Search Documents

By Alysson Tadeu Pereira Almeida

Steels with low concentrations of nitrogen, hydrogen and carbon have been in large demand lately. The RH process is a secondary refining process that can simultaneously attain significant levels of removal of these interstitial elements from liquid steel. In the RH process, the melt circulation rate plays a very important role in determining the productivity of the equipment, since it affects the decarburization rate. In the present work, a physical model of a RH degasser in a 1:5 scale of an industrial reactor has been built and used in the study of the circulation rate and of the kinetics of decarburization. The effects of the gas flow rate and of the configurations of the nozzles used in the injection of the gas have been analyzed. The decarburization reaction of liquid steel was simulated using a reaction involving CO2 and caustic solutions. The concentration of CO2 in the solution was evaluated using pH measurements. The experimental results indicated that the kinetics of decarburization can be described by a first order equation. Based on the results, it was possible to determine the contributions of the decarburization in the upleg snorkel and in the vacuum vessel.

Jan 1, 2006

By Masayuki Kudoh, Tohru Maruyama, Yohichi. Ito

When hypo-peritectic carbon steel is quenched during unidirectional solidification, the region of fine columnar grain is observed. It is classified into two coexisting phases. One is coexisting phases of liquid, delta and gamma in the upper part of the region, and the other is coexisting phases of delta and gamma in the lower part of the region. To form the coexisting part of the three phases means that solidification in this experiment proceeds in non-equilibrium state. The size of the narrow side of one fine columnar grain coincides with the arm spacing of a primary dendrite and this result is the same as the hyper-peritectic carbon steel. However, the boundary of the fine grain in the hypo-peritectic carbon steel is formed in different location from that of the hyper-peritectic carbon steel. The former is formed in the skeleton of the dendrite, while the latter is formed in the interspacing of the dendrite. The region of the fine grain changes suddenly to that of the coarse grain when the delta phase in the coexisting part of two phases disappears completely. Therefore, the delta phase in the hypo-peritectic carbon steel might prevent the growth of gamma grain. In order to recognize it, ferrite formers such as Mo, V and Ni are added in the sample. Then, the longitudinal length of the fine columnar grain extends in the sequence of the no addition, Mo, V and Nb.

Jan 1, 2000

By A. E. Isaacson

Bureau of Mines researchers developed and tested equipment to measure corrosion rates on a commercial-scale mill as an aid in predicting the effect of corrosion on minerals and how this effect relates to downstream processing. Bench-scale experiments were designed for duplicating ore grinding conditions closely enough that realistic rate determinations can be made in laboratory tests. Rates measured in a laboratory system compared favorably with those measured in the field. Cast steel was found to have corrosion rates in a copper mill and laboratory test cell of 22 and 21 mpy, respectively. Corrosion was found to account for less than 5% of the total grinding media wear in the operations studied.

Jan 1, 1987

By Gary R. Adams

Coating thickness control is typically difficult with touch-up solders for galvanized steel, and corrosion properties and abrasion resistance are sometimes poor. This paper reports on progress in ILZRO-sponsored research to develop an improved touch-up solder. Encouraging results were achieved in torch soldering trials with zinc-tin based alloys. Mouldability and coating thickness control were achieved over a practical working temperature range in which the solders consisted of a viscous mixture of solid primary zinc phase particles in a liquid zinc-tin eutectic matrix The mouldability was dependent on the microstructure of the starting material, and optimum structures could be obtained through control of casting solidification rates and/or by the addition of small amounts of copper. Hardness and preliminary corrosion test results showed potentially good mechanical and corrosion behaviour. The absence of toxic materials ensures environmental friendliness. Comprehensive performance testing is continuing on selected experimental zinc-tin-copper touch-up solders.

Jan 1, 1992

By Takao Yasugi

The majority of copper in the raw material migrates to the de-copperized dross that forms when the crude lead produced in the blast furnace is treated in the de-copperizing process. The de-copperized dross is treated in the electric furnace producing matte, speiss, and crude lead. The de-copperized dross also contains the silver. Therefore, it is important to improve the rate of silver migration to the crude lead. For this reason, the behavior of silver between the matte, speiss and crude lead phases was examined. At the same time, several tests to improve the percentage of silver migrating to crude lead were conducted.

