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By Hideaki Tokuyama

Recovery of Ni from acidic wastewater of metal surface treatment has been investigated for reuse of the metal and water. Ion exchange equilibria between Ni ion and a strong acid cation resin, DIAION SKIB, and effective diffusivity in resin particle have been studied and they related to the concentration of HCI. The amount of adsorbed Ni for unit quantity of resin decreases with the increase in HCI concentration. This trend is remarkable for acid concentration above 0.1 kmol/m3,. The exchanging ratio of Ni2+ to H+ in resin particle is I/2 and the values of equilibrium coefficient K and maximum exchange capacity Q are I.62 and 3.16 keq/m3 -dry resin, respectively. Effective diffusivity D. determined from the observed breakthrough curve increases with increasing concentration of DC!. A prototype of moving bed has been developed and applied for the recovery of Ni from model solutions of wastewater prepared by mixing HCl and NiCl2. This apparatus allows us to control the resin flow rate by changing the cross sectional area of hole I the Teflon plate installed at the bottom of resin bed. Characteristics of Ni recovery have been clarified under various liquid flow rates. In any case for Q1, Ni ion has been effectively recovered on SKIB resin and the removed fraction was more than 99.5 %. Higher loading ratio of ion is attained at larger liquid flow rate.

Jan 1, 2003

By Guo Xueyi

The reaction mechanism for the manganese dioxide reductive dissolution in acidic chloride media in the presence of ferrous/ferric ions are based on theoretical delineation and dual cell experiments. In terms of the Buttler-Volmer equation and chemical kinetic principles, a electrochemical kinetic equation was deduced, which successfully provided a theoretical basis for describing the role of Cl-, Fe2+, Fe3+ and H+ in solution, as well as their interrelationship in manganese dioxide reductive dissolution. Dual cell experimental studies indicate that the increases of Cl- and Fe2 in solution are helpful to accelerate the couple process; while, Fe3and Mn2+ hinder the coupled reaction to some degree. Higher acidity in solution is beneficial to the dissolution of MnO2. All the dual cell experimental results are consistent with the theoretical deduction. This study will be useful to understand the mechanism for the leaching of manganese nodules from the deep ocean, as well as the leaching of manganese dioxide ore from land.

Jan 1, 2003

By K. C. Liddell, B. Dou

"In producing multilayer films for magnetic data storage applications, the interfacial roughness must be controlled in order to obtain high quality materials with reproducible properties. The present understanding of the effect of roughness on multilayer properties such as magnetoresistance is sketchy, particularly for electrodeposited films. In this study, quantitative atomic force microscopy was used to characterize surface morphology before and after Ni films of varying thickness were deposited on Cu cathodes. A multinuclear multilayer growth mechanism is supported by both the deposition conditions and the AFM images, and a multinuclear multilayer model gave a satisfactory fit to measurements of the density of peaks on ultrathin Ni films between 0 and 8 nm thick.Alloys consisting of alternating ferro-and paramagnetic layers have begun to replace Permalloy in the sensing elements of magnetic hard drives. The operating principle of the new read heads is giant magnetoresistance (GMR), and they are smaller and more sensitive than previous inductive heads (1). Experimental studies on sputtered multilayers have emphasized the role of layer thickness and interlayer roughness in determining the presence and size of the GMR effect (e.g., 2,3,4,5,6). However, roughness in electrodeposited multilayers has rarely been measured, even though read heads are likely to continue to be made by this process for some time to come. Cu/Ni can be considered a model system for understanding processing-microstructure-property relationships in electrodeposited multilayers and is the most widely investigated of all such systems (e.g., 7,8,9,10,11,12). Nevertheless, the roughness of the interfaces in Cu/Ni electrodeposits has not been systematically characterized by quantitative techniques, and in all studies reported so far, the total deposit thicknesses were considerably greater than the 10 nm needed for most sensor applications (1). The thinnest such films were about 50 nm (7)."

Jan 1, 1998

By Lisa E. Helberg

"Titanium tetrachloride is produced through the chlorination of a variety of titanium bearing ores, some occurring in nature, and others enriched in titanium content by a variety of ""beneficiation"" processes. The chlorination step can produce a variety of metal chloride impurities, such as iron chlorides and vanadium chlorides, which must be removed from the TiC14 before it can be used to produce pigmentary TiO2, titanium metal or for any other commercial use. The requisite manipulations involve both physical and chemical separations in a multi-step process. The history of various purification strategies will be discussed.TextThere are a wide range of titanium-based products available, all of which start with titanoferrous ore of some type. Two main routes are used to convert ores into products, known as the sulfate and chloride processes. The sulfate process uses sulfuric acid to digest the ore, separate the impurities, and then precipitate titanium dioxide from the resulting titanyl sulfate (TiOSO4) via metatitanic acid. This process can also supply TiOS04 for other applications."

