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By Linfeng Zhou, Rong Sun, Guanghui Li, Zhiwei Peng, Tao Jiang

The effects of microwave roasting on separation of rhenium (Re) and molybdenum (Mo) from a molybdenite concentrate have been investigated based on evaluation of the heating characteristics of the concentrate in the microwave field. The results show that a variety of operating variables, namely microwave power, sample weight, sample geometry, roasting temperature, roasting time and atmosphere significantly impact on the volatilization rates of Re and Mo. The optimum conditions for Re-Mo separation are microwave power 1300 W, sample weight 20 g, sample geometry pellets, temperature 600 oC, time 1.5 h, and atmosphere 20%O2. Under these experimental conditions, the volatilization rate of Re reaches 88.12%, while that of Mo is just 5.15%. Microwave-assisted roasting provides an alternative route to separating Re and Mo from molybdenite concentrate.

Jan 1, 2016

By Guo Xian Jian

In this paper, the effects of matte grade, flux grain size, blast flowrate and blast O2 content on the process of silica flux melting in a copper converter were investigated. The results showed that the blast flowrate and the blast 02 content were not significant factors in the melting process. However, with an increase in grain size of flux and grade of matte, the amount of the flux molten decreased. The data on the melt rate of process correspond well with the mathematical model which simulates the chemical reactions occurring at the interface. The kinetic equations of melting are as follow:

Jan 1, 1996

By Klara Kodrikova, Vera Kasparkova, Michaela Uhlirova, Karel Kolomaznik

"Potentially hazardous wastes from leather industry (blue shavings) are processed into various biostimulators within two steps. The first step takes place at high pH (11-12) and hydrolyzation is implemented with potassium alkali, in the second step the pH is lowered to 9 with phosphoric acid after enzymatic dechromation occurs. The resulting hydrolyzates were analyzed in the sense of molecular weight distribution and tested as biostimulators on rape (Brassica napus). The hydrolyzates can be also directly used as universal NPK fertilizers. It has been proved that the nitrate content in the edible parts of tested vegetables (radish, lettuce, and cucumber) was approximately 200 times lower compared to the vegetables fertilized with an inorganic nitrogen fertilizer. The harvests of vegetables fertilized with the hydrolyzate and the inorganic nitrogen fertilizer were almost the same.IntroductionDuring processing raw hide into leather (tanning processes), only 20% of the collagen material is used for the final product. The remaining 80% ends up as waste, both tanned and non-tanned. Non-tanned waste such as calcimine can be used for production of artificial collagen casings for sausages, gelatine and also in pharmaceutical industry as collagen capsulates. Further processing and recycling of tanned leather waste (especially chrome shavings) is more complicated. Although many technologies producing various quality collagen hydrolyzates have been developed and tested in laboratories, few have been implemented on industrial scale. A promising turn came in the works of ERRC USDA [1,2]. They worked out an enzymatic dechromation technology (hydrolysis) and achieved a considerable decrease of the amount of relatively expensive proteolytic enzyme, which solved the difference between the quality and price of the final product. The American experience of enzymic hydrolysis were applied on industrial scale in the Czech Republic, where a plant was built with daily processing capacity of 3 tons of chrome shavings. The experience of real operation was published in [3] and the cooperation between the Czech Republic and USA partners resulted in a patent [4]. The main asset of the patent was the use of volatile organic bases in the hydrolysis process giving high quality and cheap hydrolyzates with low ash content."

Jan 1, 2008

By Zhang Hengzhong

Ni-P-Fe slag is the by-product in the production of phosphate fertilizer in blast furnace with nickel contained serpentine ore as the raw material. It contains nearly 5-7% Ni, 65-7( Fe, and 10-12% P. The slag is very hard to process, it neither dissolves in aqueous ammonia, nor in sulphate acid. In the stiff the technique to treat the slag in order to extract valuable nickel was developed, it essentially consisted of the processes of roasting, leaching, separation and purification. Nickel sulphate was prepared with this method.

