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By Vadim J. Jabotinski

Electron beam processing is potentially very attractive for the high temperature treatment of hazardous materials. The very high power efficiency of the electron beam energy source (80- 90% of the power from the electric power line is converted to useable energy) is one of the positive features of this technique. This paper will consider advanced electron beam concepts for solid, liquid, and gaseous waste treatment such as stabilization of radioactive solid and liquid hazardous streams. Fundamental aspects and applications including an analysis of the economic potential of electron beam processing of waste treatment will be presented.

Jan 1, 2000

By Binxu Zeng, Mark Jolly, Xiaojun Dai

"The traditional investment casting foundries use batch melting and chunky running systems to produce casting components. This method leaves the energy saving issue as subsidiary one. In our research project, one of the partners, the AEROMET international PLC provides the thin wall aluminium component ""filter housing"" for test. The AERO MET uses traditional casting route to produce the filter housing, which only gives 5% --10% yield. In this paper, numerical simulation method is used to analyse filling and solidification of the casting running system. The CRIMSON running system of the filter housing is designed by using casting simulation software, MAGMAS and Flow3D. By working with AEROMET, various configurations of the casting running systems were tested and analysed. Using them ultiple life cycle approach, the energy content of new process is compared with traditional one. It indicates that the CRIMSON process only uses 36% of energy consumed by the traditional route.IntroductionThe investrnent casting is a metal for ming process using expendable patterns, which is a standard casting technique and is widely used to produce quality parts. Its accuracy, versatility and integrity tie itself to important and precious engineering components in Aerospace industry. However, traditional investrnent casting process usually uses chunky runner system and gravity filling method. It not only reduces the casting yield of the product but also causes the pouring defect during the casting. As author's previous research showed that gravity filling method pouring basin and down sprue are two main resources of entraimnent defects generation. No matter how good the running system is, entraimnent defects such as double oxide films (DOF) and bubbles will I get into the casting to cause problem."

Jan 1, 2013

By Kandipati Sreenivasarao

A promising method for removing heavy metal ions from dilute effluents is ion- or precipitate- flotation, in which a suitable collector is added to form hydrophobic metal-collector complexes or compounds that can be collected as foams. We have successfully removed Cu(II), Cd(II), and Pb(ll) from dilute solutions using sodium dodecylsulfate and ethanol as collector and frother respectively. However the process would not be economically viable unless the collector could be recycled, and the heavy metals recovered in a concentrated, preferably marketable, form from the foams. We investigated four different methods to decompose heavy metal-dodecylsulfate complexes, namely precipitation of hydroxides, precipitation of sulfides, chemical stripping, and electrolysis. We compare the performance of these methods. In each case the observed behavior is related to known thermodynamic data, and potential applications are discussed.

Jan 1, 1995

By Yong .. Jun Wu

Laminated ceramics have received widely scientific and commercial attention because their properties, such as mechanical properties and electrical properties, can be tailored by adjusting the structure, thickness and composition of the different layers. For example, ferroelectric Bi4Ti3O12 (BIT) which has a positive temperature coefficient of dielectric constant (,E) can be used to modify the negative tE of typical microwave dielectric ceramic BaNd2Ti4O12(BNT), However, BaNd2Ti4O12/Bi4TiO12/Bi4Ti3O12/BaNd2Ti4O12 (BNT/BIT/BNT) laminated ceramics could not be prepared by the general method because the optimal sintering temperature of BaNd2Ti4O12 ceramic (around 1350°C) was much higher than that of Bi4Ti3O12 ceramic (around 1100°C). In this research, a new method of spark plasma sintering (SPS) combined with post-sintering was successfully proposed to prepare BNT/BIT/BNT laminated ceramics. It was divided into three steps. In first step, the BaNd2Ti4O12 ceramics were prepared by conventional sintering method. In second step, the calcined and pre-pressed Bi4Ti3O12 powders were sandwiched between BaNd2Ti4O12 ceramic pellets and spark plasma sintered at 900°C for 10min to synthesize BNT/BIT/BNT composite ceramics. In the last step, a post-sintering was employed to reoxidize the partially reduced BNT/BIT/BNT composite ceramics. The results of scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) showed that BNT layer and BIT layer were well bonded and no significant interfacial infiltration between them was observed. The sandwiched BNT/BIT/BNT ceramic with 10.7% BIT in volume has a dielectric constant of 92.85, a low dielectric loss of 01068 and a small temperature coefficient of dielectric constant of 35 ppm/°C at MHz.

