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By Martin Brueggemann

The Tyrone copper solution extraction and electrowinning plant was the first such facility built by Phelps Dodge Mining Company in 1984. Over the next 20 years, the aqueous flow rate capacity of the plant has been expanded from the original design of 12,000 gallons per minute (gpm) to 34,000 gpm to meet production goals in the face of declining copper grades in the leach solutions. The ability to process higher aqueous flow rates through existing equipment comes at the expense of increased organic loss through entrainment to raffinate. These losses of organic (diluent and extraction reagents) can account for up to 10 percent of the plant?s total operating costs. With the recent dramatic price increase of petroleum-based products, these operating costs due to losses are sure to increase. This paper will discuss recent improvements at the Tyrone SXEW plant that have resulted in a 40 percent reduction of organic losses. These improvements include picket fence modifications, new fence materials, organic recovery systems, and operational practices within the solution extraction process.

Jan 1, 2006

By Hannu Johto

Boliden Harjavalta has operated a flash smelter for nickel sulphide concentrates in Finland since late 1959. The original nickel flash smelting process was modified in 1995 to a novel nickel matte smelting (DON) with semi-low iron where the batchwise operated converting became obsolete. Since that, the process has been applied to multiple chemically variable nickel sulphide concentrates with high environmental performance. In this paper, the status of the current smelter operations is described together with the recent modernizations of the nickel flash smelting furnace and the slag cleaning furnaces.

By S. Kawamura, H. Inoue, Y. Maeda, H. Ohike

Kosaka smelter is a copper smelter located in Akita Prefecture in the northern part of Japan. It has treated complex sulfide concentrates for a long time. Recently, in addition to metal production from ores, the company has been working on the recycling of metals by using this metallurgical technology. Metals recovered are primarily gold, silver, palladium, copper and lead from copper scraps, electronic board scraps, silver oxide batteries, spent lead acid batteries, semiconductor chips, cellular phones, and automotive emissions catalyst. In particular, electronic board scraps and cellular phones can be valuable raw materials. These electronic scraps are fed into the flash smelting furnace after size reduction in a shredder that was introduced in 1999. Due to the growing demand for personal computers and cellular phones, the amount of electronic board scraps available for recycling increased. At present, these secondary materials are good raw materials for Kosaka smelter since the smelter is already used to dealing with complex raw materials. The recycled metals account for up between 5 and 20 percent of the total production at Kosaka Smelter. In particular, over 90 percent of the palladium in the secondary materials can be recovered.

Jan 1, 2000

By D. K. Panda

The behavior of single drops with gas evolution at the interface is of interest because this is one of the important reactions that occur in oxygen steelmaking vessels, where a large amount of iron-carbon drops are dispersed in an oxidizing slag. The carbon dissolved in these drops, reacts with the slag to form CO, which is evolved as a gaseous phase. A room- temperature model was used to study the nature of this type of reaction including the effect of various factors such as viscosity and the presence of surface active impurities. Experiments were done for reacting drops over a wide size range to observe various regimes of behavior. Large single drops were levitated in a counter current flow to produce a sufficiently long residence time to allow the study of the various stages in the reaction. The emphasis of this work was to obtain photographic evidence of a high quality to describe all possible modes of behavior, and so a lot of effort was given to developing and perfecting experimental techniques.

Jan 1, 1994

By Haydar Güneş

In this study, a hydrometallurgical process was evaluated for the recovery of Nd from a Nd-Fe-B magnet. Each leaching test was performed at the solid (weight) to liquid (volume) ratio of 1:50 and was mixed at 400 rpm at ambient temperature. The effects of 3 different acids (HCl, HNO3, and H2SO4) on the extraction of Nd were investigated and H2SO4 was found to be more effective than other acid solutions. Under the optimal conditions, pregnant leach solution was produced with H2SO4 for subsequent Nd precipitation testing. Each precipitation test was carried out using 100 mL of feed solution mixed at 600 rpm at 25°C. NaOH and H2C2O4 were used for Nd precipitation. The highest Nd was precipitated as Nd2(C2O4)3, 10H2O with C2H2O4 at 20 min.

By Gordon Lewis

A complex mixture of hydrated reaction products is obtained from hydrothermally treated refractory cements and castable concretes. TGA can be used both to identify the product phases in the mixture and to determine a quantitative relationship among the phases. When reacted mixtures contain compounds that decompose simultaneously, or nearly so, additional assumptions must be introduced in order to develop a quantitative phase analysis. It is the purpose of this paper to examine some of these assumptions and to demonstrate their application, particularly to refractory cement systems.

