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By Byung-Su Kim

The reaction between calcium sulfate and hydrogen is of interest both as a means of regenerating calcium sulfide as a reductant of sulhr dioxide to elemental sulhr and for producing elemental sulhr from gypsum. This reaction was investigated using a thermogravimetric analysis technique in the absence and presence of nickel catalyst. The reaction temperature was varied between 973 and 1153 K, while the hydrogen partial pressures of 12.9 - 86.1 kPa were utilized. At 1073 K and a hydrogen partial pressure of 86.1 kPa, 60 % of the original calcium sulfate in the absence, and 95 % in the presence, of the nickel catalyst was converted to calcium sulfide in one hour.

Jan 1, 1999

By Wayne Bell, Xiaodi Huang, Matthew Andriese, Jiann-Yang Hwang, Zhiwei Peng

"The equations for determining microwave field attenuation length and half-power depth in magnetic materials were derived from Maxwell’s equations. The microwave field attenuation length and the half-power depth for a magnetite concentrate were calculated and the temperature dependence of them was determined. It is demonstrated the microwave field attenuation length and the half-power depth highly depend on temperature and decrease with increasing temperature up to 900 °C. The variations of field attenuation length and the half-power depth with temperature indicate the microwave power attenuates much faster than the field strength in materials. The evaluations of field attenuation length and microwave half-power depth can be used to characterize the microwave dissipation behaviors in the sample and optimize the dimensions of the material in microwave heating.IntroductionMicrowave has been applied in materials processing for its distinguished advantages including rapid heat transfer, volumetric and selective heating [1,2]. However, most research work involving microwave heating are confined to non-magnetic materials (e.g. ceramics), with limited attention paid to the heating of mixed property materials (e.g. magnetite and other ferrites) under microwave irradiation [3-5]. Since many magnetic materials exhibit good and even better microwave absorption capability than non-magnetic counterparts, it is quite necessary and deserved to take advantage of this property and then improve the heating efficiency. To achieve this aim, further understanding on the microwave heating mechanism, especially the microwave propagation/dissipation behaviors in magnetic materials is required.The dissipation behavior of microwave in materials has been identified as one of the key factors that affect the efficiency of heating under microwave irradiation and this behavior can be characterized by several parameters. Apart from traditional penetration depth (TEM power penetration depth, Dp = 1/(2*a), where a is the TEM field attenuation factor), two other parameters, field attenuation length (Df) and half-power depth (Dh), are also applied to indicate the microwave dissipation in materials [6].The accurate determination of such parameters can help in optimizing the dimensions of the load in a microwave furnace, producing more uniform heating under microwave irradiation and avoiding thermal runaway."

Jan 1, 2011

By Tianzu Yang, Weifeng Liu, Shu Bin, Lin Chen, Wanda Bin

"Vanyukov Process has been mainly applied for processing copper and nickel sulfide ore for more than 30 years. Based on the understanding of the Vanyukov Process, researchers from China introduced the technology into the areas of lead, antimony and bismuth extraction by changing the furnace structure and technical flow, which greatly extended the application area and raised the processing efficiency, thus developed the oxygen-rich side-blow bath smelting (OSBS) technology in 2000. This contribution reviews the history of OSBS technology from four respects: the quantity, the furnace structure, the process flow and the application area. Its potential research direction and industrial application are also summarized.IntroductionVanyukov bath smelting furnace and related bath smelting technology were developed by researchers from Soviet Union who devoted comprehensive research on fundamental theory as well as engineering technology [1,5]. Vanyukov process has been applied for large industrial production since the 1970s and it is still one of the major methods in modem pyrometallurgy process. The appearance ofVanyukov double district furnace and joint double furnace in the past ten years, which are applied for copper smelting, is the most valuable advances of the Vanyukov process [7,8,9]. However, the application ofVanyukov process was limited in copper and nickel sulfide ore smelting, and few countries adopted this process except Soviet Union."

Jan 1, 2013

By Zachery Zanetell

Flotation circuit performance has become increasingly more challenging due to the complexity of available ore sources. To optimize value mineral recovery, the mineralogical composition of the ore should be evaluated and understood. Utilizing a variety of mineralogical and analytical tools, flotation processing challenges can be overcome and potential limitations understood. In this paper, several case studies will be discussed in terms of the value that has been provided through the use of mineralogical analysis to optimize flotation performance.

