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By Dong-Hyeun Koh, Yun-Soo Lee, Min-Seok Kim, Hyoung-Wook Kim

High strength AA7068 (Al - 7.88 wt.% Zn - 2.68 wt.% Mg - 2.07 wt.% Cu) aluminum alloy strip was successfully fabricated by horizontal-type twin roll casting. A simulation technique was used to obtain the range of casting conditions for fabricating strip without defects. The cast strip with thickness of about 5 mm was hot rolled, intermediate annealed, cold rolled to final thickness and subsequently annealed at various temperatures. Tensile properties of annealed and the aged specimens were evaluated at ambient temperature. Tensile strength and elongation of the annealed sheet are about 365 MPa and 28%, respectively. Also, the tensile and yield strength after the aging at paint baking condition (180 °C x 0.5 h) are 586 MPa and 551 MPa, respectively. Therefore, it is expected to show good formability prior to press or stamping and also provide high dent resistance after paint baking treatment.

Jan 1, 2015

By Bob Drew, Goran Vukovic, Bojan Zivanovic, Klaus Gamweger

Reaction bath temperature is a major factor in processing liquid metals and in many applications where a balance between process duration and temperature has to be found to run a procedure efficiently. Also extremes of temperature can decrease the output of a process if too cold or even make it impossible, conversely overheating can be detrimental to both the product and furnace integrity. With the help of the new online temperature measurement system very accurate monitoring of the process is possible in contrast to the current routine practice where the temperature is measured periodically with dip thermocouples. The system works with a digital, fiber optic pyrometer, which is embedded in a refractory housing. Installation in the lining is possible below liquid level as nitrogen is blown to keep the system open and to ensure continuous sight from the optical head of the pyrometer to the molten metal through the tuyere. This permanent temperature measurement gives optimal process control with the potential of taking appropriate actions at an early stage enabling proactive process control. Therefore energy savings and even process endpoint detections can be realized.

Jan 1, 2015

By M. A. Halim, V. I. Lakshmanan, Z. Jankovic

An innovative mixed-chloride process for the separation of iron from lateritic ore is described. The separation of Fe(III) from leach liquor is an important process step for the recovery of nickel and cobalt. The patented process of Process Research ORTECH Inc. uses a lixiviant containing hydrochloric acid (HCl) and magnesium chloride (MgCl2) for the leaching of lateritic ores/concentrates followed by the selective solvent extraction step of Fe(III) over other value metals such as Ni and Co. The use of MgCl2 increases the activity of the hydrogen ion in the lixiviant, which reduces the consumption of HCl in the leaching stage and enhances the formation of HFeCl4-, thereby increasing the solvent extraction efficiency of Fe(III) with ketone. The process produces high purity iron oxide (Fe2O3) and regenerates HCl by the pyrohydrolysis of the FeCl3 rich pregnant strip solution. The developed process flowsheet is in closed loop, economically attractive and environmentally friendly.

Jan 1, 2015

By Sejong Kim, Younghoon Moon, Youngseon Lee, Eunyoo Yoon, Yonghyun Song

"Mg alloy has a high specific strength, however, their thickness reduction was limited on most parts because of their poor stiffness. Since the modulus of rigidity is an intrinsic property, improvement of modulus of rigidity to the enhancement of stiffness is impossible. Therefore, the modification of shape and structure is available method to enhance the stiffness of real part fabricated by Mg alloy sheet. There are many thin walled parts which are located in outer section of electromagnetic system.Poor stiffness is often shown on wide surface area part with steel sheet, which has also high modulus of rigidity. In these cases, various groove patterns are used to increase the stiffness of part. However, some different methods have to be used when general groove pattern can’t be used. So, we would like to propose some new method to high stiffness on thin walled precision forging of Al or Mg alloys.An effect of proposed method on stiffness enhancement can be confirmed by fabrication of prototypes as well as structure and forming analysis based on FEM."

