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By Zhihao Yue, Honglie Shen, Yahui Teng, Ye Jiang

"In this paper, manganous nitrate [Mn(NO3)z] was used to assist the etching of silicon wafer in hydrofluoric acid (HF) for the antireflective application, and alumina (Al2O3) layer was deposited on the surface of the etched sample by atomic layer deposition method for further antireflection. The surface morphological and compositional studies of these samples were performed by scanning electron microscopy attached with an energy-dispersive X-ray spectrometer. The surface reflectance measurements were carried out using UV-Vis-NIR spectrophotometer. Binary structures of pyramids and nanopores were obtained by etching the alkaline textured monocrystalline silicon wafer in HF and Mn(NO3)z mixed solution for not more than 15 min. But excessive increase of etching time of up to 30 min resulted in the whole destruction of pyramids. The average reflectances of the 5-min-etched sample before and after being coated with 75-nm-thick Al2O3 layer are 4.62% and 3.47% in the range of 200-1000 nm, respectively.1. IntroductionAs we know, the reflectance of silicon wafer after being sliced is so high that the maximal photoelectric conversion efficiency of silicon based solar cells is limited. Therefore, alkaline texturization process was used for silicon solar cell in industrial production. But the reflectance of this alkaline textured wafer is still greater than 10% and this process can only be used for monocrystalline silicon solar cell."

Jan 1, 2013

By Toshiaki Nakai, Kunihiko Takeda, Kimio Imaizumi, Hiroaki Shirasaka

"The new type of nano-porous silica particle was considered to be constructed by the spinodal decomposition-type process which was found to have narrower pores than those of conventional porous silica prepared from boron silicate or ""Shirasu"" balloon. Nano-porous silica particles were fabricated by the calcination of silica gel mixed with well-dispersed complex salts composed of phosphorous and molybdenum compounds. Both silica and inorganic salts were not perfectly dissolved in the suspension solution. After removing of the water, the silica-inorganic salts complex was volatized and successively calcinated at a temperature ranging from 650 °C to 800 °C. Then, the inorganic salts were removed by dissolving in hot water. Other inorganic salts such as potassium halides were also found to be effective as a pore-size controller.IntroductionControl of structure has an important role in the field of industry as well as in the separation and purification technology for metals and organic syntheses. Many studies on the control of material structures have been reported regarding porous materials with pores ranging from nanometer to micrometer scale. 1 ) One example is zeolite as a naturally yielded porous inorganic material. Various types of synthetic zeolites have been studied as ""molecular sieve"" materials with ordinary pore-size of less than one nanometer. In 1992, crystalline meso-porous material with a large surface area named MCM-41 was synthesized through the use of template synthesis. 2) In direct relation to our study, amorphous borate glass having 4 to 100 nm of fine pores known as Corning glass 3l or SiO2-Al2OrB2O 3-CaO porous glass having large pore dispersity ranging from 4 to 10,000 nm have been reported. 4 ) S) 6 ) Some examples of several reported studies are as follows: phase-separated porous glass consisting of B2OrAl2O3-ZrO2-RO-R2O complex oxide 7 ) glass with finer pore induced from hydrolysis of silane alkoxide, porous material attained by condensation polymerization through the use of sol-gel process 8), alumina meso-porous material 9 ) 10), silica-zirconia material 11), carbon porous material 12), etc.."

Jan 1, 2000

By Xuling Chen, Zhiyun Ji, Min Gan, Wenqi Li, Xiaohui Fan, Zhiyuan Yu

"Specularite and vanadium-titanomagnetite are difficult to granulate, and with the increase of their proportions, the permeability of sintering bed is deteriorated together with the combustion velocity of fuel for the shortage of air through the sintering bed, which can lower sintering speed and specific production capacity significantly. The biomass fuel has a higher combustion velocity than coke breeze, therefore the productivity of specularite and vanadium-titanomagnetite ore can be improved remarkably by replacing coke breeze partly with biomass fuel .The results showed that, when the proportion of biomass fuel replacing coke is 40%,the sintering speed and specific production capacity of 35% specularite were improved from 19.06mm/min, 1.33 t/(m2·h)to 21.45mm/min, 1.47 t/(m2·h),and that of 55% vanadium-titanomagnetite were improved from 17.23mm/min, 1.11 t/(m2·h)to 22.80mm/min, 1.44 t/(m2·h). As a conclusion, biomass fuel is effective to strengthen sintering of refractory iron ore.IntroductionThe iron and steel industry of our country has achieved significant development in the recent years. In 2010, the output of steel has reached to 0.627 billion tons. The increasing scale of iron and steel has led to rigorous domestic iron ore environment, and the reserves of hematite and magnetite that have superior sintering characteristics are on the decline with continually exploiting and utilizing [1]. Therefore, the RIO (refractory iron ores) SP (specularite) and VT (vanadium-titanomagnetite) have to be applied vastly. However, the quality of sinters can be deteriorated when utilizing RIO in high proportion due to their poor granulation and metallogenic performances [2, 3]. Generally, the ratio of SP is 3~5%,which should not exceed 10% in our country currently [4]. Though high rate of VT is adopted in PZH steel for a long time, the productivity is obviously low compared with normal sintering [5]."