Jan 1, 2003

Laminated ceramics have received widely scientific and commercial attention because their properties, such as mechanical properties and electrical properties, can be tailored by adjusting the structure, thickness and composition of the different layers. For example, ferroelectric Bi4T13O12 (BIT) which has a positive temperature coefficient of dielectric constant (TE) can be used to modify the negative of typical microwave dielectric ceramic BaNd2Ti4O12(BMT). However, BaNd2Ti4O12/Bi4Ti3O12/BaNd1Ti4O12 (BNT/BIT/BNT) laminated ceramics could not be prepared by the general method because the optimal sintering temperature of BaNd2Ti4O12 ceramic (around 1350°C was much higher than that of Bi4Ti3O12 ceramic (around /1100°C). in this research, a new method of spark plasma sintering (SPS) combined with post-sintering was successfully proposed to prepare BNT/BIT/BNT laminated divided proposed to prepare ceramics. It was divided into three steps. In first step, the BaNd2Ti4O12 ceramics were prepared by conventional sintering method. In second mop, the calcined and pre-pressed Bi4Ti3O12 powders were sandwiched between BaNd2Ti1O12 ceramic pellets and spark plasma sintered at 900'C for 10min to synthesize BNT/BIT/BNT composite ceramics. In the last step, a post-sintering was employed to reoxidize the partially reduced BNT/BIT/BNT composite ceramics. The results of scanning electron microscopy (SEM) and electron probe mircoanalysis (EPMA) showed that BNT layer and BIT layer were well bonded and no significant interfacial infiltration between them was observed. The sandwiched BNT/B1T/BNT ceramic with 10.7% BIT in volume has a dielectric constant of 92.8, a low dielectric loss of 0.0068 and a small temperature coefficient of dielectric constant v/35 ppm/C at 1 MHz.

Jan 1, 2003

By E. Gutierrez-Miravete

A computational method for the simulation of mold filling processes is described. The method is based on the representation of the flowing or deforming medium as a collection of mutually interacting parcels of material. Instantaneous positions of individual material parcels are calculated by numerical integration of the dynamic equations, subject to appropriate initial and boundary conditions. So far, the method has been used to produce qualitative simulations of some flowing and deforming systems encountered in mold filling technology, and our findings are summarized herein. In all cases, individual material particle motions can be followed in detail, allowing critical examination of potentially problematic mold design features.

Jan 1, 1992

By Jafar Safarian

A new kinetic modelling technique has been applied to study the rate of MnO reduction from slags by dissolved carbon in liquid iron. Based on a consideration of the fundamental reaction kinetics, a general differential equation for the slag reduction process has been formulated, which then is solved analytically for certain special cases. By re-writing the solutions in a dimensionless form the poorly known kinetic constants are eliminated, which makes the model both flexible and applicable to a wide range of experimental conditions. For example, changes in process parameters such as temperature, metal composition, slag composition, gas composition can readily be captured along with variations in the crucible geometry. Based on a comparison with a series of experimental reduction curves being reported in the literature, it is concluded that the predictive power of the model is surprisingly good, yielding outputs that are both reliable and physically reasonable. An attractive feature of the model is that it provides an alternative way of calculating the activation energies from experimental reductions curves. For example, it suggests that the activation energy for the reduction of MnO by dissolved carbon in liquid iron is about 90 kJ/mol, which is different from the previously reported activation energies. The model also suggests that the crucible geometry, which affects both slag the volume and the resulting slag/metal interfacial area, has a significant influence on the overall reduction kinetics. This design parameter is a key to further optimisation of the process on an industrial scale.

