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By A. A. Bustos

Four Air Liquide Shrouded Injectors (ALSI ) were installed and operated for over one year in a Peirce-Smith converter at the Falconbridge nickel smelter in Falconbridge, Ontario, Canada. A shrouded injector consists of an inner pipe and an annulus, through which high oxygen enriched air and nitrogen flow, respectively The nitrogen cools the injector and protects the refractory in the vicinity of the injector tip, allowing for substantial increases in oxygen flow rates to the converting reactions. Several injector designs were tested to study the effect of changes in the cross-sectional area and changes in the entrance geometry of the annulus. An optimum design would minimize the injection pressure required for a given flow rate to achieve choked flow conditions at the tip of the injector. The operation of the ALSI was simple and did not require any special care or maintenance, either between blows or between converter cycles. In particular, the shrouded injectors did not require punching, as is the case with conventional tuyeres. In terms of refractory performance, the ALSI, operating at 30-40 % oxygen enrichment, were superior or equal to the conventional tuyeres, which operated at 21-23% oxygen. The results of the demonstration program led Falconbridge Limited to implement the ALSI technology on a commercial scale The paper presents the demonstration program results in terms of gas flow rates, accretion formation, punchless operation and refractory wear.

Jan 1, 1999

By Dmitri Goljandin, Jaan Kers, Xiangjun Zuo, Lifeng Zhang, Priidu Peetsalu

"In this paper, the mechanical milling of the electronic wastes was carried out. The metal parts and plastic parts were roughly separated. The final plastic powder size could be as small as ~100 µm. Then the pyrometallurgical recycling Printed Circuit Boards (PCB) was executed. The mechanisms of thermal degradation and combustion are investigated using TG/DTA and MS. Some chemical powders, such as Na2CO3, NaHCO3, NaOH and CaCO3 are used to control the exhausted toxic gas such as Br2. Introduction Waste electric and electronic equipment (WEEE), or electronic wastes (E-wastes), has been taken into consideration not only by the government but also by the public due to their hazardous material components [1-3]. From the point of material composition, electronic wastes can be defined as a mixture of various metals, particularly copper, aluminum, and steel, attached to, covered with, or mixed with various types of plastics and ceramics [4]. Precious metals have a wide application in the manufacture of electronic appliances, serving as contact materials due to their high chemical stability and their good conducting properties. Platinum group metals are used among other things in switching contacts (relays, switches) or as sensors to ascertain the electrical measurand as a function of the temperature [5]. Table 1 [6] gives examples of the metal composition of different electronic scraps from literatures. Additionally, non-ferrous metals and precious metals content have gradually decreased in concentration in scraps. The value distributions for different electronic scrap samples are shown in Table 2 [6], where the metal price data are from London Metal Exchange (LME) (Octoebr 2007). It can be seen that for cell phones, calculators, and printed circuit board scraps, the precious metals make up more than 70% of the value, for TV boards and the DVD player they still contribute to about 40%. This indicates that the major economic driver for recycling of electronic waste in industry is from the recovery of precious metals. Behind the precious metals come copper and zinc, while Al, Pb, and Fe are less value. Recycling of electronic waste is an important subject not only from the point of waste treatment but also from the recovery aspect of valuable materials."

Jan 1, 2008

By James D. O, DeLa&apos

Multicomponent materials are common in nearly all areas of materials science and technology, yet the use of phase diagrams to represent these complex systems is hampered by the requirement of three or more dimensions for explicit graphical representation. In the present work, the "solid-modeling" capabilities of a computer aided design (CAD) system have been applied to the representation of three-dimensional phase diagrams. Relevant phase diagrams for a hypothetical quaternary eutectic system were constructed and used to demonstrate the capabilities of the technique. These capabilities lead to relative ease of phase diagram construction and improved access to qualitative and quantitative information. Results of this work are contrasted and compared to previous efforts toward computer ,representation of phase diagrams. It is concluded that solid-modeling of three-dimensional phase diagrams can be used to advantage in both education and research.