Jan 1, 2011

By Michael J. Nicol

One of the preferred methods for the recovery of gold from refractory gold ores and concentrates involves pressure oxidation in acidic solutions. The main refractory gold-containing minerals are pyrite and arsenopyrite and there is evidence that the presence of even small amounts of chloride can inhibit the oxidation of these minerals and also substantially reduce the recovery of gold. In this paper, the results of a study of the anodic (oxidation) and cathodic (reduction) behaviour of pyrite electrodes in acidic sulfate solutions containing ferric ions at different chloride concentrations and temperatures up to 200oC and pressures of 2000KPa are presented. The electrochemical studies have been complemented by pressure oxidation experiments on a refractory gold concentrate. Results have shown that, as the chloride concentration increases, the anodic reactivity of pyrite is largely unaffected but the rate of the cathodic reduction of iron(III) decreases. The rate of oxidation of a sulfide concentrate and the recovery of gold by cyanidation of the residues decreases at high concentrations of chloride.

Jan 1, 2003

By Ledjane Barreto, Tulio Flávio Accioly de Lima e Moura, Wilson Acchar, Antonio Carlos Silva da Costal

"Clays are common ingredients in pharmaceutical products both as exclplents and active substances. Clay minerals are naturally cationic exchangers and they may undergo ion exchange with basic drugs in solution. Smectites, and montmorillonite have been studied due their high cation exchange capacity as compared to other silicates. Recently a patented study reports the use of attapulgite as the encapsulating agents both for the protecting the active substance and modulating release into the body. Some clays such as kaolinite, smectites, talc, etc are also used as dermatological protectors. Sepiolite and smectites have the ability to form complexes with organic compounds with absorb ultra-violet radiation, enabling them to be used in sun screens with protection factors. The objective of this work is to characterize the attapulgite in order to study the potential use of this clay material in the human health.IntroductionSince the begimling of time, nature has served humanity as a source of various raw materials. Among these, clays such as kaolinite and ilitte are common ingredients in the tile production. Recently, special clay materials have been investigated in order to identifY new potential uses of these class of materials. Clay materials are natural raw material and have excellent properties such as low toxicity, good biocompatibility, making them a good material to be used in biological applications. Attapulgite (paligorskite) and sepiolite is so called special clays. These special clay materials are very sin1ilar and have a great potential to be used in some technological areas due their special catalytic, sorptive and colloidal-rheological properties [1-8]. Recently some works have reported the use of these special clays materials for many applications such as drug delivery, wound dressing, oil absorbent, pesticides, fertilizers [9-12]. Brazil has a significant reserve of attapulgite located in Piaui state, making the study of the potential of this mineral in special areas, very attractive. Attapulgite is classified a fibrous alluminous silicate material and shows the presence of micro pores and channels, fine particle size and high surface area making this material a good candidate alternative material to be used in many industrial applications [6,8,9,11,12]. The objective of this work is to characterize the physical and microstructure of attapulgite."

Jan 1, 2012

By M. Yoshida, S. Hanada, T. Takasugi

"A study has been conducted to examine the effect of ternary alloying elements on high temperature deformation of the C15 NbCr2 based intermetallics in Nb-Cr-X (X=V, Mo and W) alloy systems, which have attractive properties as high temperature structural materials. The high temperature deformation of the C15 NbCr2 intermetallics can be improved by two alloying methods. One method is based on geometrical consideration for site occupation and atomic size factor of component elements and additive elements in the single phase C15 lattice; addition of Mo and V can promote dislocation movement without introducing significant hardening. The other method is based on microstructural modification through ternary alloying; moderate addition of these elements results in a variety of duplex microstructure consisting of the C15 phase and bee solid solution without forming any intermediate phases, and can enhance the high temperature deformability. Particularly, alloys with duplex microstructure equilibrating with Cr-rich bee solid solution is shown to exhibit superior deform ability. Also, lattice property of the additive atoms in the C15 structure and phase relation between the C15 structure and the bee solid solution are investigated by OM, XRD, TEM and ALCHEMI observations and then discussed in association with observed mechanical behavior.IntroductionLaves intermetallics with AB2 stoichiometry belong to the largest group in a large number of intermetallics with various kind of crystal structures, and have a variation of the cubic CIS, the hexagonal C14 and the dihexagonal C36 structures, depending on stacking sequence of XYZ type, each of which consists of four interpenetrating atomic layers (1-3). Some of the Laves intermetallics have good functional properties and therefore are considered to be used as, for instance, magnetic materials, magneto-optical materials, hydrogen storage materials and superconducting materials (2). Also, the Laves intermetallics are considered to be good candidate as high temperature structural materials operating at high temperatures and in severe environment because they have high melting point, low density, and potential resistance to corrosion and oxidation. However, the Laves intermetallics are very brittle at low temperatures because they consist of complex crystal structures similar to many other intermetallics."