Jan 1, 2003

By Mahesh C. Meyer Jha

AMAX has developed a chloride refining process to produce pure nickel and cobalt metals from mixed sulfide .precipitates, Metal chloride solutions, generated in a hydrochloric acid leaching step and purified in a solvent extraction circuit, are converted to metal oxides .and HCI gas by pyrohydrolysis. A pilot plant consisting of a 30-inch diameter fluidized bed reactor and other ancillary units was designed, constructed, and operated for over one year. Process design was aimed at minimizing energy consumption, maximizing conversion efficiency, and achieving simplicity of operation and control. The operation provided valuable information on process scale up parameters, process control strategies, and materials of construction., Several process variables such as bed temperature, solution composition, solution feeding system, bed particle size distribution, and fines recycle system were investigated to determine their effects on process efficiency and the physical and chemical characteristics of the product.

Jan 1, 1985

By Ko-ichiro Ohno

It is recently recognized that the iron reduction and melting as well as the slag separation of a composite of granular iron ore and coal are completed in a very short period of about IO minutes when the composite is rapidly heated up to approximately 1673K. These phenomena are expected to be applied to a new iron-making process. The mechanism of iron ore reduction and iron-slag separation during rapid heating has not yet been revealed and the fundamental research has just started. Carburization of the reduced iron is regarded as one of the most important steps in this process. In the present work, the composite was prepared from four kinds of coal or graphite as a carbon source and electrolytic iron powder as a completely reduced iron ore. The temperature at which the liquid formation and iron carburization occurred was monitored. Direct observation of smelting reduction behavior was made by a confocal laser-scanning microscope combined with the infrared image-heating furnace to clarify the effect of molten ash on iron carburization. It was found that the meltdown temperature of composite became lower as the melting temperature of coal ash decreased. From the observed result, it was presumed that the liquid slag would act as an important media for the carbon transfer from coal to iron. The carburization mechanism during the smelting reduction was estimated as follows. When slag containing iron oxide melted down and contacted carbon, iron oxide in the slag was reduced and the formation of the metallic iron particle as well as the its carburization occurred simultaneously at the slag-carbon interface. Carburized iron particle was carried from slag- carbon to slag-iron interfaces due to the slag convection flow caused by the difference of the interfacial tension between the carbon-slag and iron-slag interfaces. Carburization of reduced iron could proceed with a repeat of the above-mentioned process.

Jan 1, 2003

By N. Ono, H. Fujiwara, S. Otsuka-Yao-Matsuo, T. Omata

"The electrical conductivity and the oxygen release and uptake of sintered indium tin oxide (ITO) upon heating and cooling under the condition that P(O2)/P*=4.9X10-4 (P* = atmospheric pressure), :when P(O2) was approximately 50Pa, were simultaneously measured by using a closed-system oxygen-gas analyzer. A large increasing in -the electrical conductivity - upon the· oxygen release detected in 1130<T<1273K was observed. Quantitative relationship between the number of oxygen atom released from ITO and the conduction electron density in ITO was studied. The release of one oxygen atom agreed with the generation of two conduction electrons, i.e., the efficiency-carrier-generation for the oxygen release from the ITO was almost one. The oxygen atom released must be originally at the quasi-anion site in the C-type rare-earth lattice, i.e., the 16c site in the space group of Ia3, as an interstitial excess oxygen, Oi"". It was concluded that the mechanism of conduction carrier generation and compensation upon SnO2 doping into In2O3 can be expressed by the defect equation, 2SnO2-2Sn1n +2(1-z)e'+zOi""+3O0 x+(l-z)/2O2, and that the oxygen release bringing the increase in the electrical · conductivity can be expressed by the equation, Oi""-1/2O2+2e'.IntroductionThin films of SnO2-doped In2O 3 (generally designated as ITO, for indium tin oxide), which have high optical transparency for visible light and high electrical conductivity, have been used as transparent electrodes for liquid crystal and electrochromic displays. It is well known that the electrical conductivity of ITO depends on the content of SnOi-dopant and oxygen. However, a reliable relationship between electrical conductivity and the absolute oxygen content in ITO has yet to be reported. The elucidation of such a relationship is one of the important clues for realizing extremely highly conductive ITO electrodes."

