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By Lauri Gregg

How Can Man Meet the Carbon-Free Energy Challenge ? ? Increases in Energy Efficiency can displace 1/2 to 2/3 of the Carbon-Free Energy required to stabilize at 550 ppmv ? Renewable Energies require too much land and thus can displace 5 to 10 % of the energy requirement ? Large new sources of carbon free energy are needed ? Conservation is desirable but provides only a small and variable contribution ? People will have to adjust to higher levels of CO2 in the atmosphere as energy demand continues to grow

Nov 1, 2002

By Y. Wang

Phosphates and fluorides are used as regulators for the removal of silicates from diasporic-bauxite both in direct and reverse flotation. While using dodecylamine chloride as a collector, micro-flotation studies showed that sodium hexametaphosphate has stronger depressing power on diaspore than on silicate minerals with increasing sodium hexametaphosphate concentration at pH 6.5, but sodium fluorosilicate shows poor depression on diaspore with increasing sodium fluorosilicate concentration at the same pH. Zeta potentials of diaspore and silicate minerals become more negative both in the presence of sodium hexametaphosphate and sodium fluorosilicate. Adsorption density studies indicated that the adsorption density of sodium hexametaphosphate on diaspore is much higher than that on silicate minerals at the concentration of 75 mg/L. FTIR spectroscopy studies show that sodium hexametaphosphate interacted with the Al atoms exposed on the diaspore and silicate minerals surfaces to form P?O?Al bonds through the P02 groups. It is possible that sodium fluorosilicate interacted through F- or [SiF6]2- with silicate minerals surfaces based on the analysis by AES.

Jan 1, 2006

By P. J. Deveaux, M. J. Kreczmer

The Tartan Lake deposit 12 km northeast of Flin Flon, Manitoba, was discovered in March of 1984 during the investigation of a VLF anomaly. The discovery hole intersected 16.83 metres averaging 21 gm Au/tonne. Since then, 99 holes, over 21,000 metres, have been drilled outlining 419,491 tonnes grading 11.79 gm Au/tonne in a di stinct group of mineralized lenses referred to as the Main Zone. Three other mineralized zones are known on the property but no reserves have been allowed for these, the South , East and Base Line zones. The Main Zone consists of seven parallel, east-west striking, quartz lenses. The lenses dip steeply to the north and plunge steeply west to northwest. Lens number l strikes for 160m and extends vertically to the 90m level. Within th is lens there is a 60m interval of low grade materi al. Lens number 2 is located about 5-l0m within the foo twall of Lens number I. Near surface this lens stri kes for 40m, at 200m level the strike length increases to 200 m. To date the deepest mineralization on Lens 2 has been intersected at a vert ical depth of 527m. Five smaller lenses are located in the foo twall of Lens 2 , containing gold va lues similar to the two main lenses but erratically distributed. The South Zone, located 100m south of the Main Zone, strikes east-west fo r l00m above the 100m level. The East Zone, found 230m east of the Main Zone, strikes fo r 80m and may possibly be an ex tension of the South Zone. The Base Line Zone is located 275m south of the Main Zone. Sporadic, but very significant gold intersections have been obta ined1n all three zones. Gold-bearing quartz-ca rbonate tourmaline veins are generally confined to a silicous crystal tu ff hori zon. The crystal tuff exhi bits fi ve distinct types of alteration: silicification, sericitization, ca rbonati zation, chlorit ization and pyritization. Silicification has resulted in a perasive addition of silica and the generation of multiple quartz veins. Sericiti zation is restricted to the crystal tuff. All rock units are pervasively carbonatized . Ankerite is abundant in the quartz veins and within the shear zones, particul arly those located along the chilled margin of a nearby gabbro-diorite intrusion. Chloritization is widely spread th roughout the rock units, while pyritization fo rms a broad alteration halo associated with the orebody. Sulphide accesso ry minerals associated with the gold , whi ch fo r the most part appears to be free, are chalcopyrite and pyrite. Generally, the higher grade gold values are related to an increased content of sulphides in the qua rtz veins. The average sulphide content in the deposit is less than 5 %.

