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By Patrick R. Taylor

This investigation studied the inflight calcination kinetics of nuclear waste simulant using a thermal plasma reactor. A series of experiments were performed to determine the conversion of insoluble aluminum compounds to the soluble compounds and the decomposition of complex organic and nitrite compounds present in the simulant waste. Thermodynamic calculations based on free energy minimization were performed to establish a theoretical basis for this investigation. A kinetic model to describe the conversion of gibsite to sodium aluminate has been proposed. The products of the calcination were characterized using XRD, Gas Chromatography, and chemical analysis by ICP. The results of this investigation indicated 85% gibsite conversion to sodium aluminate, 90% of nitrate decomposition, 52% TOC decomposition and 90% conversion of chromium to soluble compounds. A process is identified for inflight calcination of wastes. Key words: Plasma, waste, simulant, calcination

Jan 1, 1996

By A. Kapilashrami

Slag foaming proves to be both blessing and curse for the process productivity, depending on where in the process it occurs. In pyrometallurgical processes, slag foaming is often a result of chemical reactions taking place in the slag. As the slag composition and reaction rates are changing, foaming occurs under dynamic conditions. In the present work, slag foaming was studied with XRF. The foam displayed a fluctuating behaviour, unaccountable by existing models. The concept of foaming index was found not to be satisfactory in describing the foam, resulting in the need for alternative theories. The rate of fluctuations was seen to be related to the difference between rate of gas generation and rate of gas escape from the system (Ug-Ue) as well as the bubble sizes. Thus, model development of dynamic foaming phenomenon has to take the effective chemical reaction rate as well as the bubble sizes into consideration. The first step in obtaining foam is to form bubbles. In the present work, gas bubbles were generated through chemical reaction at interface between two immiscible liquids and the bubble formation was studied optically. The gas bubble size was seen to be uninfluenced by the reaction rate. However, bubble formation was seen to take place in one of the phases and since the bubbles consequently traversed the interface under the influence of buoyancy, the viscosity of the first phase was found to influence the final bubble size where increased viscosity would yield a larger bubble size.

Jan 1, 2006

By P. A. Rusin

Many manganiferous silver deposits remain undeveloped because standard chemical extraction methods yield poor recoveries or are ' environmentally unacceptable. Biotreatment of such ore deposits in our laboratory resulted in manganese and silver recoveries of greater than 90%. Ore and sediment samples were collected from mining sites in Colorado and Arizona. Portions of samples were incubated in a semi-solid mineral salts medium amended with 20 mM glucose mid manganese dioxide (Mn medium). The cultures were incubated at 3(fC until manganese reduction was detected by a .color change fr:om .black to clear. Bacteria from these cultures were purified on Tryptic Soy Agar and individual isolates were retested for Mn reduction by an agar overlay method. Bacteria were identified according to Bergefs Manual ?of Systematic . Bacteriology. Most of the Mn-reducing bacteria are Bacillus species. Bacterial manganese reduction kinetic experiments were performed in 52 ml mineral salts broth supplemented with manganiferous silver ore instead of manganese dioiide. These cultures were incubated with agitation for 16 d. Aliquots were removed periodically and analyzed for solubilized manganese by atoniic absorption (AA). Cyanide (1,0 M) Vias added to the remaining ore-medium mixture for a 24 h bottle roll. The supernatant was analyzed for soluble silver by AA. Similar experiments were conducted on a larger scale using 15% pulp density. After bfotreatment of the ore, standard bottle rolls were performed. The pregnant solutions and the residues were analyzed for manganese and silver?using AA or fire assay as appropriate. In sterile. controls-which received no biotreatment, manganese and silver recoveries were 0.3% and 10% respectively; During biotreatment, total manganese solubilizatiori was as high as 99.8%. The reduced manganese could . be stripped from ?the growth medium using hydrometallurgical techniques. Silver recovery vaned from 70% to 92.5%. Microbial treatment of refractory mangairlferous ores can result in high recoveries of manganese and silver. Retention time varies depending upon the relative concentrations of manganese, silver, and other metals in the ore with only two days required in some cases, The biotreatment of ore is environmentally' acceptable while the use. of chemicals such as sulfur dioxide is less so.