Jan 1, 2000

By Takamasa Ishigaki, Gervais Soucy, Mohamed Rahmane

"The induction plasma jets employed for the in-flight nitridation of molybdenum disilicide (MoSi2) powders were investigated in terms of their flow characteristics. The present study shows the effect of the operating parameters of the plasma torch, as used for this process, on the plasma jet properties. The enthalpy probe techniques, along with mass spectrometry, were employed for the measurement of the jet temperature, velocity and concentration fields. The measured values were compared to the results of a numerical simulation performed on the plasma flowing inside the torch-reactor system. The process operating conditions studied were the plasma plate power, chamber pressure and sheath gas composition. The optimal conditions for effecting the nitridation process using thermal plasma are obtained at moderate plasma plate power, at around atmospheric pressure and by using a mixture of argon and nitrogen as the plasma torch sheath gas.IntroductionMolybdenum disilicide (MoSi2) based composites are considered to be one of the most promising candidates for high temperature structural material applications [!], especially because of their high melting points, good oxidation resistance and relatively low cost. However, the wide application of these composite materials is still limited by some factors such as their brittleness at room temperature and lower strength at high temperature (> 1500 K). To overcome such limitations, a number of researchers [2-4] have earlier studied various kinds of reinforcements for MoSi2, e.g. oxides, silicides and nitrides. More recently, Fan and coworkers [5-9] have demonstrated the possibility of in-flight nitridation and carburization of MoSi2, using a thermal plasma process. This work has confirmed the plasma synthesis route as one of the most promising methods for creating an in-situ second phase structure. Properties of the plasma flow, such as its temperature, flow velocity and composition, are of crucial importance for the nitridation of MoSi2 powders during their flight in the plasma. Therefore, the optimization of such a process involving plasma· generated reactive species necessitates a thorough understanding of the plasma flow characteristics."

Jan 1, 2000

By Christian Trassy, Pierre Proulx

"Inductive plasmas are now commonly used in material processing: spraying, powder synthesis, densification or spheroidization. An inductive discharge presents, in the coil region, recirculation eddies due to the Lorentz forces, resulting in an axial backflow. If the central jet is strong enough to ""pierce"" the recirculation this axial backflow disappears on the centerline, but the external layer of the injection flow is skimmed by the remaining eddy, and particulates are rejected to the discharge periphery. To avoid this disadvantage, it is common to introduce the injection pipe inside the discharge, so that its outlet is positioned after the recirculation eddy. The powders remain confined in the axial zone, to the expense of shortened residence time.In order to increase the efficiency of the particle trajectories, a double flow injector has been designed. It enables the particles to travel closer to the axis, while the outer schrouding gas is skimmed and passes through the electromagnetic eddies. This injector is made up of two concentric tubes. The powders are injected with the carrier gas in the inner tube. A schrouding gas is injected in the annular space between the inner and the outer tubes. The powder is confined to the vicinity of the axis, resulting in a more homogeneous thermal treatment.Tungsten powders have been spheroidized with and without this device. Using the double flow injection, the spheroidization yield has been increased from 70 % up to 95 %.The design of such an injection device has. been studied and improved using numerical modelling. Another useful tool, a visualisation technique described elsewhere, has been used for the experimental study, that drastically simplifies the comparison between experimental and theoretical results: injecting yttrium oxide into the discharge results in a colorful display of the 4000 K isothenn: the ""cold"" zone, below 4000, appearing as red, and the ""hot"" zone as blue. Furthermore, it is of great industrial interest since it is a very cheap and efficient way to obtain a picture of an important isotherm."

Jan 1, 1999

By Tabbetha A. Dobbins

We report studies concerning the time frame for catalytic reactions between NaAlH4 (sodium alanate) and TiCl3 during high energy milling. Spectral features in x-ray absorption spectra were analyzed for samples milled for various times (0 minutes, 1 minute, 5 minutes, 25 minutes, and 125 minutes). A structural transition from Ti3+ to Ti0 is observed within the first 5 minutes of milling. The Ti0 structure persists for samples milled for times longer than 5 minutes?even after those samples underwent a subsequent single hydrogen desorption/absorption cycle. Samples milled for less than 5 minutes retain Ti3+. For samples milled for 1 minute, the Ti-K edge position shifts from Ti3+ to Ti0 after a single desorption/absorption cycle. However, the first coordination sphere around the Ti0 absorber occurs at longer distances for 1 minute milled sample. These results hint at the formation of Ti0 pure metallic clusters upon desorption/adsorption cycling of 1 minute milled sample. Previously reported x-ray absorption spectroscopy studies have demonstrated the structural transition from Ti3+ (in TiCl3) to Ti0(determined to be TiAl3 found at the surface of the alanate powder). Aluminum deficiency on the NaAlH4 lattice is responsible for controlling hydrogen absorption capacity. These time-resolved spectroscopy studies suggest the possibility for controlling aluminum deficiency, while still maintaining titanium activation of the alanate powder, by manipulating the coordination environment of the titanium dopant during the first five minutes of high energy milling. Specifically, a possible approach to mitigating aluminum deficiency during doping would be to introduce an alternative species to which the to Ti3+ catalyst would form a metallic bond after the TiCl3 has attached at the surface of the sodium alanate powder and before the Ti3+ forms the TiAl3 intermetallic species.

