Search Documents

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

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

Jan 1, 2015

By G. E. Veins

A three-phase, continuously-operated, 250 kv.a. electric smelting furnace has been installed at the Mines Branch, Department of Mines and Technical Surveys, Ottawa, for the experimental treatment of ores and by-products of interest to the Canadian mining, metallurgical, and chemical industries. In the operation of this furnace particular emphasis is placed on the accumulation of quantitative data which will be useful in determining the most suitable smelting technique and the nature of the products, and in arriving at preliminary conclusions regarding the cast of power and electrodes. The results obtained in the experimental smelting of iron, manganese-iron, titanium- iron, nickel, and chromiumiron ores, and of a number of industrial by-products, clearly show the value of such treatment for materials of this type.

Jan 1, 1957

By L. Tafaghodi, S. Sarbishei

"Following the depletion of nickel sulfide ores, laterites are considered as one of the main sources for producing nickel and cobalt. One of the primary steps in pyrometallurgical extraction of nickel from laterites involves partial reduction of the ore at temperatures below 1000°C. Studying the kinetics of laterite reduction provides valuable information on reducibility of nickel laterites using coal as a reductant. The present study investigates the reduction behavior of a nickel laterite by thermal gravimetric analysis and differential scanning calorimetry. Non-isothermal reduction tests and X-ray diffraction analysis were performed to find the main reactions that occur during the process. The kinetic parameters were calculated by Coats-Redfern method. The general model of simple reaction f(a)=(1-a)n was used for calculating kinetic parameters.INTRODUCTION Nickel (Ni) naturally occurs in the form of sulfide and laterite ores. Laterite ores are mainly available in tropical regions. Weathering phenomena during millions of years has led to the formation of several layers with specific mineralogy (Butt & Cluzel, 2013). The three main layers downward are limonite, smectite, and saprolite (Crundwell et al., 2011). Although laterites are the most available nickel ore resource (70%), their share in the overall Ni production is limited to 40% (Crundwell et al., 2011). The main reasons for not materializing the full potential of laterites are as follows (Ray et al., 1985): •,Laterite ores contain high water content (free and combined) which in turn results in high energy consumption of the extraction process. •,As Ni is present in the form of solid solution in laterites, physical upgrading methods such as flotation are not effective in increasing the Ni content before the extraction process. •,Extracting Ni from sulfide ores involve exothermic reactions which are beneficial due to decreasing the overall energy requirement of the process, however there is not efficient release of energy in the process of extracting Ni from laterite ores."

Jan 1, 2017

By Xuanxue Mo, Zengqian Hou

"Abstract -Yidun Island Arc in Sanjiang Region is one of the important Kuroko-type volcano­ genic massive sulfide deposits (VMS) districts in southwestern China. Tectonically, the region is situated in the eastern portion of the Tethys orogenic belt, and is a late Triassic extensional island-arc. The island-arc underwent earlier arc construction, intra-arc rifting, later arc construction and back­ arc spreading during its evolution and formed a complete trench-arc-basin system, i.e., the Ganzi­ Litang suture zone, forearc basin, outer arc, intra-arc rifting zone, inner arc and back-arc basin from east to west across the island-arc.Kuroko-type VMS deposits and occurrences discovered so far are limited to within the intra-arc rifting zone of the Yidun Island Arc and tend to occur in groups or clusters distributed in separate fault­ bound basins; e.g., Zengke, Gacun and Xiangcheng basins, in which submarine volcanic rocks, especially bimodal volcanic suites, were extensively developed. The VMS deposits formed in the waning stages of volcanic eruption in the late Triassic and are hosted in the uppermost section of acidic volcanic rocks (rhyolitic-dacitic) within a bimodal suite. The orebodies are associated with these host rocks: rhyolitic-dacitic pyroclastic rocks and exhalites and chemical sedimentary rocks.Ali VMS deposits in Sanjiang are of the Zn-Pb-Cu type. The architecture of the deposits is two­fold, consisting of concordant lenses and layers of massive sulfides and an underlying discordant stockwork. Ali deposits show metal zoning. The hydrothermal alteration related to mineralization is strong and asyrnmetrical, and is found dominantly within the stockwork zone and host rocks surrounding the ores. There are two alteration patterns: (1) chloritization - sericitization - silicification from outer sides to core of the alteration pipe; and (2) silicification + sericitization - silicification + carbonate from the lower to upper part of the alteration pipe_The mineralization temperatures of ore-forming fluids vary in the range 200°C to 335°C. Thermal evolution of the fluids displays temperature profiles that first increase and then decrease with progression of mineralization processes. The majority of black-ore minerais (Groups I and II) formed during intensifying stages of hydrothermal activity, and the majority of serni-yellow-ore minerals (Group III) formed during a thermal maximum . There followed the formation of fine-grained black-ore minerals (Group IV), which interacted with barite layers during decreasing temperature phases.Oxygen and hydrogen isotope studies show that the sources of ore-forming fluids for the Kuroko­ type VMS deposits are two-fold: seawater and magmatic hydrothermal solutions, represented by the Kuroko deposits in Japan and Kuroko-type VMS deposits in Sanjiang, respectively. In the latter case the hydrothermal solutions reacted with host rocks and mixed with cold seawater percolating downward, and circulated through volcanic rocks resulting in development of alteration zones and formation of ore minerals in Kuroko-type VMS deposits."