Jan 1, 2012

By Daudi R. Waryoba

Keywords: Wire Drawing, OFHC Copper, Recrystallization, Orientation imaging Microscopy (OIM), Texture inhomogeneity Textural inhomogeneities have been investigated in oxygen free high conducting (OFHC) copper wire drawn at room temperature to a true strain of 2.31, and isothermally annealed at 250°C and 750°C for annealing times ranging from 10 s to 1 hr. Local orientations were mapped by means of orientation imaging microscopy (OIM). The microtexture of the drawn wires showed a strong <111> + weak <100> duplex fiber texture at the inner core, whereas the mid and surface regions had a comparatively weak texture. Annealing at 250°C resulted into a recrystallization which originated from the mid section, proceed towards the surface regions and ends in the inner core. Recrystallization resulted into a strong<100>+weak<111> duplex fiber texture. A similar textural inhomogeneity was observed during short annealing at 750°C. However, prolonged annealing gave rise to abnormal grain-growth that proceed from the inner core to the outer surfaces with a dominant <111> fiber component at the inner region and mixed components of <111>, <100>, and <112> at the outer surfaces.

Jan 1, 2005

By Geoffrey A. Brooks, M Akbar Rhamdhani, Md Saiful Islam

A novel electrically-enhanced metal purification using slag has been developed. This was achieved by applying DC potential between liquid metal and slag phases. The concept was demonstrated through small-scale experiments at temperatures of 1500-1600oC for the removal of boron from Si-B melt using CaO-SiO2-16wt%Al2O3. Silicon (containing B) and slag were reacted in an alumina crucible in a resistance tube furnace. A circuit was produced by immersing graphite rods into the silicon bath and the slag layer. Electrical potential differences of up to 3.5 V were applied during the reactions. The reaction rates, the opencircuit voltages and short-circuit currents (in the case when the potential was applied) were then measured and determined for various slag to silicon ratio. It has been shown from this study that both the apparent rate and the boron partition ratio were increased by a factor of approximately 1.6.

Jan 1, 2014

By Thomas Gliick, Jianming Lu, David Dreisinger

"The recovery of manganese from the Boleo project of Baja Mining is via an acid oxidation and acid reduction process in seawater. Manganese as manganese dioxide is leached into solution as manganese sulphate with the addition of sulphur dioxide gas as a reductant and then precipitated as a manganese carbonate. The use of the manganese carbonate intermediate to produce electrolytic manganese metal (EMM) has been extensively studied. The manganese carbonate can be used in place of natural (MnC03) or reduced ores (MnO) of manganese as a feed to the EMM plant. Manganese carbonate can be dissolved in spent electrolyte from manganese plating, followed by purification using ammonium sulphide precipitation of minor elements and then electrowinning in a selenium free process. The results of small cell testing of manganese electrowinning are reported.IntroductionThe Boleo Project of Baja Mining is a greenfields development currently under construction approximately 5 km north of the town of Santa Rosalia, Baja California Sur, Mexico. The Boleo property is held by the Mexican company, Minera y Metalurgica del Boleo S.A. de C. V. (MMB). MMB is owned 70% by Baja Mining Corp. and 30% by a consortium of Korean companies consisting of KORES - Korea Resources Corporation, LS Nikko Copper, Hyundai Hysco, SK Networks and lljin Copper.The Boleo deposit has Measured and Indicated resources of264.7 million tonnes grading 1.50% copper equivalent (CuEq) & Inferred resources of 159.9 million tonnes grading 1.15% CuEq. The calculation of copper equivalent is based on a combination of metal prices and predicted metallurgical recoveries (Table I). The metallurgical recoveries have been confined by extensive bench and pilot plant testing. Proven and probable reserves are available at Boleo to provide for more than a 30 year mine life. Initially, 25 years of mine life and 23 years of process plant operation have been scheduled in the February 2010 Technical Report Update (www.sedar.com)"

