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By E. M. Stiles

THE Wellington Lake power plant of the Consolidated Mining and Smelting Company of Canada, Limited, about 25 miles from Goldfields, Saskatchewan, is the second hydro-electric project operating in that Province, the first being the Island Falls plant of the Churchill River Power Company which serves the operations of the Hudson Bay Mining and Smelting Company at Flin Flon, Manitoba. The Churchill River project develops 90,000 h.p. at 56-ft. head; the Wellington Lake plant 3,300 h.p. at 75-ft. with pro-vision for an additional 3,300 h.p. unit. Churchill River power is trans-mitted at 110,000 volts over a 58-mile line of steel towers to Flin Flon and an additional 45 miles over a wooden pole-line to Sherritt-Gordon. Our steel tower-line is 22 miles long, and the voltage is 60,000; this choice be-cause certain such equipment was available from Trail. The diversion of 15,000? second-feet at 56-ft. head for 90,000 h. p. at Churchill river dwarfs our 500 second-feet flow at 75-ft. head for 3,300 h.p. In both cases, the main obstacles to be overcome during plant construction were the lack of transport facilities and the short open season. Let it be noted here that this paper deals mainly with those phases of plant construction which were particularly interesting to the writer. With-out these variations from the ordinary routine, this is just another power project whose story is better told by the accompanying charts and pictures. To many members of the Institute it is still just that; but I am writing for those who, like myself, have been too seldom responsible for major under-rakings at an appreciable distance from a railway siding. When it was planned in early 1937 to erect a 1,000-ton mill at our Box mine, both hydro and Diesel power were discussed. With ten years' ore in sight, even an expensive hydro project, such as ours turned out to be, produces kilowatts materially below the 2-cent operating cost of a Diesel plant using fuel-oil at 14 cents a gallon.

Jan 1, 1940

By K. Fagerlund, L. Rosenback, T. Mäkinen, Y. Anjala

This paper deals with the nickel smelter and refinery concepts Outokumpu has applied at Harjavalta and several other plants. Also other process routes and modifications developed and tested by Outokumpu during the recent years are highlighted. Outokumpu started nickel production in Harjavalta in 1959. Until 1995 the Flash Smelting - Peirce-Smith (PS) converting route was applied. High grade nickel matte from the converting step was further refined by means of leaching and electrowinning to produce cathode nickel. In 1995 the nickel production capacity was increased from 17 000 t/a to 52 000 t/a based on the Direct Outokumpu Nickel Smelting Process (DON). In the DON process PS converting is eliminated and high grade nickel matte with low Fe-content is directly produced in the flash smelting furnace (FSF). Metal values from the smelting slag are recovered in the electric furnace (EF) as iron containing Ni-matte. The DON process can be operated with either two matte concept, where high grade FSF matte and EF matte are produced, or a single matte concept, where EF matte is recycled to the smelting furnace and thus only one type of high grade matte is obtained. The additional refinery capacity at Harjavalta is based on hydrogen reduction producing.

Jan 1, 2005

By J. R. Welsh, D. J. Palmer, O. M. G. Newman

"The use of calcine for selective zinc precipitation requires specialist knowledge to achieve satisfactory flowsheet design. Calcine from the bed of a fluid roaster is preferred, and factors such as the size distribution of ground calcine, the stoichiometric ratio of the calcine precipitant to the initial dissolved zinc concentration and the moisture content of the resultant filter cake are parameters which require critical attention. Extensive testing in a fully-integrated electrolytic zinc plant pilot plant has demonstrated that properly designed selective zinc precipitation plants using calcine as the precipitant are reliable operating units.The advantages of using calcine instead of limestone for selective zinc precipitation include a decreased cost of reagents, as well as avoiding the formation of by-product gypsum.Process simulation modelling has demonstrated that the use of calcine in this context has widespread application in the design of zinc plants with superior impurity and water balance control characteristics. A particularly powerful approach involves closed circuit washing. In this mode, filtrate from the selective zinc precipitation step is used to wash a zinc plant residue such as jarosite, and the resulting filtrate is returned to the selective zinc precipitation section. IntroductionThe Selective Zinc Precipitation (SZP) Process, developed and patented by the Electrolytic Zinc Company of Australasia Limited (EZ) may be used to achieve simultaneously, water balance and impurity control in an electrolytic zinc plantO,2). Impurities which may be controlled by the SZP process include chlorine, magnesium, manganese, potassium and sodium.In the SZP process, basic zinc sulphate is precipitated from a zinc sulphate solution by either limestone, lime or a compound containing zinc oxide, usually calcined zinc sulphide concentrate (calcine) or alternatively zinc oxide fume .The solids containing basic zinc sulphate are separated, typically, by filtration and returned to the zinc plant circuit as a neutralizing agent. The zinc depleted solution can either be discarded, or used to wash residues, thereby achieving water balance and impurity control (Fig. I)."