Jan 1, 1991

By Manuel Zamalloa

The outstanding metallurgical performance of the Noranda continuous converter (NCv) in operation since November 1997 has allowed the company to meet production and environmental targets. This achievement positions this new technology as a strong alternative continuous converting technology for copper production. Knowledge of slag chemistry has been important in this respect. The purpose of this paper is to discuss the effect of key parameters including temperature, oxygen potential, slag composition and levels of copper oxide in slag on the conditions leading to magnetite precipitation, as well as on the conditions affecting the liquidus ranges of NCv slag. The above variables are evaluated using industrial data and thermodynamic predictions. Practical implications of customizing operational fluxing procedures to determine optimum operating windows are also discussed.

Jan 1, 1999

By C. Flores

The direct cementation of copper from a loaded D2EHPA 20 % vol. in kerosene using zinc, zinc-lead alloy and iron metallic powders was studied. Copper was loaded into the organic solvent from an aqueous copper sulfate solution. Results indicated that copper is reduced spontaneously with relatively fast reaction rates. The effects of several operating parameters such as water content in the organic system, initial copper concentration, reductant surface area, oxygen and nitrogen atmosphere, intensity of the agitation and temperature on the galvanic stripping of copper were studied. For a better understanding of the electrochemical reactions involved in the galvanic stripping, the dissolution of metallic copper in the organic solvent was also studied. Copper did not dissolve unless a small amount of water was present in the organic system. The results and possible reaction mechanisms are discussed.

Jan 1, 1999

By Jiann-Yang Hwang

The economic growth in new developing countries such as China and India has stimulated strong demands in basic materials such as steel. World steel production has exceeded the milestone of a billion tons a year recently. However, the blast furnace technology, which was invented in 1340 A.D., is still the fundamental route for today?s steel production. It is important to develop a new generation of steelmaking technology that can meet the society?s needs from the energy, environmental and economic standpoints in the 21st century. The new microwave and electric arc heating technology discussed in this paper provides a totally different mass and heat transfer mechanism from the conventional blast furnace technology and offers a great potential to meet our society?s needs.

Jan 1, 2006

By Jong-Oh Jo1

Thermodynamics of Ti, N and O in liquid iron was studied in order to establish a data base for the prediction of TiN and TiOx formation in liquid stainless steels containing various alloying elements including Cr, Ni and Si as a function of temperature. The interaction parameters of these elements on Ti and N were determined using the metal-nitride-gas equilibration technique. The TiN stability diagram for a commercial stainless steel grade was constructed from the measured thermodynamic parameters, and its validity was confirmed experimentally. The interaction parameters between Ti and O, and the equilibrium constants for Ti deoxidation reactions for the formation of Ti2O3 and Ti3O5 were also determined by the equilibration of the melts with those oxides identified by the XRD and the EPMA analyses.

Jan 1, 2006

Many studies have been conducted over the past 3 decades on the leaching of gold in solutions containing thiosulfate, ammonia and copper. However, most of these studies have been carried out using ore samples, with very few fundamental studies of this system being attempted. The majority of the published studies have failed to acknowledge the undesirable side reaction between copper(H) and thiosulfate, let alone account for its effect. The fact that the solution chemistry is constantly changing makes it very difficult to perform a fundamental study of gold leaching. With the advent of the rotating electrochemical quartz crystal microbalance (REQCM), such fundamental studies are possible as this instrument measures mass in real time. This has allowed leach kinetics to be measured in a matter of minutes and hence at essentially constant solution conditions; The present paper highlights that a sufficient concentration of copper(II) and ammonia are required in order to achieve appreciable gold leach rates. However, the use of air (oxygen) to maintain the copper(Il) concentration catalyses the undesirable copper(II) reaction with thiosulfate. The presence of ammonium ions is shown to have an effect on this undesirable reaction as well as on the gold leaching ?reaction. Preliminary electrochemical studies into .gold electrowinning using the REQCM show that gold(I) thiosulfate cannot be readily reduced to metallic gold in the potential region at which cementation usually occurs. However, it is well known that gold cementation onto copper occurs rapidly. The current study addresses this discrepancy by studying the effect that copper and silver have on the reduction of gold thiosulfate. It has been found that the presence of both silver and copper enhance gold deposition, particularly at low over potentials. While this is beneficial in cementation, the presence of copper and silver in solution has been found to cause passivation of the cathode surface during electrowinning at 'higher overpotentials.

