Search Documents

By R. B. Taylor

"The Delnite mine is in the northwest part of Deloro township, Cochrane district. The property consists of 307 acres on the so-called 'South Break' in the Porcupine camp. The Company was formed in 1934 to take over the holdings of La Roche Mines, Limited. Gold has been produced continuously since June 1, 1937. The value of the gold recovered to date (December 31, 1946) has been $7,456,000, and the average grade of ore $6.81 a con.The ore at the Delnite occurs in relatively narrow, persistent, quartz-ankerite veins, which generally contain tourmaline and have a ladder-like structure. The gold occurs in the free state, and in association with pyrite and arsenopyrite, the two chief sulphides. The host rock is fine-grained, highly carbonatized andesite of Keewatin age."

Jan 1, 1954

By T. R. Skerry, H. P. Hudson, T. E. Warren

"ALTHOUGH coal is generally the cheapest fuel on the basis of heating value it has been at a disadvantage in competition with other fuels because means have not been available for efficient •Conversion of its thermal energy to mechanical work. Taking the •railway application •as an example, the cost of Diesel oil is about three times that of its thermal equivalent in coal, but the overall efficiency of a Diesel locomotive is about five times that of a coal-fired steam locomotive. Accordingly, the Canadian railways are replacing all coal-fired steam Locomotives, as they are retired from service, with Diesel units. This conversion in itself represents a major loss to the coal industry because the value of railway fuel is approximately 130 million dollars per year, and there are other applications in the medium power range where oil is displacing coal. There is, therefore, a strong incentive to attempt development of an efficient coal-burning engine.Coal has never been a promising fuel for reciprocating internal combustion engines because of the time required for its combustion in pulverized form . This is not less than one-tenth of a second so that the speed of such an engine would have to be very slow. There are also serious difficulties of a mechanical nature arising from the necessity for intermittent combustion and the use of close-fitting pistons."

Jan 1, 1952

By A. A. Rogozhin, E. G. Likhnikevich, S. I. Anufrieva, A. V. Kurkov

The Beloziminskoe deposit in Siberia is a large, potentially productive deposit of rare metals contained in ochreous apatite pyrochlore ores formed by weathering of a carbonatite. The ores are composed of pyrochlore, columbitized pyrochlore, monazite, apatite, magnetite, ferric and manganese hydroxide, titanic iron ore, zircon, hydromica, quartz, feldspar, and carbonates. A gravity-flotation enrichment flowsheet with application of cationic and anionic collectors has been developed. This flowsheet allows for obtaining a pyrochlore concentrate containing 44.3% Nb2O5 and 1.89% P2O5 with recovery of 55.83% Nb2O5 as well as an apatite concentrate containing 39.2% P2O5 and 1.05% TR2O3 with recovery of 62% P2O5 and 43.23% TR2O3 from ores containing 0.92% Nb2O5, 16.9% P2O5 and 0.6% TR2O3. Rare-earth concentrate containing 40% TR2O3 with recovery of approximately 10% TR2O3 was obtained at the same time. Major losses of valuable elements are related to slimes, which make up more than 50% of the ground ore. The niobium concentrate does not meet the phosphorus and radionuclide concentrations needed for the production of ferro-niobium. Acid leaching and sulfatization provided a high level of phosphorous and radionuclide removal. Conditions include hydrochloric acid pre-leaching at 75- 80°C with an 18% HCl solution for four hours and low-temperature sulfatization of acid-leached concentrate at 160-180°C for one hour followed by water leaching of the residue. The apatite concentrate could potentially be processed using nitric acid leaching. This technology is based on decomposition of apatite concentrate with 55-57% strength nitric acid with transfer of rare-earth metals into solution in the form of ammonium phosphate. This technology recovers a rare-earth concentrate containing 95% TR2O3 with extraction of 86%, and highly concentrated polynutrient fertilizer (ammophos) with phosphorus extraction of 95%. The completed research shows how complex multicomponent ores of residual soil may be processed for the extraction of niobium, phosphorus, and rare-earth products.