Jan 1, 1982

By Alfonso Nájera

Turbulent flow of liquid steel and its control is studied using different geometries of turbulence inhibitors. Four designs of turbulence inhibitors were characterized through experiments of tracer injection I a water model and mathematical simulations using the Reynolds Stress Model (RSM) of turbulence. Geometries included octagonal-regular, octagonal-irregular, pentagonal and squared. A layer of oil was used to model the behaviour of tundish flux during steel flow. Fluid flows in a tundish using these geometries were compared with that in a bare tundish. Experimental and simulation results indicate that the flow in the bare tundish and a tundish using turbulence inhibitors open large areas of oil due to strong shear stresses at the water-oil interface but the squared inhibitor. These phenomena are explained by the high gradient of the dissipation rate of the turbulent kinetic energy using the squared inhibitor. Using this device the kinetic energy reports a high gradient from the tundish floor to the free bath surface as compared with other geometries.

Jan 1, 2006

By P. Ruz

A melt transfer ladle was 3D modeled by means of a mathematical fluid dynamics and heat transfer program. Internal temperature profiles were calculated as a time function for a normal ladle and for a pre-heated refractory lined ladle. It was shown that in a normal ladle the molten metal cools down quickly forming accretions. By using an inner lining there are practically no accretions build up within a typical time of operation. Therefore, by applying a refractory lining to a melt transfer ladle and keeping it at a moderate to high temperature it is possible to reduce cold dope circulation in the smelter.

Jan 1, 1999

By Mark R. Jolly, Jean-Christophe Gebelin, Aleksander Cendrowicz

"Injection of wax patterns is the first stage of the multi-stage process of investment casting. The quality of the final casting and its dimensional accuracy is highly dependent on this stage of the process. Pattern waxes used in the industry behave in a complex visco-elastic-plastic manner. The modelling of such material behaviour is therefore not simple.In this paper a number of configurations of die will be shown in which the injection of the wax has been carried out for a range of processing conditions. Some of the dies are transparent and the movements of wax front observed can be compared with those predicted by simulation. Surface defects in final components will also be shown and compared with the location predicted by simulation software. Some discussion will be presented on the limitations of the software used and the time-scales achieved for practical use as a design tool within the foundry environment. IntroductionThis paper presents the research activities carried out at the University of Birmingham on the modelling and prediction of the behaviour of industrial investment casting waxes during the injection of wax patterns. These research activities are done in the context of a more global study of the fundamental aspects of the investment casting process, the FOCAST project. Regarding the wax injection process, the aim of the project is to achieve a better understanding of the key factors that will lead to better castings. The filling of the die during the injection has been studied. Some other phenomena such as shrinkage/warpage or creep under residual stresses are also studied, but not presented here. Two commercial investment casting waxes have been characterised in order to model their behaviour and predict mould filling and subsequent defects.This paper will present the models that have been used in our work, the simulation packages used, the experiments carried out to validate the modelling and exhibit the defects due to bad filling, and finally the numerical simulation results."

Jan 1, 2001

By Abbas H. Mirza

Arsenic and selenium are found in low quantities together with other metals in several nonferrous metallurgical process streams such as scrubber blowdown solution, acid plant wastewater, gas cleaning plant water, etc. Normally, the other metals in these streams are present as cations and can be precipitated by conventional lime treatment and sulfide polishing. However, arsenic and selenium are invariably present as anions, AsO33-and AsO43 in the case of arsenic and SeO32 and SeO42 for selenium. Conventional lime treatment removes most of the arsenic, but it does not remove selenium. The present paper reviews the processes and technologies developed to date on the removal of arsenic and selenium from metallurgical process streams.