Jan 1, 1998

By Jason Eric Sallee

Ongoing operations at the Cyprus Miami Smelter involve the use of an electric furnace for settling of copper matte from discard slag. Proper operation of the electric settling furnace is a major factor in minimizing losses of copper to the discard slag. Recent test work at the smelter has shown improvement in the operation of the electric furnace with a subsequent improvement with regard to the copper losses. This paper presents a general discussion of the Cyprus Miami Smelter operation, past results with respect to copper losses, recent operational changes and test work, and the subsequent results.

Jan 1, 1999

By P. Stantke

In recent years the CollaMat process has been used successfully worldwide in a number of copper electrorefining tankhouses as an instrument for measuring the glue concentration and optimizing cathode quality. Owing to its measuring principles the CollaMat can be used not just for measuring the concentration of active glue but also the activity of other substances, which have an impact similar to glue on the copper deposition. In SX-EW plants guar is frequently used instead of glue as a levelling additive. In our laboratory the effect (activity) and the decomposition rate of guar in copper electrolyte was examined. As expected, the results show that guar has an effect similar to glue on the copper deposition. However, at the same temperature, a greater quantity of guar is required to achieve the same results. As with glue, the decomposition rate (due to hydrolysis) of guar is strongly dependent on the temperature. Therefore, in practice, its on-line monitoring is necessary to guarantee the same guar activity at any time.

Jan 1, 1999

By Neil Smith

Mineral processing plants typically procure a range of industrial services from contractors. Their satisfaction and value received is directly affected by how the services are procured, rationalized and delivered. Conventional purchasing strategies often focus on price rather than on optimizing the service relationship between supplier and customer. The nature of this relationship may have the greatest potential to reduce costs and enhance production. It has been documented that a service involves simultaneous production and consumption. A high degree of customer involvement is often necessary for a successful outcome and the expectations and attitudes of the customer can positively or negatively affect delivery of the service. This indicates that the customer can enhance or diminish their own satisfaction and value received and the supplier cannot act alone for best results. The Optimax? Program for industrial services is a service delivery framework whereby a customer and supplier work together to raise the efficiency of the service exchange. The Optimax? Program is intended to help the customer optimize costs and maximize production by connecting the customer and supplier through shared information and objectives. This paper will review the basic nature of services, provide a couple of examples of conventional procurement strategies for services and outline the features of the Optimax? Program. A Case Study showing recent results from implementing the Optimax? Program will be included.

Jan 1, 2006

By Bernard Bonnetot

The potentialities of hydrogen storage using borohydrides are presented and discussed especially in regard to the recoverable hydrogen amount and to the recovery conditions. A rapid analysis of storage possibilities is proposed taking in account the two main ways for hydrogen evolution: the dehydrogenation obtained using thermal decomposition of borohydrides or the hydrolysis of solid or dissolved borohydrides. The recoverable hydrogen is related to the dehydrogenation conditions and the real hydrogen useful percentage is determined for each case of use. The high temperatures required for dehydrogenation, even using catalyzed borohydrides, lead to poor outlooks for this storage technique. The hydrolysis conditions fix the yield of the recovered hydrogen and rule the storage capacity of the dissolved borohydride, the "fuel".