By Satoshi Yamashita, Noboru Masuko

"Newly prepared bipolar membrane is promising to become a key material of an electrolyser for a production process of strong reducing solvent. This research is basic research for using bipolar membranes as electrolysers of reducing agents, Cr(II), TI(III) and V (II) on the laboratory scale. In this report, a bipolar membrane was tried with an electrolyser, reducing chromic chloride to chromous chloride. An analysis of mass balance demonstrates advantages of it over the former electrolyser equipped with an anion and/or. cation exchange membrane. The effects of current density and concentration of Cr(lll) on the reduction rate of Cr(II) and the current efficiency were examined No deterioration of the bipolar membrane resulted from the electrolytic reduction of Cr(III). IntroductionRecently, bipolar membrane that was the development subject for a long time in the industry of ion exchange membranes has met the stage of the practical application at last [l]. The expectation of the application to the hydrometallurgy field increases. We took up the manufacturing of the strong reducibility solvent as part of the application of bipolar membrane to hydrometallurgy technology. This laboratory has much experience in the electrolytic reduction of Cr (II) aqueous .solution such as chromous sulfateusing bipolar membrane were compared in theory to chromous chloride aqueous solution manufacturing of the strong reducibility solvent. The advantage of applying bipolar membrane by substituting ion exchange membrane is described, and the experimental result is reported."

Jan 1, 2000

By Don Ibana

The use of solvent extraction (SX) in process metallurgy is particularly attractive as it is applicable to a wide range of solute concentration and pH, and it allows complete separation of chemically similar metals such as nickel and cobalt and the rare earths among others. It is therefore applicable to the processing of low grade and complex ores, which is increasing and expanding owing to the diminishing reserves of quality ores, and this has driven the increasing and expanding use of SX.The current SX technology, however, has inherent limitations owing to the use of mechanical agitation as it induces high shear mixing. Excessive shear produces very fine droplets, and while this favours mass transfer, it also leads to sluggish phase separation. High shear mixing is also known to favour crud formation. All these factors as well as high power and reagents consumptions contribute to poor process efficiency. Electrostatic solvent extraction (ESX) is similar to conventional SX except that mechanical agitation is replaced with electrostatic agitation. In direct contrast to mechanical agitation, it allows the production of very small droplets that can be made to maintain intense motion, which favours mass transfer, without affecting the phase separation. In addition, as it uses an electrostatic field, the power consumption is minimal. Hence, it promises to be a superior alternative to conventional SX mixing although an application of the technique is yet to be achieved.Our work to develop an application of the technique in process metallurgy has now established that electrostatic field has no effect on either the stability of the reagents or the chemistry of the process. A volumetric flowrate that is comparable to that of a conventional sieve plate pulse column is achievable. We have also established that electrostatic fields can be made to yield much narrower droplet size distributions than those of mechanically agitated contactors, and they allow better control of droplet motions, which include oscillation and linear motion and hence, mass transfer. These are significant advancements toward our goal and shall be discussed in this presentation.

By M. H. Lin, S. Kou

"Czochralski pulling has been a very widely used process for growing single crystals for electronic and optical applications. Dopant segregation can significantly degrade the quality and yield of single crystals. We have used the floating-crucible technique for segregation control in Czochralski pulling, our floating crucibles being unique in that the melt passageway is very long. As such, dopant back diffusion is suppressed, even when the cross-section of the melt passageway has to be relatively large to help the melt go through or when the pulling rate is very low. Single crystals of model materials K-doped NaN03 and Pb-doped Sn have been grown with very uniform dopant concentrations. IntroductionSingle crystals of electronic and optical materials are often doped with a small amount of impurities to develop required physical properties, e.g., P and B in Si for n-type and p-type semiconductors, respectively, and Nd in YAG lasers. Dopant segregation can result in nonuniform physical properties, thus degrading the quality and yield of the resultant crystals.Figure 1 is an illustration of the conventional Czochralski process for crystal growth. Several techniques have been developed to control dopant segregation in Czochralski pulling, including the push-pull technique (1,2), the drop-pull technique (3-7) and the floating-crucible technique (8-13). The first two techniques require precise sensing devices and feedback control systems to keep the feeding rate equal to the pulling rate. The last technique is simple since the feeding rate is automatically equal to the pulling rate."