Jan 1, 1996

By N. Gopalakrishnana, R. Beccard, S. Lourdudoss, R. Holz, M. Deschler

"Rapid growth of conducting and/or insulating InP, GaAs, Gao.47In0.53As, and GaAs0.6Po.4 on one or more of (001), (110), (111)A, (3ll)A and (3ll)B surfaces by Hydride Vapour Phase Epitaxy (HYPE) is demonstrated. The maximum growth rate of the binaries lies between 12 and 300 µm/hr and of the ternaries between 7 and 170 µm/hr. A simple model is developed to describe the influence of crystallographic orientation on temperature dependent growth rates. The growth rates predicted by the model is compared with the experimental values. Room temperature resistivity of insulating InP:Fe can be as high as 5xl09 ohm cm. Temperature dependent differential resistivity is also analysed. This feasibility of growing conducting and insulating layers rapidly on different orientations is very useful for electronic and optoelectronic devices.IntroductionRecently there is a renewed demand for very thick layers of III-V compound semiconductors for high performance electronic and optoelectronic devices [1]-[2]. Long wavelength high speed lasers that can be modulated up to 30 GHz necessitate epitaxial growth of semi-insulating (SI) layers [3]. There is also an increased interest on the growth of epitaxial layers on surfaces other than (001) surface. Epitaxial growth of these materials on such surfaces is of theoretical importance besides being technologically relevant. These demands led us to focus on the growth of conducting and insulating III-V compounds by Hydride Vapour Phase Epitaxy (HYPE). lnP, GaAs, Gao.471no.s3As on lnP and GaAso.6Po.4 on GaAs were grown as conducting materials using Low Pressure HYPE (LP-HYPE) on (001) 2° off substrates. Gao511no.49P on (001) GaAs substrate and lnP on lnP substrates of (001), (110), (l 11)A, (31l)A and (3 ll)B orientations were grown as semi-insulating materials using Atmospheric Pressure HYPE (AP-HYPE). In this report we present the growth aspects of these materials. We also present a simple model on the growth of InP on substrates of various orientations. The theoretically obtained temperature dependent growth rates are compared with the experimental values. Differential resistivities of semi-insulating lnP grown on substrates of various orientations as a function of temperature are also summarised."

Jan 1, 1998

By Pekka Hanniala

The falling real price level of copper metal and changes in the treatment and refining charges has been characteristic to the copper industry during the last few decades. Outokumpu's continuous development of the Flash Smelting Technology and increased productivity of the smelters based on these improvements may be one of the basic reasons that have influenced to these trends. From the early beginning of the Flash Smelting Technology, it has been characterized by low operation costs and low emissions, and the vision has been to develop the technology towards Direct Blister Flash Smelting. In Direct Blister Flash Smelting, both smelting and converting are carried out in one furnace making it possible to reduce the number of unit operation steps and thus lower both operation and investment costs. The merger of large copper production companies taken place during the last few years is a sign of a new age in copper production business. Now, the aim is to increase the productivity of copper production not just by utilizing the economy of scale but also by increasing integration and optimization of the whole production chain from mine to refinery. This also means increasing win- win based cooperation between companies. A Production Network concept based on the Flash Converting process enables existing smelters to decrease the operating costs and expand the smelting capacity with minimum investment and at the same time to decrease the emissions of the smelters. The new structure in ownership and partnership between copper production companies makes it easier to adopt the Production Network concept to both new and existing plants, where there exists a lot of built-in capacity. The paper presents Outokumpu's prediction on how the new options for the smelters will contribute to further changes in the structure of copper production. These visions are illustrated by giving examples on how the combination of matte production, Flash Converting, and Direct-to-Blister Flash Smelting could be adapted in existing and new smelters.

Jan 1, 2002

By Roberto Javier Santiago

This paper tries to make a study about the use of calcium carbide during the tapping in replacement of part of the aluminum used in the furnace tapping, analyzing theoretical consumptions and then transfering the practice to the plant.

Jan 1, 2006

By Du Sichen, S. Seetharaman, A. Jakobsson

"In the Present paper, the principles of oxygen potential measurements have been discussed along with the design details for oxygen sensors that are used in copper industry. A description of some of commercial probes is presented along with their salient features. The application of these sensors in flash smelting, converter and casting sections of copper production are discussed along with their implications on process optimization.I. IntroductionThe high temperature galvanic cells have come into prominence on account of their numerous applications in both fundamental as well as applied measurements. Since the inception of the oxygen-ion conducting electrolytes like ZrOrCaO·by Kiukkola and Wagner [1], the oxygen concentration cells have been extensively used in laboratories as well as in industries. In metal-production technology, these cells have been used to monitor the oxygen potentials in metallic, slag as well as gas phases and also to control and styr metallurgical processes. The pioneer among the various industrial users of such cells is the copper industry. To-day, high temperature solid electrolyte cells involving oxygen ion conducting electrolytes have become an integral part of copper pyro-refining and continuous casting. In the present paper some of the applications according to the industrial processes are described including the developments that are going on in the European scene."

Jan 1, 1997

By Alessandro Navarra, Joël P. T. Kapusta

"The converting cost modeling software introduced by Ng et al. in 2005 [1] has been extended to consider the reprocessing of reverts and copper scrap. The original model evaluated the operational costs of a Peirce-Smith converter; algebraic relationships had been implemented with arrays (to represent matrices, vectors and scalar ratios). The new software brings flexibility to the underlying thermochemical balances, by using linked-lists instead of arrays. It is now possible to consider the blending of several feeds, including reverts and scrap.The software computes the length of the converting cycle from the Fe and S content of the charge together with the blowing rate; the times required for other operations (charging, skimming and idle time) are also accounted for. The costs of consumables such as flux, fuel, oxygen or compressed air are all evaluated. Downtime, labor, and materials for converter lining repairs are also considered. The software is easily extended to examine the costs of alternative operating strategies or injection technologies such as sonic single pipe injection and sonic shrouded injection. The potential cost benefits of alternative operating procedures and technologies are discussed through example calculations."