Jan 1, 1993

By Xuefeng She, Qingguo Xue, Jingsong Wang, Guang Wang

Iron nugget could be got at high temperature using carbon composite pellet, which were made by the mixture of ludwigite and reducing agent. In order to reduce sulfur content in the nugget, effects of additives on the desulfurization was investigated. The sulfur content could be dramatically reduced if the CaO was introduced into the pellet and the sulfur content was as low as 0.046wt.% when the addition amount of CaO was 5wt.%. However, the melting separation of pellet became increasingly difficult and the yield of iron decreased when CaO content in the pellet gradually increased. Na2CO3 could also reduce the sulfur content in the iron nugget and made the iron and slag separate difficultly as well. When 6wt.% Na2CO3 was added into the pellet, the pellet was too difficult to melt separation and the sulfur content in the nugget was 0.084wt.%, which didn’t meet the need of steel making.

Jan 1, 2015

By Christian M. Sagedahl

The stringent environmental regulations for air pollution regarding emission control, along with the need of dry concentrates to feed autogenous smelting processes, are enhancing the development of cleaner technologies. Indirect drying of concentrates by a Kvaemer steam dryer is a technology with promising results, reducing dust entrainment to the exhaust gas stream and leading to smaller dust separation units. The Kvaemer dryers are designed for a very high availability, a high-energy efficiency, low amount and velocity of exhaust gases, no SO2, CO or CO, emissions combined with a wide range of satisfactory operating conditions and low total operational costs.

Jan 1, 1999

By Luben Xie, Lin Hu, Qiang Wang, Min Gan, Tao Jiang, Wenqi Li, Yi Wang, Xiaohui Fan

"The mineralization behaviors of typical fluxes are studied by investigating the microstructures with optical microscope. The results show that the reactions begin with between iron ore and lime, limestone with small particle to form primary liquid. Then coarse limestone, dolomite and serpentine take part in reaction under the action of primary liquid. Limestone is the easiest to mineralization, next dolomite, and the last is serpentine. The higher basicity and smaller fluxes size favor the mineralization process of dolomite and serpentine.IntroductionThe purposes of adding fluxes into sintering are that:(1) to increase the basicity of sinter, so as to reduce even eliminate addition fluxes into BF(blast furnace) and decrease the coke ratio of BF[1,2]. (2) to decrease the melting point of sintering mixture to ensure sintering can be carried out at a lower temperature and reduce the energy consumption. (3) to improve the qualities of sinter by forming binding phase with iron ore fines [3].Flux is another significant component for sinter besides iron ore, especially for high basicity sinter[4]. The proportion of flux is usually higher than 10% in sinter mixture(excluding return mine).There were many reports about the influence of the flux types on sintering, such as limestone, dolomite, lime and so on[5-7]. It is very important to choose suitable fluxes for iron ore sintering. Although the effect of flux size on sintering also has been researched, the mineralization behaviors of the fluxes in the sintering process has not been illuminated. The paper will study the mineralization behavior of fluxes in sintering."

Jan 1, 2011

By J. D. Sloop

This paper discusses the current state of EAF dust recycling at AmeriSteel's Dust Processing Division in Jackson, Tennessee. Included are a brief history of the plant, a description of the facility, a description of the process, and operating data.