Jan 1, 1988

By John B. Hodgeson

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

Jan 1, 1938

By W. M. Brewer

Introduction This paper describes some of the mineral resources that are tributary to that portion of the Pacific Great Eastern railway included in the Western Mineral Survey District, No. 6, of British Columbia. This district extends 38 miles northerly from Squamish, the ocean terminus of the railway at the head of Howe sound, to Alta lake. Beyond Alta lake the railway continues northerly through two other mineral survey districts: the Central Mineral Survey District No. 3, and the Northeastern District No. 2. District No. 6 includes that section of the Coast Range from which the waters flow southerly towards Howe sound. The division between District No. 6 and District No. 3 is represented by an imaginary line across the summit between the headwaters of the Cheakamus river, flowing south into the Squamish, and the Green river which flows north and empties into the head of Lillooet lake near Pemberton meadows, about 20 miles from Alta lake. History: - The history of the route of the P. G. E. railway dates back to the old Cariboo days when a pack-horse trail traversed the country northerly from Squamish to the Pemberton meadows, and also south-easterly from Squamish to the head of Seymour creek, thence southerly down that creek to the north arm of Burrard inlet.

Jan 1, 1925

By R. L. Alexander

"Madawaska Mines Limited, incorporated in 1975 is the successor to Faraday Uranium Mines Limited. The history of the latter's mine development and corporate changes are outlined. This paper describes the geology of the Bancroft area and the rock types found in the mine, particularly the pegmatite which is the host rock for the uranium. The structure, mineralogy and distribution of the ore shoots are described with the method of grade control and mine development. The paper concludes with a summary of the production and mineral reserves.Location, Access, and PropertyMadawaska Mines Limited is located in Faraday Township, Hastings County, Ontario. The mine is in the N.T.S. quadrant 31 F/ 4, Bancroft sheet and near 46 degrees 01 minute latitude, 77 degrees 46 minutes longitude. The mine is one-half mile north of Highway 28, five miles (8 km) west of Bancroft, and is accessible by various highways from Toronto, Ottawa, Peterborough, and Belleville. (Fig. 1). A landing strip for small aircraft is located at the northwestern edge of Bancroft. Bancroft is a modern community with a population of 2,400. The company has the mineral rights to 2982 acres (1207 hectares) surrounding the mine workings and plant which are situated in the north parts of Lots 16 and 17, Concession XI, Faraday Township."

Jan 1, 1986

By W. Griffith

"While oxalic acid precipitation practices are commonly applied on purified rare earth elements (REEs) pregnant leaching solutions (PLS), few efforts have been reported using oxalic acid (OXA) to recover REEs directly from untreated PLS. High oxalic acid demand is the most significant issue in all these direct oxalic precipitation (DOP) practices. Preliminary research on DOP of REE from a dilute PLS originating from an acid bake followed by water leaching was conducted. At 75°C, the oxalic acid demand was between 12 and 18 times the stoichiometric requirement for complete REE precipitation. Conducting DOP at 25°C had superior REE recovery but the product purity and filterability declined. Between 75°C and 100°C, REE recovery increased with increasing temperature. When sodium hydroxide was used to adjust the pH during DOP, in the range of 0.5 to 1.5, higher pH benefited REE recovery. Using ammonium hydroxide in place of sodium hydroxide, the REE recovery was reduced by close to 5%. Sodium chloride addition to the PLS was also investigated and the results showed that at both 75°C and 25°C, the REE recovery was enhanced substantially. At 25°C, when the oxalic acid addition was controlled at 4.7 times the stoichiometric requirement, the overall REE recovery reached 95% with the addition of 240 g/L NaCl. Other reagents such as KCl, NH4Cl also showed significant enhanced REE recovery at the same oxalic acid addition. The addition of sodium sulphate appeared to largely enhance the precipitation of LREE but inhibited the formation of HREE oxalate. All results indicate the formation of rare earth double salts may play an important role in REE DOP sulphate media.INTRODUCTIONThe conventional routes for recovering rare earth elements (REEs) from a sulphuric acid pregnant leaching solution (PLS) involves an initial purification step for removal of iron, aluminium for example by precipitation through neutralization, followed by precipitation of REEs as hydroxide, oxalate or carbonate salts, or by bulk solvent extraction for REE recovery (Xia, 2013). Another route was used by Bayan Obo in their historical flowsheet, where the PLS was first subjected to double sulphate precipitation, then the remaining REEs, mostly heavy rare earth elements (HREE), were recovered by oxalate precipitation (Li, 2011)."