Jan 1, 2009

By C. L. Lin

Multiphase, irregularly-shaped randomly-oriented PARGEN particles were grown to determine the breakage/liberation characteristics of such locked particles. The simulated locked particles were randomly broken to establish the liberation characteristics of the broken fragments. The progeny size distributions are consistent with Gilvarry's volume and surface flaw model for single particle breakage. The extent of liberation of both continuous and dispersed phases can be described from the conservation of interfacial area. In this regard the data can be normalized and liberation described for a wide range of dispersed phase grades and dispersion densities.

Jan 1, 1988

By J. B. W. Bailey

The Noranda Horne smelter in Quebec, Canada has change considerably during the last two decades to accommodate varying custom concentrate receipts, closure of the Horne mine, better working conditions, environmental programmes, new technology and increased energy and labour costs. This paper highlights the reasons for changing the smelter from two calcine charged and one wet charge reverberatory furnaces fired by coal to a smelter using. tonnage oxygen oil, natural gas and coal in a single wet charged reverberatory furnace and a Noranda Process continuous Reactor. The current operation 1 described, including three major topics; the use of oxygen/fuel burners on the charge banks of the reverberatory furnace which has increase the smelting rate from 680 to 1100 tonnes of concentrate per day; the oxygen enrichment of the Noranda Process converting air to achieve smelting rates of over 1800 tonnes of concentrate per day; the converting of the mixture of 73 percent copper matte produced from the Noranda Process and the 33 percent copper matte produced from the reverberatory furnace.

Jan 1, 1983

By G. Van Weert

The pellet reactor was developed approximately 20 years ago in the Netherlands for softening drinking water. Since then, some 35 plants have been built, ranging in capacity up to 8500 m3/h. Applications now also include removal of phosphates and fluorides and the production of metal carbonates and sulphides from waste streams. The pellet reactor consists of a fluidized bed, wherein the process solution is thoroughly mixed with the precipitation reagent at special inlet nozzles to give over-saturation of the compound to be precipitated. In water softening applications, the compound is CaCO,. In the case of nickel or other metal waste streams, Na2CO3 solution is added in sufficient amounts to precipitate metal (hydroxy) carbonate on the fluid bed particles. These grow typically to dense spheroids, which are removed when they reach 0.8 to 1.0 mm diameter. These spheroids are easily dewatered, free flowing and low dusting. The latter property is becoming an attractive advantage in connection with new plant hygiene regulations. The operation of a 60 cm diameter pellet reactor on nickel containing plating waste is described and the properties of the produced nickel carbonate spheroids are discussed.

Jan 1, 1993

By K. Olsen

As aluminum alloy usage in automobiles grows, there are increasing demands on recycling processes and facilities to deal with mixed alloy automotive aluminum scrap. These processes and facilities strive to produce near virgin aluminum stock, which can be relatively costly and difficult. One alternative is to use physical processing methods to upgrade the scrap properties instead of chemically refining the scrap. The Impulse Atomization Process (LAP, patent pending) is a new process for making metallic and ceramic powders. It can produce fine homogeneous microstructures in scrap aluminum alloys due to high undercooling and rapid solidification. The particles have a very narrow size distribution and are in a convenient form for consolidation. This paper compares and contrasts the microstructural features of Impulse Atomized. and quenched Impulse Atomized powders,' for both AL6061 and a scrap aluminum alloy composition.

Jan 1, 1995

By S. Ikenobu

This paper describes a method for processing high-silicate zinc concentrates by hydrometallurgical zinc refining. Silica in concentrates reacts to form zinc silicate during roasting. The zinc silicate readily dissolves and slowly precipitates in sulfuric acid solutions during leaching. However, if proper operating parameters are not maintained, the colloidal silica may form an unfilterable gel. That is, according to the investigation results obtained, the silica concentration in the reactor has to be maintained at 5 g/1 or less (preferably 2 g/1 or less) by promoting the precipitation reaction. The proposed method has made it possible to precipitate silica in a form having excellent solid-liquid separation characteristics, without the need for facilities having a high filtration capacity, and to maintain a low silica concentration in the reactor by feeding a composition containing pre-adjusted silica contents.

Jan 1, 2000