Jan 1, 1994

By Toshiyuki Kozuka

CdTe metal composite semi-conducting material has high potential in good performance of energy conversion efficiency for solar cell and there is much room for improvement of the performance by developing a process of making a thin CdTe film. In this paper, the imposition of intense magnetic field on CdTe electro-depositing surface is proposed, which is one of the possibilities for improving the energy conversion efficiency. In the experiment, cryogen-free super-conducting magnet up to 5T was used and CdTe film was deposited electrically in -0.72V vs. SHE The electrolyte was Cd and Te ammonia alkali solution with controlled temperature in the acrylic cell of 70mm diameter. Electro-deposition behavior of CdTe has affected by the imposition of the intense magnetic field due to microscopic convection in the vicinity of the depositing surface. Electro-deposited surface of CdTe becomes smooth due to microscopic convection around the surface, and the crystallization behavior is also affected, where crystallization temperature and the grain size is changed by the imposition of intense magnetic field.

Jan 1, 2003

By R. W. Smith

The flotation response and electrokinetic behavior of Chlorella vulgaris and Chlamydomonas sp . when using dodecylamine hydrochloride as collector were studied in the absence and presence of Pb(I1). Also, an electron microscopy study was made of the algae after Pb accumulation. The flotation behavior of the organisms after Pb accumulation appears at least partially related to the location of the abstracted Pb onto or into the organisms.

Jan 1, 1991

By M. Tomita

One of the most essential factors for a custom smelter to strengthen its competitive power is to Improve its comparative standing in purchase of concentrates from the world market. It is especially critical for Japanese smelters who depend almost 90% of their raw materials on import. In order to accomplish this breakthrough, the development of the new technology which enables us to treat concentrates containing higher Impurities is inevitable. Nippon Mining Company Ltd. made an intensive research on processing complex ore for three years from 1979, and successfully developed an original hydrometallurgical process to treat converter dust for eliminating impurities from the copper smelting circuit. The commercial plant was constructed at the Saganoseki Smelter & Refinery in 1982, and its nine years operation has been satisfactorily proven the advantages of the technology. The concept of this process and its operational performance are discussed.

Jan 1, 1992

By Richard B. Stein

Bechtel's BEMSIM computer program is a useful tool for solvent extraction-electrowinning plant design optimization. Its power (up to 90 stream components, 240 process streams, 180 process steps) has been applied to investigate floweheet configurations in order to perform basic engineering, sizing of plant equipment and to optimize performance of commercial-size copper plants. Flowsheet variations presented include series, parallel and series-parallel extraction stages, while heat balances simulate operations in summer and extreme winter conditions. The BEMSIM program has also been applied to nickel-cobalt, gold and manganese extraction.

Jan 1, 1993

By Serdar Aksu, Fiona M. Doyle

"CMP will be an essential process in the production of integrated circuits containing copper interconnects. This study aims to improve our mechanistic understanding of the role that organic chelating agents might play in the reactive slurries used in copper CMP. Copper dissolution behavior in EDTA arid glycine was first examined by producing potential-pH diagrams for the copper-water-EDTA and copper-water-glycine 'systems. The results of potentiodynamic polarization experiments were then considered in light of these diagrams. . In-situ polarization experiments were conducted to gain insight into the electrochemistry of copper during dynamic polishing in slurries prepared from EDT A and glycine.IntroductionCopper has recently started to replace aluminum as the interconnect metal in integrated circuits. Copper interconnection offers faster and more reliable integrated circuits due to its higher electrical conductivity and superior electromigration resistance (1). The damascene method is used to form multilevel interconnects in the manufacture of integrated circuit devices with copper metallization (2, 3). Copper is deposited by CVD or electroplating into vias and trenches etched in the interlayer dielectric (IDL), over a diffusion barrier usually made from titanium, tantalum or their nitrides. Chemical mechanical planarization (CMP) then prepares the wafer for the next deposition step, by removing excess copper and planarizing the surface. During CMP, the wafer is rotated and pressed against a rotating platen covered with a polishing pad. Chemically active slurries containing submicron size abrasive particles (Si02, Al20 3, ceria, diamond, etc.) are applied. Both the mechanical action of the abrasive particles and the chemical action of slurry constituents remove material from the wafer surface. Planarization results because material is removed faster from protruding regions on the surface than from recessed regions. Since CMP can globally planarize .the entire wafer, it has become one of the key technologies for producing integrated circuits with copper metallization."

