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By O. M. G. Newman

Research into potential applications of spouted bed electrowinning (SBE) in the zinc industry was conducted, in a collaboration between our two organizations. The main system investigated was zinc from acidic sulfate electrolytes. However, SBE can be extended to other electrolytes, or recovery of other elements. Electrolytic tests were carried out at the 0.01 to 0.1 m2 scale. Spouting behaviour has been studied at a larger scale, approaching a size suitable for an industrial unit cell. Much of our work was carried out using a micro-porous separator (Daramic®). However, we have also shown that ion exchange properties can have a controlling effect on the process chemistry, electrochemical efficiency, and plant flowsheet. In initial 0.1 m2 scale electrolytic tests, design and engineering issues for scale-up were identified. We review the major achievements, promising areas for application in the zinc industry, current status, and remaining barriers to development of SBE technology.

Jan 1, 2003

By Vânia L. L. Andrade

Igarapé Bahia Mine is located in Carajás area, northern Brazil. Currently Companhia Vale do Rio Doce operates there a CIP / heap leaching plant treating an oxide gold ore containing about 4 g Au /t and 0,2% Cu, which produces 11 t of gold per year. Recent geological survey has identified a signifcant copper-gold reserve underneath the oxide gold ore. The processing aspects of this copper-gold sulphide ore are described in this paper. It includes ore characterization studies, grinding and flotation tests, orebody variability assessment, flowsheet selection and preliminary economical evaluation Emphasis is given to studies aimed at depressing fluorine bearing minerals to achieve a clean and marketable flotation concentrate.

Jan 1, 1999

By Kenji Monden

A simple technique is presented to evaluate optical property of biomimetic microlens array (BMA) as an antireflective surface on a polydimethylsiloxane (PDMS) sheet. The integration of these structures is done by a thermoforming process. We have only UV-VIS spectrophotometer for optical evaluation apparatus. The transmittance of the sheet is measured with angled sample holder. The 50 deg. transmittance of 270nm pitch BMA on PDMS sheet increases from 87 to 92% after the moth-eye structure is introduced. The transmittance of 350nm pitch BMA on PDMS sheet increases from 87 to 96% after the moth-eye structure is introduced. The transmittance increases with increasing pitch of BMA. The results obtained using UV-VIS spectrophotometer with handmade sample holder.

Jan 1, 2015

By H. Bernier

The Noranda Inc., CCR Division, copper refinery located in Montreal-East, Québec, Canada, has expanded over the years to reach a capacity of 410,000 metric tons of cathode production per year. The expansion process resulted in nine, parallel, 200 m. long bays each equipped with its overhead cranes and manually operated washing machines. Anode scrap washing and piling was done manually. The mechanization of the tank house involved the elimination of 18 cells at one end of each of the bays in order to install transfer conveyors where anode scrap and cathode loads are deposited by the bay cranes. The cathode loads are brought by new transverse cranes to new machines where cathodes are washed, piled in predetermined bundle weights, check weighed, strapped then shipped in trucks or railroad cars. Suspension bars are automatically removed, stacked in magazines and sent back to the starting sheet machines. Anode scrap loads are brought to machines located near the anode furnaces where they are washed and piled in bundles for easy charging. The mechanization has eliminated numerous hazardous jobs and has realized a reduction of 0.2 man-hours/ton. After these modifications, the refinery production capacity now stands at 370,000 metric tons per year.

Jan 1, 1987

By Roberto Javier Santiago

The main properties of Calcium Carbide seem to be the grain size and the CaC2 content. This paper tries to describe the Calcium Carbide used in the South-American steel plants and how and where it is added.

Jan 1, 2006

By John R. Hugens

Modifications in the ALSCAN method of measuring hydrogen dissolved in liquid aluminum have made it possible to monitor the level of hydrogen dissolved in liquid copper. Measurements from the tundish show a correlation with eddy current readings from the continuously cast and rolled copper rod from the continuous casting and rolling system at Amarillo. The measurements also indicate that the copper in the tundish is supersaturated with hydrogen.