Jan 1, 2016

By W. L. Nelson

The orebodies at Copper Mounta1n lie along and within a few hundred feet of the contact of an intrusive stock of gabbro with a series of bedded volcanic rocks of the Nicola formation. These. orebodies are all entirely within the volcanic series but in many cases the centre line of the orebody at depth is directly under the gabbro contact at the surface, due to a slight overhang of the gabbro. The gabbro and volcanic rocks are cut by a number of faults and fault zones which did not materially affect early mining operations, but, as undeground openings increased in size, the faults became more important factors in determining mining methods and procedure. Caving methods were adopted to take advantage of ground weakness in fault zones, and the effect of ground subsidence which resulted from the division of the ground 1nto large, independent blocks by faulting had to be considered in planning the sequence of mining of certain ore blocks. The faults have been divided into two classes: the longitudinal system and the cross faults, or 'breaks' as they are termed locally. In addition to the two classes of faults, the zones of parallel ore fracture also control mining procedure, but to a lesser degree, in regard to caving or ground subsidence. A third structural feature which influences mining procedure is the mine dyke system. The longitudinal or main fault system roughly parallels the gab? bro contact and is made up of a number of branches and auxiliary fractures. The main fault itself is essentially vertical, but there are a number of branches and fractures on each side of it which, though parallel m strike, may dip as flat as 50 degrees toward or away from the main fault. The full width of the main fault system has not been determined, but it is known to extend beyond the zone of mine workings. A marked schistosity follows the main fault and both schistosity and chloritic alteration have been noticed along the secondary faults of this system. Several prominent orebodies lie along the main fault and its branches. The influence of the main fault system on mining is probably related more to subsidence than to actual cavi.ng, although it is effective in both.

Jan 1, 1950

By S. H. Ash

Introduction Probably the newest thing in mining safety is the apparent dissatisfaction on the part of the mineral industry, as represented by both management and labour, and the general public of many nations in which mining is conducted, with the safety record of the mining industry. This is reflected by published comments in the technical press;' in labour periodicals, in popular Journals and periodicals, and in the daily press (5, 11). Despite what may be said to the contrary, mining in the United States is becoming safer, and this trend has been evident for several years (see Figures 1 to 4). Because the author's experience has been mostly in the United States this paper will discuss briefly some recent observations in the United States that have a bearing on mining safety. Because coal mining is of primary interest to the Mining Society of Nova Scotia, the paper treats mostly of coal-mining safety; however, many hazards in mining .are common to all mines, regardless of the minerals mined.

Jan 1, 1950

By Henri-Louis Jacob

Le secteur des substances non-metalliques repose au Quebec sur !'exploitation et la transformation d'une dizaine de mineraux ainsi que sur la production de materiaux de base destines surtout a l'industrie de la construction. L'ensemble de cette production representait en 1982 une valeur estimee a plus de 797 millions $, soit tout pres de 400Jo de la production minerale du Quebec. L'amiante et Jes scories de titane destines a la production de pigments, qui comptent parmi Jes plus importantes substances minerales produites au Quebec, representent respectivement 370Jo et I 70Jo de la valeur totale des non-metalliques tandis que le groupe des materiaux de construction represente pres de 400Jo. Les autres substances, parmi lesquelles ressortent nettement la tourbe, la silice et la magnesite, representent une valeur totale de 61.5 millions $.