Jan 1, 1993

By D. A. Karvonen

In 1970, the Government of Saskatchewan instituted a program aimed at resolving the dilemma of excess productive capacity over the market demand which existed for potash produced in Saskatchewan. The two primary elements of the program were prorationing of potash production to market demand and a minimum selling price. The paper reviews the factors, both local and international in nature that led to the introduction of the program. The licensing mechanics and the operation of the program, along with the changes that have been introduced in two and one-half years of operation, are discussed. Attention is given to the results of the controls as they affect the industry and the province. Also discussed is the outlook for Saskatchewan potash in world markets.

Jan 1, 1973

By J. Dilbeck, J. K. Ratliff, T. Petrov, Z. Brown

"In efforts to improve dust control during deep cut continuous mining a supplemental atomizing spray system, mounted on 14CM15 continuous miner, has been designed and successfully implemented in a U.S. coal mine. The mine is 2.1 m (7-ft) high and uses a blowing curtain face ventilation system with 1.1 m (3.5-ft) curtain offset from the rib. The face ventilation design parameters were set to 9.4 m3/s (20,000-cfm); 4.2 m3/s (9,000-cfm) line curtain flow rate, and 3.8 m3/s (8,000-cfm) scrubber capacity. The performed in-mine measurements, before and after the implementation of the atomizing spray system, showed a significant decrease in the respirable dust levels at the operator place as well as at the return. The paper describes the supplemental water spray system design and performance supported by three-dimensional computational fluid dynamics (CFD) simulations and in-mine test data.INTRODUCTIONThe work on this project have started in 2015 with a study of the conventionally applied face ventilation layouts. The specific behaviour of the face ventilation system have been analyzed trough in-mine measurements and computer modeling of typical cut scenarios. An computer modeling methodology have been developed for estimation the respirable dust concentration (RDC) using tracer gas to RDC contour mapping, calibrated by a single point value, provided by in-mine measurement. Utilizing the results of this study the engineering staff of the mine designed and implemented a supplemental atomizing spray system to improve the dust control during the deep cut continuous mining. Today the atomized spray system is successfully applied demonstrating steady performance and a significant decrease in respirable dust concentration on the working places of the continuous miner (CM) and coal transporters (CT) operators as well as at the return air stream. Information about the applied type of spray nozzles provided by other researchers (Cheng, 1973; Dick et al., 1996; Organiscak & Page, 1998; Pollock & Organiscak, 2007) and spray system manufacturers (Spraying System Co, 2011–2018; Steinen Mfg., 2016) have been used in this project. CFD code and simulation approach validated in a study conducted in 2000-2014 have been applied (Turner et al., 2002; Wala et al., 2004, 2007; Petrov, 2014)."

