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By Cui Wang, Kexin Jiao, Qiuye Cai, Jianliang Zhang

Prolonging the campaign life of the blast furnace has been an important task for iron makers, and it has been studied for decades. Adding titanium-bearing materials is a generally agreed and effective technique to protect the blast furnace hearth. Titanium from titania additions in the burden or tuyere injection react with carbon and nitrogen and form scaffolds on the hearth surface to protect the hearth from subsequent erosion. In this article, the progress on blast furnace hearth protection of titania additions in Chinese steel companies and research institutions is investigated, and the difficulties in the operation and production, such as little effect after adding titaniumbearing materials and the property deterioration of liquid iron and slags, are analyzed. The future research for protection in Chinese blast furnace is proposed, and a comprehensive process which combines protection of titanium bearing materials with reasonable thermal balance and slagmaking regimes should be established.

Jan 1, 2015

By M. M. Sadawy

"The increased rate of exploitation of iron ores has resulted in a rapid depletion of high-grade iron ore deposits in Egypt. New iron reserves have to be discovered to secure the iron ore for steel production. This paper aims to study the characterization and magnetic separation of low grade Aswan iron ore. The results showed that Aswan iron ore is composed of oolitic hematite, goethite, quartz and kaolinite. The screen analysis indicated that Aswan iron ore had a uniform distribution of iron and silica in the different particle size fractions and there is no any particle size has high amount of iron or low content of silica. On the other hand the results of dry high intensity magnetic separation illustrated that this technique is not suitable for upgrading this ore.IntroductionIron is one of the common metals used in industry, as well as being the fundamental raw material used in iron-steel industry; products are wide spread even in daily uses. The total iron ore reserves of the world have been estimated as 3 70 billion tones; 160 billion tones is classified as economical, while 210 billion tones as potentially economical [1]. An estimated 98% of the iron ore exploited in the world is used in the manufacture of pig iron and steel, which are non-substitutable backbones of modem society. The rapid increase of world steel production over the last few years have required an equal increase in iron ore production, from 876.8 Mt in 2006 to 948.1 Mt in 2007 [2]. The increased rate of exploitation of iron ores has resulted in a rapid depletion of known high-grade iron ore deposits. This, in turn, has led to a dramatic increase of prices. In the absence of any major new discoveries of high-grade iron ore deposits, mining companies have turned to lower-grade materials to assess their beneficiation potential to expand their production base and beneficiation capacity, in order to satisfy future demand. Egypt is going to face shortage in iron production, consequently new iron reserves have to be discovered to secure the iron needed for the country [3]. Exploitation of low grade ores requires special equipments and techniques for recovery of minerals values. High gradient magnetic separators offer promise and great potential of application both technologically and economically in the processing of fine particles containing weakly or feebly paramagnetic components [4-6]. Within this existing framework, this research was initiated to assess the beneficiation potential of low-grade Aswan iron ore by high intensity magnetic separation."

Jan 1, 2013

By S. Gupta, M. Fuka

This paper reports for the first time the synthesis of deintercalated MoAlB particulates which belongs to a family of novel ternary borides called MAB phases by selected etching of Al from these particulates by treating them with a solution of LiF and HCl. The FESEM analysis showed that these particulates hada stacked 2D-particles like morphology reminiscent of multilayered MXenes, but unlike MXenes, the 2D layers were interconnected with anisotropic porosity between them with an average length and width of pores being 257 ± 126 nm and 35 ± 10 nm, respectively. The EDS analysis of particulates showed that a typical particulate had a chemistry of (Mo Al )B{O F } which indicate partial 0.67 0.33 0.19 0.02 deintercalation of Al from the particulates. These novel particulates were also referred to as MABenes due to their microstructural similarity with multilayered MXenes.

Mar 1, 2018

By Gunther Klamp

Disposal of arsenic compounds from washing acid in metallurgical plants is becoming a severe problem when using lime neutralization. A further problem is the disposal of relatively large quantities of gypsum which is produced during this neutralization step and which Is also conta-minated with other toxic metal compounds. The Sachtleben-Lurgi process removes arsenic and other metals from washing acid in the form of insoluble sulphides. The purified acid contains less than 0.5 ppm of arsenic and can be used for standard sulphuric acid applications. The process Is demonstrated commercially at Sachtleben's acid plant since more than five years.