Jan 1, 2012

By Chuan-fu Zhang

The fibrous precursor can be obtained by coordination precipitation process, using oxalate, cobalt chloride and ammonia. XRD pattern of precursor precipitated at pH=9.0 is different from that of ß-CoC2O4?2H2O precipitated at pH=1.0 which indicates that the precursor powders are one type of cobalt complex. According to the results of element analysis and IR spectra, it can be inferred that the composition of the precursor is [Co(NH3)x]C2O4?H2O(x=1.2?..6) formed by the coordination reaction at pH=9.00 in the Co(II)-C2O42--NH3-NH4+-H2O system. It?s found that the fibrous cobalt powders greatly inherited the morphologies of the precursors. Many factors could affect the formation of the fibrous cobalt precursor powders, such as the initial Co2+concentration, pH value and so on. The SEM images show how they influence the morphologies of the precursor powders. By adding proper surfactant, the dispersion of the precursor powders would be improved. At last, the final product-fibrous cobalt powders which are about 0.3~0.5min size and 40~60 in aspect ratio were produced by thermal decomposition of fibrous cobalt complex at 400~500°C in the weak reducing atmosphere.

Jan 1, 2006

An EAF dust generated in a Swedish steel mill has been leached in hydrochloric acid at The solution obtained has been subjected to purification by cementation followed by precipitation of zinc with sodium carbonate. The thermal decomposition of the precipitate was studied using thermal analysis and X-ray diffraction. The results show that during the calcination of the precipitate three different reactions occur. The decomposition of the solid phases Zn5(CO3) (OH)6, CaZn(CO3)2 and CaCO3 occur completely at 370°C, 560°C and 940°C respectively, yielding a final product containing 61.9% ZnO and 38.1% CaO. Methods to minimize calcium and manganese in the final product are discussed.

Jan 1, 2003

By Sharif Jahanshahi

Calcium ferrite slags are often associated with Professor Yazawa due to his pioneering work on the thermodynamics of this type of melts. Over the past years CSIRO has invested some effort in studying physico-chemical properties of such melts to fill in some gaps in our knowledge and explore opportunities for application of the understanding developed. These investigations cover thermodynamics, transport properties of calcium ferrite based slags, as well as the kinetics of reactions of such slags with refractories. The present paper provides an overview of some of these studies and highlights some of the interesting behavior of such melts, The oxidation state of copper and arsenic in calcium ferrite based slags are predominantly Cu+ and As3+, respectively, at oxygen potentials below 10-7 atm. The concentration of CU2+ in such slags becomes significant at oxygen potentials of greater than 10-7 atm at 1300 °C. The activities of CuO0.5 and AsO1.5 in calcium ferrite slags show strong deviations from the Raoultian Law, while that of CoO is very close to ideal behaviour with respect to pure solid CoO. Addition of SiO2 to calcium ferrite slags can have significant effects on the activities of FeO and Fe2O3 and hence the stability of magnetite phase. Transfer of oxygen in calcium ferrite slags is fast with diffusivity of 2x 103 cm2/s at 1350 °C and activation energy of 16 kcal/mol. Presence of solid phases, such as magnetite, has pronounced effect on the viscosity of calcium ferrite slags. The observed dependence on solid loading and shear rate indicates deviation from Newtonian behaviour. The interfacial tension between copper mattes and calcium ferrite slags is strongly dependent on the matte grade, with the determined values being much lower than the corresponding ones for interfacial tension between similar mattes and iron silicate slags. MgO, Cr2O3 and MgCr2O4 have low solubility in calcium ferrite slags and their solubility increases with increasing copper oxide content of the slag at 1300°C. The oxidation state of the slag has strong effects on phase transformation, dissolution rate and disintegration of refractories in calcium ferrite slags. Other key factors with major impact on slag-refractory interactions include viscosity and surface tension of slags as well as the contact angle between slag and refractory material,