Jan 1, 2019

By John D. Godfrey

A brief account of economic developments in and around northeastern Alberta is presented and mention is made of mining and industrial developments currently of interest in the area. Planned and projected operations are briefly discussed for this region. The history of geological surveys and mining activities in the Shield area of Alberta and the adjoining parts of Northwest Territories and Saskatchewan is traced. Reassessment of the presently-known economic picture of northwestern Canada in conjunction with some recent information on Precambrian structures of northeastern Alberta points to some interesting mining possibilities, particularly in and around that province.

Jan 1, 1960

By Dale C. H. Nevison

One of the most intensive of material rivalries is the confrontation between zinc die castings and plastic injection moldings. Pressed hard by the plastics industry, zinc die casters are learning how to make parts with less material yet without sacrificing quality. The key to this new trend is the technique of Thin Wall die casting. The obvious benefits of Thin Wall are lighter weight and lower cost. Again, obviously, these are the very selling points that put plastics into many appliance and automotive parts formerly made of zinc. One of the factors that has been most conducive to the outstanding growth of plastics has been the increasingly prevalent concept that "adequate" properties are sufficient, especially if there are cost advantages. Most of modern design today is oriented around the reasonable life of a product, rather than indefinitely extended life. This is simply an acknowledgment of the existence of a design environment that pervades many areas, reflecting the life-cyclic desire for change. Too often, so-called "weight-saving" materials end up being very costly - not only in production, but in durability and dependability. Change for the sake of change usually doesn't effect a change for the better. In the majority of cases, the best bet is to design in traditional materials and minimize the material needed, while maximizing the efficiency of the production process. Component prices of products to be produced from either plastics or zinc must be studied in detail to determine which material will produce the lowest cost of manufacture. It is not uncommon for two parts, similar in appearance at a casual look, to have a considerable difference in energy requirements and production costs. Detailed cost estimates of the advantages of each material should therefore be prepared for zinc and plastic parts before the final design and material selection decisions are made.

Jan 1, 1978

By M. H. Moys, J. A. Engelbrecht

"Large-diameter flotation columns are subject to severe axial mixing which has reduced column recovery and has generally limited it to cleaner applications. It has been assumed that columns with diameter greater than 1 m should be baffled to reduce axial mixing, but little work has been reported quantifying the effectiveness of baffling. Tests were done on a 0.2 m by 2 m column fitted with baffles of different geometry. It was generally found that the inclusion of baffles in the column worsened rather than improved mixing conditions in the column. This is explained in terms of a model for the effect of poor gas distribution on the behaviour of the column; this showed that under typical conditions a 16% excess of gas flux in the one compartment of a two-compartment column could result in one of the compartments being ""dead"" (i.e. with no net flow of slurry through it), resulting in a substantial loss of performance. The quality of mixing in the laboratory column was only reliably improved when the baffle was raised so that its top was positioned above the froth-slurry interface level. It should be possible to increase column recovery substantially with this configuration. The improved residence time distribution also means that columns can be used more effectively in roughing and scavenging applications. IntroductionFlotation columns have generally been used in cleaner applications, starting with their dramatic success at Mines Gaspe(1). Their lack of applications as roughers and scavengers is probably due to their poor residence time distribution (RID) when compared to the conventional cells they would replace. Espinosa-Gomez et al,(2) recently used them in rougher applications but installed three columns in series, presumably to cope with this disadvantage.Dobby and Finch in their seminal papersl(3,4) on the scale-up of flotation columns were the first to quantify the impact of axial mixing on the performance of industrial flotation columns. Laplante et al.(5) collected further data from the literature for column diameter D, ranging between 5 cm and 183 cm, gas superficial velocity Jg ranging between 0.7 cm/s and 2.8 cm/s and per cent solids in the feed S ranging between 3% and 52%. These data were analyzed with reference to the axial mixing model using the boundary conditions for closed vessels (the latter are more appropriate for flotation columns but the model is more difficult to use because analytical solutions for the RID are not available). The data were correlated by:"

Jan 1, 1993

By C. G. Anderson

Industrially proven and applied nitrogen species catalyzed (i.e. NSC) acidic pressure leaching has been utilized to treat a number of ores, concentrates and recycled materials. This versatile technology offers many advantages including low temperatures, low pressures, low capital costs, low operating costs, faster throughput and less costly materials of construction than conventional pressure oxidation. This paper will elucidate the application of this technology for production of gold, silver, palladium, rhodium, zinc, germanium, gallium, cobalt, copper and nickel. Recycled material applications will also be elucidated. In addition, details of an application for treatment of a refractory chalcopyrite copper and gold bearing ore will be presented and pertinent economics discussed.