Jan 1, 1986

By J. Q. Chen

The elastic-plastic behavior and the fracture mechanisms of two 2198 Al-Cu-Li thin sheets are investigated. The first material (2 mm thick) is in a recrystallized state after cold rolling. The second material (6 mm thick) is hot rolled and has a fibrous grain structure. The two materials are studied in both T351 and T851 conditions. Tensile tests are carried out along different sheet directions using flat and notched specimens. Fracture resistance was characterized using Kahn tear specimens and M(T) panels. Macroscopic fracture surface of smooth tensile specimens depends not only on testing material but also on the loading direction. For Kahn tear specimens, fracture is initiated in a small flat triangle whereas slant fracture is observed during crack propagation. Fracture mechanisms were investigated using scanning electron microscopy (SEM) and X-ray 3D tomography.

Jan 1, 2011

By C. R. Whittemore

IT can be truly stated that no branch of the engineering industry has progressed more rapidly in the last few years than that of welding. In spite of depressed economic conditions, this industry has continued to advance along scientific lines, replacing the old hit-and-miss method of welding. The development work is intensive, and increased activity is recorded in every sphere of the industry, new applications of existing methods, together with new processes, being added to those already proved in practice. The general acceptance of the welding processes can be measured by their utilization as a manufacturing tool in the metal-working industries. Many manufacturers have partially or wholly adopted welding. These concerns have on their staffs welding specialists, design engineers, and metallurgists, who are qualified to design and supervise the manufacture of welded parts, at a considerable saving to the purchaser. The steady, consistent, and sound growth of welding is based upon investigation of the fundamentals of the various processes, together with their proper application. The classification of welding processes varies in different countries. In Europe, they are divided into two main classes, namely, heterogenous and autogenous. In the former, the parts are joined, as a ruler without melting the edges, and by using as filler a metal different from that of the object welded. Such welding differs from soldering and brazing in that higher temperatures are required to effect the union of the parts. In autogenous welding, the parts are joined by melting of the edges, with or without the addition of a material similar to the parts being joined.

Jan 1, 1936

By J. A. Brusset

Introduction I am indebted for most of the information in this paper to Mr. P. S. Lea, Deputy Chief Inspector of Mines of Great Britain, and Mr. A. E. Crook, Engineering Inspector of Mines, Ministry of Fuel and Power. Other coal-mining men in Canada may be as surprised as I was to learn that there are twenty-five Diesel locomotives in service underground in British gassy coal mines. Many more are in use underground in non-gassy coal mines and in metal mines. Approval has been granted for an additional fifty flame-proof locomotives to be used in gassy mines, and these should be in operation by the end of 1946, or as soon as manufacturing facilities permit.

Jan 1, 1946

By C. O. Swanson

CALCULATING the average grade of a gold deposit is a problem that presents certain unique difficulties. Particularly troublesome is the fact that the average of the samples taken from a deposit is likely to be higher than the grade of the ore that is eventually mined, even when allowance is made for dilution and other factors resulting from the mining operations. It would seem that this situation is due to the presence in the deposits of structural peculiarities which have not been properly taken into account, since estimating the average grade of the broken ore produced from the deposits does not present the same difficulty. It is therefore evident that structural considerations are of prime importance in estimating the grade of a deposit. This fact is clearly realized and taken into account in cases where the boundaries of the orebodies and the variations within them are easily recognized. But in many gold deposits this condition is not satisfied, a circumstance which can be regarded as the main source of difficulty. Lacking definite information concerning the structure, we are apt to use certain procedures which are either empirical or based on general probabilities.

