also be used for quantitative phase estimation in bauxite ores and red muds.

Jan 1, 2016

By C. Nikolic

A process utilizing ozone for the precipitation of cobalt from nickel sulphate liquors containing ammonium sulphate has been developed. Best results were obtained using nickel carbonate to maintain solution pH at 5.0 to 5.5. Work was performed both in column and stirred-tank reactors. Variables studied included neutralizer type and concentration, NH4+ concentration, temperature, Ni++ and Co++ concentration, per cent O3 in the O2 carrier gas, O3 input rate and agitation. The over-all rate of cobalt rejection increased sharply with increasing agitation and ozone concentration in the gas phase, reflecting relatively slow transfer of ozone from the gas to the liquid phase.

Jan 1, 1978

By I. Vazaios, M. S. Diederichs, N. Vlachopoulos

"As rock engineering moves from continuum to more discontinuum approaches for modeling, the engineer must make decisions regarding the degree of complexity to simulate for a given application, balancing the level of structural detail within the rockmass model with computational cost and result accuracy. It is important to consider that model does not need to include all the existent fractures and that representative geometrical properties for a given rock mass volume can be defined including only major structural entities.Within this paper, the scale-dependency associated with the geometrical properties of fractured rock is investigated utilizing a Synthetic Rockmass (SRM) approach with a view to characterize such ground to aid in the design of geotechnical works. In terms of process, the concept of the Representative Elementary Volume (REV) is used to determine the equivalent structural properties of the rockmass in order to justify the applicability of far-field behaviour of such ground. A large size Discrete Fracture Network (DFN) measuring 60m x 60m x 60m has been generated using the structural data obtained from LiDAR scanning of the Brockville Tunnel, Ontario, Canada. A number of DFN samples of varying sizes are extracted from the master network, generated using MoFrac, in order to be used as a the basis of the structural analysis of the rockmass. Volumetric measurements for the density and the intensity of jointing are employed in order to approximate the geometrical REV for the networks.In this paper a complete methodology of how to generate a DFN from LiDAR data and its analysis in order to determine the size of a geometrical REV is demonstrated. For the specific rockmass found in the area of the Brockville Tunnel, a geometrical REV measuring 3.5m x 3.5m x 7m is established. The results are generally in good agreement with the in-situ observations."

Jan 1, 2015

By X. T. Zeng, X. Z. Ding, W. R. Chen, L. R. Zhao

The effect of deposition defects in metal nitride coatings on erosion behavior is presented. AlCrN, AlTiSiN, TiSiN and TiSiN:MoS2 coatings were fabricated by reactive cathodic arc evaporation and unbalanced magnetron sputtering processes. The microstructure and mechanical properties of the coatings were characterized by X-ray diffraction, scanning electron microscopy and nanoindentation, and the erosion property was assessed by solid particle impingement testing. The erosion characteristics on the coating surface and cross section were analyzed and correlated to the defects, which played an important role by promoting formation of erosion pits.

Jan 1, 2006

By S. Shairp

"After cooling and thickening, slurry from the second stage of the Hudbay zinc pressure leach circuit is filtered and washed on a belt filter prior to disposal. At times, the belt filter can be a bottleneck to the process. Preliminary studies show that filterability of the second-stage (HAL) autoclave leach residue can be indicated by particle size distribution of the filter feed and filtered residue cake. In particular, the Volume Weighted Mean Diameter, D[4,3], generated by a laser diffraction particle size analyzer from samples of HAL Filter feed, shows residues that filter more poorly have a lower Volume Weighted Mean Diameter than those that filter better. INTRODUCTIONHudbay produces cast zinc metal from blends of zinc concentrates at its metallurgical complex in Flin Flon, Manitoba, Canada, using Sherritt’s two-stage pressure leach process (Collins et al., 1994; Collins et al., 1995; Barth et al., 1998; Shairp et al., 2006). Pressure leaching replaced the original roastleach- electrowinning process in 1993.Filtration for the second-stage (HAL) leach residue originally consisted of two stages of vacuum drum filtration with intermediate cake repulping stirred tanks. As part of Hudbay’s 777 Project, with a designed increase in cast zinc production, a pre-feasibility study by SNC-Lavalin Inc. showed that losses of soluble zinc in the zinc pressure leach residue could be reduced by installing more efficient filtering and washing equipment. Based on laboratory performance, capital cost, installation ability, and potential operating cost savings, a 70 m2 Filtres Phillipe belt filter was chosen for the HAL residue, and commissioned in 2000/2001.When the HAL belt filter is performing well, there is no pooling of water on the surface, moisture content is relatively low, and subsequent analysis shows that water soluble zinc content is relatively low. There have been occasions where the filter has performed poorly with respect to the aforementioned parameters. Aside from the filter experiencing mechanical difficulties, there are several variables affecting leach residue filtration:"

Jan 1, 2012

By H. P. Kang, Y. J. Feng

The hard roof in underground coal mines is generally considered as a main cause that induces disasters in working faces and entries, such as rock burst and windblast. Hydraulic fracturing technology is an effective approach to weaken hard roof to reduce ground pressure and control rock burst. The state and achievements associated with hydraulic fracturing technology applied in Chinese coal mines are summarized in this paper. Theories related to hydraulic fracturing are of the essence in fracture design to determine the fracture initiation and propagation pressure and predict the geometry and the characteristics of hydraulically induced fractures. Initially, theory of elasticity was employed to determine the breakdown pressure for a vertical borehole where the rock medium is assumed to be elastic. However, porosity and pore fluid have an influence on the borehole breakdown pressure, and then the poroelasticity theory was applied. Arbitrary deviated boreholes in practice are rather common and the maximum tensile stress criterion was employed to determine borehole breakdown pressure. The effect of natural crack in the rock medium on the initiation pressure has been taken into consideration through fracture mechanics. Meanwhile, considerable achievements have been made on hydraulic fracturing tools and equipment, and a set of mature hydraulic fracturing technologies for hard roof control are available. Some comprehensive investigations on the hydraulic fracturing for hard roof weakening are presented, and successful field applications in the Jincheng and Luan coal mining districts are introduced. Finally, the unsolved problems related to hydraulic fracturing are also put forward.

Jan 1, 2015