Jan 1, 2004

By Celine Y. Zhang, Chloe J. Feng, Charles Q. Jia, Donald W. Kirk

Oil sands petroleum coke (OSPC) is a by-product of coking - a high-temperature process that converts the mined bitumen to the synthetic crude oil (SCO). For every barrel of the SCO produced, about 20 kg of OSPC are generated. Over 70 million metric tons of OSPC have been produced and stockpiled as a result of the development of oil sands industry in the past few decades. Unlike conventional petroleum coke, OSPC has uniquely high impurity contents, particularly sulphur (~ 7 wt%) and metals (e.g. vanadium at ~0.15 wt%), which has hindered its large-scale applications as a solid fuel. Vanadium is a valuable metal that is widely used as an alloy for strengthening steels. The stockpiled OSPC contains about 100,000 tons of vanadium, while the world’s production in 2013 was only 75,600 tons. At the current price of $25US/kg, the OSPC-bound vanadium represents a total value of $2.5 billion US dollars. In this work, we investigate the technical feasibility of extracting vanadium from OSPC. The work focuses on the characterization of vanadium in OSPC and the conditions for effective extraction of vanadium from the OSPC.

Jan 1, 2015

By Roger V. Pierce

IN the last few years, much study has been devoted to increasing stoping efficiency. The reasons for this are shortage of manpower, shorter working hours, operating regulations, and shortages of essential materials. More efficiency in mining methods is needed to offset these adverse factors. In the past, attention has been centred upon haulage, hoisting equipment, mill flow-sheets, etc., but recently the spotlight has been focused on the cost of stoping and the cost of handling materials. Scrapers and scraper hoists have thus assumed greater importance. In order to make it possible for certain orebodies to be mined at a profit, it has been necessary to apply assembly-line practices to the streamlining of mining methods. All cycles of the mining operation must balance, and the sooner broken ore is removed from the working face, the sooner another round can be started. Since the introduction of scraper hoists in metal mines more than thirty years ago, much progress has been made in their design and application. Alert operators are now constantly watching for methods in which to apply scrapers. The saving of manpower in development work and the changing of mining methods that once employed manual handling of materials are increasing vital wartime tonnages. Essential ores from newly discovered orebodies are moving rapidly from stopes to reduction plants-because it is now possible to develop an orebody and place it in production with a minimum of manpower and development work. Today, speed is one of the prime essentials o mining. Everywhere, there is a concentrated effort to use experienced miners in breaking rock, in timbering, and in carrying out the various phases of mining that require many months of training. Much effort is being made to mechanize the working places because experienced men naturally prefer to work where the majority of materials are handled mechanically. In line with this policy, many new men are being taught the details of scraper work, because even green men can quickly become acquainted with scrapers and thereby release older heads to perform the more skilled phases of mining.