Jan 1, 2006

By Varadajan Seshadri

The increase in production of continuous casting machines requires long ladle sequences without interruption. Very often the production schedule has to accommodate a variety of steel grades. In such cases downgrading may be inevitable. Models must be made available to study the alternatives that would make possible mixing of steels in the tundish but minimizing the losses due to downgrading the slabs. Physical modeling was used to evaluate the influence of variables such as internal geometry of the tundish, presence of turbulence inhibitors, depth of ladle long nozzle, weight of steel in the tundish, steel throughput upon the tundish transition curve. Expressions for minimum residence time and transition period have been determined. Mixing-transition is allowed to continue inside the liquid pool in the mold and the final solute distribution in a given cross section is captured by a solidification model. The result is a map of the transition in the final product.

Jan 1, 2006

By Mark W. Sajewycz

Creating technology, securing patent rights, and managing a patent portfolio are time-sensitive and dynamic activities. Agreements should be in place with technology partners (employees, contractors, joint venture partners), prior to embarking on research and development projects, so as to mitigate future disputes over patent rights. Technology partners should be educated on patent law basics so as to be mindful of patent bar triggering events. Accurate records must be maintained to capture information relevant for preparation and filing of patent application, including subject matter, names of inventors, and invention date. Developed inventions should be evaluated for whether to file for patent protection, delay patenting until technology is further developed, maintain trade secrecy, or effect deliberate public disclosure. Once decision is made to file for patent protection, time is of the essence, and application for patent protection should be filed as soon as possible, as many countries award patents on a "first-to file" basis. Decisions on where to file are made having regard to potential competitive advantages versus cost considerations, and can be delayed by taking advantage of priority rights recognized in patent legislation of most countries. Once patents are granted, competitors must be policed for potential patent infringement, and legal action may be necessary to prevent patent infringement.

Jan 1, 2006

The increasing need for robust pyrometallurgical furnace construction is driven by two trends in the copper and other base metals smelting industry: ? the desire for increased production within a single furnace line by greatly increasing smelting intensities, which generates high heat fluxes to the crucible. walls, and ? the operational and economic imperatives of maintaining high percentage on- line times and long campaign lives between rebuilds. A key feature of furnaces capable of producing at high rates, while containing intense processes, is a strong, thermally robust wall cooling system. Equally important design aspects include the furnace steel structure, refractories, a cooling water supply and piping arrangment for safety from leaks and disruptions, and instrumentation/controls for monitoring and rapid mitigation of process excursions. Integration of the cooling elements into these furnace systems is essential for optimum performance of the cooling elements, and indeed the entire furnace. This paper discusses the development of a composite copper / refractory water- cooled design, which has been successfully implemented on several copper smelting and converting furnaces, including Kennecott's flash converting furnace, INCO's MK reactor, and Kidd Creek's converting furnace.

Jan 1, 1999

By Chenhui Liu, Hong-ying Xia, Bingguo Liu, Wei Li, Jinhui Peng, Libo Zhang

"Dielectric property is an important limiting factor in the development of microwave processing of minerals and ores. In this study, we used an open-ended coaxial sensor method to measure the complex permittivity of an ilmenite concentrate (41%TiC>2) and microwave absorption properties from room temperature to 100°C. The results show that the dielectric constant, loss factor and loss tangent increase with temperature rising at 2.45GHz. Microwave absorption properties of this ore are highly dependent on temperature and frequency. Ilmenite concentrate can be used as raw materials to prepare wideband microwave absorbing material. The research will be helpful in explaining the thermal running of microwave dielectric heating the ilmenite concentrate.IntroductionAs the sources of high-grade titanic mineral are decreasing worldwide, the utilization of low-grade minerals such as ilmenite has attracted more attention [1,2]. Because Panzhihua ilmenite has complex minerals and high contents of MgO, CaO, S1O2 , it is difficult to upgrade the ilmenite to titanium-rich slag and farther produce synthetic rutile and titanium dioxide pigment [3]. Therefore, it is desirable to develop new technology for processing ilmenite ore [4]."