Jan 1, 2006

By T. Shibasaki, S. Kamio, K. Kanamori

"Mitsubishi Process has been proven through fifteen years operation to be highly productive, cost efficient and easy to abate environmental requirements. However, in order the process to remain competitive from now on, it should also be adaptable to a variety of varying conditions. Various test works have been conducted from such a stand point of view and some of the new concepts have been implemented to the actual operation.The paper discusses the adaptability of the process to the change of concentrate grade with respect to copper and also impurities, acceptability of the secondary materials and the potential to increase unit capacity. IntroductionThe first commercial plant of Mitsubishi Process with 48,000 mt copper annual capacity started its operation at Naoshima Smelter of Mitsubishi Metal Corporation in 1974, and the second plant with 65,000 st annual capacity started in 1981, at Kidd Smelter, Timmins, Ontario, now Kidd Creek Division of Falconbridge Limited 2. These plants have increased their capacities to 90,000 mtpa respectively by adding oxygen and acid plant capacities while maintaining the original furnace design uncharged. Thereby both smelters have established more cost efficient operations. (3), (4)Mitsubishi Process applies so-called multi-furnace continuous system. Figure 1 shows conceptual flowsheet. Backgrounds that required and justified the development of such system are as follows:"

Jan 1, 1988

By D. W. Hoey

Eight years use of the ISA Process is reviewed and current design and operations described. Nodern Technology used for impurity control and disposal as well as the use of mechanised electrode handling equipment, cell voltage monitoring, cell insulation and an efficient contact bar system are described. Improvements achieved in terms of energy usage and plant productivity are detailed.

Jan 1, 1987

By Michael S. Moats, Jan D. Miller, Wlodzimierz W. Zmierczak

"For many, hydrogen in a pure hydrogen economy would be like natural gas in today’s energy economy. Unfortunately, hydrogen’s physical properties are unsuited to the energy market’s requirements in terms of packaging, storage, transfer, and delivery. In this paper, a hybrid energy economy that packages hydrogen chemically on carbon atoms from various sources including recycled carbon dioxide is introduced and discussed. For this new hybrid energy economy to become a sustainable reality, the ability to recycle carbon dioxide and use hydrogen to create an appropriate energy product, such as dimethyl ether (DME), is needed. DME is recognized as a potential next generation, “beyond-petroleum”, environmentally benign commodity for energy storage and distribution. It is expected that to maximize the sustainability of the proposed hybrid energy economy, “green” hydrogen will be utilized. The “green” hydrogen would be created by the electrolysis of water powered by renewable energy sources, such as solar, wind or geothermal heat.IntroductionWith the growing concerns surrounding trends in global warming and increasing concentrations of “greenhouse” gases, such as CO2 and CH4, efforts to mitigate the emission of these gases from industrial sources are growing. With respect to CO2, the demonstrations of various capture and sequestration methods are underway around the world.The sequestration of CO2 is mainly focused on storing the gas underground or deep in the ocean. The Intergovernmental Panel on Climate Change (IPCC) estimates that 2000 Gtonnes of CO2 can be stored underground in depleted oilfields, un-minable coal beds and other geologic features [1]. Additionally CO2 may be stored at the bottom of the ocean. The lure of storing carbon dioxide in depleted oilfields or un-mineable coal seams is that an economic benefit (enhanced oil or methane recovery) can offset the costs of gas capture, transportation and storage. Unfortunately, all of these storage methods have potential for the release of CO2 or CH4 back into atmosphere or creating environmental damage (mobilizing heavy metals, disrupting deep sea ecology)."

Jan 1, 2008

By C. M. Diaz

The chemistry of the main unit processes in nickel extractive pyrometallurgy is reviewed. Key re1a ions between smelter feed composition and process selection are discussed, with particular reference to operating conditions, energy requirements and products. The paper a1 so includes a brief discussion of current nickel smelters, based on the results of a recent survey carried out by TMS.

Jan 1, 1988

By Kenichi Moriyama

The Sumitomo Toyo Copper Smelter started operation in 1971, as an epoch-making smelter at which 9996 of the charged sulfur could be captured. In the past ten years, the amount of treated copper concentrate has-been increased from 1,300 l/ day to 1;900 t/ day by the extremely effective application of the oxygen enrichment for a flash smelting furnace and converter furnace. The sulfuric acid production capacity at the acid plant has also been increased up to 1,900 t/ day corresponding to the increase of copper concentrate smelting rate without installing an additional acid plant. Furthermore the sulfur fixed ratio is kept at a high level, more than 99.996. despite the SO. strength fluctuation of the wide range of 596 to 1396 which is attributed to the combination of flash smelting furnace and, P.S. converter. These -operational results at the? acid plant were achieved by several modifications. and two examples are briefly described as follows; (1) Converter modifications in order to cope with the high SO, strength -gas (2) Introduction of the anodically protection shell and tube type acid coolers In addition. the quality of sulfuric acid has been positively increased. For example, the concentration of iron and arsenic, which were the main Impurities in ?sulfuric acid, was successfully .reduced.