Jan 1, 2015

By E. Ghali, C. Su, G. Houlachi

"The influence of lead ions on zinc electrowinning process was investigated by means of electrochemical noise measurements (ENMs) and cyclic voltammetry in conjunction with scanning electron microscopy and X-ray diffraction. All electrochemical experiments were performed in sulphuric acid electrolyte containing different lead ion concentrations as impurity. Lead was added in six trace levels between 0.05–0.8 mg/L in the bath. The lead content of the zinc deposits was dependent on the introduced lead concentrations. The overpotential associated with zinc electrodeposition shifted to higher values with the increase of lead concentration in the solution. An appropriate correlation was found between the different concentrations of lead in the electrolyte and the morphology of zinc deposit by ENM. The results showed that the increase of lead ion concentrations is generally accompanied with the decrease of skew and increase of kurtosis values that could be related to the morphology of zinc deposit. Effectively, the morphology changes from well-defined hexagonal platelets to large hexagonal, layered platelets and finally to non-symmetric refined crystalline structure, respectively.INTRODUCTION In commercial zinc electrowinning, zinc oxide is leached from the roasted calcine with an aqueous acid sulfate electrolyte. Then the zinc-rich solution is purified and transferred into an electrolytic cell. During electrolysis, zinc is deposited on aluminum cathode where lead-silver or pure lead is served as anode. Electrodeposition of zinc could be influenced by several parameters such as bath acidity, temperature, current density, the nature and concentration of impurities as well as additives in electrolyte. Metallic impurities play a complex role during zinc electrowinning and they can adversely"

Jan 1, 2016

By W. Evans, C. E. Ells

Nuclear power reactors using zirconium alloy pressure tubes generate electricity in several countries. Such reactors are particularly important in Ontario, where CANDUs* generate about 30% of the total electricity produced in the Province. Starting with the commitment of NPD-2 in 1956, the pressure tubes of the first five CANDU reactors were made of coldworked Zircaloy-Z, an alloy of Zr and Sn. This alloy was developed by the US Navy, but the decision to use it in a cold-worked condition was based on AECL work. In 1958, the USSR published information on a new alloy, Zr-2.5 wt% Nb. The Nb promotes stabilization of the (3-phase in the material, thus presenting opportunities of exploiting metallurgically strong pressure tubes analogous to the heat-treatable cx-{3 titanium alloys. After construction of two reactors using Zr-2.5 wt% Nb in a quenched and aged condition, an extensive development program on cold-worked Zr-2.5 wt% Nb pressure tubes resulted in them becoming the reference tubes for all CANDU reactors committed since 1966. Anticipating the future needs of the domestic and export markets, AECL have pressure tubes of Zr-3.3 wt% Sn-0.8 wt% Nb-0.8 wt% Mo (Excel) in an advanced state of development. These tubes will be used in an annealed condition; our projections show that they will have improved dimensional stability over the lifetime of the reactors. These improvements result from experimental programs leading to an understanding of the relationship between microstructures and fabrication variables and effects of the environment during service in nuclear reactors.

Jan 1, 1981

By R. Pakalnis, H. Miller, Madill. T.

"This paper describes a methodical approach to the estimation of the orientation and the magnitude of in-situ stresses. The study was performed at the Ruttan Mine, Sherritt Gordon Mines Ltd. , a 6,000 T.P.D. underground operation, located in northern Manitoba, Canada. It involves an initial estimate to be made based upon: structural interpretation • virgin stress measurements conducted in other areas (world wide, regional)The verification of the prevailing stress regime was made by conducting CSIRO hollow inclusion(1) overcoring measurements. The current cost for a virgin stress determination is about $7000 per measurement(2) and the difficulty encountered in attaining a good reading is high. This paper will describe the analytical procedures employed at Ruttan in evaluating the in-situ stress magnitude and orientation based on three overcore tests. It is proposed to perform an additional six measurements in order to verify the following results:Vertical stress = av (MPa) = 0.027 by depth (m)Major principal stress = o! """" 2.5 xav (340°/-20°)*Intermediate principal stress = a2 - 1.2xav (070°/0°)Minor principal stress = a3 """" o.8xov (160°/-70°)IntroductionThe Ruttan Mine of Sherritt Gordon Mines Ltd., a 6,000 T.P.D. underground operation, is located in northern Manitoba, Canada (Fig. I). The Ruttan copper-zinc orebody is a multi-lensed, steeply dipping (70 degrees) en-echelon deposit. Individual lenses have a maximum strike length of 350 m with widths varying from 7 m to 61 m. The mining method is o pen stoping with delayed backfilling and extends from surface to 860 m below surface."

