Search Documents

"Accelerated expansion of Western Canada's metallurgical coal industry has again stimulated considerable exploration activity in the Rocky Mountain Foothills Belt and influenced much of the R&D related to transportation, processing and carbonization. Preparation R&D has included further pilot-plant work on desulphurization, spherical agglomeration and modified compound cyclones (which are also proving themselves in other mineral beneficiation studies). Combustion research, aside from increasingly stressing control of combustion source pollution, has directed special attention to lignite PF firing and problems arising from lignite ash. Studies directed toward the non-fuel utilization of coal have centered on such diverse topics as active carbons, carbonaceous filter media, plant nutrients and industrial applications of humic acid derivatives. In addition, a number of long-range research projects related to such matters as coal chemistry and pyrolysis have been actively pursued, and further attention has been given to improved sampling techniques and analytical methods."

Jan 1, 1969

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 J. B. Boisvert, W. Board, C. R. Mooney

"Traditional geostatistical modelling methods are difficult to apply to heavy-tailed deposits because the extreme positive skew of the grade distribution leads to bias. The focus here is on an innovative method of modelling the high-grade population by conditionally simulating discrete volumes (nuggets) of gold with marked Poisson and Cox processes. Capping and other ad-hoc manipulation of the assay data is not required; however, an intensity map for the point processes is required. The method is demonstrated on a dataset from an epithermal deposit and demonstrates an improvement in reducing smearing and controlling the skew of the grade distribution.RÉSUMÉ Les méthodes traditionnelles de modélisation géostatistique sont difficiles à appliquer dans des gisements dont la distribution de la teneur est à queue lourde car l’extrême asymétrie positive de la distribution de la teneur génère des biais. Dans le présent article, l’accent est mis sur une méthode novatrice de modélisation de la population à haute teneur par la simulation conditionnelle des volumes discrets d’or (pépites) au moyen de procédés marqués de Poisson et de Cox. La limite d’utilisation et d’autres manipulations ad hoc des données ne sont pas requises; toutefois, il faut une carte des intensités pour le processus ponctuel. La méthode est démontrée sur un ensemble de données d’essais provenant d’un gisement épithermal et elle montre une amélioration dans le lissage du flou et dans le contrôle de l’asymétrie de la distribution de la teneur."

Jan 1, 2015

By M. Saghaeian, R. Hejazi, Fakoor Sanat Tehran Company, H. Abedini, M. Zare

"Dewatering of final tailings is one the biggest issues in iron ore processing plants. Because of the fine and hydrophilic particles in the iron ore tailings, dewatering of such material is difficult and, in most of the cases, needs to be processed using expensive and complicated equipment. In this study, a novel method based on classification of small and large particles has been proposed to improve the dewatering performance of iron ore tailings. In the proposed method, a hydrocyclone has first been used to separate the fine and coarse fraction of iron ore tailings. Then, the coarse fraction (hydrocyclone underflow) is easily dewatered by using vacuum belt filter. Then, the fine fraction (hydrocyclone overflow) is primarily dewatered by using a high rate thickener. Finally, the thickener underflow is added to the bed of solids on the same belt filter, which is used for dewatering of hydrocyclone underflow. The efficiency of this method has been compared with other solutions for tailings dewatering including changing vacuum filtration parameters, using fabric with larger pore size, and using pressure filtration, all through laboratory scale experiments on the tailings of an iron ore processing plant in Iran. The results indicated the superiority of this method compared to the other ones, which increased the specific filtration capacity of the tailings by around 46%.INTRODUCTIONWet beneficiation of minerals requires a substantial amount of water to enhance the efficiency of the process. Used water should be recovered at the end of process to minimize shipping costs, meet contract specifications, and reuse process water (Wills and Napier-Munn, 2006). Dewatering equipment is usually divided into sedimentation (thickening) and filtration (pressure and vacuum) equipment, the choice of which depends on particle size, solid content of slurry, and material nature (Mular et al., 2002)."

Jan 1, 2016

By D. W. Tully

Sedimentary and volcanic rocks of the Timiskaming series trend west-ward across the property of the Upper Canada mine, forming part of the north limb of a regional syncline which is truncated on the south by the Larder Lake fault zone. A wide zone of schistosity strikes east-west through the sediments and volcanics. The central portion of this zone is occupied by a system of narrow gouge-filled fractures in highly altered rocks, mainly tuff, trachyte, trachyte porphyry and syenite porphyry. The alteration zones have developed through repeated stages of deformation and accompanying metamorphism. The initial stages were marked by carbonatization and sericitization, followed by silicification and the introduction of minor amounts of sulphide minerals. Gold was finally de-posited in relatively late fractures within silicified zones and pyrite. Repeated movements along the Up-per Canada break have offset post-ore dykes of minette and diabase, and have resulted in minor displacements within the orebodies.