Jan 1, 2000

By Hideki Yamamoto, Shigeno Matsumoto, Junji Shibata

"Some fundamental studies were carried out in order to produce composite powders comprising of two or three metal oxides ~y using liquid-liquid extraction and to develop the control technology of the particle size. The combination of samarium and cobalt was selected as the two component composite powders. Both stripping and crystallization occurred at the same time by emulsifying the organic phase loading the two metals extracted with Versatic Acid 10 and the aqueous solution containing oxalic acid. The effect of aqueous pH, oxalic acid concentration and agitation speed was examined on some properties such as crystallization percent, particle size and shape of each metal oxide powders obtained in this process. The analysis by using EDX showed that the two metal oxides were distributed uniformly.IntroductionComposite metal and metal oxide powders with high purity are indispensable as industrial materials in the fields of electrical engineering, electronics and metallurgy. It is difficult to mix metal powders or metal oxide powders uniformly for the production of alloy powders. If insoluble metal salts are allowed to collect as crystallization products in the crystallization-stripping process, the conventional melting and crushing process can be avoided. After mixing of the organic phase containing metals in fixed composition, fine metal and metal oxide powders of alloy composition are produced by using a crystallization-stripping method. Versatic Acid 10 and D2EHPA, both acidic extractants, were chosen in this experiment, and the metal oxide powders were produced by using oxalic acid as a crystallization reagent. Mixed metal oxalates containing samarium and cobalt were precipitated from the mixed organic phase containing these metals. Furthermore, the physical properties of the powders, such as particle size, shape and thermal decomposition, were measured in order to evaluate them for industrial purposes."

Jan 1, 2000

By Hiroaki Kawamura, Takeshi Yoshikawa, Kazuki Morita, Yutaka Yanaba

"To develop an alternative metallurgical process for phosphorus removal in the production of solar-grade silicon (SOG-Si), slag treatment of metallurgical-grade silicon (MG-Si) was conducted, followed by acid leaching. Phosphorus-doped silicon alloy or MG-Si containing certain amounts of phosphorus and calcium was reacted at 1723 K and 1773 K with CaO--CaF2 of several compositions. Phosphorus removal from the molten silicon into the slag phase was confirmed by reduction to phosphide ions, P3-, and phosphate ions, P3-. These ions were separately determined using a wet chemical analysis method developed by ourselves. The highest phosphorus distribution ratio obtained was 2. 7 after reaction for 18 h with 17.5 mass% CaO--CaF2 slag. We then conducted acid leaching of the silicon and achieved removal of a large fraction (over 90 % ) of the phosphorus, which was much higher than that obtained by ordinary oxidizing slag treatment.IntroductionIn recent years, the production of solar cells has been increasing rapidly. Because of this, the demand for solar-grade silicon (SOG-Si) has also been growing rapidly. The development of lower-cost mass production processes is therefore needed to provide silicon feedstock. Phosphorus is one of the impurities in metallurgical-grade silicon (MG-Si). Because of its large segregation coefficient (kp = 0.35) [l ], it is difficult to remove phosphorus using a solidification refining process. Vacuum melting is considered to be a promising method for removing phosphorous from MG-Si [2], but the issues of high cost and large energy consumption have still to be resolved.Slag treatment is often used to remove impurity elements by oxidizing reactions during general oxidation refining processes. For example, phosphorus in molten steel is removed into a slag phase as phosphate ions, PO4 3-l-, by the following reaction:"

Jan 1, 2013

By Eiichi Kuzuno, Atsushi Shibayama, Toyohisa Fujita, Kazuo Koike, Toshio Miyazaki, Hitoshi Masuda

"A solid sulfur is more useful to recover and store than a sulfuric acid as a by-product in the zinc hydrometallurgy. In this experiment a zin concentrate (sphalerite) was leached with ferric sulfate at about 373 K for 3 to 6 hours. Zinc was leached more than 95%. After a solid-liquid separation, the leached residue contained solid sulfur was obtained. The particles in the residue were dispersed by lignin and the solid sulfur of approximately 85% was recovered as float product by a flotation with frother in the pH 4. The dried float product was heated at 413K for 2 hours. The pure solid sulfur was recovered. On the other hand in the leached liquid a zinc oxide was ·added and ferrous .iron was oxidized to ferric iron by blowing oxygen. This ferric iron was returned to the zinc leached process after solid-liquid separation.IntroductionZinc concentrate is usually roasted as pretreatment in zinc hydrometallurgy and the produced S02 is changed to sulfuric acid. However, recently in Japan the utilization of sulfuric acid has been limited and it is more costly to store. Instead of producing sulfutic acid the solid sulfur recovery has been examined by direct leaching of zinc_ concentrate in this experiment.In the direct leaching, several kinds of effects have been studied for leaching of sphalerite in ferric sulfate solution. The addition of lignine siilfonate1 • 2) and fine· grinding3) increases the · speed arid leaching fraction of sphalerite. The leaching ratio depends on impurities in sphalerite ores4 • 5). Here, the zinc concentrate is leached ferric sulfate solution under atmospheric pressure at 373K. The solid sulfur in leached residue is separated as float products from other solids by sink-float separation and flotation. The sulfur in float products is purified by evaporation at 413K and recovered."