Jan 1, 2003

By T. Gunawansa, T. L. Alford, Zhao Zhao, A. R. Lanz, N. David Theodore

Many sustainability issues arise during the manufacturing processes that are currently used for solar cells. Solar energy is a renewable energy source that is independent of the earth’s resources, and it is therefore important for the development of more sustainable technologies. Microwave annealing (MW) has been proposed as a technically feasible fabrication scheme for large area silicon solar cells. Apart from that, microwave annealing has been demonstrated to be a promising alternative for repairing damage and electrically activating dopants in ion-implanted semiconductors for integrated circuit manufacturing. A microwave oven is cheaper than conventional furnace systems. In addition, microwave heating is much more efficient than conventional furnace heating, as heating is directly produced inside the material. This minimizes the loss of energy due to heating of the ambient. There is a need for more efficient processing techniques. In this study, microwave annealing is used as an alternative to the current postimplantation processing. Arsenic-doped silicon was microwave annealed (with an aluminacoated silicon carbide susceptor) to activate dopant atoms and to repair damage that was caused by ion implantation. Sheet resistance and Hall effect measurements were used to assess the extent of dopant activation. Rutherford backscattering spectrometry (RBS) with ion channeling was conducted to determine the extent of recrystallization. The dopant activation and recrystallization resulting from microwave annealing is compared with that resulting from conventional rapid thermal annealing (RTA) with the same heating profile. The results show that when compared to RTA, susceptor-assisted microwave annealing results in better dopant activation for shorter anneal times under the same heating conditions.

Jan 1, 2015

By Wei Han, Zhenwei Liu, Jianhong Yang, Qingwei Qin, Tiejun Chen, Zili Huang

The preparation of industrial ammonium molybdate from molybdenum concentrate was conducted according to the process of roasting—leaching—purification—precipitation—crystallization. The optimum technological conditions were determined: the roasting temperature was 680 degrees C, the roasting time was 2.5 h; in the leaching process the alkali excess coefficient was 1.2, the reaction temperature was 80 degrees C, the liquid-solid ratio was 3:1, the leaching time was 3 h; the amount of (NH4)2S added into the solution was 1.1 times of the theoretical amount, the temperature was 80-85 degrees C, and the terminal pH was 8.5-9 in the purification process; the density of the solution was 1.4-1.6 g/mL, the pH was 1.5-2 in the precipitation process; temperature of dissolution was controlled at 80-90 degrees C. The recovery of the preparation of ammonium molybdate can reach 85.18%.

Mar 1, 2017

By Jing-she Li, Hai-yan Tang, Cheng-song Liu, Wei Liu

"In order to effectively utilize cheap and low quality iron ores, a hematite ore in a certain steel plant in Xinjiang was researched on to obtain ""iron increase and silicon reduction"" by ore dressing operation experiment and the performance indexes of the hematite ore were optimized. Based on the fundamental characteristics and high-temperature properties of the concentrate after ore dressing and other five kinds of iron ores which were co=only used in this steel plant, ore matching principles were proposed and a sintering ore blending optimization model was established. Finally, sinter pot test was carried out to verify the validity and practicability of the sintering ore blending optimization model which was aimed at giving consideration to the sintering indexes and the cost.IntroductionIn recent years, the price of imported iron ore with high quality is always at a high level, while iron ore self-sufficient rate in China is less than 50%. Enormous market demand and high dependence of domestic enterprises on imported iron ore makes the price of it hardly return to rational. In order to get rid of the situation of long-term meager profit and even deficit, more and more iron and steel enterprises in China transit their focus of reducing production cost to the utilization and development of relatively cheap but low-grade iron ore resources at home[l-4l_ However, besides the disadvantages of low iron grade, high content of impurities and complex embedded properties, the high-temperature properties of iron ore often go beyond the suitable ranges for producing sinter with high quality. Thus directly utilization of this kind of iron ore without ore dressing process would probably affect the metallurgical performance and indexes of sinter ore.Previous research and production practice have shown that traditional iron ore matching in sintering mainly focus on the reasonable collocation of properties of iron ores with low quality and high quality, but pay less attention to ore dressing process of low quality iron ores and matching them with high quality iron ores. Actually, compare with directly utilization, iron ores with low quality after ore dressing have higher suitability for matching with high quality ones which is beneficial to reduce the consumption of iron ores with high quality and control the production cost of sintering [5-s1."