Jan 1, 1963

By D. Duffy, V. Papangelakis

"MgCl2 brines present a number of potential advantages for the processing of saprolite ores for nickel production. With a chloride system it is economically requisite to recover hydrochloric acid, which can be performed in a more energy efficient manner by precipitation and subsequent decomposition, as compared with conventional pyrohydrolysis. In addition, concentrated MgCl2 solutions enhance the activity of acid used, allow atmospheric leaching at elevated temperature and inhibit magnesium dissolution, which reduces acid consumption and increases metal selectivity. Leaching and iron control experiments have been conducted in concentrated MgCl2 brines, up to 4.5 m, to determine the most amenable process conditions. INTRODUCTIONChloride metallurgy has received an increasing amount of attention in recent years, especially with respect to the treatment of nickel laterites. Although the limonitic fraction can sometimes be economically treated by High Pressure Acid Leaching (HPAL), acid-consumption problems are encountered with the higher magnesium content of the saprolite fraction. As magnesium does not hydrolyze under HPAL conditions, as iron and aluminum do, any sulphuric acid used to leach magnesium is subsequently neutralized and wasted. In addition, this magnesium must later be disposed of in some fashion, further complicating the process. The most common method used to process saprolite is the Rotary Kiln-Electric Furnace (RKEF). This uses a kiln to dry and preferentially reduce nickel, before sending the calcine to an electric furnace. Although nickel recoveries are high, and the problems of acid consumption are avoided, the capital and energy costs associated with this process are high (de Bakker, 2011).The problems outlined above have led to the investigation of an atmospheric chloride process for the treatment of saprolite ores. The use of a chloride system presents a number of advantages, but also a few limitations. Metal chlorides tend to be very soluble, with a few notable exceptions (silver, mercury and lead), allowing for smaller processing equipment through more concentrated solutions. This solubility also serves to reduce the potential for scale formation. In addition, a hydrochloric acid leach is more aggressive than a comparable sulphuric acid system, and the activity of the hydrogen ion can be augmented by further chloride addition (Peek, 2011). This activity augmentation in concentrated chloride systems, first reported by Jansz, has repeatedly been referenced as a motivating factor behind chloride hydrometallurgy (Jansz, 1983; Harris and Magee, 2003; Harris et al., 2004; Demopoulos et al., 2008; McDonald and Whittington, 2008; Demopoulos, 2011; Peek, 2011; Verhulst and Lakshmanan, 2011). This activity increase allows a similar amount of acid to perform more in a concentrated solution than in a dilute solution, decreasing overall acid requirements. As such, much focus has been placed on leaching in concentrated chloride systems, or brines, using calcium, magnesium or sodium as the cation (McDonald and Whittington, 2008)."

Jan 1, 2012

By C. Lambert

It has been shown that contacts between host rock and engineered barriers may be critical in the design of deep radioactive waste repositories. Water is expected to reach the interface zone after the re-saturation of the geological massive and its presence may lead to concrete leaching. Such a phenomenon could increase the interface transmissivity and compromise the confinement of radioactive waste. Recent experimental results from Buzzi et al. (2008) have enhanced how concrete leaching can drastically change the mechanical behaviour of such interfaces. Because of the local loss of strength resulting from leaching, shearing resulted in a degradation of the interface asperities. Similarly to rock joints, intact interfaces exhibit a usual contracting-dilating behaviour. On the contrary, depending on the extent of leaching, the degraded interface can display a fully contracting. This paper intends to investigate the influence of concrete leaching on the mechanical behaviour of host rock-concrete interfaces. The leaching process consists in the dissolution of some of the hydrates of the cement paste, leading to a reduction of the strength and Young's modulus. A discrete model has been developed with PFC3D where a simplified interface morphology has been introduced using a saw-tooth description of the asperities.

May 1, 2009

By Smortchevskyk N. J.

THIS paper describes the electrical features of the locomotive now (August, 1962) under construction for Craigmont Mines. Intended for non-specialists, it avoids details of design and calculations interesting to electricians only. The paper is divided into three sections. The first deals very briefly with the mine layout and with operating conditions -existing and expected. Reference is made to economic considerations leading to the selection of the type and size of locomotive, as well as to traction diagrams and the calculations. This material is not included in the paper because of its length and because it does not represent anything new. The second section deals with engineering and economic considerations and shows, in some detail, why the A.C. system was chosen. The third section describes the basic components of the locomotive, including the voltage regulator, the rectifiers, the control arrangement and the filter, and deals with considerations affecting the selection of their rating and design. A concluding sub-section describes, very briefly, the track and trolley details and the power distribution switchgear.