Jan 1, 2006

By Viktor Ashikhin, Pavel Arkhipov, Yurii Zaikov

"Lead alloys electro-winning from chloride melts was under investigation. Impurities concentration in cathode lead is strongly depended on temperature, electrolyte composition, anode current density. The equilibrium electrode potentials of lead-antimony alloys with the various content of electropositive metal in the alloy were investigated in the wide temperature interval. Thermodynamic properties of Pb-Sb alloys containing 20-95 mol% of Pb were studied by EMF method in temperature interval 723-873K in molten mixture of potassium and lead chlorides. Partial and integral thermodynamic characteristics were calculated. Small negative deviations from Raul’s law were found. Anode processes were investigated. The lead dissolution was found to be the only process in certain interval of current densities and electropositive metal content in alloy.IntroductionAt present human race is facing the problem of pollution by lead and its compounds and also the pollution influence on population health all over the world. One of the solution ways is the recycling lead containing technical wastes by ecologically clean technologies.World scientific community pays much attention to the electrolysis of molten salts. The usage of salt mixtures, as electrolytes, discovers new possibilities in the production of metals, metal compounds and alloys. ?????????? of the electrolysis at the temperature 50 - 200 °? above the melting temperature of chosen salt mixture allow to unbreaks processes, that undergo in the pre-electrode layer. The rate of the electrodepositing of elements are much higher than in the water electrolytes. At present there are technologies developed for production of metals (Ta, Nb, Ti, Zr, Hf, Ca, Al, Mg, Be, Li and others) by the electrolysis of the melts. Electrolysis of melts might be used in order to convert different technological formations containing lead and other nonferrous metals, that produced by different enterprises. According to the level of the influence on the living organisms lead is in the group of highly dangerous substances alongside with arsenic, cadmium, mercury, selenium, zinc, etc. Toxity and ability to accumulate in the human organism are two main sources of danger for the human being."

Jan 1, 2008

By Lanre M. Oshinowo, André Bakker

"An understanding of the parameters that govern the just-suspended impeller speed, Njs, and the distribution of solids, is critical to the efficient operation of hydrometallurgical and other processes involving solid-liquid suspensions. In this paper, the distribution of solids in stirred tanks under a range of solids loadings (0.5 to 50 vol%) was predicted using CFD and validated against experimental data obtained from the literature. The multiphase flow is modeled using the Eulerian Granular Multiphase model. This paper will also review the established design parameter Njs in the context of scale-up and compare it to the quality of solids dispersion as a means of assessing correct scale-up in suspension tank design. The results of this study will describe a straightforward procedure to obtaining comprehensive information about reactor behavior with complex CFD models.The performance of hydrofoil impellers and a 45° pitched-blade turbine at suspending solids under different agitation speeds was studied. Both single and dual impeller operation have been evaluated. The settled solids fraction for speeds below N js, and the cloud height for impeller speeds above Njs were predicted. The CFD predictions are in good agreement with experimental literature data on velocity distribution and cloud height."

Jan 1, 2001

By Howard K. Worner

"In a rewarding career spanning nearly two thirds of a century, the author has worked at the frontier of such diverse fields as the creep of metals, structure properties and production of novel dental and surgical materials, molten salt electrolysis for titanium production, greatly improving the productivity of large iron blast furnaces and of oxygen steelmaking. While each of these has given great satisfaction, special thrills have derived from the development of new methods for the continuous production or refining of both ferrous and non ferrous metals. A rewarding segment was the evolution of various aspects of WORCRA technology. Unfortunately, several of these inventions have been ""ahead of their time"". Introduction""I am greatly honoured by the convening of this meeting to recognise my contributions to pyrometallurgy. My appreciation is the greater because this is the third Howard Worner Symposium; the first took place in the University of Newcastle in 1988, close to my 75th birthday. It was arranged by the local branch of The Australasian Institute of Mining and Metallurgy with the theme, ""Frontiers in Pyrometallurgy"". The second was organised by the University of Wollongong in conjunction with the Australian Academy of Science and the Australian Academy of Technological Sciences and Engineering; it celebrated my 80th birthday and, at my request, covered a broad range of topics under the heading of ""Recent Advances in Science and Technology"". Now, this very international meeting on ""Injection in Pyrometallurgy"" has been convened by the G K Williams Co-operative Research Centre for Extractive Metallurgy in my alma mater. I am both delighted and honoured that the cosponsors are the TMS (USA) and ISIJ (Japan).Dr Madhu Nilmani consulted me about the field to be covered and I readily concurred because ""injection"" has been of keen interest to me since the beginning of the 1960s when I began my pioneering work on sequential oxygen (or air) injection into flowing streams for both refining of blast furnace hot metal to steel and for the continuous smelting-converting of copper and nickel."