Jan 1, 2000

By Hongbo Zhu, Kun Yang, Jingyan Jia, Jinhui Peng, Libo Zhang, Yi Xia

"Titanium dioxide is broadly considered as the most potential useful photocatalytic material. In this work, titanium dioxide was synthetized by microwave solid-state method and characterized by thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result demonstrates that through microwave solid-state synthesis, we can obtain uniform size and anatase TiO2 photocatalyst, with the precursor being Ti(C2O4)2·2H2O. And its degradation kinetic parameter of MO can reach to 0.21232.IntroductionSince Fujishima and Honda found the photovoltaic property of titanium dioxide TiO2 [l], it has been widely used in the field of pollutant degradation, virus killer and environment protection [2-5]. Compared to other semiconductors, TiO2 has the advantage of low toxicity/cost, chemical stability, excellent photocatalytic activity, and long lifetime of electron/hole pairs, thus it is considered to be a most potential useful photocatalyst material [ 6]. Solid-state synthesis of oxide nanoparticle is a new method developed in recent years, which not only overcomes the shortcomings of easily aggregation existing in traditional hydrometallurgical process, but also fully demonstrates the unique technologic advantages of without solvents, high yield, easy control, less environmental pollution in solid-state reaction [7-11]. Researches show that the new method of microwave synthesis shows a lot of advantages such as fast reaction rate, efficient, high purity of product, uniform morphology, energy-efficient, and nonpolluting [12-15].In this work, we associated microwave heating and solid-state synthesis to prepare TiO2 photocatalyst material. Its photocatalytic activity was studied in the degradation of MO queous solution. Meanwhile, the formation process as well as the crystal structure and morphology of the synthesized powders were characterized by means of chermogravimetrydifferential scanning calorimetry (TG-DSC), X-ray diffractometry (XRD) and scanning electron microscopy (SEM) techniques."

Jan 1, 2014

By Takashi Miyamoto, Hideo Nakae, Hideki Yamaura, Takeshi Yanagihara

"For the production of partially composed metal matrix composites, namely discontinuous MMCs, using a casting· process, the interpenetrated phase composites with SiC particles were fabricated by pressureless iDfiltration using molten Al-Si alloys. This process is based on a wetting phenomenon, therefore, we discussed the technique based on the reactive wetting. The SiC particles coated by diluted water glass were sintered in a mullite Tammann tube and simultaneously infiltrated with molten Al-Si alloys in air at 1173~1573K. As for the improvement of the wettability between the SiC and the liquid aluminum alloy, Fe3O 4 powder was mixed with the water glass due to the thermit reaction between Fe3O4 and molten aluminum alloy. In some experiments, pure aluminum powder was placed on the sintered SiC to increase the interfacial area and the chemical reaction between the sintered Sic. and the melt. By combining these conditions, we succeeded in the complete infiltration without pressure at 1173K.IntroductionAs is well known, the mechanical properties of metal matrix composites (abbreviated MMCs) are superior than that of ordinary metals. However, their use has not been widely accepted because the production cost is very high due to their poor machinability. Therefore, the production of partially composed, namely discontinuous MMCs, by as the Lanxide process [l,2] has been investigated for many years. The Lanxide process, it takes a long time, sometimes up to 10h, in a nitrogen atmosphere for the infiltration. Therefore, the cost will be higher for common use. On the other hand, a high 'pressure process has been adopted for the production of discontinuous MMCs by the Toyota Motor Corp.[3]."