Jan 1, 1985

By P. A. Christopher, R. H. Pinsent

"The Adanac molybdenum porphyry deposit near Atlin, in northwestern British Columbia, was discovered in 1905. It was explored extensively between 1967 and 1980.The deposit is within a complex, multi-phase, quartz monzonite stock that is a satellite of the post-accretionary, Surprise Lake Batholith. Biotite K-Ar dates range from 703 ± 2.4 Ma to 71.6 ± 2.1 Ma, indicating a Late Cretaceous age of emplacement.The deposit comprises an irregular-shaped ring or halo peripheral to a quartz monzonite porphyry dome, or ""cupola': The shape of the ring, and of a smal~ fine-grained quartz monzonite intrusion, and the presence of higher-grade mineralimtion on the eastern flank of the cupola, suggest partial control by a preminera/ structure. The deposit is truncated by a steep, northwesterly dipping, normal fault (Adera Fault) that down-dropped the northern half of the deposit by a minimum of 100 mThe deposit lacks strong zonal alteration but there are narrow envelopes of potassic alteration around some veins and local zones of intense wall-rock silicification. There is considerable retrograde alteration along postminera/ faults and fractures.Molybdenite occurs in veins and fractures, many of which are relatively flat-lying. They occur in all phases of quartz monzonite. Molybdenum is the only element of economic significance. There are vein and skarn occurrences with tungsten, tin, lead, zinc and precious metals peripheral to the deposit.In 1981, Placer Development Limited reported an ""undiluted mineable mineral reserve"" of 151 971 000 tonnes grading 0.063% Mo at a cutoff grade of 0.04% Mo and a strip ratio of 1.5:1."

Jan 1, 1995

By Robert B. Parsons

"It is generally felt that flow-through shares face a bleak future under the set of tax rules proposed in the federal government's tax reform white paper. Industry and government circles are beginning to give thought to alternatives to flow through as a mechanism for facilitating equity financing in the exploration industry. Despite suggestions that grants and tax credits may someday be on the table, industry is sticking to its position that there is no substitute for flow-through. Alternatives toFlow-throughProposals in the federal government's tax reform white paper have cast significant doubt on the ability of the mining industry to raise risk capital after 1989by way of flow-through shares. There is serious concern that introduction of the ""cumulative net investment loss"" (CNIL) rules, the phase-out of the mining explorati0! 1 depletion allowance (MEDA), and the Increased capital gains inclusion (750/0 versus 50%, at present) will make the economics of flow-through so unattractive after 1989 that these shares will hold little appeal to most investors. The question might be raised, then, as to what alternatives exist by way of tax or other government assistance that could help the exploration sector.The purpose of this paper is to survey the types of government incentives that could be of some value to explorationists and to the mining industry in general. For the past several years, flow-through has been in the spotlight insofar as incentives to the exploration industry are concerned. Other potentially useful and attractive incentives have been partially hidden in the shadow of flow-through. These incentives, in certain circumstances, can be of considerable benefit, and should not be ignored."

Jan 1, 1988

By H. J. Chalmers

"Since the advent of large volume flotation machines, Cominco Ltd. has actively studied possible application of such machines to their various milling operations. A number of installations have been made and more are on the drawing board. This paper gives a description of these units, information as to choice of equipment, and information as to operating experience. Mechanical and operating details of six installations are summarized. Three different types of machines are discussed.Pine PointThe original Pine Point zinc flotation circuit comprised conventional roughing with two stages of cleaning. Over the years with increase in feed tonnage there have developed two adverse conditions; namely, a reduction in zinc concentrate grade coupled with an increase in MgO in the concentrate. This resulted in higher freight payments along with more severe smelter penalties. An intensive test program, in 1971, showed that the concentrate grade could be raised by 1.5 units of zinc along with a reduction in MgO from 0.8% to 0.47.. Subsequently this was done by adding two additional stages of cleaning using 16 cells of Denver 200-V's. The project was completed in January 1973 at a cost of $510,000 to give an estimated annual savings of about $390,000.Selection of the Denver Model 200-V was based on minimum floor space requirement, availability, and favourable operational and maintenance experience with Denver 100’s. As it happens it was possible to ""shoe-horn"" the 16 cells into place with a minimum of plant alteration. Some problems have been encountered with a tendency to ""sand up"" at high pH, particularly at the corners. Otherwise operational service has been very good."

Jan 1, 1974

By T. Gerritsen, R. MacRosty, R. Pula, P. Gebski, W. L. Ying

Furnace run-outs can cause extended furnace downtime for repair, while leaks or more severe failures in the cooling system can lead to brick hydration or in severe cases, steam explosions. These incidents can result in lost production, damage to equipment, injuries and casualties. To prevent such incidents, reliable and accurate techniques to monitor the critical components of the furnace such as refractory lining, furnace structure, taphole integrity and main water circuits are required. This paper describes several advanced methods that have been developed to assess the condition of furnace integrity, refractory lining, tapholes and cooling water circuits.