Jan 1, 1991

By Ann M. Hagni

Flash reduction of zinc oxides is an alternative, environmentally safe method to leaching and electrowinning for zinc recovery. Zinc and lead are volatilized in a flash reactor, a non-hazardous residue is generated, and the fuel source is inexpensive coal in the flash reduction process. Results from experimental laboratory tests yielded low zinc recovery for this process. Mineralogical and textural characterization of the residues from the flash reduction tests for different feed materials and temperatures were conducted to determine the cause for the low zinc recovery. Reflected light microscopy, cathodoluminescence microscopy, scanning electron microscopy-energy dispersive spectroscopy, and X-ray diffraction were utilized in this applied mineralogical research. The original zinc calcine is composed primarily of fine-grained, iron-bearing zincite particles, 25-40 um in diameter, in a porous texture. Pellets processed at 1150°C were found to produce reaction rims of franklinite-magnetite-jacobsite solid solution that are 125-200 um thick and surround cores of unreacted iron-bearing zincite in a Zn-Fe-Si-Ca glass matrix. The reaction rims have subsequently oxidized to form an outer 10 ~m thick rim of hematite. Slags from calcines processed at 1275°C are primarily triangular particles with porous centers, cenospheres, and spheres of iron-bearing zincite, in addition to rectangular particles composed of non-porous franklinite-magnetite solid solution cores with iron-bearing zincite rims. Slag particles from calcine processed at 1200°C are predominantly 100-250 ~m triangular-shaped, spheres, and cenospheres containing fine-grained franklinite and franklinite-magnetite solid solution in an iron-bearing zincite matrix. Slag from calcine processed at 1300°C are also predominantly 1 00-250 um triangular-shaped, spheres, and cenospheres but contain coarser-grained iron-bearing zincite. The zincite in the penets and the slags typically contain 10-20% iron. Based upon these mineralogical observations, it is concluded that the significant amounts of iron in the zincite prevent volatilization of the zinc in the flash reduction process.

Jan 1, 1995

By Hani Henein

"Heat transfer between droplets/particles and a gas phase plays an important role in the transport of numerous materials processing operations. These include rapid solidification operations such as gas atomization and spray forming, as well as chemical systems such flash furnaces. Chemical reaction rates and solidification are dependent on the rate of gas-particle or gasdroplet heat transport. Using a heat transport model validated using single fluid atomization of molten droplets; the effect of process variables on heat losses from droplets was examined. In this work, the effect of type of gas, droplet size, gas temperature, gas-droplet relative velocity on the heat transport from AA606 l droplets was examined. The most critical of these process variables to heat transfer is identified and will be presented.IntroductionIn materials processing, droplets are often encountered and used in processing a wide range of liquids and slurries. The small size of the droplet enables high reaction rates or high solidification rates in many systems. In order to capitalize on these high rates of transport processes, sprays are· also developed to maximize throughput. The design of these sprays, however, does not account for the transport steps and rate limiting mechanisms at the droplet surface. Rather, spray design focuses on maximizing the break-up of a stream or slurry into small size droplets or controlling the spread of the spray. Spray systems in industrial use typically generate droplets of wide size distribution leading to a wide range of reaction times for each of the droplets. Often the generation of a spray involves a number of coupled phenomena such as stream break-up, droplet-gas transport, droplet size distribution and spray geometry. Using gas generated sprays, it is not possible to identify how individual process variables contribute and control each of these coupled phenomena. While many mathematical models have been developed of sprays and they attempt to simulate coupled droplet transport, they do not provide insight into the contributions of different mechanisms in heat transfer. This is primarily because the basic fundamental heat transport between droplet and gas cannot be isolated from other gas spray phenomena experimentally such as two-way thermal coupling [l]. Thus, experimental validation of heart transfer of large and complex industrial spray models is not carried out. Hence, the validity of spray models remains in question and the approach required to optimize spray processes cannot be clearly identified"