Jan 1, 1943

By Fathi Habashi

"Hydrochloric acid (HCl), although more expensive than sulfuric, find uses as a leaching agent in reactions involving iron oxide. The reason for this substitution was the discovery that oxyhydrolysis of ferrous chloride by which HCl can be recycled economically. This avoided the pollution of the environment by ferrous sulfate. It was found further that the rate of leaching of sulfides is faster when HCl is used as compared with sulfuric apparently due to the formation of aqueous chlorine. In case of refractory gold ores, HCl leaching under pressure avoids the use of cyanide solution since gold chloride is produced which can be recovered by standard methods. Hydrochloric acid find also uses in the leaching of scheelite and apatite but its use in leaching clay and anorthosite is questionable.INTRODUCTION Sulfuric acid is the cheapest acid and is used as a leaching agent in many hydrometallurgical processes. However, hydrochloric acid (HCl), although more expensive since it is prepared by reaction of sulfuric with sodium chloride, has replaced sulfuric acid in many reactions involving iron oxide. It replaced sulfuric acid for the first time in 1960s in pickling of steel because of pollution problems (Habashi, 2000). Ferrous chloride produced in pickling can be economically decomposed to ferric oxide and HCl according to:2FeCl2 + 2H2O + 1/2O2 ? Fe2O3 + 4HCl (1)which also shows that the acid can be regenerated but ferrous sulfate cannot be economically decomposed to recover sulfuric acid for recycle. Since then, HCl has been used in many leaching processes. Hydrochloric acid is a corrosive acid and is usually handled in rubber-lined equipment. REGENERATION OF HYDROCHLORIC ACID Regeneration of HCl is conducted in fluidized bed or in spray roaster Fluidized bed oxyhydrolysis In a fluidized bed, ferrous chloride solution is introduced onto a bed of hot ferric oxide where heating is provided by the hot fluidizing combustion gases (Figure 1). The solution is fed on top of the bed of oxides. The liquid feed wets the outer layer of the hot oxide particles and is quickly evaporated to form a layer of new solid oxide on top of the existing oxide, thereby producing dense homogeneous particles."

Jan 1, 2017

By A. Warczok, T. A. Utigard

"Slags from smelting of copper concentrates contains from 1 to 15% of copper. Copper is present in the form of copper or copper matte inclusions of size from 2 to 1000 micro, and as dissolved cuprous oxide. Removal of the copper requires the slag reduction, primarily reduction of magnetite and co-reduction of cuprous oxide. Thus, the kinetics of the slag reduction play an important role in copper recovery. Instantaneously, at the contact of carbon and a slag the gaseous film is formed. The magnetite and cuprous oxide reduction is going through a gaseous film, separating the slag and carbon of a coke or electrodes. The thickness of a gaseous film grows to a critical value and gas bubbles, containing CO and CO2, are created and rise up in the slag. Results of measurements of kinetic of the slag reduction with graphite showed high value of activation energy, close to the value of activation energy of Boudouard reaction. Strong temperature dependence of the reaction rate points out the thermal instability of the reacting system. It was found that the slowest process in the reduction stages determines the loop of CO and CO2 transfer and magnetite diffusion to the slag/gas film boundary. Strongly endothermic Boudouard reaction seems to cause thermal instability on the reaction surface. So, heat transfer to the reaction surface is very important. Due to low thermal conductivity of a slag the convection dominates in the heat transfer. So, any slag stirring accelerates the rate of reduction and coalescence of metallic copper or copper matte inclusions."

Jan 1, 2015

By G. Ellie, D. F. Coates

"The mining of coal in thick and inclined seams is difficult, and there are only a few countries in the world that are really interested in the problems associated with their exploitation. In France a considerable amount of investment has been made in the mechanization of systems appropriate for such conditions.For seams inclined up to 50 degrees, of normal thickness, a new system was introduced in 1967. It consists of a longwall advancing to the rise with walking props, a shearer and hydraulic backfill. During the first two years the panel productivity was an average of 25 TN/MS, and they foresee the possibility of reaching an average of 30 TN/MS.A system for thick beds, both horizontal and inclined, is in p•rocess of being mechanized. In 1969 they started with a method consisting of a longwall in a footwall slice, or sub-level drifts with walking props, and caving and drawing up to a height of 20 m of coal. Recent experiments with a shearer have produced panel productivities between 9 and 11 TN /MS, and there is hope that with experience an average of 16 TN/MS will be obtained.In 1964 a method was initiated for beds inclined from 60 to 90 degrees, based on a mechanical cutter designed by the collieries in Lorraine. An overhand slice of 4.2 m in height is taken with a drum cutter mounted on the end of a boom. Hydraulic fill is placed at the completion of a slice. The face productivity, which has been from 13-20 TN /MS, can be perhaps increased to an average of 22 TN/MS. For those companies with important reserves in inclined and thick seams, these French systems may be worth the trouble of examining in some detail."