Jan 1, 1995

By John G. Reid

When the paper "Operations at the Greenvale Nickel Project Mine and Refinery" was delivered at the 1st International Laterite Symposium in February 1979, the Yabulu Caron plant had been operating for four years and production had just stabilized. The design had been based closely on the Caron plant at Nicaro, Cuba, built in 1944, also by Freeport. Yabulu had 10 Herreshoff ore roasters and production in 1978 was 18,682 tonne nickel as impure oxide sinter and 763 tonne cobalt in a mixed sulphide with a cobalt to nickel ratio of 1 :2.5. In the 25 years since the 1st Symposium, two more roasters have been added, but dry ore processing rate has remained relatively unchanged at 2.4M Uyr to allow a lower feed rate per roaster with associated higher recovery. The ore source has changed from the domestic Greenvale mine to imports from New Caledonia, Indonesia and the Philippines. Nickel production between 1978 and 2003 has risen by 67%, cobalt has risen by 146% and the products have changed to high purity nickel compacts and "ChemGrade" cobalt salt. The plant changes that have contributed to the increased recovery, production and product value are discussed. Keywords: Caron, Yabulu, nickel, cobalt, ammonia

Jan 1, 2004

By V. Gornitz

The Orphan mine uranium deposit, Grand Canyon, Arizona, is a cylindrical collapse-breccia pipe, 70 to 150 m in diameter and 500 m deep. Pipe fill was derived from the Supai Group, Hermit Shale, and the Coconino Sandstone. Uraninite, with Cu, Fe, Pb, Zn and Ni-Co sulfides is concentrated along the pipe boundary ring fracture (annular ring) and within the central porous sandstone matrix. There is some suggestion of vertical and lateral zonation of U with respect to Cu. Reduction of ferric oxide cement from red beds and recrystallization of carbonate, with formation of kaolinite preceded major ore deposition. Early Ni sulfides, arsenides and disseminated pyrite were followed by massive pyrite, and botryoidal uraninite, which in turn was suc-ceeded by Cu, Zn and Pb sulfides. A second, later generation of uraninite was closely intergrown with hematite and base metal sulfides. Oxidation of primary minerals may have been associated with Tertiary regional uplift. The paragenetic sequence closely resembles that of other Grand Canyon breccia pipes, except for the extensive development of the distinctive uraninite-hematite association. Mineral assemblages at the Orphan suggest possible mixing of the metal-bearing solution(s) with a more oxidized fluid, containing soluble uranyl complexes. Homogenization temperatures of fluid inclusions in calcite (GO-lIO?C) at the Orphan fall within the lower end of the range observed at other breccia pipes.

Jan 1, 1987

By Santo Ranieri

We will briefly review the nickel market in 2003 and look forward to the supply demand balance for the next few years focusing in on the key factors influencing future price dynamics. On the supply side we will examine slated brownfield and greenfield expansions including the Norilsk factor and the small to mid-range 'supply creep'. We will also review the cost side of the industry and what to expect going forward. On the demand side, we will discuss the stainless steel and non-stainless demand, the China factor and the stainless steel scrap supply cycle. We will conclude by pinpinting where the market is on the current price cycle, and where we believe the mid-term direction is headed.

Jan 1, 2004

By Yun Li

In 1999 Yunnan Copper Corporation (YCC) decided to modernise their copper smelter and change the existing sinter plant I electric furnace process to a combination of ISASMEL T and electric slag cleaning furnace. The main aim of the project was to improve the environmental performance and decrease the energy consumption. Generally the project has been successful, partly attributable to the selection of a reliable and fully demonstrated technology. The design capacity for the ISASMEL T furnace is 600,000 tonnes of dry copper concentrate per year. The furnace has been running smoothly since heat up in May 2002. YCC expended considerable effort in the preparation for plant operation. An extensive training program for key YCC personnel at the Mount Isa Copper Smelter improved their understanding of the process significantly and ensured successful hand-over of the technology. This paper describes the project history and summarizes initial operating results.