Jan 1, 2015

By M. J. Steffens

ESPLIM is a novel separation technique that combines the advantages of solvent extraction and electrostatic dispersion but its application in the extraction of nickel by the direct solvent extraction route and the effect of high electrostatic field on the stability of organics have not been explored. These were investigated in this study and it was found that the technique allows 97% extraction of the nickel in a single stage compared with 3 stages by the conventional solvent extraction. Also, three months of exposure to 5.0 kV under simulated operational conditions had no adverse effect on the stability of organics.

Jan 1, 2005

By A. Zaidi

"The mining and metallurgy industry is highly energy intensive and one of the largest energy users in Canada. Energy costs are also a major component of total production costs in this industry as described in the 1990 Report of The Canadian Industry Program for Energy Conservation (CIPEC). For some plants, energy costs are reported to be up to 30% of total production costs. Therefore, a reduction in energy costs provides an opportunity to improve industry profitability. The specific energy intensity and production costs can be reduced by using modem energy efficient natural gas technologies. In addition, these technologies often improve product quality and increase productivity. Natural gas not only offers economic benefits, but is also environmentally benign as compared to other major energy sources. Emissions of NO"", CO2 particulates and SO2 are lower with natural gas than other fossil fuels.This paper provides a brief overview of some state-of-the-art gas technologies for the mining and metallurgy industry including cogeneration, oxy-air-fuel burners, ceramic immersion tube heaters, direct gas contact process, low NOx burners, and energy efficient liquid heating systems.CogenerationCogeneration is defined as the simultaneous production of electricity or mechanical power and useful process heat from a single fuel source. One of the primary considerations in selecting a cogeneration system is the relative quantities of electrical and thermal energy which are to be produced. Two types of systems are discussed below."

Jan 1, 1993

By D. R. Reeves

This paper describes the geophysical Jogging of coal that is being carried out for the National Coal Board in the United Kingdom. An explanation of the technique is given and results are presented showing estimations of seam thickness to within ±0.5 in. and ash content to accuracies of ±2.5 per cent. The basic method of interpretation is outlined and some conclusions regarding the conditions of roof and floor material which may be deduced from the logs are explained. An indication of future developments in this field, including the identification of coal type and moisture content, is given.

Jan 1, 1971

By L. A. Gomieroa

The Caetité-Brazil uranium facilities produce about 340 t/y of uranium from an ore averaging 0,25 U %. The process steps are ore crushing, heap leaching with sulfuric acid, U separation and purification by solvent extraction with tertiary amine followed by stripping with sodium chloride solution and precipitation as ammonium diuranate that is dryed. A change in the milling process is being evaluated to increase the production and the uranium recovery. Heap leaching will be changed to conventional tank agitated leaching of the ?590 ground ore slurry in sulfuric acid medium. The replacement of the stripping reagent is also being considered.

Aug 1, 2010

By B. I. Boyko

As part of the Ministry of the Environment's Resource Recovery Program, the Province of Ontario has constructed a $13 million "Experimental Plant for Resource Recovery" in Metropolitan Toronto. The technology and unit operations involved in the processing of municipal solid wastes at a rate of 40 tons per hour at this facility are reviewed. Shredding, air separation and classification, screening, magnetic separation and composting are some of the operations featured at this plant. Recoverable commodities expected include paper, ferrous metals, an air-classified light fraction (shredded paper and film plastic), glass and compost. Existing and potential markets for these materials are discussed.