Jan 1, 1945

By M. B. Kime

"A set of experimental batch leaching tests studied the effect of pH, time, temperature, and stirring speed on the relative Cu, Co, Ni, and Fe leaching yields of an oxidized copper-cobalt ore sample in an aqueous hydrochloric acid solution. The results were statistically analyzed and modelled using the structural equation modelling method. Models showed that Cu, Co, and Ni leaching yields were strong functions of the leaching time and leaching temperature, whereas the Fe leaching yield depended on the leaching temperature, stirring speed, and pH. Under optimum leaching conditions yields were 99.8% Cu, 82.4% Co, 91.3% Ni, and 30.6% Fe.RÉSUMÉ Une série d’essais expérimentaux de lixiviation en bâchée ont été menés pour étudier l’effet du pH, de la durée d’attaque, de la température et de la vitesse de brassage sur les rendements relatifs de lixiviation du cuivre (Cu), du cobalt (Co), du nickel (Ni) et du fer (Fe) d’un échantillon de minerai de cuivre-cobalt oxydé dans une solution aqueuse d’acide chlorhydrique. Les résultats ont été analysés et modélisés statistiquement à l’aide de la méthode de modélisation par équation structurelle (SEM, de l’anglais structural equation modelling). Les modèles ont montré que les rendements de lixiviation du Cu, du Co et du Ni dépendaient énormément de la durée d’attaque et de la température de la lixiviation ; le rendement de lixiviation du Fe, quant à lui, dépendait de la température de la lixiviation, de la vitesse de brassage et du pH. Dans des conditions optimales de lixiviation, les rendements étaient de 99,8 % pour le Cu, de 82,4 % pour le Co, de 91,3 % pour le Ni et de 30,6 % pour le Fe. INTRODUCTIONThe Katanga province in the Democratic Republic of Congo hosts the northwestern part of the Central African Copperbelt. This region abounds with large, rich deposits of sulfide and oxidized copper-cobalt ores. In general, the main valuable minerals present are malachite (CuCO3Cu(OH)2) and heterogenite (CoO(OH)). Common impurities found in heterogenite are Cu, Ni, Si, Al, Mn, and Fe. The substitution of Co by other cations (e.g., Cu, Ni, and Fe) has an influence on the crystallinity of heterogenite (Deliens, 1974). In general, well-crystallized varieties of heterogenite have lower impurity contents, whereas amorphous heterogenite types usually contain more impurities (Thys et al., 2009). Further, in heterogenite, Co can occur in the 2+ and 3+ oxidation states. The gangue generally consists of quartz (SiO2), talc (Mg3Si4O10(OH)2), kaolinite (SiO2·Al2O3·2H2O), limonite (Fe2O3·3H2O), and goethite (FeO(OH)). Oxidized copper-cobalt ores are often treated by hydrometallurgical methods, whereas sulfide ores are often treated by flotation or pyrometallurgy, depending on their grades. Hydrometallurgical methods typically entail selectively dissolving the metals of interest (Cu, Co, and Ni) in aqueous solutions (leaching), transferring the dissolved metals to an organic solution, and retransferring these to a second aqueous solution (solvent extraction). Copper and nickel are readily dissolved in an acidic aqueous media. In contrast, cobalt is difficult to dissolve, especially if it is present in the third oxidation state; however, this species becomes soluble after it is reduced to Co2+ (Mwema, Mpoyo, & Kafumbila, 2002; Kime & Makgoale, 2016)."

Jan 1, 2017

High Pressure Grinding Rolls (HPGR) are said to be a good option in new grinding circuits. Due to their low energy consumption compared to other grinding systems such as SAG milling, there is a strong incentive to check their behaviour for certain ore types. With rising energy prices the operation will become even more beneficial in future. As published in the past, the HPGR is claimed to increase the liberation of the valuable mineral component within an ore. An investigation at the research centre of Polysius was conducted to substantiate the liberation behaviour in finish grinding operations. A pilot scale HPGR test unit (POLYCOM MAGRO) with a roll diameter of 950 mm and processing capacity of 80 t/h was used. Grinding tests were completed with a screen and a two stage drying air separation process (SEPOL). Analysis included standard screen analysis, fractional XRF and modern MLA technology. A technique was developed to oppose the amount of produced slimes (resuming bad flotation) against the positive effect of producing high mass fraction at flotation-easy sizes. The paper shows how effective the use of a dry grinding separation could be in terms of production of mass of liberated metal.

Jan 1, 2012

By J. Girard, V. Aubé, M. Barakate, S. Bellec, M. R. Eddahabi, Y. Chaik, M. Deshaies