Jan 1, 1984

By Yong-neng Feng, Xiao-ping Chen, Wei Guo

"While the uniaxial compressive strength of rock has been extensively investigated, the relation between the saturation and natural compressive strength is relatively unexplored. This paper studies on 1865 statistical data of Chongqing Rail Transit Line 1 and Line 6, which located in the Middle Jurassic of Shaximiao formation. The research focuses on the relation between the saturation and natural compressive strength. The statistical data are categorized and quantified in order to ascertain the softening properties of sandstone and sandy mudstone. The findings suggest that the saturation compressive strength is significant effected by its natural compressive strength, and an empirical formula is introduced to explain the relation. These findings have implications for researchers and engineer who concerned with Chongqing rail transit construction.INTRODUCTIONIn the engineering construction and surrounding rock classification, the uniaxial compressive strength index (Ministry of Water Conservancy, 1995; Ministry of Railways, 1999) is one of the essential parameters of rock mass. Usually, there are two types of the uniaxial compressive strength index, natural and saturation compressive strength, and the ratio of them is the softening coefficient. Most of the previous studies on rock strength had focused on the influence factors (Liu et al., 2008; Liu et al., 1998; Liu et al., 2013; Wang, 2013; Zhang et al., 2008; Zhang et al., 2010; Zeng & Lin, 2003) with experiment and in-situ tests. But few publications that reports a long and formal research project on the relationship between natural and saturation compressive strength. In order to figure out this issue, this study investigated the distribution of Solidity Classification of Rock Mass and softening coefficient based on the statistical data of Chongqing Rail Transit Line 1 and Line 6. Based on the analysis, an empirical formula was proposed to explain the relationship."

Jan 1, 2015

"IntroductionNOTE.-All figures on the supply and consumption of coal in Canada cited in this paper were collected and reported by the Dominion Bureau of Statistics. The friendly and efficient co-operation of the officials of the Bureau. is the foundation upon which it has been my privilege to rely in the preparation of this and two earlier papers ( 1). My thanks are due also to our own staff on the Dominion Coal Board, who spared neither time nor effort in helping to prepare this paper.STATISTICS are comparatively dull and, to many people, coal statistics are duller than most. Coal is, however, the one basic mineral upon which our whole way of life depends and it may be well if attention is drawn to this fact by an occasional statistical review of the coal position in Canada. The recent furore over the oil and gas discoveries has so obscured the basic position of coal in many minds that a little basic coal information may be useful. It is for this reason that, for the third successive year, a factual survey of the coal position is being presented.In the previous papers (1) explanations have been given of the basic considerations in the preparation of these reports and some special phases of the overall picture have been examined. For these explanations, the earlier papers may be consulted."

Jan 1, 1952

By R. S. Jones

"Fording Coal Ltd. is now in its fifth year of a 15-year contract to supply 3 million long tons of clean coal per annum to its Japanese steel-making customers. The mine employs both conventional truck-shovel and unconventional ""walking"" dragline coal mining techniques in multiple-seam pits. This paper describes the present and future application of the 60-cu.-yd dragline and truck-shovel pre-stripping fleet in 1•ecovering 5- to 40-footthick coal seams in mountainous terrain. Deep blastholes, coal flow demands, spring ""run-off"", seam and inter-seam thrust faulting, limited seam outcrop data and regional faulting are a few of the problems encountered in this application. The author discusses these problems and their solutions as applied at Fording Coal Ltd."