Jan 1, 1972

By Z. Z. Öztürk, N. Sarica, A. H. Üçisik, C. Bindal

"Titanium oxide films were fabricated on commercially pure titanium surfaces via anodization procedure. Anodization parameters, anodization time and voltage were altered, whereas temperature and chemical composition of anodization bath were kept constant. The main idea in this study is to obtain rough titanium-oxide surfaces. The type and feature of titanium oxide formed were observed via SEM and EDX analyses. What was revealed from SEM and EDX analyses were combined with Ti-O phase diagram in order to make judgment on the type of phases obtained, e.g. solid solution and/or compounds. Studies on the different regions of each sample showed that surfaces consist of different titanium oxide compounds with various O/Ti ratios in nano level and solid solutions varying in terms of chemistry on the same sample. Thus together rough surfaces and inhomogeneous distribution of "titanium oxides" were obtained. It was also found that when anodization time and voltage were increased, more granular surface with higher O/Ti atomic ratio was obtained."

Jan 1, 2015

By Marc Arpin

La Bolivie possède tout pour réussir. Son vaste territoire de plus d'un million de km2 et qui occupe une position stratégique au coeur du continent sud-américain recèle des ressources naturelles (forêts, minéraux, gaz naturel, etc) variées et abondantes. Elle a une frontière avec pas moins de 5 pays dont le géant que constitue le Brésil ainsi qu'avec l'Argentine, l'autre puissance régionale. Pourtant, malgré tous ces atouts, la Bolivie demeure l'un des pays les plus pauvres du continent. Ce paradoxe n'est nulle part mieux reflété que dans le secteur minier. Celui-ci fait face à une situation de crise en dépit d'une tradition minière de plus de quatre siècles et d'un potentiel géologique indiscutable ayant conduit à la découverte et à l'exploitation de fabuleux gisements d'argent et d'étain. Les habitants des districts miniers vivent dans des conditions de pauvreté extrême et les indicateurs de développement humain de ces régions sont parmi les plus bas en Amérique du Sud. La Bolivie réussit difficilement à attirer les compagnies minières alors que, chez les voisins, et particulièrement en Argentine, qui n'a pas de tradition minière, les investissements miniers majeurs affluent. Dans cette conférence, nous chercherons à expliquer les causes de cette situation et proposerons des solutions possibles.

May 1, 2001

By Tassos Grammatikopoulos

The St. Lawrence deposit is a large wollastonite skarn (ca. 9 Mt @ 41.3% wollastonite) adjoining the gabbroic-to-syenitic Leo Lake pluton in the granulite facies of the Frontenac Terrane of the Grenvillian Central Metasedimentary Belt. It occurs within a horseshoe-shaped horizon of quartzite, open to the east. The skarn extends over 1.2 km2, and comprises wollastonite-dominant, wollastonite-clinopyroxene, and diverse quartz-feldspar-sulphide (-titanite) layers, interbanded with, and strongly folded within, the quartzite. As in the world-class wollastonite deposits of the Willsboro district, New York State, no carbonate protolith is preserved and calcite is a negligible constituent of the mineralized zones. Wollastonite development is nonetheless ascribed to metasomatism of a metacarbonate unit by magmatogene, silica-rich, CO2-poor (XCO2 < 0.05) fluids, at P = 350 MPa and ca. 560 oC, or, alternatively, 550 MPa and ca. 630 oC. Several high grade zones, averaging >40%, but locally exceeding 80%, of translucent, white, tabular wollastonite grains, with lengths of 0.2 - 2 cm, have been delimited by drilling. Preliminary beneficiation studies yield high aspect-ratio and high-purity (low Fe and Mn) concentrates. St. Lawrence compares favourably to other known prospects and operating wollastonite deposits; having good chemical and physical properties, low iron content, and high aspect ratios (>20:1). In addition, the deposit has a favourable size and location, and will benefit from a low Canadian dollar. Canada currently has no wollastonite production.