"The activated carbon used in the carbon-in-leach (CIL) process to absorb gold is subject to breakage. This carbon breakage can be minimized, but it will always be necessary to deal with fine carbon particles, known as carbon fines. These fines contain a significant amount of gold and mining operations generally struggle with the treatment of this product. Since IAMGOLD’s Essakane mine is located in Burkina Faso, shipping carbon fines out of the country was not considered a viable solution due to the logistical burden and legal procedures in place. A benchmarking study demonstrated the complexity of treating carbon fines on site. IAMGOLD partnered with the host government to find an innovative approach to economically recover the gold locked in these fines. This paper describes the new circuits commissioned in July 2016 built to improve carbon fines collection, incinerate the carbon fines and leach the gold in the ashes produced by incineration. These new circuits successfully demonstrate that it is possible to extract more than 94% of the gold content in the carbon fines. This is profitable for the company as it improves the overall mill recovery rate by 1.0% to 1.5% and significantly decreases gold inventory build-up on site.INTRODUCTION The activated carbon used in the carbon-in-leach (CIL) to absorb gold is subject to breakage. This breakage can occur in the CIL tanks, the stripping circuit, the regeneration process or anywhere throughout the pumping and handling processes of carbon through the circuit. Fine carbon particles are invariably created and, because of their small size, present a large specific surface which favors gold absorption (Hilsher et al., 2014). At the very beginning of operations at Essakane, the carbon fines were recovered by means of a thickener and a filter press, but the circuit was undersized and inefficient. Subsequently, a decantation basin was used to settle the fines before the thickener. The settled fines were shovelled from the basin into bags. All these bags were stored in the backyard of the plant. The average tonnage of carbon fines recovered monthly was 23.5 tons with a gold grade at 1938 g/t."

Jan 1, 2017

By H. Memarian

In the last few decades, many developing countries have tried to expand and improve upon higher education, which is acknowledged to be the leading factor for development. In this respect, develiping countries have significantly increased the number of tertiary institutions and their students. These rapid expansions, along with all the benefits, have drawbacks as well. An example is the status of mining engineering education in Iran. Presently, the number of active mining engineering departments in Iran (27) is more than the sum of similar departments in Canada, Australia, the United Kingdom, and South Africa (23 altogether). Also, the number of annual mining graduates in Iran (645) is more than the cumulative graduates of the United States, Canada, the United Kingdom, and Australia (613). The expansion of mining engineering education in Iran has coincided with the closing or merging of similar mining departments, as well as a decline in the number of interested students in the industrialized world. The present study shows that the need for development and the excessive number of high school graduates, resulting from high population growth in the early 1980s, are the two primary factors influencing the significant expansion of mining engineering education in Iran.

Jan 1, 2007

By Thomas Clark

This report presents a review of the distribution and exploration potential of platinum-group elements (PGE) in Québec; it is based on published and unpublished analytical data. This qualitative evaluation of the PGE potential, whether in PGE-dominant deposits or in Ni-Cu-dominant deposits with co-product PGE, is based on interelement ratios such as Ni/Pd, Cu/Ir, Cu/Pt, and Cu/Pd. Good PGE targets, i.e., deposits associated with magmas fertile in PGE, are identified. Less favorable PGE targets, i.e., deposits associated with PGE-depleted magmas, are also mentioned. The importance of exploring for deposits similar to those at lac des Îles and East Bull Lake (Ontario) is emphasized.

May 1, 2001

By X. L. Song, G. W. Zhang, F. Y. He, X. Xiao, L. L. Huang

This paper presents the design of a model and process simulation of a vertical mill based on a population balance model. The simulator, Simulink, which is a systematic modeling tool within MATLAB, was used for the simulation. The model will simulate the real time variation trend of each size fraction in the feed material to the vertical mill, as well as, the size distribution of the batch grinding products. Breakage distribution and selection functions are calculated based on batch grinding laboratory experiments using Back-calculation method. The simulated size distributions correspond with those in the actual mill operation having a relative error of less than 0.50%. This work lays the foundation for future research on modelling and simulation of a closed circuit grinding operation consisting of a vertical mill with hydrocyclone classifier.