Jan 1, 1996

By Tam Tran

Most new gold mines in Australia are required to treat tailings to reduce cyanide levels before they are discharged to storage ponds to meet the stringent environmental management guidelines set by government statutory authorities. In New South Wales, the average level of weak acid dissociable cyanide allowed in open tailings dams is now limited to 20 ppm, As stringent environmental guidelines continue to be enforced in Australia as well as in other parts of the world, the management of cyanide wastes has emerged as a key issue for the gold mining industry. This paper provides a critical evaluation on technical aspects related to the use of ion exchange resins and affiliated processes in cyanide management and tailing treatment. Particular attention is given to the use of ion exchange resin technologies in the processing of mixed gold-copper ores, where cyanide usage is the highest. Information presented in this paper is heavily drawn from the experience on the application of ion exchange resin processes at May Day mine, in New South Wales, Australia and associated pilot plant test programs. Issues related to the management of thiocyanate, especially with respect to the recovery of cyanide from thiocyanate are also discussed.

Jan 1, 1998

By Mamoru Kuwahara, Tomohito Taki, Masamichi Sano

"Theoretical basis and experimental results on ultrasonic separation of dispersed inclusions from molten metal are outlined. Transitional formation of an ultrasonic standing ·wave field in a liquid bath is numerically predicted based .on the wave equations. Numerical solution of the equation of motion of a fine particle in a standing wave field indicates that the inertia term can be neglected during conventional ultrasonic separation of fine particles: Analytical solutions for the position at which particles are coagulated the minimum power for separation, and the ultrasonic separation time are derived to incorporate such key process parameters as the density difference and the acoustic energy density exerted. Cold model experiments have been carried out to observe ·transitional coagulation of polystyrene particles in an aqueous sugar solution with the incidence of standing ultrasonic plane wave. Experimental results agree well with the theoretical predictions.IntroductionDespite of recent progress of fundamental and applied researches in metallurgical systems, advanced materials· with less inclusions and better properties may demand more innovative processing in a: molten state. It may be realized by applying electromagnetic and/or ultrasonic external fields to the systems. The present authors1)·2) have been proposing : new methods of ultrasonic processing of materials based on such phenomena as acoustic streaming, acoustic radiation pressure on dispersed phase in a standing wave field, and the cavitation in liquid associated with use of high-intensity ultrasound and so on. Taking account of common physical natures between ultrasound and sound wave, we call such · a processing assisted by acoustic wave as ""sonoprocessing"". This report ·deals with some theoretical and technological aspects on the ultrasonic separation of fine particles from liquid, which could become an important operation to produce clean materials. Fundamental theory and ·supporting experimental results will be given below to give an insight into the liquid metal sonoprocessing."

Jan 1, 2000

By Basak Anameric

Pig iron nugget process was developed by Kobe Steel as an environmentally friendlier, economical alternative to traditional blast furnace process. The process aimed to produce highly metallized, slag free pig iron nuggets throughout a single stage heat treatment, utilizing coal as a reducing ? carburizing agent. The objective of this work was to determine whether the pig iron nuggets produced at the laboratory conditions had comparable physical and chemical properties with the blast furnace pig iron. The physical and chemical properties of the pig iron nuggets were determined utilizing x-ray fluorescence spectroscopy, x-ray diffraction, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and apparent density measurements. The pig iron nuggets had similar chemical composition and apparent density values (6.7 ? 7 g/cm3) with blast furnace pig iron and they had microstructures similar to low carbon white cast iron. These properties make them a competitive alternative to blast furnace pig iron.