Jan 1, 2016

By G. P. Holmes

"Bell Copper is situated (Latitude 55°0''N, Longitude 126°14W) on Newman Peninsula on the east side of Babine Lake at an altitude of 2,450 feet above sea level. The mine site is approximately 170 miles north west of Prince George and 40 miles east of Smithers. Access to the property is by way of 30 miles of paved road to the Village of Granisle on the west shore of Babine Lake and then a further 9 miles of unpaved road to Bell Copper's west dock. The two mile lake crossing is made using a tug and barge. A compressed air bubbler system maintains an ice free channel for the barge during the winter months.Temperatures range from summer maximums of around 32 °C to winter minimums in the region of minus 40°C. Long periods in winter may be spent with temperatures in the range of minus 15""C to minus 28°C. Freezing temperatures usually start in October and last for six months. The lake normally freezes over in mid December and the ice breaks up in mid May. Snow accounts for approximately two t11irds of the annual precipitation of twenty-one inches."

Jan 1, 1976

By E. M. De Souza, P. Lausch, D. O. DeGagné, J. F. Archibald

"The potential use of industrial and municipal waste glass as a partial pozzolanic replacement for Normal Portland cement in mine backfill has been investigated. Considerable quantities of glass are currently discarded into landfill sites at high cost to municipal and industrial users with no foreseeable environmental benefits being gained by such disposal. This research study was undertaken to assess the viability of using ground waste glass materials as partial binder replacement of Portland cement fractionswithin consolidated mine backfill materials. The program was implemented to review various factors that could influence successful incorporation of glass waste replacement of cement, these factors being the feasibility of glass waste procurement, determination of process economics and the physical and chemical suitability of ground waste glass materials to generate adequate backfill strength when replacing Normal Portland cement fractions. A series of laboratory assessment trials were established to evaluate backfill component characteristics and mixture strength properties for both standard Portland cement-consolidated and blended Portland cement/ground waste glass-consolidated backfill materials. Side-by-side review of the strength behaviour of various component backfill/cement mixtures was designed to permit comparative evaluation of the capabilities of ground waste glass and Portland cement products as backfill consolidating agents"

Jan 1, 1995

By William A. Price

The objective of this paper is to outline the approaches used in British Columbia to address the challenges posed by metal leaching and acid rock drainage (ML/ARD). Challenges include the large financial costs, the need for site-specific assessments, the large information requirements, the need for mitigation measures to be designed and financed in a manner that permits long-term performance, the lack of long-term operating experience, the ongoing changes in many important processes, the need for pro-active detection and resolution of concerns, difficulties in predicting the potential for ARD or significant metal leaching, the need for new tools, and the multidisciplinary, highly specialized nature of the work. Consequently, mines must be planned, operated and closed in a manner that permits regular review, detailed monitoring and adaptive management. Proper consideration of the challenges involved, including a plan of how all outstanding concerns will be addressed, studies to address areas of significant uncertainty and caution in the absence of the required understanding, should ensure environmentally safe practices in the future.