Jan 1, 2016

By H. A. Halupka, I. A. Mozer

"At its plant in San Juan, Peru, Marcona Mining Company operates two grate pelletizing furnaces for the agglomeration of 3.5 million long tons of magnetic concentrates annually. Line One, installed in 1963, was built by Lurgi as a downdraft process furnace utilizing a furnace fan for the recuperation of hot gases from the cooling zone. This line was modified in 1966 to include both updraft drying and downdraft drying, and the original roof burners were converted to side-wall burners. Line Two, a Dravo-Lurgi furnace with an annual capacity of 2.4 million long tons, was built in 1966. This line, in contrast to the modified Lurgi furnace, employs direct recuperation of hot gases from the cooling zone and utilization of process gases from the firing zone for updraft drying.At its plant in San Juan, Peru, Marcona Mining Compa-ny operates two grate pelletizing furnaces for the agglo-meration of 3.5 million long tons of magnetic concentrates annually. Line One, installed in 1963, was built by Lurgi as a downdraft process furnace utilizing a furnace fan for the recuperation of hot gases from the cooling zone. This line was modified in 1966 to include both updraft drying and downdraft drying, and the original roof burners were converted to side-wall burners. Line Two, a Dravo-Lurgi furnace with an annual capacity of 2.4 million long tons, was built in 1966. This line, in contrast to the modified Lurgi furnace, employs direct recuperation of hot gases from the cooling zone and utilization of process gases from the firing zone for updraft drying. 5 per cent increased capacity, 30 per cent lower fuel oil consumption, and approximately 400 per cent reduction in grate bar and pallet corrosion. Firing of the pellet bed was improved by conversion from roof to side-wall burners. This modification also permitted utilization of monolithic refractory in place of pre-fired shapes, thereby improving over-all furnace availability and reducing refractory stock requirements from 154 different shapes to 18.Data are presented to compare operating performance of the Dravo-Lurgi furnace and the modified Lurgi furnace. These data show 30 per cent lower fuel oil consumption and 10 per cent higher capacity per unit grate area for the Dravo-Lurgi furnace, which also averages higher availability due to greater operating flexibility."

Jan 1, 1970

By K. Hasselwander, K. Knabel

"A significant area of Outotec’s business involves fluidized bed roasting. With several decades of experience, more than 300 reference plants and strong R&D capabilities, the company provides several industries with optimum processing solutions. Applications include oxidation and sulfation of sulfides found in copper, pyrite and zinc concentrates. Gold production and de-arsenifying roasting are also within this scope. This paper describes the latest furnace developments and includes novel trends. Moreover, hot and wet gas cleaning systems are examined focusing on unit operations related to the removal of components such as dust, SO2 for sulfuric acid production, fumes, halides, Hg, hydrocarbons, nitrous oxides and metals.INTRODUCTIONGenerally, when defining roasting processes, it can be stated that the respective primary pyrometallurgical reaction is exothermic, of gas-solid nature and relates to a value solid product. These processes are a key focus within Outotec’s scope and include: (i) dead roasting (ii) sulfating roasting (iii) partial de-arsenifying roasting and (iv) two-stage, de-arsenifying roasting.Dead roasting involves the oxidation of a given sulfide, thus allowing for a subsequent leaching process, and has been applied to producing ZnO. Dead roasting of pyrite has also been extensively utilized with a primary goal of producing sulfuric acid. In contrast, sulfating roasting involves converting a sulfide to its sulfate, enabling a selective sulfation of components, such as Cu or Co, and their separation from ferrous components during leaching (produced sulfates are soluble). Partial roasting involves partially oxidating the metal sulfide to its oxide with the simultaneous production of gaseous As4O6, which is handled during gas cleaning. The solid product, containing hardly any As, is rich in S and can be fed to a respective smelter (e.g. in the case of Cu). Alternatively, if the production of oxide is required, a dead roasting step is added after the partial roasting step, with the overall process considered as two-stage roasting."

Jan 1, 2012

By Leslie S. Weldon

THE Lake Shore mine has been developed by two vertical shafts, with level intervals at 200 feet to the 2200 level and at 125 feet below this horizon. A main cross-cut joins the two shafts on all levels to the bottom of No. 3 shaft, and opening into these cross-cuts are the ore passes and sand passes, which are completed from surface To the 4450 level. In the west part of the mine, additional connections have been made between No. 1 and No. 2 veins, through which the major part of the ore from No. 2 vein west is routed to drifts in No. 1 vein. With the lesser amount of stoping on No. 1 vein, this arrangement permits better haulage to be maintained. The ore passes are driven at 50 degrees from the ends of short cross-cuts off the main ones and are broken through to the levels above at the mouths of the short cross-cuts, to allow for dumping on each level. The passes are controlled at each level by ball-and-chain gates and deliver to crushers and thence to loading pockets, shown in Figure 1. That system is quite flexible in that it is possible to by-pass the crushers at any station and load from either shaft at a number of different pockets. The sand passes are driven from the main cross-cuts at the same inclination as, and parallel to, the ore passes. Each is equipped with a chute and dump hole, so that waste or sand fill may be loaded or dumped at each level. A transfer door, hinged on the bottom, is installed opposite the chute for by-passing fill from one level to the next, and in the closed position protects the opening at the top of the pass. The dump hole situated beside the transfer door is protected by a grizzly with 10-inch spaces. Waste rock may be withdrawn from the system through No. 3 shaft loading pocket at the 2950 level to a waste bin on surface. Levels are developed by drifts in No. 1 and No. 2 veins for their entire lengths. Subsidiary breaks are followed at a later date, when full information has been obtained by exploration, and a considerable amount of development by sub-drifts is carried out in the upper part of the mine, particularly in more or less erratic sections of No. 1 vein.