Jan 1, 2004

By Z. Zhang, Cuihuan Huang, Zongshu Zou, Nan Wang, Xueqian Xin

"Vitrification is considered as an attractive procedure for municipal solid waste incineration ash, which can realize the volume reduction and innocent treatment of incineration ash, as well as reuse of bottom ash. The main oxide components of molten ash slag are CaO, Al2O3, SiO2, Fe2O3, MgO, and Na2O, accounting for more than 90% of the total mass. The phase relations and thermodynamic properties of the CaO-Al2O3-SiO2-FeOx-MgO-Na2O oxide system is highly required, and is of great scientific significance for optimization of vitrification processing and sustainable resource utilization of melting slag. A study on the equilibria phase relations of CaO-SiO2-MgO-FeOx system was done by using CALPHAD method based on FactSage in this paper. The modeling parameters for the thermodynamic properties of liquid phase in CaO-SiO2-MgO-FeOx system were established and the equilibrium phase relations of MgO-SiO2-FeOx and CaO-SiO2-FeOx-MgO systems were calculated for different temperatures and oxygen partial pressures.IntroductionThe main oxide components of vitrified bottom ash slag are CaO, Al2O3, SiO2, Fe2O3, MgO, and Na2O, accounting for more than 90% of the bottom ash by weight [1]. During slag processing and modification, the knowledge of thermodynamic properties and liquidus temperature in the related slag system is highly required [2-5], which is not yet available. Through literature survey [6-9], it is clear that the systematic information on the concerned complex slag system is scarce. Most binary subsystems except FeOx-Na2O have been investigated well. Among ternary subsystems, few phase relations of the Na2O-MgO-SiO2 ternary system are available. For the phase relations of the system Na2O-MgO-Al2O3, all the studies are focused on the Al2O3-rich region. Investigation on the CaO-Al2O3-FeOx system is limited to Fe2O3-containing system with relatively higher oxygen potential. Most quaternary systems are not studied well except the CaO-MgO-Al2O3-SiO2 system, mainly due to their metallurgical importance. Figure 1 demonstrates the research status of the vitrified bottom ash slag with almost zero effort [10]. The effort here is defined based on the published literature by considering the number of publications, the investigated composition ranges, and the research details. So far the engineers in the field have to make assumptions of the thermodynamic properties of the simplified oxide system, without taking into consideration the interactions of the different oxide components, which hinders the development of the slag valorization and utilization. In order to provide thermodynamic properties for the application of the vitrified bottom ash, the six-component oxide system (CaO-MgO-Al2O3-SiO2-FeOx-Na2O) will be investigated through both experimental approach and computer modeling."

Jan 1, 2011

By W. D. Cho

Fast dissolution of nonmetallic inclusions such as alumina particles in molten slags has been required in secondary steelmaking -ladle and tundish - to minimize the amount and the size of nonmetallic inclusions in steel products. In the present work, the dissolution behavior of alumina particles in molten CaO-A12O3 and CaO-A12O3-SiO2 slags at the temperatures between 1450 and 1550°C have been investigated in terms of kinetics and mechanism. Alumina particles were added directly into the slags and the variation of the particle size with time was determined using optical and electron microscopies. The conventional types of slag for ladle and tundish were included in the dissolution study. The effects of Al2O3, Siq, CaF2 and MgO contents on the dissolution rate of alumina particles have also been determined. The diffusion boundary layer between alumina particle and bulk slag phase has been observed and analyzed using SEM and EDS. Based on the analysis of kinetic data and the boundary layer, the dissolution mechanism has been discussed.

Jan 1, 2002

By A. N. Lasseigne

Hydrogen storage capabilities of LaNi5 intermetallic compounds were investigated utilizing the combination of thermoelectric power, Beeghly Ester-Halogen digestion, and Leco hydrogen determination. Thermoelectric power has demonstrated a rapid hydrogen assessment capability and can achieve the equivalent of the pressure-composition-temperature (activity) diagram. Effective use of hydrogen storage materials occurs in the two-phase, alpha+beta region of the PCT diagram. A thorough assessment of the content of each phase in this two-phase region to optimize performance of the hydrogen storage materials is described. Practices using the combination of these three analytical practices for rapid characterization of LaNi5intermetallic alloys are discussed.

Jan 1, 2006

By A. J. Davidson

A novel sensor is described for the measurement of the copper content of copper matte. Due to the high copper concentrations found in matte, potentiometric sensors are not sufficiently sensitive. A highly sensitive sensor has been developed based on a modification of the amperometric technique using a copper ion conductor, Cusicon. The results correlate closely with the theoretical predictions.