Nov 1, 2002

By Fazel G. Jahromi, Ahmad Ghahreman

"Several studies were performed on the atmospheric leaching of copper sulfide minerals in the presence of activated carbon and a new catalyst, AF 5. AF 5 is a carbon based catalyst with similar properties to those of activated carbon however much better mechanical properties. The activated carbon surface chemistry has been investigated in various studies; however the connection of the surface chemistry of activated carbon and AF 5 with the sulfide minerals during the atmospheric leaching process is not well-understood yet. Based on the surface analysis, AF 5 showed higher surface area than activated carbon (AC). Adsorption and oxidation of copper, arsenic and iron ions in the presence of different activated carbon were investigated. Adsorption properties of both catalysts were similar and 18-24% of iron, 12-18% of copper and 10% of arsenic adsorbed on the catalysts surface form 5 g/L Fe(III) and Cu(II) and 2 g/L As(III) at 80°C. In oxidation experiments, both catalysts reduced Fe(III) and Cu(II) ions and re-oxidized the reduced species in the presence of oxygen and oxidized As(III) ions. The addition of oxidizing ions can enhance the oxidation process kinetics and increase the catalytic capability of carbon.INTRODUCTION Hydrometallurgical processes of copper sulfide concentrates are under development and various different methods have been proposed to increase the atmospheric leaching rate of copper sulfide minerals. These methods include using different media, reagents, and catalysts. Among different methods, leaching of the copper sulfide minerals in the chloride media has some advantages over sulfate media. Smaller scale of operation, increased leaching rates, and lower sulfate formation are some of the benefits of the chloride leaching media over other similar media. Moreover, using ferric and cupric ions as oxidants and utilizing activated carbon as a catalyst has been proven to enhance the leaching rate of copper sulfide minerals effectively. Activated carbon (AC) and AF 5 (micro porous carbon based catalyst) are two of the most efficient and practical catalysts in copper sulfide leaching processes. AC can enhance the copper recovery of enargite in chloride media from 69% to 92% after 96 hours of leaching under the similar conditions (Jahromi & Ghahreman, 2016). It has been shown that AC at acidic pH can generate hydrogen peroxide in the presence of oxygen which can leach copper minerals (Ahmumada et al., 2002)."

Jan 1, 2017

By Y. Tanaka, M. Maeda, S. Suzuki, C. Tokoro, T. Kato, K. Muto

Boron (B) co-precipitation was investigated with ettringite to establish a cost efficient method of removing B from acid mine drainage. For 25 mg/L of B solution, most appropriate pH for B removal was pH 11.5. The most appropriate amount of reagent for B removal within Japanese effluent standard (10 mg/L) was B:Al:Ca:SO4 = 1:3:9:4.5, which corresponds to the composition of Ettringite (Al:Ca:SO4 = 2:6:3). The effect of silicate, carbonate and temperature on efficiency of B removal is important as groundwater and hot spring water are often contaminated. When silicate and carbonate are present, more Al and Ca salts are needed for B removal since some aluminum and calcium precipitate with silicate and carbonate as kaolinite and calcium carbonate. These precipitates do not contribute much to B removal. As the temperature raised, the most appropriate pH for B removal decreased. B removal became less efficient as monosulfate precipitated more rapidly as ettringite.

Jan 1, 2015

By R. W. Luhning, S. D. Gittins, J .. A. Haston

"The Underground Test Facility (UTF) project operated by the Alberta Oil Sands Technology and Research Authority (AOSTRA) north of Fort McMurray has achieved marked success in field testing mining access and horizontal well in situ recovery of bitumen from the Athabasca oil sands.Mine access has provided for effective placing and operation of horizontal wells in the oil sands from a tunnel system in the underlying limestone. Performance of the in situ recovery process, Steam Assisted Gravity Drainage, has substantially exceeded forecasts made at the start of the project. Over-all results of the program to date show great promise for horizontal well in situ technology as a competitive source of bitumen from Alberta's vast oil sands deposits. The potential economics of a commercial expansion at the site are reviewed in this paper.IntroductionIn situ recovery o f bitumen from the Athabasca oil sands has puzzled the oil industry for many year s, but a breakthrough appears close at hand. The Underground Test Facility (UTF) project initiated by the Alberta Oil Sands Technology and Research Authority (AOSTRA) has had notable success in the piloting of horizontal well processes, which offer prospects for commercial development even under the highly competitive situation facing the Canadian industry . This paper describes the project briefly and presents the potential economics of commercial development on the UTF lease."