Jan 1, 1992

By S. A. Platias

Large amounts of dunile tailings can be recycled for olivine produdion from the existing beneficiation adivity of chromite ore in northern Greece. This olivine production aims at the preparation of a material suitable for the substitution of the environmental hazardous quartz sand in the foundries of Europe In smelting of chromite ore the losses that occur ore usually of the order of 6-8% Cr that report in the slag. Most of this is in the form of oxides that cannot be recovered, but usually 30-35% is in the form of FeCr alloy that can be recovered by gravity methods. About 90% of the produced slag is sold for road construdion after crushing to a desired grain size. Finally, recycling of chromites sludges from the ferrochrome produdion plant, through the preparation of pellets, improved the total chromite yield by 2%.

Jan 1, 1996

By R. G. Reddy

Nickel solubilities in spent pickling solutions (i.e. HF-HNO3-H2O solutions ) were measured as a function of HF and HNO3 acid concentrations. The chemical analysis of the industrial pickling solutions and sludges were made. The stable phases observed in the sludges are FeF3?3H2O, and ( FeCr ) F3?3H2O. Pure Ni, and stainless steel type 316 were used in this study. The results showed that the solubility of Ni increased with increase in concentrations of HF in pickling solution at a fixed concentration of HNO3: An excellent agreement between the experimental solubility data and the theoretical data was obtained. X-ray diffraction analysis showed that the solid solubility product formed is mainly NiF2?4H2O compound.

Jan 1, 1992

By Pan Gu, Zhen Zhang, Jiang Diao, Bing Xie, Hongyi Li

Viscosities of FeO-SiO2-V2O3-CaO-P2O5 slags have been measured at the temperature range of 1673 K to 1773 K (1400°C to 1500°C). This investigated system represents the major components of basic vanadium slag that is an important intermediate product of a novel vanadium extracting process, in which removal of phosphorus and extraction of vanadium can be achieved from the vanadium-containing hot metal simultaneously. It was found that higher CaO/SiO2 ratio resulted in lower viscosity in the composition range of interest. Also, the viscosities increase with the increasing P2O5 concentration. The varying viscosities can be attributed to the modification in complexity and polymerization of the slag network. The variation of apparent activation energies are in tune with the viscosity measurements. The results of this work revealed the effect of CaO/SiO2 and P2O5 on the viscous properties of FeO-SiO2- V2O3-CaO-P2O5 slags and therefore provide the theoretical foundation for the control of the coupling de-P and V-extraction process.

Jan 1, 2016

By Honorio Oliveros Gómez, Oscar Jaime B. Restrepo

"Colombia produces nine tons of electronic waste per year and there are approximately 60 tons accumulation generated in the last nine years. This work aims to establish a general methodology in the laboratory to recover gold, silver and platinum group present in electronic waste, also explore other forms of recovery of metals contained in electronic waste. We selected seven types of electronic cards present in the computers, which have their parent desoldering electronic components. Initially, we characterized the components of the cards through X-ray diffraction and SEM, to identify the metal species and composition. Tests were conducted laboratory hydrometallurgical recovery of metals. This paper proposes a methodology for laboratory-scale work.INTRODUCTIONColombia produces nine tonnes of electronic waste per year and build there in about 60 tons generated in the last 9 years [1], Computers, TVs, audio equipment, monitors, cell phones, remote controls, printers and operated toys battery, among others are part of this inventory, which mostly comes to landfills, because the lack of legislation to control the final destination of waste electrical and electronic equipment, and lack of efficient technologies to recover materials [2]. Under these circumstances which have environmental implications, technological and economic recovery is essential metals present in the electronic cards of computers, by hydrometallurgical with subsequent base metal electrodeposition [3]. Pyrometallurgical route is discarded by major implications for economic and environmental [4]. Recovery From this perspective, the determination of the metal fraction and the relationship between the different metals, using the SEM characterization techniques - BSE and XRD is indispensable [5] It follows with electrolytic dissociation processes in the leaching and electrodeposition [6], and unit operations in the laboratory to carry out successfully these processes on a larger scale. Were randomly selected computer twenty-four postcards for nine types of cards have different functions in the computer, which, through the absorption desoldering technique, they broke the resistance (thermal, surface, photoresist, power), capacitors (ceramic, electrolytic), diodes (silicon, germanium, high frequency), transistor (NPN, PNP), processors, integrated (high, medium and low frequency), the RAM card and pin parallel port serial"