Jan 1, 1994

By G. Ramadorai

"This paper addresses processing options for recovering gold from carbonaceous sulfidic gold ores. These include, but not limited, to the following methods: (1) Hypochlorite pretreatment followed by cyanidization; (2) Chemical blanking agents pre-treatment followed by cyanidization; (3) Non-cyanide heap leaching techniques; (4) biological pre-treatment followed by cyanidization; (5) biological pre-treatment followed by non cyanide heap leaching. Issues of costs, economics, recoveries, testing methods, state of advancement etc., will be discussed in the paper.ABSTRACT ONLY"

Jan 1, 1997

By Juliana G. Gutierrez-Paredes, Gabriel Plascencia-Barrera, Fidel Reyes-Carmona

In Mexico, many tonnes of nickel from waste petrochemical catalysts are dumped every year. In order to recover all that nickel, a hydrometallurgical reactor was designed. This design was performed in a systematical fashion, which included the chemistry of the system under study, both a kinetic and mass transfer study, and finally the use of the RID function, to optimize the reactor size. It was found that the NiO leaching with sulfuric acid is well represented by a first order reaction. The mass transfer results are in good agreement with the experimental results, obtaining over 95% nickel extraction in both cases. A marketing study was also completed that determined that it is possible to make a good profit by processing this residue provided the capital cost was low.

Jan 1, 2000

By E. S. Geskin

"This paper is concerned with the construction of a formal technique for the selection of a metallurgical technology. Exergy consumption is used as the criterion of process efficiency. Different items of the exergy balance are considered and techniques for the reduction of exergy consumption are determined. The selected techniques of exergy saving enable us to identify processes which should be used at different stages of steelmaking. The combination of the selected processes enables us to suggest a technology for conversion of iron ore into steel products. The selection of this technology narrows the range of further search of metallurgical processes. The paper shows that qualitative thermodynamic analysis can be used as the first step in the design of metallurgical processes. IntroductionThe existing processes for making, shaping and treating of steel enable us to convert the available iron bearing ores into marketable steel products. However, the energy cost of metal production is much higher than thermodynamically required, while the metal properties are much lower than thermodynamically available. Increasing cost and declining availability of energy and raw meterials make the creation of new steelmaking technologies imperative. In recent years, the number of novel processes for the making, refining, and shaping of steel have been suggested and tested. Some found a practical application. However, the tested technologies make up a small portion of the physically available routes for the conversion of iron ore into a marketable product. It is also not evident that the optimal routes have been tested and that the selected technologies are the best among those tested.Although the development of new metallurgical technologies must be based on the experimental and practical information, the number of the alternative routes for the making, shaping and treating of steel, as well as the cost of examining each single route, make necessary the use of analytical techniques for the evaluation of the possible ways of process development."

Jan 1, 1988

By Renato G. Bautista

"The development of processing methods for the preparation .of three electronic materials with rare-earth components is discussed. The resulting processing innovations are the results of a search for an economically competitive pilot scale or industrial production flowsheet without compromising the required properties of the final products. The three cases highlighted in this presentation are: 1) The preparation of high energy (Pr-Nd-Ce)FeB magnets for MRI application from a mixed-rare-earth oxide with a narrow range of composition directly prepared from the solvent extraction circuit of bastnaesite ore. 2) The kg production of the giant magnetocaloric effect Gds(SixGe1-x)4 magnetic refrigerant materials from commercial grade gadolinium metal (95 to 98 at. % pure) instead of high purity gadolinium metal (99.8 at. %); and 3). An industrial chemical synthesis flowsheet for the production of the superconductor precursor of YBa2Cu3O7.INTRODUCTIONIn the laboratory discovery stage, the synthesis of a new material is carried out using very high purity components, usually the highest purity available. As the new material is studied and characterized, the effectiveness of its desirable properties becomes better defined and understood. The evaluation of the effectiveness of the .property over the range of a given parameter and other interactions are further studied. Once it's potential application becomes clear, a practical and economical processing method need to be developed. The successful material processing flow sheet does not necessarily have to be a scale up of the laboratory procedure. At this stage, substitution of starting components and with lower purity materials is considered as the economics of the processing becomes a major issue. In addition, other approach to it's synthesis"

Jan 1, 2000

By Marcel Sturzenegger

Though the extraction of copper is well established, generation of sulfur dioxide (S02) is still a troublesome issue. Conventional processes are further challenged by the increasing amount of impurities in the concentrates. Direct decomposition of the metal sulfides into the metal(s) and elemental sulfur under concentrated solar radiation offers a promising path to solve both problems. Thermogravimetric measurements under inert atmospheres have shown that synthetic chalcocite or chalcopyrite yield copper at temperatures as low as 1773 K. Even though optimum reaction temperatures might be somewhat higher, such temperatures are straightforwardly accessible in solar chemical reactors. The absence of oxygen will reduce the extent of slag forming reactions and thereby alter the evaporation characteristics of volatile impurities such as arsenic or antimony. Chemical equilibrium calculations for a chalcopyrite-enargite feed, e.g., have shown that under inert atmospheres arsenic compounds are completely evaporated at temperatures above 1000 K and an effective separation of arsenic from the matte is expected. An important step towards a solar production of copper is the design and testing of prototype solar chemical reactors for this reaction. Numerical modeling is a key tool supporting a rational design but it requires data of the high-temperature properties that prevail in these processes. Development of techniques for determining the essential quantities such as decomposition rates or radiative properties at temperatures up to 2000 K is therefore a main activity in our laboratory in order to control and optimize the process. Though developed in the frame of high-temperature solar technology, the experimental techniques are also suited to advance the understanding of conventional high-temperature processes. Keywords: Solar technology, Sulfur dioxide, Solar Radiation, Thermogravimetry, Chalcocite, Chalcopyrite, Numerical modeling.