Jan 1, 1936

By R. Carpenter, H. Muntanion, P. Kleespies, E. Flood, M. Tansey

Abstract - BHP Minerals discovered the Archean lode gold ULU deposit on the western margin of the High Lake Volcanic Belt in 1989. The greenschist to amphibolite facies mafic volcanic and sedimentary rocks on the property are folded into a 5 km-long anticline. There is a close spatial association of Au-As zones to the trace of this F2 ULU anticline. The largest of these auriferous zones, the Flood zone, is localized at the core of the fold. The southeast-trending Flood zone consists of several anastomosing lenses that have been traced for 435 m on surface. Overall, it dips steeply (70° to 80°) to the southwest and has been intersected to depths below 600 m. The hosting high-iron tholeitic basalt displays a lower amphibolite mineral assemblage of ferrohornblende + plagioclase + ilmenite with accessory quartz and epidote. Alteration minerals include biotite, chlorite, hornblende, actinolite-tremolite, and potassium feldspar (microcline) with minor calcite, epidote, tourmaline, and titanite. The highest gold values occur where brecciated basaltic wall-rock clasts are replaced by acicular arsenopyrite + quartz + K-feldspar. BHP Minerals completed 54,783 m of both exploration and resource development drilling before selling the ULU property to Echo Bay Mines in 1995. Development of ULU as a satellite deposit to Echo Bay’s Lupin mine began in 1996. A -15% ramp was extended to the 155-meter level, and 16,011 m of underground drilling were completed before the decline in gold prices forced a suspension of activities at ULU in August 1997. The current owners, Wolfden Resources Inc., drilled 18,569 m in 2004 to increase confidence in the resource blocks. Following this drill program, a revised resource calculated by an independent consultant determined that the ULU deposit contains an inferred/indicated mineral resource of 1,130,000 t grading 11.34 g/t gold (373,748 oz) to the 360-m level. The portal was re-opened in 2005 and a prefeasibility study is underway.

Jan 1, 2004

By Claudio Rocha Rosales

"Peñoles is a mining group with integrated operations for the smelting and refining of non-ferrous metals, and it is also a chemicals producer. Peñoles is the world’s foremost producer of refined silver, metallic bismuth and sodium sulphate. It is also the leading Latin American producer of refined gold, lead and zinc. The Met-Mex Peñoles Zinc Plant commenced operations in 1973 with an annual production capacity of 105,000 t/y zinc. Since then, production capacity has increased, and at present, it stands at 240,000 t/y zinc. In this paper, the leaching process and particularly the operation of the jarosite circuit is reviewed, specifying process improvements to treat high iron calcines.INTRODUCTIONTwenty years ago the Electrolytic Zinc Plant in Peñoles was treating high quality zinc concentrates with low concentrations of iron (~7.5 wt.%) and silica (1.8 wt.%). Nowadays the quality of zinc concentrates is poor with a typical iron content of around 11 wt.% and silica at 2.0 wt.%. This has created numerous processing problems in our roast-leach-purification- electrolysis sections. In order to meet customer requirements it is necessary to find processing solutions to assure the operational continuity of the plant. These processing solutions are the focal point of this paper.REVIEW OF THE LEACHING PROCESSThe purpose of the leaching process is to recover the metals, mainly zinc, through a series of extraction stages with sulphuric acid solutions, which progressively increases the zinc dissolution. After the series of acidification stages, the solution, which is rich in iron, is sent to the jarosite circuit to separate zinc from iron (Garcia & Valdez, 1996). The first step of the leaching process is the neutral leach circuit which produces a zinc sulphate solution that is sent to the purification section for the removal of impurities such as cadmium, cobalt and copper. Then this solution is sent to the tank house to feed the electrolytic cells."