Jan 1, 1976

By R. Khanna, K. Hyun Ko, A. J. Berkovich, J. Hook

"The co-pyrolysis of synthetic polymer polyethylene terephthalate (PET) and agricultural wastes (naturally occurring polymer-macadamia nut shell) was investigated in the temperature range 473K to 1273K using a horizontal furnace with an aim to understand their thermal degradation under isothermal conditions. In-depth characterization of pyrolysis residues was carried out using x-ray diffraction (XRD) and solid state nuclear magnetic resonance (NMR) for carbon structure, and through determination of the concentration of unpaired electrons using electron paramagnetic resonance (EPR). In previous studies, it has been found that PET thermally decomposes ~ 650K-700K, releasing (~80 wt % of initial weight) gaseous products due to random chain scission. In the case of macadamia nut shell, three types of byproduct can be obtained from pyrolysis: char, tar and gaseous products. In the co-pyrolysis of macadamia nut shell with PET in 50-50 wt% ratio, total product weight ratio could be modified with the addition of PET acting as a hydrogen source. This is because a recombination of thermal cracking products of cellulose could be suppressed by hydrogen from PET, which will later lead to an enhancement of tar formation. In addition, pyrolysis around 673K is sufficient for bond cleavage to occur in cellulose and lignin leading to the formation of negatively charged activated carbon with high surface area, providing bonding sites for volatiles evolving from PET. Therefore the co-pyrolysis may be able to enhance the product yield (tar/char/solid carbon residue) along with a reduction in the release of gaseous products. During the co-pyrolysis, temperature was found to have a significant influence on the kinetics of thermal degradation and solid residual by-products after co-pyrolysis.INTRODUCTIONPlastics are being used worldwide in a wide range of applications in the modern society; their usage has resulted in increasingly a massive waste problem. The production of most synthetic plastics requires hydrocarbons that are produced from petrochemicals derived from fossil oil and natural gas, a non-renewable source (Speight 2011). Currently, plastic manufacture utilizes ~4% of world oil and gas production, and it is expected to drive further increases in petroleum demand by 1-2% due to their large volume of manufacture (Hopewell, Dvorak et al. 2009). Landfilling and incineration of plastic waste are the two main routes to plastic waste management (Encinar and González 2008). In Australia, only 10% of waste plastics were recycled in 2006 (White and Hyde 2011). This means that large amount of fossil fuels from plastics has either been simply burned for energy recovery or buried in the ground. There is an urgent need for developing alternative avenues for recycling waste plastics. Our group at UNSW has carried out extensive research on the recycling of waste polymers as carbon resource in steelmaking including slag foaming and carbon dissolution from waste plastics into liquid steel at 1600°C; the effect of basic plastic characteristics such as chemical composition, structure, bonding network etc. was examined (Sahajwalla, Rahman et al. 2009)"

Jan 1, 2012

By C. Hunt, J. Vivas, D. M. Allen

"In this paper we present the results of a combined remote sensing - numerical modelling study to improve our understanding of groundwater seepage in open pit and natural rock slopes, and to investigate the interaction between groundwater, in-situ stress conditions and brittle fracture. The location of seepage is a key element in the characterisation of rock slope stability in open pits and natural slopes; definition of the fracture network geometry and its inter-relationship with seepage, however, remains a challenge in engineering practice. Current techniques used to characterize groundwater seepage locations require direct access to the rock slope for a detailed and exhaustive investigation, and can be severely limited due to access and the limited coverage of the survey methods both with respect to the height and length of the sampled rock slope. Herein, we describe remote sensing methods, which allow the collection of structural and seepage information over a wide spatial area. Remote sensing techniques are shown to have the potential to provide additional insights into the orientation and general connectivity of fractures that may play a major role in the general stability of a rock slope. A preliminary methodology for the use of remote sensing in the characterization of seepage zones in a natural slope through the application of ground-based LiDAR and Infrared Thermography (IRT) is presented.One of the most challenging problems in rock slope engineering is the realistic simulation of fluid flow through fractured and deforming rock slopes. Deformation and the development of brittle fractures can cause significant local changes in the permeability and strength of the rock mass, potentially affecting rock slope performance. Understanding fluid flow through fractured and deforming rock slopes, especially in highly-stressed environments is of great importance for slope stability analysis. Changes in the interconnectivity of fractures during slope failure are an important, yet are relatively unstudied in rock slope engineering. We present the results of hydromechanical UDEC-Trigon rock slope models focussing on the potential role of brittle fracture in rock slope failure, its interaction with groundwater pressures, and the influence of the assumed in-situ stress ratio. Damage intensity parameters are used to characterize damage within different regions of a biplanar slope failure."