Jan 1, 2003

By F. J. Hogan

In early 1982 Atlantic Cement Company, a wholly-owned subsidiary of Newmont Mining Corp. will come on line with a new water granulating grinding facility at Sparrows Point, Maryland to produce 800, 000 tons a year of separately ground granulated blast-furnace slag. The process and product will be unique to the United States. This paper will review some initial investigations undertaken to evaluate the cementitious properties of granulated slag. The effect of slag fineness on strength development is discussed and data is presented showing a relationship between glass content and hydraulicity and grindability of slag.

Jan 1, 1982

By David Tisdale, Phillip Mackey, Nagendra Tripathi, Matthew Kreuh, Pascal Coursol

Xstrata Nickel’s Sudbury smelter operation is based on fluid bed roasting of Ni-Cu sulphide concentrate, followed by electric furnace reductive smelting and Peirce-Smith converting to produce a Bessemer matte for electro refining, along with sulphuric acid produced from smelter gas. While the site dates back to the 1930s, the present smelter configuration has been operational since 1978, and currently has a nominal capacity of about 67,000 tpy of contained nickel and is investigating options to expand in future up to 85,000 tpy. As part of a review of plant capacity options, a new metallurgical model of the plant was developed in order to examine a number of processing alternatives. Based on the METSIM™ platform, the present model includes the ability to examine the impact of a number of plant parameters on potential plant performance including; for example, the following: percent of sulphur elimination in roasting, matte grade, degree of matte metallization, temperature, coke requirements, sulphuric acid production, CO2 emissions and overall energy requirements. The process model also includes a number of special features adopted; for example, approaches to effectively model the complex Ni-Cu-Co-Fe-S-O matte system. This paper provides a description of the model and gives an overview of the results. As well as presenting the results of the present study, the applicability of this modeling approach to pyrometallurgical systems in general is also briefly discussed in the paper.

Jan 1, 2009

By Yutaka Shiraishi

Two methods were developed to measure the viscosity of the slag from the glassy to the liquid states in an ascending temperature process. The first method employs rotating parallel plates within which is placed a solid cylindrical sample in line with a sphere. The second method uses a tube which is pushed into a sample held in a rotating crucible. Both methods were tested using standard glasses, including boron trioxide and NBS standard glass #711. The main difference between these two methods is in sample preparation. Comparative measurements between two methods were performed using a sodium boro-disilicate glass containing 5%mol of alumina. The results showed good agreement in the mid-range of glassy viscosities, 105 to to7 Pa.s. In the liquid state, there were no significant differences between the two methods.

Jan 1, 2003

By Tiejun Chun, Marcus Emrich, Jian Pan, Deqing Zhu, Vinicius Mendes

"Joint projects of studies of hematite acid pellet have been implemented to develop technological solutions for using Vale hematite pellet feed in Chinese palletizing plant. Beneficial improvements on the pellets quality were achieved by adjusting the blends composition and using new technology of pre-treating the blended pellet feed with HPGR (High Pressure Grinding Roller) on rotary kiln pellet technology. The drop strength of green balls increased from 3.4 to 6.0 times from 0.5m height, at the same time, the bentonite dosage decreased from 1.5wt% to 0.7wt%. The compressive strength of roasted pellets reaches 2500 N/pellet. The reduction swelling index of roasted pellets is below 15%.IntroductionWith the fast development of steel industry in China, the production of pellets has been further expanded. Pellets are used as a high quality charge for blast furnace and the annual output is around 80Mt pellets [1]. According to the developmental trend, sinter will be replaced by pellets due to the larger environmental impact of sintering plants when compared to pelletizing plants. For example, the specific CO2 emission in sintering process is around 2.5 times higher than in pelletizing process. However, the steel industry of China has been confronted with a serious shortage of domestic pellet feed due to the low iron grade of Run-of-Mine ore despite of huge reserves of iron ores [2]. Therefore, more pellet feed, mainly hematite, has been imported to make pellets."

Jan 1, 2011