Jan 1, 1963

By Longjiang Li, Song Mao, Zhengyang Qiao, Qin Zhang, Guizhou University, Ling Wang

"After a study on the advantages and disadvantages of flotation column, according to the limitation of ordinary flotation column only is used for a flotation of microgranular minerals, the paper designed a new kind of layered convection coarse particle flotation column.Using a bauxite to test the rationality of the flotation column.The test results show that the new layered convection coarse particle flotation column is feasible.It has certain advantages about coarse particles flotation.INTRODUCTIONFlotation column has many advantages, for example,a simple structure, high efficiency and energy saving, the obvious advantage of fine particles flotation , the index superior and so on. The advantages gradually getting people's recognition. Research of flotation column has been a breakthrough, however, due to it only is used for the flotation of microgranular minerals, and the microgranular mineral particles will lead to a series of problems, and makes the processing cost is increased. Due to increase grinding fineness can save the grinding time and reduce the cost of grinding, also can avoid the disadvantage of fairly granular mineral particles cause a deterioration in the flotation. So it is necessary to research a kind of coarse particle flotation column.After a research on the advantages and disadvantages of flotation column, the authors designed and manufactured a new layered convection coarse particle flotation column, the flotation column both in theory and operation is better than flotation machine.DESIGN OF THE LAYERED CONVECTION COARSE PARTICLE FLOTATION COLUMNAdvantages and Disadvantages of the Traditional Flotation ColumnIn the field of mineral processing, as the increasing proportion of ore that has low grade, fine dissemination size, complex mineral composition characteristics. The limitations of traditional flotation machine is increasing[1],for instance, the high energy consumption, severe wear, inconvenient configuration , large amount of maintenance and so on. Compared with flotation machine, the flotation column with high separation efficiency, low investment and production cost, covers a less area low installation cost, less reagent dosage, more suitable for separation of fine particles and can automatically control, etc[2]. At present, the ore is facing the world energy crisis situation, and becoming increasingly difficult to flotation. So it is important to invent a coarse particle flotation column."

Jan 1, 2016

By A. C. Elliott, A. J. Lafreniere

THE Hamilton Works of The Steel Company of Canada is a fully integrated steel plant with an annual capacity of three million tons. Located on the south shore of -Hamilton bay, it is in the centre of Hamilton's industrial belt. The heavy concentration of industrial activities found in this area, accompanied metallurgical well-known sources of pollution which are normal to urban areas is creating a pollution problem which concerns both industry and the general public. The Steel Company of Canada has recognized this problem and, accordingly, has adopted the policy of integrating suitable pollution control devices into its new installations. Much effort is also being expended to control the emissions of air contaminants from the existing equipment. At the Hamilton Works, there are two main sources of metallurgical dust emissions to the atmosphere -the Open Hearth furnaces and the Sinter Plant. Of these two, the Open Hearth furnaces are, undoubtedly, the largest single source of

Jan 1, 1962

By L. J. Cunningham

Introduction The property of Rouyn Merger Gold Mines, Limited, is in Rouyn and Joannès townships, Western Quebec, seven miles east of the town of Rouyn. Traversing it is the east-west trending Cadillac-Bouzan fault. Diamond drilling in 1944 and 1945 along a shear zone south of the fault indicated an ore deposit lying at the contact between sedimentary and volcanic rocks and dipping approximately 60° to the northwest. In the summer of 1945 it was decided to sink a shaft to investigate the indicated ore zone. In the immediate vicinity of the deposit, bed-rock is overlain by clay beds, in some places as much as 70 feet thick. Consequently, possible shaft sites were limited to those locations where overburden would not be excessive. The most favourable site was about 125 feet to the south of the ore zone as projected vertically from bed-rock to the surface. Accordingly, it was decided to sink the shaft at this point, with an inclination of 60° N. W., paralleling the dip of the ore zone.