Jan 1, 1990

By A. Navarra, C. Arrancibia, R. Yañez, C. Acuña, F. Valenzuela

"Discrete event simulation (DES) is a suitable framework to evaluate and optimize the dynamics of sulphide smelters. In particular, iron-nickel-copper-cobalt sulphides undergo continual oxidation within a roasting or smelting operation, followed by batch oxidation within the converting operation, thus producing iron-free Bessemer matte (or blister copper, in the case of copper smelters); this semi-finished product undergoes further processing to produce nickel, copper and cobalt products, and to recover precious metals. The juncture between continuous smelting and batch converting is often an appropriate focus for the earliest phases of DES development, since it is typically a major bottleneck within nickel and copper smelters; later phases may include increasing levels of detail for auxiliary unit operations, as well as plant logistics. Moreover, DES can support matte-slag chemistry, including Gibbs free energy balances to determine the iron speciation within the slag. DES is therefore capable of linking the fundamentals of oxidation reactions to the intricacies of plant dynamics.INTRODUCTION Discrete event simulation (DES) is gaining acceptance within the extractive metallurgy community, as a technique that quantifies the system-wide performance of metallurgical plants under conditions of uncertainty (Wheeler & McGinty, 2015). In particular, over 90% of smelters that process nickel-copper-cobalt sulphides and copper sulphides exhibit similar semi-continuous dynamics (Crundwell et al., 2011b; Schlesinger et al., 2011b), in which the converting aisle produces batches of material that are sent for further processing (Figure 1). Thus the tools and practices that are developed for a specific sulphide smelter are often relevant to numerous other smelters.The juncture between continuous smelting and batch converting has long been a focus for discrete event simulation (Welgama et al., 1996). Nonetheless, the broad acceptance of DES in nonferrous smelters has been hindered by interdisciplinary barriers that divide industrial and metallurgical engineers (Navarra et al., 2016; Noorossana et al., 2012); this divide has been less severe in steel plants (Hollocks, 2006). In recent years, DES has been used in copper smelters to analyze crane-and-ladle motions (Coursol et al., 2009a), reverts production and consumption (Noorossana et al., 2012), and innovative control systems (Herrera et al., 2016); additionally, DES models have accounted for shutdowns and random breakdowns to provide realistic assessments of copper smelter capacities, thus guiding equipment upgrades (Campbell et al., 2013; Coursol et al., 2009a). All of these studies feature a Peirce-Smith converting aisle similar to Figure 1 that, under normal operations, constrain the smelter throughput, and are thus a bottleneck (Campbell et al., 2013; Navarra et al., 2016)."

Jan 1, 2017

By M. Epiney, A. Ghahreman, R. Kim1and

"In the presence of sulfidic refractory ores, increasing the dissolved oxygen (DO) concentration can positively affect the gold leaching rate. To identify the role of DO in gold cyanidation, electrochemical behavior was studied in the presence of 3 different ores. Sample 1 was a low sulfide pyrite ore, contained 5.14% pyrite, 0.19% galena and 3.09% S. Sample 2 was a pyriticore as well, contained more sulfide as 8.35% S, and 12.4% of pyrite. Sample 3 was a tailing of silicate gold ore, still containing75 g/tAu, 0.13% Pb and 0.18% S. Gold cyanidation kinetics were studied by cyclic voltammetry (CV) and chronoamperometry tests. With sample 1, the gold oxidation peak current density from CV curve was increased to 1.38mA/cm2under oxygen injection, while it was only 0.66 mA/cm2with air injection. From chronoamperometry test, the reaction rate was also faster under oxygen injection. Sample 2 showed similar behavior with sample 1, but the gold oxidation peaks higher than sample 1, i.e. 1.75 and 2.27 mA/cm2, under air and oxygen injection, respectively. However, it seemed that the gold oxidation was impeded by sulfide ions for a longer period. In the presence of sample 3, the gold oxidation peak was the highest among three ores –2.75mA/cm2under oxygen injection, because of its lowest sulfide content. However, from chronoamperometry test, it was also shown that the gold oxidation was impeded because of a significant amount of Pb in the ore sample.INTRODUCTIONIt is well known that gold is leached under oxidative condition (Marsden &House, 2006). Through the most representative and oldest gold leaching technique, cyanidation, more than 90% of gold can be selectively leached from an ore. According to Elsner’s equation, gold is leached in cyanide solution by forming cyanide complex [Au (CN)2–], and oxygen is consumed as an oxidant(Eq. 1)."