Jan 1, 2003

By O. Tiitu

Drying is a unit process that has numerous applications in metallurgical process industry. Kumera Technology Center is a worldwide equipment and process supplier, who has expertise on both direct and indirect drying. In a conventional direct heated dryer, the required energy is obtained from combustion of fossil fuels emitting a considerable amount of off-gases. However, thermal energy can be already available in some metallurgical plants such as modem copper smelters where steam is produced by waste heat boilers of flash smelting furnaces. The total volume of off-gases, and especially the amount of harmful gases, released into atmosphere can be remarkably reduced when using steam as an indirect energy source for drying. Kumera Technology Center has developed a new type of steam dryer for drying of, for example, abrasive copper concentrate with silica sand. In the development of the new dryer, Kumera's approach has been to combine the best properties of both the existing steam dryers and the rotating drum dryers. In the design, special attention has been paid to overcoming the reported problems of excessive wear and clogging of steam tubes and to reducing the required maintenance operations. The Kumera Steam Dryer, having a patented flexible steam tube arrangement inside the rotating shell, has a high effective heating area - drum volume ratio without leading to problems with build-up and clogging. It can also be easily scaled up so that a single dryer can dry all of the feed for a large flash furnace. In this paper, we will present the operational and maintenance experiences from two years operation of the first full-scale Kumera Steam Dryer at Norddeutsche Affinerie Aktiengesellschaft in Hamburg, Germany. We will also provide an overview of the future developments with respect to construction and scale up as a response to market demands.

Jan 1, 2002

By Kurt Westerlund

Three years operating experience of the FLUXFLOW waste heat boiler (WHB) 20.000 nm3/0h at Boliden Rönnskär Sweden on a TBRC smelting galena (PbS). Operating experience from the Kivset flash WHB 11.900 nm3/h at Samim, Porto Vesme, Sardinia, Italy. Conceptual features of the 93.600 nm3/h FLUXFLOW (WHB) on the Isasmelt smelting in melt furnace for 180.000 t Cu/a at Mount Isa, Australia.

Jan 1, 1992

By George R. St. Pierre

A method for the quantitative description of activity interactions between solutes in a metallic solvent which is consistent with stalistical thermodynamic principles is presented. The chemical potential of a solute in an alloy is derived from the weighted mean of its values in the individual solvent components, µi = S?jµi(i). The weighting factors, ?j, are obtained from the distribution functions. The resulting equation contains far fewer adjustable parameters than the Epsilon Formalism and because of its correct functional form it provides an improved fit to the available data on a variety of alloy systems containing oxygen, carbon, sulfur, nitrogen, and hydrogen. For a binary metallic solvent ( A, B ) containing a solute (i), it is shown that

Jan 1, 1995

By Michal Rehor, Vladimir Cablik, Peter Fecko, Tomas Lang

"1. Introduction The North-Bohemian Basin area is known for its largest Czech brown coal deposit. About 50% brown coal reserves have been exploited in the North-Bohemian Basin by the mining company of Severoceske doly, a.s. (North Bohemian Mines, j.s.c.) today. The opencast mining of brown coal naturally led to vast landscape damages. Therefore reclamation work has acquired great significance. The specific feature of Severoceske doly, a.s. mining is the fact that the mining has been realized in two geologically absolutely different localities. This fact demands even rather different methods of reclamations. The main problem at Doly Bilina localities is the occurrence of overburden rocks from the series of rocks of coal seams. These rocks are texturally light but large amounts of coal (cca 5 %) and sulphur (cca below 3 %) which makes the soil reaction extremely acid. If they appear on the surface of the dump, they create a phytotoxic area, reclamation of which requires special methods. Rocks from Doly Nastup Tusimice localities are more suitable to reclamation use, but texturally extremely heavy rocks with large fraction of physical clays appear there that can generate a sterile soil area. Their reclamation requirements are completely different from those on Doly Bilina phytotoxic areas. That is the reason of the application of some non – traditional restoration methods. This report briefly summarises the experience in application of fertilizable soils, power plant stabilizer, power plant ash and aerial sowing of charlock. The results are documented by the monitoring of the physical, mineralogical and pedological parameters of rocks in testing areas.2. Properties of Overburden Rocks in Opencast Mines Bilina and Libous The reclamation work methodology in the North Bohemian Basin is above all determined by the properties of overburden rocks which occur in the top horizon of the reclaimed sites. The research of the rocks reclamation properties dealt with four current mining localities in the central part of the basin. It concerned the Bilina and Libous mines. This chapter states the stratigraphic status properties of these sites with respect to reclamation availability. The total status of the area of interest is shown in the figure No. 1."