Jan 1, 2016

By K. Sawamukai, S. Ogasawara, D. Umenai, T. Tsuruta

"Removal of cobalt, strontium or cesium ion from the aqueous solution containing each metal ion only using microorganism was examined. Arthrobacter nicotianae which had a high ability to remove cationic metal ion was used for the removal of each metal. The removal of cobalt, strontium or cesium using A. nicotianae cells was affected by the solution pH, concentration of metal ion, and cell amount. The effects of above mentioned factors on the removal of each metal and time course of strontium from the solution containing each metal only using A. nicotianae cells were reported in this paper. INTRODUCTIONRadioactive elements, such as cesium, iodine, strontium, plutonium, barium, cobalt, lanthanum, yttrium, and tellurium, were detected around Fukushima Daiichi nuclear power plant, which was damaged by the magnitude 9.0 earthquake and the tsunami followed.The removal of radioactive elements from contaminated sources is a worthwhile subject to investigatein terms of environmental control. Research efforts have been especially concentrated on studying microorganisms that remove uranium including bacteria (Andres et al, 1993, Hu et al, 1996, Marques et al, 1991, Strandberg et al, 1981), actinomycetes (Byerley et al, 1987, Friiss and Myers-Keith, 1986, Golab et al, 1991), fungi (Byerley et al, 1987, Galun et al, 1983a, Galun et al, 1983b,Tsezos and Volesky, 1981, White and Gadds, 1990) and yeasts (Strandberg et al, 1981, Schmate II et al, 1978).We have investigated removal and recovery of uranium from aqueous systems using microorganisms isolated from uranium mines. We identified some strains of bacteria with extremely high uranium removing abilities (Sakaguchi et al, 1996), and thus, the microbial biomass may be considered as an adsorbing agent for the removal and recovery of uranium and heavy metals present in aqueous systems around Fukushima Daiichi nuclear power plant.In the present study, we screened various species and strains of bacteria, actinomycetes, fungi, and yeasts for their ability to adsorb uranium (Tsuruta, 2002). Basic features affecting uranium adsorption?co-existing cations and anions, cell amounts, pH, and the adsorption time course?by Arthrobacter nicotianae cells, which adsorbed the largest amount of uranium, were also investigated. In addition, we examined the removal of an other actinoid element, thorium ion, which may be present with uranium in refining effluents.In this paper, the removal of cobalt, strontium, or cesium from the solution containing each metal ion using A. nicotianae cells is discussed."

Jan 1, 2012

By Donald Roberts

"Parameters f or design and development of an emergency hoist system (Fig. I) were submitted to Timberland Equipment Limited of Woodstock, Ontario by the Potash Corporation of Saskatchewan Mining Limited.The unit is the first of its kind in Canada. Not only does it comply with the province of Saskatchewan's mining regulations, but has the added advantage of being completely mobile and self-contained.As well as being useful in the mining industry, the mobile hoist unit could be used in other emergency situations such as rescuing people trapped in wells.JustificationRevisions to the Mines Regulations under Section 13 of the Occupational Health and Safety Act, 1977, of the Province of Saskatchewan stipulate as follows:"" Section 410 .04(4) The Mine Employer shall make adequate provision at every mine where any worker is hoisted in a shaft not equipped with a manway to enable an y such worker trapped in a conveyance in the shaft to be rescued . "" It was not possible to equip the shafts at PCS Mining' s Divisions with "" manways"" and therefore an alternative was required.BackgroundThe Potash Corporation of Saskatchewan Mining Limited, a subsidiary of the Potash Corporation of Saskatchewan, operates four potash mines. Of these, three, Cory, Rocanville and Lanigan Divisions are wholly owned while the fourth, Allan Division, is 40% owned by Kidd Creek Mines Ltd., but managed by PCS Mining. The four underground operations all have a service and production shaft.From 1979 to 1981 the PCS Mining Division, along with Central Canada Potash, were developing an idea to use the existing ground-mounted timberland hoist at Lanigan as an emergency hoist. This hoist was used in the past for rope-up work at both Rocanville and Lanigan and other potash mine s. The Department of Labour at this time had concerns about the time it would take to load, t ran sport and re-install the hoist on a foundation when needed for an emergency. Weight and size made this particular unit very cumbersome for transporting.In addition, the speed at which this hoist operates is too slow for rescue work. When the Department of Labour expressed concern that this unit would be unsuitable for these rea sons, a search for a suitable unit was initiated.The project responsibility for procuring an emergency hoist for the Potash Corporation of Saskatchewan Mining Limited was assigned to the author, a shaft/ hoist specialist a t PCS Mining."

Jan 1, 1986