Jan 1, 2017

By K. Miao, W. Mu, M. Sharma, A. Haas, N. Dogan

"The ever increasing demand for cleaner steels with low inclusion content has highlighted the limits of our current knowledge for controlling and predicting inclusion agglomeration and removal during liquid steel processing. Key knowledge gaps in this area result from the complex nature of the problems associated with measuring and visualizing the phenomena studied. Confocal scanning laser microscope (CSLM) allows for continuous in situ observation of micron-size samples in real time, at high resolution, under conditions relevant to the steelmaking process. This paper summarizes some of recent CSLM applications in our laboratory to illustrate the methods of analyzing transient behavior. The reaction between inclusions and slag is given as an example. The dissolution rate of calcium aluminate inclusions in CaO-SiO2-Al2O3 slags has been studied at elevated temperatures: 1500, 1550 and 1600°C as well as thermodynamic/kinetic analysis. It is found that total dissolution time decreased with increasing temperature. The rate limiting steps are discussed. It is shown that the diffusion through a product layer is responsible for dissolution at 1500°C. At higher temperature, dissolution is most likely controlled by both boundary layer diffusion and chemical reaction at the slag-inclusion interface. In this paper, the evidence for and against the theory will be critically examined and repercussions of the theory to steel refining processes will be discussed.INTRODUCTION Inclusion formation during liquid steel refining is an unavoidable consequence of current ladle steelmaking processes. The nature and quantity of the inclusions formed in steel is critical in steelmaking, as it affects both productivity through clogging, and downstream physical properties of the steel. It is therefore crucial to better understand and control the formation, agglomeration and dissolution behaviour of inclusions in a slag in order to improve the removability of inclusions from liquid steel. Most research (Sandhage & Yurek, 1988; Sandhage & Yurek, 1990a; Sandhuge & Yurek, 1990b; Sandhuge, 1991) relevant to the kinetics of inclusion removal has been obtained by using a technique where simulated inclusion material (ceramic rods) is dipped in slag and the dissolution rate is measured. While much has been learned using this approach, the difference in scale from bulk materials to inclusions is likely to have a significant bearing on the dissolution kinetics of inclusions in a slag and will certainly result in a very different influence of capillary effects. Further, the data obtained using an indirect (dip test) procedure relies on a comparison of the initial and final conditions of a sample rather than in-situ observation which can be achieved in a confocal microscope in real time."

Jan 1, 2017

By G. Kachaniwsky, M. Bédard

"The Noranda Continuous Smelting Process at the Home smelter was commissioned in March 1973. The ability of the process to handle a wide variety of feed materials and a steady stream of technical innovations in recent decades has served to maintain the Home as an efficient and versatile custom smelter. This paper reviews recent technological development and capabilities in areas such as sampling and preparation of secondary and complex materials, as well as the smelting and related environmental control issues. Future trends and improvements are also addressed.IntroductionThe Noranda Home smelter commenced operations in 1927. It was originally designed to treat 910 tonnes per day of copper concentrates and ores coming from the new Home mine site. In the 19305, the company opened its doors to other mines in northwestern Quebec. Treatment of feed materials on a custom basis has, therefore, always been an important factor in the operation of the Home smelter. Throughout the years, the Home gradually increased its custom smelting capacity, while maintaining its production from the Home mine. By the early 1950s, 65% of the materials processed was from outside customers, and by 1974, this figure had increased to more than 85% . With the closure of the Home mine in 1976, the company extended its smelting operations beyond ore and concentrate, and began to treat more scrap metals and residues rich in copper and precious metal content.Corresponding with the ever-changing pattern of feed sources, the Home smelter has adopted technological improvements to meet new and challenging business conditions. The technology of the original smelter of 1927has been completely replaced over the years in the quest for improvement. One of these major changes occurred in 1973 with the start-up of the Noranda Process Reactor. This extremely efficient smelting system has been exploited to treat a wide variety of copper and precious metal (PM) containing custom materials. This paper reviews recent developments and improvements achieved at the Home smelter, in the receiving, sampling and treatments of copper and PM scrap and secondaries, with particular emphasis on the development of new technology and equipment in complex feed materials treatment."