Jan 1, 2011

By Sun Ying, Zhang Jing, Li Qiu-ju, Wang Yan-ze

Copper smelter slag was leached using sulphuric acid solutions under atmospheric conditions. Base on the composition and phase of copper slag, the effect of the concentration of sulfuric acid and leaching temperature to the leaching growth rate of Fe, Cu, Co and Ni in the copper slag were investigated in this paper. Simultaneously, the influence of sulfuric acid concentration, leaching time, leaching temperature and the amount of sulfuric acid (solid-liquid ratio) to the leaching rate of these metal elements were researched. Experimental results showed that: with the increasing temperature, the dissolution rates of the metals elements increased first and then decreased. Due to the influence of silica gel which was obtained in beginning of leaching, the higher the concentration of sulfuric acid is not conducive to dissolution of the valuable metal elements. The dissolution degree of Fe, Cu, Co and Ni were 92.83% 96.76% 93.62% and 63.41% respectively.

Jan 1, 2016

By I. Barin, G. Eriksson, F. Sauert

Computer-aided calculations using data bases and program systems are more and more needed for the rational development and optirnization of high-temperature processes. The calculation of mass and energy fluxes between different process steps as well as the determination of the chemical equilibria will be discussed, giving examples from nonferrous metallurgy. The simulation of a waste-material treatment process including high-temperature combustion and gas-cleaning systems will also be demonstrated.

Jan 1, 1988

By Z. Smieszek, J. Botor, Z. Miczkowski, S. Sobierajski

"From 1978, the direct process for the smelting of chalcocite concentrates in a flash furnace by the Outokumpu method has been applied at the Glogów II copper smelter. The chemical composition of these concentrates make it necessary to control the process very strictly. In this paper, the method for controlling and measuring the main technological parameters of the copper production by flash smelting is being presented. It includes the determination of the chemical composition of the concentrate, its grain structure, the temperature of liquid products of the process, oxygen content in process gases, as well as lead concentration in copper and copper concentration in slag.The main process parameters are determined from the mass and energy balances. The relations between parameters, such as an effect of grain structure of a concentrate on oxygen and oil consumption, and dependence of chemical composition of a concentrate on capacity and products quality are discussed. 1. IntroductionThe Polish copper concentrates, as most concentrates occurring worldwide, contain from 18% to 30% Cu, and less sulphur (7-11%) and iron (2-5%). The main copper-bearing mineral contained in the concentrates is chalcocite, while bornite and chalcopyrite are present in smaller quantities. Moreover, the organic carbon (5-7.5%), arsenic (0.05-0.3%) and lead (1.2-3.0%) are also contained in the concentrates. The gangue consists mainly of silica, aluminosilicates, calcium carbonate and magnesium carbonate. Their proportions make the addition of slag-forming agents unnecessary.The composition of Polish concentrates, especially their low iron content, allows their application in the direct flash smelting process for blister copper production. Low sulphur content is the factor which determines the necessity of oxygen application in this process."

Jan 1, 1989

By Shusen Cheng, Kun Yan

A three-dimensional mathematical model of hot blast stove pipe shell has been established and used for analyzing the stress distribution and deformation. The results show that stress concentration happens along the intersection line of hot blast main and the hot blast manifold. There is no plastic deformation on the whole pipe region. The shell near the intersection elongates along the vertical direction and shortens along the horizontal direction, and deforms into an oval. The shell of hot blast main rises up, and inclines upward around the end of hot blast main. The hot blast main moves away from the hot blast and the displacement near the middle region is larger, the main deforms into an arch on horizontal surface. The deformation of shell may form a gap between shell and refractory inside and damage the security and stabilization of hot blast stove piping.

Mar 1, 2017

By Leonid M. Lerner

High temperature aluminum Alloy 8009 is a rapidly solidified/powder metallurgy aluminum-iron-vanadium-silicon alloy. This alloy in combination with hard oxide aluminum film has unique engineering properties which may recommend its use in compressors and impellers for aerospace applications. Various anodizing processes (including Sanford Low Voltage DC+AC Process) for these task will be evaluated and normal chemical composition, physical properties, and macrostructures of 8XXX aluminum alloys will be presented.

Jan 1, 2006

By Ma Lijuan, Zhang Yubing, Wang Bo, Sun Huilan

The effect of lime ratio on phase composition and alumina leaching property of MgO-contained calcium aluminate clinker were investigated by analytical reagent, the XRD analysis of its mechanism was discussed. The results showed that: when the sintering temperature was 1350 ℃, C/A was 1.4, A/S was 1.3 and the content of MgO was 4%, the increase of the C/A promoted the formation of C12A7 and restrained the formation of Q-phase. The alumina-leaching ratio of the clinker (A/S was 1.3) was increased from 74.33% to 91.34% when the content of CaO was 5.21%.