Jan 1, 1948

By Xing-Liang Sun, Xian-Min Han, Zheng-Guo Zhu

The study on the material properties of frozen soils in China was being developed quickly in the past decades of years, because of the increase of the engineering constructed in frozen soil regions on the Qinghai–Tibet Plateau, and numerous research results were achieved mainly about strength and deformation behaviour and constitutive models of frozen soils. Studies have shown that the deformation procedure of frozen soils is irreversible; therefore, it is more appropriate to research mechanical properties of frozen soils by means of damage mechanics theory. In this paper, an elasto-viscoplastic anisotropic damage model is presented by introduction of Perzyna viscoplastic equation into analyzing the deformation of frozen soil. In addition, an anisotropic damage evolution equation is obtained by means of extending non-viscous damage to viscous damage. Triaxial tests at different strain rates are chosen to illustrate the application of this model, and good agreement between experimental data and numerically simulated results is obtained. The calculated results indicate that, under the same conditions, the damage at higher strain rate is less than that at low one. So the phenomena are explained from damage mechanics that the frozen soil has larger elastic modulus and shear strength at higher strain rates, and explained from mechanism that the emergence and development of micro-cracks in the body of frozen soil can be to some extent retarded at higher strain rates.

Jan 1, 2015

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 L. Heber Cole

The search for potash in western Canada during the years of the great war led to the staking of claims on many of the "alkali lakes" and sloughs which occur in numerous localities in the morainic areas of the prairies, as well as in British Columbia, in the hope that potash salts would be found in commercial quantities. While the search for potash, up to the present time, has been disappointing, the prospecting of these areas has demonstrated that Canada possesses large reserves of sodium and magnesium compounds, principally in the form of sulphates, carbonates and chlorides. he writer first became interested in these deposits in 1911 while investigating the sodium chloride springs of northern Manitoba. In the fall of that year a number of the sulphate ? deposits in Saskatchewan and Alberta were visited, but owing to the excessive rains at that period, all the deposits were under water and only a few brine samples were obtained. Owing to pressure of other work investigations of the alkali deposits in western Canada, by the Mines Branch of the Department of Mines, could not be undertaken until the field season of 1921, but since that time the work has been continuous. During the summer of 1918 a reported discovery of a large deposit of potash bearing salts was featured in western papers and in a short time practically all the lakes and sloughs of the prairie provinces, which showed the least indication of being saline, were staked for potash. This reported discovery was not substantiated on investigation and many of those who had staked claims allowed them t~ lapse without the slightest effort to determine the character of the material in the deposits which they? had leased.

Jan 1, 1924

By Rodgers Peale

The Waite mine, as it is locally termed, is situated in the Rouyn district, in the townships of Duprat and Dufresnoy, Quebec, and lies about 340 miles north of Toronto. Due to the impetus given prospecting in the Rouyn district by the discovery, some years ago, of copper-gold ore on the Horne claims, many exploration parties were put into the field. Early in 1925, J. H. C. Waite, C. H. Ackerman, and T. Montgomery staked the claims which now comprise the mine beating their names. Trenching and diamond drilling soon disclosed an ore-body of commercial size and grade, and by the end of 1928 a shaft had been sunk 300 feet and the mine was producing 150 tons of direct-smelting copper ore a day. In the summer of 1925, Dr. H. C. Cooke, of the Geological Survey, made a reconnaissance survey of the property (1), and since that time work of the same nature has been done by several others. MacGregor has published some interesting data on the Amulet mine (2). Using as a background a summer's work on the Horne claims at Noranda, the writer spent the summer of 1929 at the Waite.

Jan 1, 1931

By Hugh P. Godard, K. Winslow

"AbstractA number of panels of various aluminum alloys in different combinations and secured by steel and three types of aluminum rivets were exposed underground at two locations in a Northern Ontario gold mine for two years and then examined to determine the extent of corrosion. The results indicate Alcan 65S-T to possess considerable advantages over Alcan 178-T, which has been employed in the construction of light skips and cages with considerable success for almost twenty years. Information on the behaviour of these alloys when used with steel rivets and in mixed combinations with themselves was obtained.IntroductionBy the complete substitution of aluminum alloys for steel in the fabrication of mining skips and cages, their weight can be reduced as much as 50 per cent. Lesser savings are possible though its savings are possible through its plates, doors, reinforcing members, etc. Reduced weight leads to economy through increased hoisting efficiency.For a new installation, the basis of design is the rate of production, which thus fixes the live load to be hoisted per trip. A lighter skip permits the use of a lighter rope and a smaller hoist. In deep shafts with high-speed hoists operated in balance, the power required for accelerating is considerable. The hoist size is determined by the weight of skip, load, and rope plus the force required to accelerate or decelerate these three elements A light skip may result in a considerably lighter rope. This is important because, even though the skip can be completely balanced this is not true of the rope. Partial balancing is possible, but conical hoist drums or other devices for this purpose are costly; thus a smaller rope results in a smaller hoist, with consequent general reduction in cost of the whole installation. A reduction in power consumption is also obtained as a result of keeping to a minimum the amount of unbalanced load and the weight of all moving parts which must be accelerated."