Jan 1, 1991

By G. Goodall, M. Muinonen, R. Pandher, R. Jabbar, S. J. Muinonen

"The implementation of a new and highly efficient converting practice at the Glencore Sudbury Integrated Nickel Operations Smelter has opened the possibility to further capacity increases by using larger ladles. To quantify the impact of increasing ladle sizes from 200 to 300 ft3, XPS constructed a detailed discrete event simulation using the commercial software package Rockwell Arena®. The challenges associated with implementing a model on an intricate and tightly scheduled process, and the solutions needed to derive meaningful results will be presented. The aisle capacity is predicted to increase by approximately 17 %, with a reduction in furnace tapping demand of 8 %. Arena modeling capabilities and the key factors contributing to the overall capacity increase at the Sudbury INO Smelter will be reviewed and presented.INTRODUCTION The Glencore Sudbury Integrated Nickel Operations (INO) comprises two Ni-Cu-PGM mines, Strathcona Mill, and the Sudbury Smelter. The Smelter has operated continuously since 1929 using different processes to produce nickel-copper Bessemer matte. Feeds to the Sudbury INO Smelter are a blend of concentrate from Strathcona Mill, Raglan concentrate produced at the mine-mill complex in Raglan, Quebec, as well as third party concentrate feeds shipped to Sudbury from around the world. In 2016, the Sudbury INO Smelter produced 75,900 tonnes of nickel and 20,000 tonnes of copper in Bessemer matte. The product matte is shipped to Glencore’s Nikkelverk refinery in Kristiansand, Norway where it is refined to produce nickel and copper cathode. A schematic of the Sudbury INO Smelter’s flowsheet is shown in Figure 1."

Jan 1, 2017

By V. G. Papangelakis, G. A. Moldoveanu

The use of anhydrite (AH) seed, control of acidity levels and ageing were assessed as means to promote the conversion of freshly produced metastable gypsum generated in-situ to the less soluble anhydrite phase and force deposition of calcium sulphate on seed as opposed to on equipment as scale, while achieving lower terminal aqueous calcium concentration as well. It was found that moderate sulphuric acid levels (0.25M) and ageing in the presence of AH seed accelerated the gypsum-AH conversion, achieving 100% transformation of the metastable gypsum generated in situ to the more stable, less soluble AH in 6-7 days, while lower/nil acidity did not promote more than 30% AH conversion for 10 days, even in the presence of AH seed. These findings indicate that anhydrite seeding, ageing and incomplete neutralization are beneficial for scale control as well as achieving lower calcium levels, thus rendering the resulting solution more amenable for recycling.

Jan 1, 2015

By George Carico

Research and related demonstration projects are being conducted in West Virginia on both existing and former coal surface mine lands to determine potential post-mine land re-use options that offer the greatest likelihood of future benefit and success. Examples of projects include renewable energy considerations that incorporate solar, wind, and/or biomass options, and contain components designed to educate business, government entities and the local community on renewable energy options and potential opportunities Multiple property re-use options are being researched and evaluated, based on site-specific conditions and characteristics, including infrastructure, local community needs and regional economic conditions. Re-use options being explored include innovative uses and needs, such as specialty housing, unique business and industrial needs, and an extensive variety of recreational and small business opportunities that best fit the specific needs of the local community and regional economic structure.