Jan 1, 1998

By Kuiting Wang, Jinshan Liu, Ninglei Sun, Aiguo Dong, Yeda Lu

"Eliminating the environmental threat caused by waste effluent containing magnesium sulfate derived from the process of nickel laterite sulfuric acid leaching and subsequent nickel precipitation is always a focus in the metallurgy field. A new flowsheet whose procedures include vaporization, crystallization, two stages precipitation of magnesium, causticizing treatment of filtrate and ammonia recycle was investigated. Both the details of the flowsheet and its application are described in this article. It is confirmed to be an effective and economical method to prevent the pollution by the waste effluent, simultaneity, a series of magnesium products recovered during the process own good economic returns.IntroductionSulfuric acid leaching is the conventional procedure of extraction valuable metals from ores in hydrometallurgy field. During the process of nickel laterite sulfuric acid leaching, several metals, including Ni, Co, Al Mn, Fe, Mg etc., migrate into the leachate in the form of soluble metal sulfate. After subsequent procedure of purification, precipitation of Ni and Co and neutralization, an enormous stream of waste effluent which contains a concentration of approx. 15-40g/L Mg is exhausted. Such solution containing magnesium sulfate is toxic, which causes diarrhea for both human and animals. On the other hand, large amount of sulfate acid was consumed during the process of leaching by the compound of Mg, which increases cost of a hydro nickel plant.In arid areas, the waste effluent mentioned above is treated via evaporate pond owning large acreage, which needs not only the appropriate meteorologic condition, but occupies much land. In coastal areas, it is directly discharged to the sea, which probably deteriorates ecological system of offshore strip. The most widespread method to treat with the waste effluent is neutralization by lime cream, the residues of which containing magnesium hydroxide and gypsum are transported to residues pool. Neutralization is a simple process, but it never recycles the Mg and sulfate anion into new application, meanwhile, the residues are potential threat to the environment."

Jan 1, 2012

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 Stephen M. Testa

Several methodologies are available for the remediation of contaminated soils including bioremediation, vapor extraction, chemical fixation, incineration and direct disposal. A proven innovative and cost effective alternative for the fixation of contaminated soils is via cold-mix Environmentally Processed Asphaltm (EPA"'). EPAm methodology utilizes contaminated soil as an ingredient in an industrial process to produce a commercially viable product. Petroleum hydrocarbon and metal affected soil is incorporated with a water-based asphalt emulsion and varying amounts of aggregate to produce a range of cold-mix asphaltic products that fulfills the requirements of a variety of end uses. This viable and creative use which is within the intent and spirit of current regulations in producing, in lieu of a landfill waste, an end product for use as a berm, road base, liner, or other site specific application. Consideration of certain engineering and environmental factors including durability, stability, chemical resistance and ageing, biological resistance, permeability, leachability and geochemical aspects suggests that cold-mix asphalt incorporation of affected soil will perform more than adequately under normal conditions for a long period of time.

Jan 1, 1994

By Shulan Wang, Xuan Liu, Li Li

"Electrochemistry of Fe(III) in 69CaCl2-12CaF2-19KF and 81CaCl2-19KF (mole percentage, %) was investigated at 827 oC on molybdenum electrode by cyclic voltammetry, chronoamperometry and galvanostatic electrolysis using Fe2O3 as the Fe(III) source. The reduction of Fe(III) to Fe was conducted in one step and controlled by diffusion process. Fe(III) shown greater reduction rate and diffusion coefficient in molten 81CaCl2-19KF than in 69CaCl2- 12CaF2-19KF. Galvanostic electrolysis of Fe was performed in both molten salts with a cylindrical cathode rotating at 200 r/min and dendritic iron deposit was obtained.Keywords: iron; electrolysis; electrochemistry; molten saltIntroductionThe production of iron and steel causes huge emissions of CO2. Iron electrowinning in molten salts with dissolved Fe2O3 using an inert oxygen evolving anode is an alternative process to reduce or eliminate the formation of CO2. Research on novel process of producing metal has been reported recently [1-2] by using CaCl2 as the main electrolyte and dissolving CaO in CaCl2 due to the high solubility of CaO in the melt. This process has been used in preparing many active metals and alloys [3-14]. In the present work, the electrochemical behavior of iron in CaCl2-KF was studied and transport property of iron ion in the melt was discussed.ExperimentalCaCl2,CaF2 and KF (in analytical purity) were dried in air for 48 h. Mixed salts used in experiments were placed in a graphite crucible (??58 mm inner diameter). The graphite crucible together with the salts was heated at 473 K for 12 h in a furnace with flowing Ar (99.99%) before further heating. Temperature inside the furnace was measured by an S type thermocouple. Electrochemical measurements, such as cyclic voltammetry and chronocoulometry, were performed in a three electrode cell by EG&G PAR273A potentiostat/galvanostatand. Galvanostatic electrodepositon of iron was conducted in a two electrode cell. Molybdenum (??2 mm) and iron (??5 mm) were used as the working electrode (WE) and the reference electrode, respectively. A graphite crucible and a magnetite rod (??25 mm ) consisted of 100% magnetite and sintered at 950 oC in argon atmosphere for 2 h with electrical conductivity of 366 O-1m-1 at room temperature were used as the counter electrodes in the galvanostatic electrolysis experiment. Carbon (??10 mm) was used as the counter electrode in electrochemical measurement. The deposits were washed in distilled water bubbled with argon and dried in air before being characterized by X-ray diffraction (PW3040/60 diffractometer) and scanning electron microscope (SEM, SSX-550)."