Jan 1, 2006

By Kent D. Peaslee

When supersonic oxygen jetting is used in electric furnace steelmaking, the lance jet axis is typically inclined at larger angles to the vertical than is used in basic oxygen steelmaking. The supersonic jet is important not only for refining the steel, but for sustaining the foamy slag in the electric furnace. Physical modeling was carried out using a room temperature, two-dimensional slice apparatus in which mercury represented the metal and water-glycerol the slag. High speed video photography with image analysis was used to study the effects of the angle of inclination on the slag/metal bath. Mathematical modeling using FLUENT provided a method of predicting flow patterns and the trajectories of drops injected at various points in the flowfield. A one-half scale water model of the system, in which lance heights, angles, and flowrates simulated those encountered in steelmaking operations, was used to provide a better understanding of some aspects of the oxygen blowing process in electric furnace steelmaking.

Jan 1, 1994

By T. J. White

A synthetic Mineral Immobilization Technology (SMITE) has been developed for stabilizing municipal and hazardous waste incinerator ash. Tailored additives are introduced to the ash in a' first stage that pre-stabilizes all the toxic metal components in non-volatile forms. and in a second pyrometallurgical stage, these are converted to insoluble mineral analogues. It has been found that a combination of apatitie. spinal, anhydrite and monazite can immobilize all the ash components at high waste loading and high density. Typically the stabilized products contain in excess of 50 wt% ash and have densities of 2.5- 3.0 g.cc-1. Toxicity Characteristic Leach Procedure (TCLP) testing has demonstrated that the products well satisfy regulatory requirements. The cost of production and disposal of SMITE waste forms in 2-5 less expensive than. convential methods of solidification/stabilization. This paper will describe the principles of SMITE design for ash stabilization, outline the fabrication procedure, and present comprehensive microstructural and chemical data to validate waste form performance.

Jan 1, 1996

By Seong-Jong Kim

The formation behavior and corrosion characteristics of anodic oxide films on pure Mg and Mg-AI alloys were investigated focusing on the effects of anodizing potential, Al content, temperature and NaOH concentration. Pure Mg and Mg-AI alloys were anodized for 10 min at 3, 10, 40, and 80 V in NaOH solutions. Mg(OH)2 was generated by an active dissolution reaction at the surface of the specimen and the product was affected by temperature while MgO generation increased with NaOH concentration. Moreover, the current density after anodizing for 10 min at a constant potential decreased with increasing AI content in Mg-AI alloys,

Jan 1, 2003

By Zhong g. Shui-ping

A new type Pb-Ag (0.8wt%)-Bi (0~5.0wt %) alloy used as anode in electrowinning of zinc from sulphuric acid electrolytes was prepared. The electrochemical properties of this ternary lead alloys have been tested and compared with those of Pb-Ag (0.8wt %) anodes used in industry. Results show the anodic overpotential decreases with the increasing of Bi content in the alloys. When the content of Bi was 1.0 wt% and 5.0 wt%, the anodic overpotential is about 40?50 mV and 60?80 mV lower than that of Pb-Ag (0.8wt %) alloy, respectively. The formation of oxide layers on the surface of these alloys was traced by LSV methods and the composition of the anodic oxide layers was characterized by XRD and SEM analysis. The surface layer on the two type anodes examined is mainly composed of a?PbO2 and ß?PbO2. But different structure of the surface layer was observed, Pb-Ag (0.8wt%)-Bi (1.0wt %) has a more fine-grained structure as compared to Pb-Ag (0.8wt %). But the film on Pb-Ag (0.8wt%)-Bi (3.0wt %) alloy is rather friable, cracked and not tightly attached to the anode.

Jan 1, 2008

By Yong Kuk Park

The horizontal cold chamber die casting process can produce a wide range of near-net shape, non-ferrous castings with small dimensional variation, excellent surface finish and very complex geometries. However, top quality die castings can be achieved only when optimal performance of the cold chamber and plunger is maintained during the molten metal injection phase of the process. Cold chambers (shot sleeves) are known to deteriorate fast and sometimes fail catastrophically because of poor design. Catastrophic fracture and wear due to deformation are leading causes to degrade quality, increase downtime and thereby decrease productivity and profitability. Therefore, a systematic approach to minimize irregular and adverse conditions which prevent an intended injection profile, is highly desirable. To eliminate them, design criteria for shot sleeves were developed using analytical tools and available experimental data. The correlation between design and mechanical failures of shot sleeves was shown by the data obtained from the die casting industry. Also, the relationship between die casting process parameters and deterioration/ failure mechanisms were carefully evaluated.