Aug 1, 2013

By Ian Ewart, Trevor Bergfeldt, Gourab Satapathy, Ajay Patel

"Conventional electrowinning (EW) of nickel from sulfate electrolytes is complicated by several factors including the requirement for a diaphragm cell to separate the anolyte and catholyte and the need to minimize nickel mist emissions. Developed and commercialized by emewCorporation, this novel process electrowins high purity nickel cathode (99.5%) from copper refinery bleed streams using the proprietary emew vortex EW technology. The emew nickel process incorporates high flow rate in an enclosed cylindrical EW cell operating at high current densities that overcomes the challenges of conventional nickel EW and completely eliminates the risk of nickel mist emissions. The tubular cathodes are easily harvested and mitigate the effect of plating stresses inherent in nickel EW. The present paper describes the emew nickel process and its most recent application to copper refinery bleed streams at full-scale.INTRODUCTION To meet the stringent demand of customers, nickel producers are giving prime importance to production of high purity nickel cathodes. The major challenge for refineries is to improve cathode quality and appearance despite fluctuating electrolyte impurity levels. The basis of achieving good quality cathode includes the control of electrolyte impurities and consistency of specific process conditions. The commercial operation of emew nickel technology has been successfully implemented and has demonstrated the ability to produce high quality nickel cathode from refinery bleeds. This paper emphasizes the importance of upstream impurity removal to achieve the required nickel emew feed composition by evaluating the benefits of using selective precipitation as a purification scheme with the aim of improving the overall nickel recovery while ensuring suitable nickel concentration in the advanced electrolyte is achieved. Nickel electrowinning is similar to other electrowinning processes that employ insoluble metal anodes & cathodes. It requires the passage of direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. For the recovery of nickel from solution, the most common methods are electrowinning and hydrogen reduction. Electrowinning usually occurs from sulfate, chloride or mixed sulfate/chloride electrolytes. In sulfate electrolytes, nickel electrowinning cells are normally designed to achieve specific criteria as outlined below (Robinson & Tuppa, 2002):"

Jan 1, 2017

By M. Kim, M. Ha

"The effect of red mud on the melting behavior of ferronickel slag was investigated by a laboratory-scale horizontal tube furnace. Melting and softening of slag samples fluxed with different amount of red mud was examined by in-situ visualization technique at temperature range from 1400 to 1550°C. FactSageTM 7.0 was used for the thermodynamic calculation of multi component system of ferronickel slag and red mud. Liquid phase area was extended to lower temperature by adding red mud indicating its suitability as a flux material. X-ray diffraction analysis confirmed the dependency of the phase changes on the red mud content. Microscopic observation by scanning electron microscope (SEM / EDX) clarified the phase transformations from olivine to spinel along with red mud additions.INTRODUCTION Ferronickel smelting by submerged arc furnace (SAF) is an energy intensive process performed at high temperature range 1500–1600°C. During the smelting process of saprolitic nickel laterite ore with a nickel content of 2.2–2.3 pct, a large quantity of ferronickel slag is being produced that account for 97 pct of ore charged. To achieve ferronickel grade of 15–20 pct Ni, electrical energy of 80 to 85 MW is used for the melting and reduction of nickel oxide (NiO) and iron oxide (FeO) in the ore (Rodd et al., 2010). Unreduced components, mostly MgO, SiO2 and partly FeO are removed from the furnace in a liquid slag form by a tapping operation. Due to the high melting temperature, forsterite (Mg2SiO4) based slag containing approximately 10 pct FeO requires typical process temperature of 1600°C. Flux in metallurgical process is a medium that decreases melting and operating temperatures while it increases fluidity of the liquid slags. Calcite and fluorite are examples of flux materials used for the ironmaking, steel refining and continuous casting process. Oxide systems based on CaO - CaF2 - SiO2 - Al2O3 - MgO cover most of the slag composition in ferrous metallurgy accordingly. Crucial operating factors for ironmaking and steelmaking slags are basicity (typically CaO/SiO2 ratio), viscosity and impurity levels. These are extensively controlled by the fluxes. General metallurgical fluxes such as limestone, dolomite and calcium fluoride are abundant in nature and supplied to steel mills at low prices. Meanwhile, in copper flash smelting process, silica is supplied with copper concentrate to remove iron oxide (FeO) generated from sulfide oxidation. FeO - SiO2 binary system formulates eutectic area at 25–38 pct of silica that has low melting temperature below 1205°C. Fayalitic system (Fe2SiO4) that has low viscosity (0.1 Pa·s) (Park et al., 2011) facilitates easy separation of slags from molten sulfide mattes. Recently, copper plants actively utilize recycled raw materials as a flux. Various recycled glasses are ground and fed to copper smelting process as a partial replacement of silica ore. Applying industrial wastes to smelting processes is advantageous since the operators can reduce the production cost remarkably. Not to mention the consumption of recycled materials can ultimately minimize the environmental risks and the waste management costs. The authors, therefore, investigated the reasonable waste materials that can be effectively used for ferronickel smelting process. Prerequisites for potential fluxing materials are non-recyclable property, low transportation cost and excellent performance as a flux."