Jan 1, 2015

By G. S. Hume

THE discovery of natural gas with naphtha in 1924 in the Upper Palaeozoic limestone of Turner Valley, 35 miles southwest of Calgary, has led to continuous developments in this field. Drilling undertaken soon after this discovery demonstrated that the anticlinal structure was in reality a major drag-fold cut off on the east side by a westerly inclined fault of large displacement. The faulted edge of the .limestone at depth determines the eastern limits of the field, which between 1924 and 1936 was shown to have a gas area 14 miles long by about 1 mile wide. Since the strata dip westerly, away from the axis of the fold, drilling becomes progressively deeper to the west and, with the advent of deeper drilling, crude oil was discovered in 1936 on the west flank of the structure but in the same porous reservoir rocks as the gas on the crest and upper parts of the fold. Since 1936, drilling has been undertaken wholly for the production of crude-oil and at present two producing areas have been found within the Turner Valley structure. The larger of these, at the south end of the field, in the vicinity of Highwood river, has a length of about 4 3/4 miles and a proved width of one mile, whereas the smaller, in the north end of the field, south of the north fork of Sheep river, has only a few producing wells.

Jan 1, 1939

By Robert Yobou, Jacques Naho, Benjamin A. Allou, Jacques Carignan, Huan-Zhang Lu, Jayanta Guha, Koffi Pothin

"Résumé - Les seules productions de columbo-tantalite en Côte d'Ivoire sont effectuées dans les éluvions, colluvions et alluvions d'Issia, au Centre-Ouest de la Côte d'Ivoire. Même si un lien direct avec les roches granitiques est suspecté, aucune attention particulière n'a été accordée à l'étude de la minéralisation primaire en relation avec l'évolution de ces granites et des pegmatites associées. Ces granites, qui sont en intrusion dans les roches sédimentaires du Protérozoïque inférieur, comprennent: le granite orienté à deux micas (type Lobo), le granite orienté à muscovite dominante (type Bitapia) et le granite porphyroïde non orienté à muscovite dominante (type Issia). Les résultats de cette étude indiquent que les pegmatites à Nb-Ta-Be-Li sont liées au granite de type Issia. Les observations de terrain et les analyses sur roche totale montrent que: (1) les trois principaux granites de la région sont de type-S et peralumineux dans leur composition, (2) ils ont été formés pendant la période tardi- à post-Éburnéenne, (3) le granite de type Issia fut le dernier à se former.Les pegmatites liées au granite de type Issia ont été classées en quatre types : A- pegmatites stériles; B- pegmatites à Be; C- pegmatites zonées à Nb-Ta-Be; et D- pegmatites zonées à Be-Nb-Ta-Li. Les pegmatites zonées comprennent les zones suivantes: I- zone à aplite; II- zone graphique; III- zone à albite, microcline, béryl et columbo-tantalite; IV- zone à microcline massive; V- zone à quartztourmaline. Ces pegmatites présentent une zone d'altération métasomatique externe.La minéralisation de Ta, Nb, et Be est liée à la zone III des pegmatites de types C et D, la minéralisation de Li est associée aux greisens qui peuvent être observés n'importe où dans les pegmatites de type D. Les données de terrain et de laboratoire indiquent que le granite de type Issia est la roche parentale des pegmatites à éléments rares de la région. Les pegmatites minéralisées sont distribuées seulement autour du granite de type Issia et les patrons des terres rares des granites et ceux des pegmatites à éléments rares sont très similaires. Les analyses de la composition totale montrent un lien génétique entre le granite de type Issia et les pegmatites à éléments rares. Il est suggéré que les pegmatites ont été formées durant le transport et la cristallisation fractionnée du magma. Les éléments rares sont restés dans le liquide résiduel jusqu'à ce que les conditions favorables à leur précipitation soient atteintes.L'établissement de ce lien génétique ouvre des voies pour des nouvelles stratégies d'exploration."