Jan 1, 2014

By T. Yoshida

The Ni-MH (nickel metal hydride) rechargeable battery was developed several years ago. Its higher electrochemical capacity and greater safety compared with the Ni-Cd rechargeable battery have resulted in very rapid Increase in its production. The Ni-MH rechargeable battery consists of Ni. Co and rare earth metals, so that recycling is important to recover these valuable mineral resources. In this study. a basic recycling process for used Ni-MH rechargeable batteries has been developed, in which the Ni. Co and rare earth elements are recovered through a combination of mechanical processing and hydrometallurglcal processing.

Jan 1, 1995

By Neeraj Saxena, Madhu Huggahalli, Jerry Bednarski, Ken Grieshaber, David Stoffel

"The use of oxy-fuel burners in secondary aluminum melting applications offers several advantages over air-fuel burners including reduced fuel consumption, faster charge to tap times and lower NOx emissions. Their successful, safe and economical use in a furnace depends on several factors and considerations such as burner and flue placement, metal circulation, charge practices and the type of refractory used in the furnace.These factors required in the successful conversion of furnaces from air-fuel to oxy-fuel based burners are discussed in this paper. Critical parameters are identified and examined using computational fluid dynamics (CFD) simulations. Parameters are estimated via laboratory testing and validated through trials performed at commercial installations. Guidelines and a simplified approach to estimate a priori the economic impact of converting from air-fuel to oxy-fuel are presentedThe final products of this research are simplified and validated tools for modeling aluminum furnaces. These include improved heat and energy balance models and parameterized CFD solutions which provide rapid customization to individual furnace configurations. These tools provide field engineers with immediate and accurate predictions of performance, allowing for repeated precise scenario analyses."

Jan 1, 2001

By Alexandre Chagnes

The extraction properties of two synthesized cationic exchangers, i.e. bis (1,3-dibutoxypropan-2-yl) phosphoric acid (BiDiBoPP) and bis(1,3-diisobutoxypropan- 2-yl) phosphoric acid (IPA), have been studied for the liquid-liquid extraction of Co(II), Ni(II) and Mn(II) contained in 1 M HCl. A comparison of the extraction properties of these extractants diluted in kerosene with Cyanex® 272 shows BiDiBoPP and IPA extract advantageously at lower pH than Cyanex® 272 and a better Co(II)-Mn(II) separation is achieved using BiDiBoPP or IPA than with Cyanex® 272.

By Sumantra Mandal

The hot deformed microstructure of the 15Cr-15Ni-2.2Mo-Ti modified austenitic stainless steel (commonly known as alloy D9) was investigated employing electron backscatter diffraction (EBSD). Hot compression tests were conducted in a Gleeble thermo-mechanical simulator at temperatures of 1173K-1373K (in steps of 100K) with a strain rate of 10 and 100 s-1 to different strains. Various kinds of deformation patterns were observed inside the deformed grains. These were inferred as the development of geometrically necessary boundaries or formation of parallel set of micro-bands. Recrystallized grains were partitioned from the deformed grains employing grain orientation spread approach. Extent of dynamic recrystallization (DRX) was found to be minimal at 1173K. DRX was predominantly found to happen at and above 1273K which increases with increase in strain. DRX nucleation and development mechanisms were discussed with respect to bulging of the parent grains and sub-grain rotation. Special emphasize is given on the role of annealing twins on DRX nucleation and subsequent expansion.