Jan 1, 1996

By Na Wang, Chao Du, Hongmin Zhu, Kai Huang, Shuqiang Jiao

"Niobium aluminides were directly synthesized by a sodiothermic reduction process of NbC15 - AlCb which was dispersed into LiCl - KCl - NaCl - CaCb melts. The melt supplied a homogenous reaction medium which was substantially beneficial to the co-reduction of Nb and Al to form niobium aluminides in situ. The reduction was performed at 500°C for 4 hours. The products were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The corresponding results indicated that niobium aluminides powders were successfully synthesized.1. IntroductionNiobium aluminides have received considerable attention as high-temperature structural materials, due to their high melting points, relatively low density, high strength, excellent oxidation and creep resistance [1-4]. Figure 1 shows that there are three intermetallic compounds in the Nb - Al binary [5], which includes Nb3Al (A15 structure, Cr3Si type), Nb2Al (D8b structure, cr-CrFe type) and NbAb (D022 structure, TiAb type). These niobium aluminides have been used in turbine blades or in stationary gas turbines [6-8]. However, despite their attractive features, the ir applications are still limited by the long and costly fabrication process [9, 10].Niobium aluminides were industrially fabricated by the mechanically alloyed process [11-13]. Traditionally, niobium is extracted from Nb2O 5 or K2NbF7 by a metallothermic reduction process while aluminum is produced by the Hall-Heroult process of Ah03 electrolysis. Based on the extraction of Nb and Al, respectively, niobium aluminides is synthesized by a mechanical powder alloying process. The present process for making niobium aluminides requires a set of complicated equipment, has high production cost and time consuming [14, 15].The purpose of this work is to present the simple, economic and direct synthesis of niobium aluminides powders utilizing a sodiothermic reduction from NbC15 - Al Cb dispersed into molten salts."

Jan 1, 2011

By Jay R. Hitchings

A technique that enables excellent color photograph production from black and white negatives of electron microprobe x-ray images is described in this paper. The photographs are made by superimposing one, two or three negatives of black and white x-ray images individually through assigned primary color filters directly onto color print paper. When used to examine metallurgical or geological microstructures, the resulting color photograph provides detailed, qualitative information about spatial arrangements, elemental associations and relative concentrations of at least three elements. The technique is simple and straightforward, requiring only standard darkroom equipment. The use of color to display or present complicated microprobe data also allows a non-technical reader or audience to better understand the data.

Jan 1, 1981

By Wilky Desrosin, Alicia E. Ares, Carlos E. Schvezov

"In the present research the horizontal directional solidification Zn-Sn alloys (Zn-4wt. %Sn, Zn- 6wt. %Sn, Zn-10wt.%Sn and Zn-30wt.%Sn) was carried out by extracting heat in two opposite directions. For this purpose, ceramic molds, a muffie, a horizontal furnace with two heat extraction systems at the ends, a measurement, acquisition and recording temperature system, eight K-type thermocouples and an electronic recorder were used. The main parameters involved in the columnar-to-equiaxed transition, CET, were: the moment of start and end of solidification at each position under consideration, cooling rates, the average temperature gradients and critical temperature gradients at the CET, the average speed of liquid and solid interphases left and right, advancing in opposite directions. Also, solidification kinetics was found to be different between horizontal solidification two-way heat extractions, with preliminary results of the vertical unidirectional solidification. In the solidification experiments, the velocity and accelerations of the liquidus and solidus interphases usually occurs at the end solidification zone of the samples.IntroductionSolidification of metal alloys, which starts in the external equiaxed region (chill), results in two basic types of structures in a single solidified alloy sample: columnar and equiaxed. The presence of both structures indicates the occurrence of the colunmar-to-equiaxed transition phenomenon[!].Studying the colunmar-to-equiaxed transition, CET, is of great technological interest for the evaluation and design of the mechanical properties of the solidification products. To this end it is necessary to understand the mechanisms by which it occurs. As found in previous studies [2-5], the CET occurs by competition between columnar and equiaxed growth. Mainly is controlled by the parameters of casting, such as the alloy composition, the density of the present nuclei in the liquid, the cooling capacity of the metal I mold, and the degree of convection in the liquid [7-10]."