May 1, 2002

By L. B. Hale

"Introduction This paper will discuss the current operations of Westar Mining Ltd. and give a brief history of the company and of the Crowsnest Pass area. Westar is an integrated company involved in mining, processing and marketing coal from its mines in southeastern British Columbia and shipping coal from Westshore Terminals at Roberts Bank, located just south of Vancouver, B.C. It is two-thirds owned by the B.C. Resources Investment Corporation and one-third owned by the Mitsubishi Corporation of Japan and a consortium of Japanese coal consumers. Operations in southeast British Columbia consist of four coal mines and two processing facilities (Fig. 1). The Elkview Coal Processing Plant near Sparwood, B.C. receives its raw coal from Balmer operations (Harmer open pit), Balmer South (Panel 6) an underground hydraulic mine, and Balmer North an underground room-and-pillar mine. The fourth mine, Greenhills, an open-pit operation, is located near Elkford, B.C. and has its own processing plant. The Balmer mining and processing complex is the largest metallurgical coal facility in Canada producing up to 7 .5 million tonnes of clean coal per year. The Greenhills operation, completed in mid-1983, has a capacity of 2.8 million tonnes. The high-grade metallurgical and thermal coal produced is primarily for export markets. The major customers are Japan, Korea, Brazil, Pakistan, Chile and Taiwan.Our coal and that produced by other mines in Alberta and British Columbia is shipped to the international markets through Westshore Terminals Ltd., a wholly-owned subsidiary. Westshore will have an annual capacity of 22 million tonnes of coal and accommodate ships of up to 250,000 dead weight tonnes by 1984 when its current expansion program is completed."

Jan 1, 1985

By Masahiro Eguchi, Giuseppe Granata, Chiharu Tokoro, Hiroki Fukuda, Yuichiro Toba, Shungo Hobo

"Currently, large amounts of wastewater containing boron are discharged from industries like coal-fired power plants. Although coagulation-sedimentation is widely employed for their treatment, only a little consideration has been given to its mechanism. An additional problem is that the produced sludge has poor solid-liquid separation. This study is focusing on coagulation-sedimentation using magnesium, examining the mechanism and improving the solid-liquid separation. First, the co-precipitation with magnesium hydroxide was conducted against high-concentration boron wastewater with 500 mg/dm3as B. Second, in order to improve the solid-liquid separation by maintaining high reactivity, low-crystalline magnesium oxide was synthesized from magnesium carbonate by calcination at 400–700°C. It was tested as an adsorbent of boron and compared to co-precipitation with magnesium hydroxide. Co-precipitation showed high removal capacity. X-ray diffraction (XRD) of the sludge revealed the presence of other compounds besides magnesium hydroxide. This result suggests that other processes play a role other than simple adsorption on to magnesium hydroxide, and provides a plausible explanation for the observed high separability. As for the adsorption, the synthesized magnesium oxide immobilized as much or more amount of boron than co-precipitation. Furthermore, the results of fourier transform infrared spectroscopy (FT-IR) suggested the residual magnesium carbonate improved solid-liquid separability due to its poor solubility.INTRODUCTIONBoron is used in various industrial applications. In glass industry, the addition of a little amount of boron into glass products can enhance heat-resistance and chemical-resistance. Semi-conductor industry also employs boron as dopant for silicon. From these industries, large amounts of wastewater containing boron have been discharged. Additionally, coal-fired power plants have been recently discharging highly concentrated boron wastewater because the amount of boron contained in coal has been increasing due to a gradual decrease of the quality of coal. Since boron is partially proved to be toxic for animals, plants, and human beings (WHO, 1998),the guideline of the World Health Organization limit the boron concentration in drinking water to 2.4 mg/dm3(WHO, 2009).Because boron does not precipitate from solutions by simply changing the pH, the removal could be carried by operations such as adsorption or ion exchange. However, since ion exchange is an expensive operation with relatively low capacity, it is not suitable to treat the large amounts of wastewater produced by heavy industries like the coal-fired power plants. Therefore, coagulation-sedimentation method is still widely used as a suitable alternative way."

Jan 1, 2017