Jan 1, 1978

By Clemens Kuhnert

"Nickelhütte Aue GmbH is specialized in the recycling of waste materials containing non-ferrous metals. We treat nickel, copper, cobalt, vanadium, molybdenum and precious metal containing materials like spent catalysts, ashes, dusts, grindings, liquids, slurries and sludge's as long as they contain one or a combination of the above mentioned metals. In our pyrometallurgical works we produce non-ferrous metal concentrates suitable for further treatment in our hydrometallurgical plant where we refine Ni-, Cu-, Co- and V-chemicals. Our production is based on synergy effects due to the combination of pyro- and hydro-metallurgy. As an example we can mention our heat recovery system and internal recycling of by-products. Furthermore, the use of alternative fuels instead of fossil fuels contributes to the economic and environ-mentally friendly treatment system.INTRODUCTION Nickelhütte Aue GmbH (NHA) can look back on nearly 400 years of tradition as a pyrometallurgical works and recycling company. The existence since its foundation in 1635 as a blue dye works shows responsible and successful action in the past. Therefore, we see highest customer service, minimization of interferences with nature by closing material cycles and maximized health and occupational safety protection by avoiding injuries and diseases, still as our future duties. These duties are evaluated and monitored by an integrated management system that meets the standards of DIN EN ISO 9001, 14001, 50001 and BS OHSAS 18001. We commit ourselves to the observance of all juridical and customized demands. The management and the department managers perceive their model function. We require responsible action from all employees. To protect the continuity of our enterprise, we will also perform in future continuous improvement of products and their quality, as well as steady progress in the areas of environment protection, health protection and industrial safety. Equally the effectiveness and propriety of the management system is checked and developed regularly. In order to obtain the objectives resulting from this policy, our company determines activities and measures by involving all employees."

Jan 1, 2017

By Shintaro Takamiya, Kazunari Yoshida

"Recently, small sized micro-needles for medical are required more frequently by patients. The biggest reason is that it presents great burden on the patients, due to the size of the needle injection. People need to use a very small needle to lower the pain, but the downfall is that it makes them more expensive due to their complicated manufacturing method. Therefore, we need to fabricate a needle by wire-drawing to decrease its price. Tube-drawing is beneficial for its production value; however, in conventional tube-drawing it is difficult of control the wall thickness of the tube and makes it 1mmor lower in diameter. That is why, we propose fluid-mandrel drawing for new tube drawing. This method allows fabrication of a fine tube by using the pressure of the fluid in the tube. In this research, the goal is the fabrication of a fine tube by fluid-mandrel drawing and its evaluation. Finally, the fabrication of a fine tube by fluid-mandrel drawing was conducted and in result a tube with a diameter of 0.2mm, high strength and thin wall and fine inner surface was drawn, which can be used as a lesser pain micro-needle.INTRODUCTIONThe main manufacturing method of the current medical needles is roll forming. With this method, it is difficult to make a tube with a diameter lower than 1mm. Deep drawing has been proposed and used as method to further reduce the diameter, but this method is costly and the injection needle obtained by this method is several times more expensive.Therefore, we need to obtain a fine medical needle by drawing process that can be mass-produced and inexpensively manufactured. However, with the conventional drawing process, it is not possible to obtain a syringe needle with a reduced diameter easily, that is why, a fluid-mandrel drawing has been proposed which can reduce the diameter without damaging the inner surface. The methodology of the method is, a fluid is filled in the sealed tube and the pressure inside the tube during drawing is responsible for the good inner surface and wall thickness. It is also expected that the fluid can be easily discarded and that the tube can be manufactured on a long scale."

Jan 1, 2017

The Curtin University Gold Technology Group has been involved in surveying, modelling and optimisation of batch centrifugal concentrator type gravity circuits and CIP/CIL circuits for nearly two decades. The most commonly asked question regarding gravity recovery is, “What is the benefit of a gravity circuit”, which can be hard, if not impossible, to quantify. With the help of the AMIRA P420 Project’s Integrated Liberation Leach Model (ILLM) it is now possible to evaluate the effect of gravity recovery on total gold recovery when changes are made to the grind size, gravity and/or leach/adsorption circuits. This paper demonstrates how the ILLM can be used to determine the net benefit of introducing or modifying a gravity circuit and assess the effect of operating conditions (grind size, coarse gold size distribution, leach residence time, carbon activity, etc.) on plant performance.

Jan 1, 2017

By Seong-Ho Ha, Shae K. Kim, Young-Ok Yoon

In the this study, surface segregation of Mg and Ca with Mg addition range from 5 to 10wt% in Al-Mg alloys with Mg+Al2Ca master alloy and its effect on the oxidation resistance were investigated. The addition of Mg+Al2Ca master alloy as the Mg alloying element led to the surface enrichment of Mg and Ca during high temperature oxidation. As a result of the oxidation test by TGA, the oxidation resistance of all the examined alloys was significantly improved with increasing Al2Ca content. The weight change of Al2Ca added Al-5Mg and Al-7.5Mg alloys indicated the complete oxidation resistance during the whole oxidation test time, while a slight weight increase was shown in the case of Al-Mg alloys even with Al2Ca addition. The improvement of the oxidation resistance in Al2Ca added alloys may be attributed to the formation of the protective oxide layer mixed with CaO and MgO on the surface.

Jan 1, 2015