Jan 1, 2014

By Sergio N. Monteiro

Wastes generated by our society and the question on how to dispose them is, nowadays, a relevant matter of concern. The objective of the present work was to characterize the technical properties of composites made of discarded jute sackcloth with its coarse wove fabric, serving as reinforcement phase, and polyethylene wastes collected from city dumps, as continuous matrix. Different amounts, up to 30 wt.% of jute plain weave, fabric were press molded at 160°Ctogether with sieved polyethylene particles. The resulting composites displayed mechanical properties that could compete with those of low-density wooden board. Both by presenting a solution to, otherwise, disposed wastes and by helping to prevent deforestation, the investigated composite may be regarded as an environmentally correct material.

Jan 1, 2006

By Zhang Chuanfu

Keywords: solid solution, Ni-Co alloy powders, thermal decomposition, fibres. Synthesis of fibrous Ni-Co alloy powders was achieved by thermal decomposition of precursor of complex Ni-Co oxalates solid solutions obtained via modified coprecipitation method among intimate mixing solution of NiCl2?6H2O , CoCl2?6H2O and H2C2O4?2H2O in the presence of surfactant polyvinylpyrrolidone (PVP) and organic solvent ethanol. Scan electron microscopy (SEM), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), disperse energy X-ray analyses (EDX) were used to characterize the structure features and chemical compositions of the as-prepared fibres. The influences of decomposition conditions, including temperature, time, the flow rate of N2+H2, and the heating rate, on the morphology, average size and specific surface area of the Ni-Co alloy powders were investigated. It is found that a trend of the mutual alloying of nickel and cobalt: the formation of perfect solid solution for any compositions NixCo100-x was indicated and corresponding NixCo100-x alloys with fcc phase can be obtained under the optimal conditions.

Jan 1, 2005

By María Eugenia Castro, Silvia Galasso, Jorge Duca, Claudia Osuna, Ernesto Esparza

"We present a procedure for treatment of non-active solutions equivalent to the solutions obtained from dissolution of ionic exchange resins used in purification of a nuclear reactor primary cooling system containing Co, Ni, Cs and its isotropic varieties as main radioactivity source. Finally it is immobilized into a ferritic matrix by calcination which avoids its future leaching into environment.In order to achieve the objective of this treatment, a bivalent and a trivalent iron salt is added to the solution. Then, either a base or an acid is added, depending on the initial pH of the treated solution, with a Cs precipitating additive in order to reduce Co and Cs by precipitation, flocculation and adsorption. Controlling the amount of precipitating reactives it is possible to modify the activity/volume rate becoming a medium into a low radioactivity waste.The leaching test result applied over the ferritic sample is lower than the minimum limit established by law. Therefore, it can be kept safely in a interim storage."

Jan 1, 2008

By J. R. Kiji

The Cerro Matoso S.A. mine and smelter, in the Cordoba lowlands of northwestern Colombia, consist of a dedicated laterite nickel mine, ore blending, drying and an RKEF process to produce high-quality ferronickel. At a project investment of $400M, first production of ferronickel was in September 1982, and in its inaugural year CMSA produced 6,150 tons of contained Ni from a mined ore grade of 3.2% Ni. Initial operational difficulties resulted in a number of furnace run-outs, which impacted ramp up to design ore throughput of 128 dry t/h Since then CMSA has steadily incorporated process improvements and initiatives to take the single line operation to an ore throughput of 175 dry t/h. A second 175 dry t/h line was added in 2001 (investment of US$ 300M) to consolidate CMSA as one of the world&apos;s lowest cost Ni producers with an installed annual production capacity of 50-55,000 tons Ni. The most recent addition is commissioning of Phase I of an ore-upgrading project to counteract the effect of declining ore grades. Keywords: Laterite, ferronickel, pyrometallurgy, smelter.

Jan 1, 2004

By M. Hochenhofer

Due to economic aspects and environmental regulations recycling of slag and waste from ferroalloy production became a very important issue for the companies during the last years. The treatment of slag depends prior on the composition, especially on their content of valuable metals and impurities. The final aim should be a total re-use of these materials in the industry e.g. cement industry, pig-iron production etc.. Therefore, to reach the required physical and chemical properties for a further use, possibilities of a metallurgical treatment have been investigated. The conditioning of slag with a high V-, Mo- and P-content via reducing metal bath showed to be one alternative. To determine the optimal process parameters, practical investigations with different slag compositions and thermodynamic calculations were carried out.