Jan 1, 2015

By Joseph Hamuyuni, Fiseha Tesfaye, Daniel Lindberg

E-waste management through traditional methods such as disposing in landfills, burning in incinerators or exporting abroad for disposal are no longer options due to the strict environmental regulations. Fortunately, the presence of valuable metals in the e-waste and increasing demand for the metals as well as complexities of the currently available primary raw materials make recycling an attractive and viable option both environmentally and economically. Moreover, it is efficient in terms of resource management by closing the loop of metals. Consequently, urban mining such as the recovery of precious metals from e-waste streams through sustainable recycling processes have emerged. The sustainable recycling practices address the scarcity of primary resources and reduce consumption of energy for metals production while managing environmental issues related to hazardous materials from the e-waste streams. In this paper, valuable metals recoveries from e-waste streams through pyrometallurgical and hydrometallurgical processes are critically reviewed. And, innovative ideas for different steps of the thermochemical processes in the valuable metals and energy recovery from the e-waste streams are discussed.

Mar 1, 2017

By J. L. Sanchez

Using a special double-zone transpiration reactor, the vapor transport chemistry of vanadium pentoxide in the presence of water vapor has been investigated. Three possible volatile hydroxides above V,O,(s) are reported in the literature: VO,(OH),, V,O,(OH),, and VO(OH),. In the present study, it was established that VO(OH), is the principal gaseous hydroxide species formed. The predominant reaction was found to be: { } The vapor pressure of VO(OH), was measured as a function of temperature, water pressure, oxygen pressure and flowrate. The results have been used to determine the Gibbs free energy of the above reaction as a function of temperature: { } The results of the present work were combined with thermodynamic data reported in the literature to obtain expressions for the AGO for the reaction above V,0,(1) and the AGO of formation (units in cal/g-mole).

Jan 1, 1993

By QinGuo, Shenghui Guo, Jinhui Peng, Linqing Dai, Libo Zhang

This paper adopts a simple and novel preparation. Taking cellulose as a template, a tubular morphology structure of micro/nano ZnO crystals was obtained by microwave roasting at high temperature. The higher the microwave roasting temperature, the larger the degree of crystallization. The experiments indicate that the best photo catalytic effect can be obtained at 850 : At this temperature, the oxidation of cellulose is complete. Large quantities of hexagonal shaped ZnO crystal can be observed, specifically the (0001) crystal face. Under ultraviolet-visible irradiation, taking long arc mercury lamp as light source, the material had good photocatalytic activity. The decomposing efficiency of methylene blue reaches 97% in 60min, which is superior to that of preparations without templates at the same temperature.

Jan 1, 2016

By K. Morsi

The interest in spark plasma sintering has been growing considerable over the past few years. This has been brought about by the unique advantages of the process, which include reduced sintering temperatures and times and the production of materials with unique microstructures and properties. Despite its current reputation as an outstanding process that has solved major problems such as nano-powder consolidation, it has so far been largely limited to the manufacture of simple shapes, due to its inherent geometric configuration. In this paper we present preliminary results on spark plasma "extrusion" that can allow the production of extended geometries via electric-current processing. Preliminary results on the processing and microstructure of spark plasma extruded aluminum are discussed.

Jan 1, 2009

By Y. Maeda

Kosaka Smelter is a copper smelter located at the nothern part of Japan? and has been treating. complex sulfide concentrates using flash smelting technology for a long time. The flash smelting technology has an advantage in the point of controllability of matte grade and heat balance in the reaction shaft. But the disadvantage of this process, is that the dust generation ratio is high compared with other smelting process such as injection smelting technology. This reason why is that the flash smelting process is the oxidation process for the fine sulfide concentrates applying flash reaction in the oxygen enriched stream In addition of this disadvantage, the sulfide concentrates contains much volatile impurities is resulted the dust; eneration ratio more. This paper outlines the recent improvement of the flash reaction in the furnace and the behavior of impurities in Kosaka Smelter.

Jan 1, 1998

By G. L. Watt

Fine sized titanium diboride (TiB2) powders have been synthesized in a thermal plasma reactor. Precursor for the synthesis were rutile, boron oxide, and methane. The effect of plasma gas type, precursor ratio, and input power on the synthesis was studied. The produced powders were characterized by X-ray diffraction and chemical analysis. The purified powders were CIP'd, HIP'd, sintered and characterized for porosity, hardness, and microstructure and the results compared with a commercially available TiB2 powder sample.

Jan 1, 1995