Jan 1, 2008

By Luis M. González, Guzmánm Guillermo D., Davis Juan C.

"The Teniente converter (CT) of the Ventanas Smelter and Refinery of Codelco-Chile has two tuyeres for dry concentrate injection directly into the melt.The diluted phase injection system can feed 15 to 20 kg of concentrate for 1 kg of air, which creates a very abrasive solid/gas phase. The tuyeres commonly used lasted for about 3.5 days due to the accelerated decay of the shell, and 1.5 hours were necessary for the replacement of new ones in the reactor.Tests were carried out with common shell tuyeres with a tungsten based welding cover, and a life span of 28 days was reached, increasing the Teniente converter operational continuity between 1.5 to 2 %."

Jan 1, 2009

By A. Valenzuela

During the last years, Chile has been the largest copper producer, either as concentrates or cathodes. Copper obtained via pyrometallurgy is produced by seven smelters, which have carried out modernization plans to increase smelting capacity or to achieve environmental regulations established in the Chilean legislation. Thus, the present work updates technological innovations in smelters, environmental regulations and presents solutions for S02 handling, particulate matter and arsenic. Also, the authors emphasize the important role of CODELCO Chile, the most important state-owned copper company, in developing technologies such as El Teniente Converter and El Teniente Slag Cleaning Furnace.

Jan 1, 2003

By A. I. Okunev

The investigation results are submitted on separation into layers in the systems Cu (Ni) - Fe - Ca - 0 - S - (Si), as well as on physico-chemical properties of oxide - ferrite, oxide-sulfide melts (density, surface tention, viscosity, electric conductivity), on kinetics and oxidation macromechanism of iron and sulfur in the oxide-silicate, oxide-ferrite and oxide-sulfide melts, kinetics of reduction of oxide-silicate and oxide-ferrite systems. Conditions are discussed for copper, nickel and zinc recovery from oxide-silicate and oxide-ferrite slag in liquid and solid states. Some promising technique is the technique of future, as is considered.

Jan 1, 1988

By A. R. Laplante

Recent developments in gold metallurgy are used to illustrate how the interface between gravity recovery and hydrometallurgy has evolved in recent years. Of particular interest is the use of gravity recovery to produce high-grade concentrates that can be subjected to intensive cyanidation. It is expected that a growing proportion of gold production, possibly close to 50% in certain countries, will follow this route. Other examples of the interaction between gravity recovery and cyanidation are also provided. Implications for new and renewed research directions are discussed.

Jan 1, 2003

By A. V. Tarasov, S. D. Klushin

493 The most common method for minimizing the copper content of residual slag in the process of autogenous smelting of sulfide raw materials is treatment of molten slag in an electric furnace, with optional addition of solid reducing agents, such as coke, and/or sulfiding agents such as pyrite. A drawback of this technique is the fact that the final slag produced still contains 0.5% or more Cu. We have tested a method for treating molten slag obtained as a result of autogenous smelting by a gaseous mixture of sulfur dioxide and methane at a ratio of. SC:SO2 = 0.75 :1.0 in the presence of oxygen. Interaction reaction within the SO2-O2-CRi system proceeded at a high rate at 1373 to 1573 K to form reducing and sulfiding agents: H2S, S, COS, CO, CO2, H2, H2O. The gas mixture requirement was about 100 to 150 Nm3 per 1 tonne of slag. A decrease in the ferric iron concentration (Fe3+) from 10-15% down to 2-3% resulted in lower solubility of copper in slag, and agitation of the melt with gas stream accelerated. the separation of the sulfide phase and slag. Removal of copper from slag was performed in a pilot unit within the second V anyukov furnace zone where slag arrived with a copper content of 0.8-1.3%. The temperature of molten slag was maintained within 1523 to 1573 K. The copper content of the final slag was at a level of0.12 to 0.14%. The matte sent to converting was a mixture of bottom matte from the smelting zone and the slag treatment zone. It had a copper content of about 50 to 55%. Process gases from both furnace zones were combined and sent to the acid plant for sulfur recovery. This process was offered for commercial use at two copper smelters in Russia and CIS.

Jan 1, 2000