Jan 1, 2009

By J. M. Figueiredo, A. R. Silva, M. C. Coelho, R. M. Guedes

"With the continuous depletion of conventional sources of non ferrous metals, low grade complex sulphide deposits have been regarded as an alternative source of supply of zinc, copper, lead and also silver and gold. In spite of very important efforts in research in this domain it is still a long way to go in order to achieve reliable technological solutions both in ore dressing and metallurgical treatments which enable these complex materials to be regarded as commodities. The RLE process to treat bulk concentrates such as those obtained from portuguese ores, under development at LNETI and QUIMIGAL premises, combines experienced unit operations and innovative configurations and is an effective contribution for the future use of these materials. The results of three years of experimental work and main conclusions on the overall feasibility of the process are presented.IntroductionIn spite of the very well-known problems associated to the development of complex sulphide deposits, the economical importance of the enormous reserves of these materials, widespread all over the world, is so evident that its future use as source of supply of basic and precious metals and other minor elements is almost unavoidable.Critical steps in that direction are mainly concerned with favourable economical conditions and sound metallurgical practice for the treatment of nonferrous metals concentrates, which are nowadays still considered as non-conventional raw materials.Since Portugal is one of the countries where these orebodies occur more extensively, Portuguese authorities have dedicated since the beginning of the seventies, a big effort on finding economical and reliable processes for the recovery of copper, lead, zinc and also gold and silver, and for this purpose, several alternatives on ore dressing and metallurgical processing were studied, however without full sucess.Five years ago LNETI, a research laboratory, and QUIMIGAL, a chemical company, both state owned, decided to launch a research programme for the development of a metallurgical process for the treatment of NFM concentrates, which received financial support from NATO under its programme ""Science for Stability""."

Jan 1, 1988

By María Cristina Ruiz

Hematite precipitation is a convenient alternative for the removal of iron from leaching circuits because of its chemical stability, high density and high iron content. The precipitation of hematite from ferrous sulfate solutions was studied in a batch reactor. The precipitation occurs by two sequential steps: oxidation of the ferrous to ferric ions followed by hydrolysis of the ferric to hematite. The main objective of this study was to determine the effect of the main operating variables on the rate of two steps of hematite precipitation. The variables studied included: stirring speed (100 to 600 rpm), temperature (160 to 200 ºC), concentration of sulfuric acid (1 to 10 g/L), initial iron concentration (1 to 15 g/L), and partial pressure of oxygen (1 to 6 atm). The sulfur content and the particle size of the solids that precipitated under various conditions were also determined. The results showed that at low temperature and high acid concentration the rate of Fe3+ hydrolysis is the step that controls the overall process. The variable that affects most the rate of Fe2+ to Fe3+ oxidation and the rate of hematite precipitation is the temperature.

Jan 1, 2008

By Nagahiro Saito, Takahiro Ishizaki, Daisuke Yata, Akio Fuwa

"Ternary compound-semiconductor, CuInTe2, film was deposited cathodically under potentiostatic conditions on titanium substrate from aqueous solution containing CuCl2, InCl3, TeO and HCI in this study.The deposition parameters such as electrolytic solution composition, potential and temperature were optimized· for electrodeposition of CulnTe2. Structural characterization of the: deposited film was also carried out using XRD and SEM. Electrodeposited films Were prepared and analyzed for their chemical composition using ICP. The ICP analyses showed that the stoichiometry of the films could be controlled by (1) the deposition potential and/or by (2) the electrolytic bath composition.1. IntroductionThe ternary chalcopyrite type compound semiconductors exhibit such electrical, chemical and optical properties that make them promising for photovoltaic devices (Kazmerski and Wagner 1985)(1). Many researches have been devoted to the characterization of these materials for over one and a half decades. High efficiency solar cells based on p-CulnSe2/n-CdS have been reported (Mickelson and Chen 1983)(2).The electrodeposited fil ns of semiconductors have more advantage than other physical and chemical deposition techniques; it is relatively easy and economic technique and the semiconducting properties such as band-gap variation, concentration of dopant stoichiometric composition and so on can be controlled with some accuracy. The electrodepositions of the ternary CuInS2, CulnSe2 have been reported by many workers (Hodes and Cahen 1986, Bhattachaya 1983, Singh et al 1986, Lokhande and can be prepared as both p-type and n-type. Therefore, its potential for application in optical and photovoltaic devices is one of the great interests. Bhattacharaya and Rajeshwar (1986)(9) reported the electrodeposition of CuInTe2 from an acidic bath· on indium tin oxide (ITO) and Mo substrate. Triethanolamine (TEA) was used as a complexing agent for indium. The electrodeposited CuInTe2 films were non-stoichiometric in composition under all their experimental conditions by electron-probe micro analysis (EPMA) and Auger depth profile analysis. In this paper, we report our results on the behavior .of Cu-In-Te electrodeposition from ·acidic baths; the preparation of CulnTe2 and the effect of bath composition on electrodeposited films obtained."

Jan 1, 2000