Jan 1, 1950

By H D. Smith

T HE production of coal in Canada was slightly higher in 1964 than in the immediate past, and the major users continue to be the electric utility and metallurgical industries. There are continuing trends toward the increased use of cokes and chars in various metallurgical applications. Geological Research During 1964, the coal drilling program of the Research Council of Alberta (RCA) was concentrated in the extreme south of the Province (notably in the Milk River area and the region immediately to the northeast of this area). Field work commenced on June 1 and was completed at the end of September, by which time a total of 376 holes, aggregating some 48,500 ft., were drilled in 132 townships. Although no new major coal occurrences were intersected, the pro-gram yielded useful data for defining the extent of the known coal deposits in the area. Detailed results will be analyzed during the winter and reported in due course. Meanwhile, a full report on the

Jan 1, 1965

By W. J. Langford

"Conventional design criteria assume that the fracture strength of a structural material exceeds its yield strength. Fracture below the design load is not expected, y et many structures have failed in this way. The causes of the fractures are almost always discontinuities such as cracks and welding defects. Linear Elastic Fracture Mechanics (LEFM or simply 'fracture mechanics') provides an analytical framework for assessing the influence of sharp defects on the load-bearing capability of a structure. Fracture mechanics techniques have reached the point of acceptance by ASME Design Codes for nuclear components, and ASTM Standards now include well-defined rules for measuring fracture toughness. Starting with a simple equation which relates applied stress and crack size, the influence of the material's thickness and yield strength can be calculated. Thus, the size of defect which will cause failure under the applied stress may be determined. Armed with this information, the metallurgist can assess the safety of a structure from the viewpoints of non-destructive testing standards, construction standards and conditions of operation throughout its service life."

Jan 1, 1976

By J. J. Baz-Dresch

"The Cannon Mine, a joint venture between Asamera Minerals (the operator) and Breakwater Resources, is located in the centre of Washington state at the eastern base of the Cascade Mountains. The mine complex is located three blocks south of the city limits of Wenatchee, part of an urban area with a total population of 47 000. The closest residence is 350 feet from the mine portal.The B-Neath zone is a narrow, high-grade, downward extension of the southern tail of the mine's main ore body, the B-North zone. It also underlies the northernmost portion of the B-West zone (Fig . I) . The ore is usually reasonably competent but completely surrounded by very weak rock consisting of shear zone and unsilicified sandstones and siltstones.The zone has maximum dimensions of 420 ft in thickness, 500 ft in length , and 200 ft in width . The economic reserves extend from the 70-ft elevation (elevation above sea level) to the 630-ft elevation and consist of about 1.3 million tons of geologic reserves (proven and probable) at an average grade of 0.33 ounces per ton.Acquisition and ExplorationInitial DiscoveryThe initial discovery of the B-Neath zone was made by Tenneco Minerals during July through September, 1984. Their 22-hole surface drilling program consisted of 18 200 ft of drilling. Tenneco Minerals had acquired the 91/2 acre lease from United Mining Corporation.Asamera Minerals subsequently purchased Tenneco's lease in July, 1985; Tenneco retained a royalty position which was later purchased by Echo Bay Mining.Follow-up drilling by Asamera Minerals consisted of both surface and underground drilling. Eight surface holes (7200 ft) were drilled commencing in December, 1985. Following evaluation of the geologic data, an access drift was driven on strike along the top of the ore zone on the 500 level. Diamond drilling from this platform consisted of 17 200 ft in 79 holes."

Jan 1, 1990

By K. Murase

Potentiostatic electrodeposition behavior of dendritic copper from acidic copper(I) chloride (cuprous chloride) baths containing sodium chloride and sodium bromide was investigated. The morphology, or appearance, of copper dendrite and the sodium content in the dendrite as an impurity were both influenced by deposition potential (0 to ?150 mV vs. SHE) and bath temperature (R.T. to 60 C), while the current efficiency for the deposition was 99% or more irrespective of the deposition conditions examined. The bath pH did not affect the deposition behavior in the pH range of 0 to 2. Bath temperature was found to be the most important factor influencing the deposition current. The current density of the dendrite deposition on a titanium cathode was lower than that onto a copper cathode with the same substrate surface area. The reproducibility of the current for the dendrite deposition was poorer when an as-polished titanium cathode was used, although it was improved by surface treatment of the cathode with an HF-HNO3-H3PO4 solution before electrodeposition. The deposition behaviors were discussed with the potential-pH diagram of the Cu-Cl-H2O system.

Jan 1, 2007