Jan 1, 1996

By Jannie S. J. van Deventer

Geopolymers are novel engineering materials with the potential to play a highly significant role in the transformation of the construction materials and building products industry in the push towards sustainable development. These materials are formed by activation of industrial aluminosilicate waste materials such as coal ash or blast furnace slag with alkaline solutions. Geopolymers derived from coal ash can exhibit superior mechanical properties and chemical stability when compared to ordinary Portland cement (OPC). The use of waste-based geopolymers can also result in significant (up to 90%) reduction in carbon dioxide emissions when used in cement replacement applications. In addition to the formation of conventional pre-cast products, these high performance mineral binders are ideally suited to use in the encapsulation of mine tailings, immobilization of heavy metals and back-filling of mines due to their chemical stability and resistance to acid attack. A key attribute of geopolymer technology is the robustness and versatility of the manufacturing process; it enables products to be tailor-made from a range of raw material sources (waste and/or virgin) with specific properties for a given application at a competitive cost. Despite these key technical and environmental attributes, it is the ability to add significant value to coal ash or and/ or metallurgical slag waste streams which drives the commercial development and uptake of the technology.

Jan 1, 2006

By Chuan-fu Zhang

In present work, the physical properties of molten FenO-MgO-CaO-SiO2 slags were measured .It is shown by the results that when the slag composition is as follow: MgO 8%~12%, CaO 2%~8%, Fe/SiO2 1.2~1.6, the viscosity of the slags decreases with the increase of temperature. When the Fe/SiO2ratio and the MgO content are fixed, the electrical conductivity increases and the viscosity decreases as CaO content increasing, while the content of CaO exceeds 6% its influence weakens. When the MgO content is 11% and the CaO is 6%, the viscosity of the slag decreases markedly as the increase of Fe/SiO2 ratio. Its influence to viscosity is inconspicuous when the Fe/SiO2 ratio exceeds 1.5. When the CaO content is 6% and Fe/SiO2 is 1.2, the electrical conductivity decreases with the increase of MgO content as temperature is below 1290, but increases when temperature is above 1290. When the MgO content is 11% and the Fe/SiO2 ratio is 1.2, the electrical conductivity increases with the increase of CaO content. When the CaO content is 6% and MgO content is 11%, the electrical conductivity increases as the increase of Fe/SiO2 ratio, while its influence weakens as the temperature increases continuously. The electrical conductivity rises when temperature increases at any slag content. The melting temperatures of FenO-MgO-CaO-SiO2 semi- synthesis slags from this work were below 1290.

Jan 1, 2006

By Xin-liang Gao, Qing Li, Gui-qin Fu, Duo Jin, Miao-yong Zhu

"Optical microscope together with alternative wet-dry cyclic accelerated corrosion tests and XRD, SEM were employed on bridge weathering steel samples with different Mn and Ni contents which were vacuum induction melted and rolled to study their effects on the microstructure and rust layer evolution in er' containing condition. The results show that the microstructure is mainly ferrite and pearlite when Mn and Ni contents are 0.75 %, 0.42 %, respectively. Both the increase of Mn and Ni contents will make pearlite disappear while granular bainite appear, meanwhile the grain size decreases. With the increase of Mn content, the corrosion rate decreases in the initial stage, but the effect becomes little in the later stage. The increase of Ni not only improves the corrosion resistance of steel base at the initial stage but also hinders the tendency of further corrosion. As Mn content increases, a-FeOOH contents in rust layer decreases. With increase of Ni content, the content of a-FeOOH in the rust increases while that ofy-FeOOH decreases.IntroductionWeathering steels had been ~radually applied in manufacture of bridges owing to reducing the corrosion rate remarkably [I- l .Good weldability was needed for high performance bridge weathering steels. Since carbon was thought to be bad for weldability, low carbon content steel was adopted and Mn was added to amend the mechanical strength loss. Some scholars[6, 7l believed that Mn was beneficial for increasing corrosion resistance performance of the steel in marine atmospheric environment. Some scholars [S, 9l thought that Mn had little effect on corrosion resistance in marine atmospheric environment. Presently, the effect of Mn on bridge weathering steel in marine atmospheric environment still remained poorly understood. Ni was considered to be beneficial for increasing corrosion resistance performance in marine atmospheric environment [JO-l4l However, the high cost limited its application range. What would bring to the rust and corrosion by decreasing Ni content needed further research.Most researchers assumed that microstructures only affected the corrosion behavior of bare steel. But the study of Guo et al. P5l showed that the homogenous microstructures were beneficial for the corrosion resistance of steels. The effect of Mn, Ni content change on microstructure and microstructure on corrosion still remained poorly understood. In the present work, the effect of Mn and Ni on the microstructures of steel matrix, as well as the microstructures on the rust and corrosion was investigated."