Jan 1, 2017

By Jamie N. Burdeski, Susan E. Hartfield-Wünsch

Aluminum sheet use has been steadily increasing in the automotive industry to achieve mass reduction and improve fuel economy. One significant manufacturing challenge for aluminum sheet implementation is the reduced formability compared to the steel alloys it replaces. This paper includes friction results from the draw bead simulator (DBS), twist compression (TCT) and strip draw (SDT) tests, for two oil based lubricants and four hot melt lubricants. Formability testing was done with the same lubricants and materials, testing in pure stretch with a hemispherical punch, and in draw with a breadpan shaped die.

Jan 1, 2015

By D. Paul Bishop, Kevin P. Plucknett, Hung-wei Liu

"Spark plasma sintering (SPS) process has been evaluated for producing the commercially pure (CP) Ti, TiAl and a TiAl-B4C composite. Comparisons were made between the materials in terms of the sintered density, resultant hardness and microstructures. In the present work, the titanium aluminide powders (Ti-48Al, producing a mixture of y-TiAl/a2-Ti3Al) were synthesised „in-house? using a simple reaction-sintering and mechanical attrition approach. This allowed various size distributions to be generated. The powders were then blended with a fine boron carbide (B4C) powder (up to 6 wt.%), and the resulting mixtures were consolidated using spark plasma sintering (SPS) under vacuum in graphite dies. An applied stress of 50 MPa was used for all SPS runs. The SPS parameters were varied in terms of the ultimate sintering temperature (up to 1300°C) and hold time (up to 10 minutes) for each material. It is demonstrated that high densities can be achieved this approach (exceeding 95% of theoretical, with optimised samples close to full density). Microstructural characterisation was conducted using optical microscopy, scanning electron microscopy, and X-ray diffraction. The B4C additions were seen to partially react with the TiAl to form reinforcements, such as TiCx and TiBx. Preliminary mechanical property assessment will also be briefly discussed.INTRODUCTION Titanium- and titanium aluminide-based alloys possess many unique properties, such as excellent corrosion resistance and high temperature strength, respectively (Cardarelli, 2001; Leyens & Peters, 2003). Compared to many other competing materials (e.g. stainless steel or Ni-based alloys), Ti- and TiAl-based alloys also have relatively low densities (~4.5 and ~3.9-4.1 g/cm3, respectively), which is critical for performance in aviation and automobile applications. However, the manufacturing cost is high, due to the expensive raw Ti material and difficulties in machining. TiAl-based alloys are particularly difficult to produce because of their limited ductility (Lütjering & Williams, 2007). To overcome those problems, powder metallurgy (PM) technologies have shown great potential as near-net shape processes for Ti- and TiAl-based alloys. The general PM process largely avoids laborious post-machining and minimises material use. In industrial production, the PM approach has been successfully utilised to manufacture aluminium- and iron-based alloys (Huo & Heath, 2008)."

Jan 1, 2017