Jan 1, 2014

By Melvin H. Miles

"Considerable research has been conducted on the anodic oxidation of methanol in fuel cells. The electrochemical reduction of carbon dioxide in aqueous solutions to form methanol is the same reaction in reverse, i.e. CO2 + 6 H+ + 6 e- ? CH3OH + H2O. The same catalysts and conditions may operate for both reaction directions. This carbon dioxide reduction reaction, however, must be able to compete with the electrochemical reduction of water to form hydrogen gas. Thermodynamically, the reduction of CO2 to form CH3OH is slightly more favorable than the reduction of water. The use of nearly neutral electrolytes rather than acidic electrolytes makes the reduction of CO2 kinetically more favorable. The thermodynamics of various reaction steps are presented. Similarities exist with the electrochemical reduction of CO2 and the green-plant photosynthesis process that converts CO2 to carbohydrates.IntroductionVirtually all of the oxygen in the earth’s atmosphere is of biological origin having been generated by green-plant photosynthesis from water and carbon dioxide [1]. The net reaction can be represented byCO2 + H2O ? O2 + [CH2O] (carbohydrates, etc.) (1)Chlorophyll and enzymes promote this reaction, and the energy required comes from sunlight. The actual photosynthesis process is a complex multistage reaction and requires 469 kJ mol-1 of energy supplied by the sun. Isotope tracer experiments using 18O have shown that both the oxygen atoms in the O2 molecule originate from H2O, whereas oxygen atoms in the carbohydrates come from CO2 [1]. The total amount of water on the earth is split by photosynthesis and reconstituted by respiration and combustion once every 2 million years or so. The photosynthetically generated oxygen gas temporarily enters the atmosphere and is recycled about once every 2000 years [1]. The carbon dioxide is partly recycled in the atmosphere and oceans after an average residence time of 300 years and is partly fixed by precipitation of CaCO3 and other carbonate minerals [1]."

Jan 1, 2008

By Eric J. Grimsey

Nickel smelting and converting can be viewed as processes in which iron is either partitioned or transported between matte and slag. Metal recovery depends on the mass of iron transported to slag, the thermodynamic environment in which the transport is made, and the extent to which the slag, once formed, is left in contact with the matte. The importance of these effects is discussed with reference to a new equation which describes metal recovery in terms of a mass balance and a thermodynamically related parameter which is easily measured in practice.

Jan 1, 1993

By Mala Nath, Atjit Mallick, Asheesh Kumar

"The present research work is aimed to focus on the development of chemically stable light weight microporous carbonaceous material, such as activated charcoal incorporated either with titanium n-butoxide, titanium diisopropoxide bis(2,4-pentanedionate), vanadium 2,4-pentane-dionate or zinc 2,4-pentanedionate having varying wt% of the metal (2-8%) using ethanol as solvent at 40--50 oC followed by calcinations at 100, 150 and 200 cC, except the samples with titanium diisopropoxide bis(2,4-pentanedionate) which are calcinated at 80 oC. Atomic absorption studies along with FESEM revealed that the maximum incorporation of metals (Zn, V and Ti) in activated charcoal was observed with 4 wt% of zinc 2,4-pentanedionate calcinated at 150 oC , 4 wt% of vanadium 2,4-pentanedionate at 100 oC, 2 wt% of titanium n-butoxide at 100 oC and 2 wt% of titanium diisopropoxide bis(2,4-pentanedionate) at 80 oC, and equilibration time of 20-24 h was used in each case. Hydrogen sorption behavior in these carbonaceous materials has also been studied at 77.4 K and low pressure up to I bar. The highest hydrogen uptake obtained was 1.45 wt% (164.5 cm3 (STP)/g at P/Po = 1.0) for activated charcoal incorporated with 4 wt% of zinc 2,4-pentanedionate calcinated at 150 oC.IntroductionTwo of the major challenges for humanity in the next twenty years are the shrinking availability of fossil fuels, the global warming and potential climate changes that result from their ever-increasing use. So it is necessary to fmd an energy source that is convenient, flexible and controllable. One possible solution to these problems is to use an energy carrier such as hydrogen, and ways to produce and store hydrogen in electric power plants and vehicles. Hydrogen storage is the bottleneck for the breakthrough of hydrogen as energy carrier in automotive applications [1]."

Jan 1, 2012