Jan 1, 2006

By Haldun Kurama, Cenk Karakurt, Ilker Bekir Topçu

"The usage of binders or pozzolanic materials in the production of concrete is not new. However, in recent years, the use of the pozzolanic siliceous material such as natural zeolite and coal combustion ash (CBA) has received re-attention due to the generated considerable interest in the economical use of both naturally occurring raw materials, recycling of the waste material and saved energy. In this study, the potential and utilization opportunities of natural zeolites and bottom ash (BA) in concrete applications were reviewed. Case studies, conducted to determine the possible usage of the natural zeolite and BA in concrete production, i.e. light weight concrete (LWC) were also presented. The physical and mechanical properties of cured concretes were examined to find out the competitive material usage on the final product properties. Autoclaved aerated concrete (AAC) with 1.1 nm tobermorite (5CaO 6SiO2 5H2O) as binder is a lightweight construction material that mainly uses in place of concrete to manufacture various building materials, including blocks, panels, slabs and the like. The material is a mixture of sand, lime, cement, gypsum, water and an expanding agent, which causes the raw material to rise like bread dough, with countless small air pores. AAC can be molded and cut into precisely dimensioned units and cured in an autoclave, which steam cures the concrete under pressure. During this process, the ingredients combine to form the calcium silicate hydrate gels that establish the special properties of the finished product. The process produces a material that is only one-fourth to one-third the weight of a conventional concrete block (bulk density of 400-800 kg /m3) of the same size. Regular AAC offers considerable advantages over other construction materials such as high thermal and sound insulation, excellent fire resistance, high resource and energy efficiency, low environmental impact, and finally outstanding structural performance (especially for earthquake zones) [1]. Its lightweight also makes it easy to use during construction, and its aerated structure gives it better thermal insulation and sound absorption properties than conventional concrete."

Jan 1, 2008

By Elli Nurminen

Keywords: Thermal conductivity of sulphates, flash smelting, heat recovery boiler, flue dust Accretions and build-ups in metallurgical heat recovery boilers decrease the efficiency of the heat transfer and may cause process shut downs. Transient plane source method (Hot Disk) has been applied to measure the thermal conductivities of the Copper Flash Smelting flue dusts. Thermal conductivities of copper, iron and zinc sulphates, and process flue dusts were measured. The results indicate that all the components are effective thermal insulators, having a thermal conductivity of less than 1 W/mK. Decreasing dust layer porosity has an increasing effect on thermal conductivity. Insulating layers on the boiler walls decrease greatly the heat transfer efficiency of the boiler. The gathered information will be used in CFD-modelling of the process, and in the process control.

Jan 1, 2005

By D. Gu, R. G. Anthony, C. V. Philip, M. E. Huckman

"In this paper, we review the equations needed to construct an ion exchange column model. These models contain three major components: 1) a differential material balance around the column, 2) a differential material balance around an ion exchange particle, and 3) a constitutive equation for diffusive flux. We then examine the ability of a fairly simple mathematical model to predict ion exchange column experimental data. This model contains the traditional absorption theory equations and is used to predict the behavior of a column filled with a hydrous crystalline silico-titanate and which is removing trace amounts of Cs+ from a high pH, complex electrolyte solution. Finally, we propose replacing Fick's law with the Nemst-Planck equation as the constitutive equation for diffusive flux. We use a NemstPlanck type model to predict batch experimental data, then evaluate it by comparing it's ability to predict experimental data to that of a more traditional Fick's law type model. The data from this comparison suggests that the Nemst-Planck type model yields better results.IntroductionMillions of gallons of strongly basic, radioactive waste are currently stored in underground storage tanks at Hanford and Savannah River and several locations within the United States. Due to the limited life expectancy of the tanks, there is a pressing need to remediate these wastes. This need has prompted the recent development of new ion-exchange materials for removing radioactive elements from aqueous solutions. A novel material called TAM-5 has been developed jointly by Texas A&M University and Sandia National Laboratories. TAM- 5, a crystalline silico-titanate, is highly selective for Cs + in the complex electrolytic solutions typical of these wastes. It is stable in very basic solutions and in radioactive environments [1, 2 ,3]. In laboratory testing to determine the selectivity of various materials, TAM-5 was superior to other candidate ion exchangers [4, 5]. The selectivities were determined by measuring a distribution coefficient, Kd, which is defined as the concentration, gig or mmols/g of Cs in the solid phase divided by the concentration, mg/L or mmols/mL, of Cs in the liquid phase. The units of Kd are ml/g or L/kg. Table 1 shows Kd values for TAM-5 compared to 9 other candidate materials in a typical waste solution [6]."

Jan 1, 1996