Jan 1, 2012

By Alex Moyano

The Codelco-Chile is considering different processing options for the projected concentrate from the Alejandro Hales mine (former Mansa Mina mine with high arsenic and antimony content of 6% and 0.6%, respectively), that will produce complex blister copper with high impurities contents, higher than the present values produced at the converting process of the Codelco Norte smelter processing only Chuquicamata concentrates. In order to know both the anodic copper quality and the metallurgical implications when a complex blister copper is processed in the refining process of the CN smelter, the Codelco and IM2 ?task force? evaluated positively the refining process for the complex blister copper by addition of alkaline fluxes at laboratory and industrial scale tests. The promising results of the tests done at laboratory scale at the Tohoku University facilities, allowed a large scale test planning to validate the lab-scale results in 3 refining furnaces of 250 t capacity at the CN smelter. The obtained results demonstrate the industrial technical feasibility to process a complex blister copper in the refining furnaces producing an anodic copper quality suitable for the electrolytic process.

Jan 1, 2006

By María Guadalupe Sánchez-Loredo

Silver from nitrate aqueous solutions was extracted by commercial organophosphorous extractants (tri-n-butylphosphate, Cyanex 471x, Cyanex 301 and Cyanex 302). Quantitative silver extraction was obtained using the Cyanex reagents. After loading, aqueous solutions of several reducing reagents were used to prepare fine silver powders by reductive stripping. Only both extractants Cyanex 471x and tri-n-butylphosphate (TBP) could be reductive stripped and regenerated by aqueous solutions of ascorbic acid, and Cyanex 471x was decomposed to the corresponding phosphine oxide by using sodium borohydride as reducing agent. Silver was recovered as fine particles, which were characterised by means of scanning electron microscopy (SEM). Micrographs showed that the powder size and morphology were directly affected by the composition of the applied organic phases and aqueous reducing media.

Jan 1, 2003

By Samson Adeosun, Sanmbo Balogun, David Esezobor

"In a typical year, approximately 1.7 million tons of residues and wastes are expected from Ajaokuta integrated steel plant, Nigeria. They will be generated mainly from sinter plant, blast furnace (BF), and basic oxygen furnace (BOF) operations and during rolling and finishing. The residues and wastes include slag, dust, sludge and slurries from gas cleaning, waste water, mill scales and other associated scraps. In this paper concepts for the utilization of residues and wastes in Ajaokuta Steel Plant where no reclamation routines have been provided for in the first and second phases of its project implementation is designed. The paper analyses the sources of the iron oxide wastes and evaluates the quantities expected from the main production facilities of the plant which include the two 312 m2 capacity sintering machines, the two 2000 m3 blast furnaces and two 130-T BOF (of the 2nd phase expansion of the Steel Plant). A reclamation routine designed for Ajaokuta residues and wastes is presented.IntroductionIn the steel industry, approximately 550kg of residues per ton of crude steel arise from the production processes and from pollution control facilities [1- 4]. These residues consist of slag, dusts and sludge, mill scale, spent pickle liquor, and other iron bearing materials. The main by – products generated in the steel industry are listed in Table I.Although major progress has been made in the recycling and use of some of these residues, particularly flue dust, blast furnace and steel making slag, yet a significant quantity are land filled or stockpiled. These unsightly stockpiles occupy valuable real estate and may become a source of environmental pollution if not otherwise disposed. In any case, the dumping option has become quite costly. For instance, one ton of iron ore costs between 28 and 34 US dollar, whereas as much as $20 per ton of steel produced is required to meet environmental compliance obligation in the USA [5, 6]."

Jan 1, 2008

By Shaolong Chen, Carl-Gustav Berg, Hannu Mansikkaviita

Kumera Steam Dryer has been developed particularly for nonferrous metal concentrates with steam as heating source generated from waste heat boilers. Its unique structure enables the dryer to work at high capacity, up to 240 t/h, and high availability, over 95%. With half a century of engineering experience, and more than twenty industrial steam dryer installations worldwide during last 15 years, Kumera has demonstrated significant benefits of the steam drying technology in terms of energy efficiency and emission reduction to the end users. The dryer of this type can also be applied for other suitable mineral materials.

Jan 1, 2015