Jan 1, 2014

By Shuo Wang, Yu Wang, Bing Xie, Rui Tang, Hong-Yi Li, Kun Wen

"During present converter vanadium extraction process, phosphorus could not be removed from hot metal due to absence of CaO in slag though it is an efficient way for vanadium extraction. In order to improve the phosphorus remove and produce CaO-containing vanadium slag, which could be directly used in subsequent roasting process, during the converter vanadium extraction process, lime dissolution in FeOx-Si02-V203-Ti02 slag was investigated by using a rotating cylinder technique and the slag-lime interface was characterized by SEM/EDS. Results showed that changes in the slag chemistry and phase compositions during the lime dissolution process were similar to that in CaO-Si02-FeOx based slag during the BOF process. The V and Ti in the slag were expected to diffuse into the lattice of2CaO·Si02 solid solution, which formed a rather thinner layer in thickness at the slag-lime interface than that in BOF process, leading to improvement of lime dissolution in the slag.IntroductionVanadium is important material that widely applied in industries. The traditional technique to extract vanadium was to leach vanadium after sodium salt roasting. However, the sodium salt roasting process has several problems including lower yielding rate[!] and environmental pollution[2]. Therefore, the more environment-friendly technique of calcium roasting[3-4] was proposed. In order to increase roasting efficiency of vanadium slag, it is essential to study the dissolution/reaction mechanism between lime and vanadium slag. Many investigations about the dissolution reaction of lime in molten slag have been carried out from the standpoints of rapid slagging to De-Pin steelmaking process[5-6]. However, their studies were focused on BOF slag and the reaction mechanism between solid lime and slag containing vanadium has not been reported yet. In present work, the dissolution process was studied with rotating cylinder technique and the reaction interfaces were observed and analyzed by SEM/EDS to elucidate the dissolution mechanism of lime in vanadium slag. This work was supported by National Natural Science Foundation of China No. 51090382."

Jan 1, 2013

By Qingbo Yu, Qin Qin, Junxiang Liu

"Dry-granulation is a new process of molten blast furnace slag treatment and air is used as heat exchange medium. There are some shortages: poor effectiveness of granulation, high air-slag ratio and high energy consumption, which are the obstacles to popularize dry-granulation. Based on rotary cup atomization, the technique of recovering waste heat of molten blast furnace slag through waste heat boiler producing high pressure steam is exploited. The molten blast furnace slag is granulated to uniform small slag granules with high temperature, and slag granules pour into the waste heat boiler. It could produce steam, obtained in first row and second row tubes, when descending velocity of slag granules equaled 1.1mm/s and the Reynolds number equaled 7100. The application of the system for recovering waste heat from high temperature molten blast furnace slag has a significant meaning.IntroductionBlast furnace slag is one kind of solid waste in iron making process, which is discharged at the temperature range from 1723 to 1923K. In China, there was 0.162 billion tons of slag discharged in 2009, and the energy contained in the slag is equivalent to the energy in 9.4 million tons of coal equivalent. The sensible heat of molten slag is a very valuable waste heat source, so it is worthwhile to recover the sensible heat. At present, the molten slag is treated by a water quenching method. But in this process, the sensible heat is not recovered, moreover, an amount of water is consumed and harmful waste gas is discharged into the environment. Due to the considerations of energy conversation and environmental protection, the iron making industry pays close attention to dry-granulation, which is useful to obtain more benefits [1-4]. The sensible heat is recovered and an amount of water is saved by the method of dry-granulation. The amorphous content of slag granules obtained from dry-granulation is over 95% [5, 6], so the slag granules can be used as a perfect raw material for cement [7, 8].In the late 1970s, the Sumitomo Metal Industries, Ltd. and the Ishikawajima-Harima Heavy Industries, Ltd. jointly undertook the research of rotary drum granulation. This method has several disadvantages: the processing capacity and efficiency are low, and it is not adoptive to operate continuously in production [9]. From 1980, Nippon Steel, NKK, Kawasaki Steel, Kobe Steel, Sumitomo Metal Industries and Nisshin Steel were engaged on air granulation, and the experiments were operated for 6 years on the blast furnace in Nippon Steel. In the process of air granulation, there was great power consumption. The complexity of structure and the great floor space of the air granulation device caused high cost of investment. In 1986, Ukraine exploited a new method of heat recovery referring to the technology of Continuous Casting and Rolling [10]."

Jan 1, 2011