Jan 1, 2005

By L. Lamothe, C. H. The

"Pilot precipitator tests were conducted at Noranda's Horne Smelter in late 1978 to evaluate methods of improving converter dust collection efficiency. A bout 35 Nms/min. of converter off-gas were isokineticatly diverted from the converter flue to the pilot precipitator leased from Flakt (Canada) Ltd., consisting of three fields, one transformer-rectifier set per field and 77-m2 total collecting plate area. The effects of gas volume flow rate and conditioning the gas with sulphur trioxide and/or additional moisture were tested. II was found that gas flow rate and moisture level had the most pronounced effect on collection efficiency. Based on a techno-economic assessment of different options for improving converter Courell efficiency, waffle hoods and water sprays were installed on the converters to reduce air infiltration and increase the moisture level in the gas.BackgroundThe Horne Smelter of Noranda Inc. is situated in northwestern Quebec and, since the closure o f the min e in 1976, has been operating as a custom smelter. The concentrates treated at the smelter come from various mines with mixed sulphide ores , many o f them containing significant amounts of lead and zinc which makes dust collection in electrostatic precipitators mo re difficult than normal.As part of a continuing program on reducing smelter dust emissions, the No . 6 Cottrell was installed in 1972 up stream of Nos. 2 and 4 Cottrells (in parallel) in a n attempt to improve dust collection by increasing the over- all precipitator capacity ( Fig. I). However, it has never per formed a t its designed efficiency o f 94%. The average efficiency established in various test s was in the range of 60 – 65%."

Jan 1, 1985

By R. Amata

"The Gakara Rare Earth deposit in Burundi (East Africa) is unique for its high grade (e.g., 54.3% TREO on average) and low uranium and thorium levels. The majority of the light rare earth (RE) elements in material from Gakara are contained within the familiar RE minerals bastnaesite and monazite. Extensive metallurgical test work was conducted by SGS Minerals Services on mineral samples collected from the Gakara deposit. Various whole ore hydrometallurgical processing routes were examined in a scoping level test program. Preliminary beneficiation testing was also conducted, though it was determined that only marginal upgrading would be achieved with significant RE losses. Thus a hydrometallurgical process on whole ore was developed to minimize the overall process complexity and achieve maximum RE recovery. Results from the test work will be presented, along with the selected base case flowsheet involving agitated atmospheric sulphation of the RE minerals, RE double sulphate precipitation, caustic conversion, redissolution, and carbonate precipitation. Following the base case flowsheet, a purified cerium free mixed RE carbonate with low levels of radioactive elements was produced.INTRODUCTIONRainbow Rare Earths Limited (Rainbow) is a mining company engaged in the exploration and development of the Gakara rare earth deposit in Burundi; Figure 1 shows the project location. The project is located in the Bujumbura Province and 45 km from the Burundi capital of Bujumbura. Notable for its exceedingly high in-situ grade – 54.3% on average total rare earth oxide (TREO), low uranium and thorium levels and familiar rare earth minerals, bastnaesite and monazite – Gakara is the world’s richest rare earth deposit. The project, a previously operating mine from 1948–1978, has a significant mineral inventory base, a long life of mine, well understood mineralogy, and robust economics. Rainbow is focused on bringing Gakara into production in the near term, ramping up to produce 5,000 t/y of a 54%+ TREO concentrate."

Jan 1, 2016

By Wengui Su, Qi Zhang, Junce Wang, Zhijun Ma, Xingyuan Weng

"Mesoporous materials with large specific surface area, pore size, and pore volume have been widely used in many fields such as ion exchange, gas separation, adsorption, and catalysis. Mesoporous materials prepared using natural zeolite have the advantages of both acid and alkali resistance. In this work, mesoporous materials were prepared using natural zeolite as the starting material and diethylenetriamine (DETA) as a template. The resulting samples were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and N2 adsorption-desorption experiments. The influence of the crystallization temperature and crystallization time on the specific surface area, pore volume, pore size, and morphology of the resulting mesoporous materials are also discussed. Our results show that for an increase in both the crystallization temperature and time, the average pore size first increases then decreases, while the specific surface area first decreases then increases. Based on this work, we concluded that the optimal crystallization temperature was 2003 and the optimal crystallization time was 60 h. These conditions gave an average pore size of 17.93 nm, a pore volume of 0.048 cm3g-1, and a specific surface area of 16.48 m2g-1.INTRODUCTIONMesoporous zeolite, as the name implies, is a highly porous crystalline zeolite. This material is of interest due to its high hydrothermal stability, its adsorption and diffusion properties for macromolecules, and its excellent selectivity and activity as a catalyst. In recent years, it has become a hot spot among research of porous catalytic materials and has been widely used in petroleum and natural gas processing, fine chemical processing, various adsorption and separation tasks, and other uses (Carvalho & Urquieta- Gonzalez, 2015; Teh, Triwahyono, Jalil, Mukti, Aziz, & Shishido, 2015)."

Jan 1, 2016