Jan 1, 2000

By D. W. Collins

Several organic and inorganic substances are widely used to control deposit structure and morphology during the electroprocessing of copper. Methods for monitoring the levels of thiourea, glue and guar gum during electrorefining and electrowinning have been successfully developed under the trade names of Reatrol and CollaMat. Other instrumental methods have been developed for additives and decomposition products associated with the electroplating of copper and other metals. Generally, these methods have been found to be either insufficiently sensitive or lacking in the desired selectivity for some or all of the additives. These procedures have mostly employed DC techniques; i.e., cyclic voltammetry, Tafel analysis, etc. In this work, chronopotentiometry (CP) and AC voltammetry were used to examine the interaction of glue, guar gum, thiourea and chloride during the electroplating of copper onto a platinum electrode. In addition, the interactions between the additives have been explored. It was found that glue in pure electrolyte (H2S04 and CuS04 only) had no effect on the chronopotentiogram. Glue was only active if chloride ions were present. The addition of thiourea resulted in several different chronopotentiograms depending on the presence of either chloride or chloride and glue. Thiourea used in conjunction with glue and chloride showed a significant increase in the polarization during copper deposition when compared to the electrolyte containing only glue and chloride. The use of a modified channel electrode further increased the sensitivity of CP. The use of AC voltammetry was explored as a technique to monitor some of the additives. AC voltammograms have more spectral detail then their DC counterparts and it is possible to monitor some of the additives at very low concentrations with AC techniques.

Jan 1, 1999

By M. Vijayalakshmi, S. Saroja, C. Sudha, T. N. Prasanthi

"Ti-5Ta-2Nb alloy and 304L austenitic stainless steel were joined by explosive cladding process. Investigations on 'as received' explosive clad revealed high hardness very near the interface due to martensitic transformation of 304L steel base plate. To improve ductility, explosive clads were heat treated in the temperature range of 823 to 1073 K for 1 to 20 h. Consequent change in the microstructure and microchemistry of the clad interface was studied. No change in the interface microstructure was observed for heat treatment at 823 K. Increase in temperature lead to the formation of various reaction zones at the interface, their number and width increase with temperature and time of thermal exposure. Growth kinetics of the reaction zones was monitored and activation energy required for formation was calculated. From elemental redistribution profiles, effective inter-diffusivities of alloying elements were calculated as a function of concentration and activation energy required for inter-diffusion was evaluated.IntroductionFor engineering components exposed to highly oxidizing and corrosive environments, a titanium based alloy i.e Ti-5Ta-2Nb (Ti-Ta-Nb) is often chosen as a structural material [1,2]. For economic consideration, vessels and piping exposed to non-oxidizing conditions are fabricated from 304L austenitic stainless steel (304L SS). Hence, dissimilar joint of Ti-5Ta-2Nb alloy and austenitic stainless steel becomes unavoidable. Fusion welding processes are not suitable for joining Ti and Fe based alloys due to the propensity for the formation of intermetallic phases and subsequent reduction in the bond strength [3,4]. Hence, explosive cladding, a solid state welding technique, was used to achieve high integrity, corrosion resistant joints between the two alloys."

Jan 1, 2012

By Nan Zhang, Lei Zhang, Gai-feng Xue, Lina Wang, Pu Liu

"A novel ß-diketone modified silica gel was synthesized by a simple reaction. The prepared material was characterized by diffuse reflectance FTIR spectroscopy and it was used for the adsorption of heave metal ions in the industrial waste water. The main parameters affecting the sorption of heavy metal ions, including pH, water flow rate, and elution, have been investigated in detail. Under the optimized operating conditions, most of the targeted heavy metal ions could be removed. The material could be simply regenerated by hydrochloric acid solution. The method is rapid, selective, economic and applicable to the removal of heavy metal ions from industrial waste water.IntroductionToxic organic pollutants and heavy metals ions mainly from industrial activities such as plating, metallurgy and dyeing industries, are a threat to human health and the surrounding environment, because of their toxicity and persistence after being released into the natural environment [1]. These pollutants must be removed or degraded to an acceptable level, before being discharged to the receiving waters. Therefore, detection and determination of heavy metal ions in industrial waste water is very important.Inductively coupled plasma optical emission spectrometry (ICP-OES) is the most used technique for the determination of heavy metal ions because of its capability for rapid multi-element detection over a wide concentration range and with relatively low detection limits. Compared to other techniques such as neutron activation analysis (NAA), X-ray fluorescence spectrometry (XRF) and inductively coupled plasma mass spectrometry (ICP-MS), ICP-OES has the above advantages. Some constituents in industrial waters, such as organic compounds and inorganic salts, may cause matrix effects. In order to achieve accurate and reliable results, an efficient preconcentration of heavy metal ions and their separation from the matrix are usually required."

Jan 1, 2012