Jan 1, 2000

By Yuanbo Zhang, FENG ZHOU, Guanghui Li, Zhengwei Yu, RuijunWang, Tao Jiang

Composite agglomeration process (CAP) of iron ore fines has been proved an effective route for ironmaking burden production, and is characterized by low the fuel consumption and high the productivity compared with the traditional sintering process. Sintering behavior of pelletizing feed in CAP has not been studied fully yet. In this study, individual pellet and simulated CAP cells were roasted under the simulated sintering conditions. The compressive strength, FeO content and microstructures of roasted samples were investigated. The results show that pelletizing feed either from magnetite ore hematite concentrate can be indurated under the conditions of conventional iron ore sintering. Hematite pelletizing feed has better sintering property than magnetite pelletizing feed. Pelletizing feed consolidation in CAP cells is identical to the individual pelletizing feed, but the strength of CAP cells is much higher than the individual pelletizing feed. Higher basicity in both pelletizing feed and matrix feed is beneficial to the strength of CAP cells. Individual strength of pelletizing feed is not the decisive factor in CAP as the pelletizing feed has been embedded into the matrix with high basicity and formed an organic whole. The main chemical compositions and basicity of pelletizing feed and basicity matching with matrix feed is important.

Jan 1, 2015

By M. Kobashi, T. Choh, N. Kanetake

"A new processing route, which enables the cost-effective and energy- saving fabrication of metal matrix composites, have been proposed. The pressureless infiltration of the reactive powder blend with molten aluminum was investigated in this work. The molten aluminum infiltrated into the [Ti + C] powder blend spontaneously, whereas the spontaneous infiltration into the TIC powder phase did not occur under the same experimental condition. The processing time was shortened and· the processing temperature was .lowered by adding the aluminum powder in the [Ti + C] powder. The differential thermal analysis revealed that the aluminum powder in the powder blend melted at 933K and then ignited the reaction between titanium and ·carbon. However there was an .optimum additional amount of aluminum in the powder blend. The TiC formed in situ had three-dimensionally continuous morphologyIntroductionThe squeeze casting process has been used as one of the processing routes for aluminum matrix composites. [1, 2]. Non-reactive metal-ceramic systems have been, generally, used in this technique in order to prevent the degradation of the ceramic phase. Materials obtained by this process basically consist of a continuous metal matrix and discontinuously dispersed ceramic particles. Reactive systems have begun to be introduced into the infiltration process· recently [3A]. Since the ceramics are synthesized in-situ, this process can provide a continuous ceramic matrix [5]. This is one of the outstanding features of this technique in that a bulk ceramic-can be synthesized at relatively lower temperatures in a short time. Another advantage is that the highly reactive combination of a ceramic with a molten metal is in many cases wettable [6], which enables a spontaneous infiltration."

Jan 1, 2000

By Qian Xu, Guangshi Li, Xionggang Lu, Xingli Zou, Hongwei Cheng, Cong Xu, Changyuan Lu

The roasting of nickel-bearing sulfides is a complex but important process which has not been adequately characterized. Combination of X-ray diffraction and scanning electron microscopy has been proved to be useful for such experiments. The leaching results of nickel, copper, iron and cobalt was analyzed by ICP methods. Process possibility of polymetallic sulfide concentrates through a three-step procedure (oxidation roasting - chlorination - water leaching) was suggested. Ammonium chloride could react with nickel/copper oxides to produce intermediate complexes. At the temperature range of 280~340 oC, these complexes further decomposed to the corresponding simple chlorides. Roasting sulfide concentrate using NH4Cl is effective for complex ores.

Jan 1, 2016

By Honggang Zhong, Tan Yi, Qijie Zhai, Zhao Dan, Xinping Mao, Huigai Li

"The influence of superheat degree on the distribution and volume content of inclusions were studied in 65Mn thin slab produced by compact strip production(CSP) in Zhujiang Steel in China, The results showed that the diameters of inclusions are mainly less than 5µm. Most of the inclusions gathered at the 1/4 thickness direction for the thin slab of 27? superheat degree, compared with the center position for that of 37?. There are more inclusions larger than 50µm in the low superheat samples, which is caused by the short floating time. In addition, the inclusions were observed and analyzed by metallurgical microscope, SEM and EDS in order to ensure their composition, type and further find their source. It was find that the types of these inclusions mainly are Al2O3, SiO2,CaO and their composites, a few of them are TiN and MnS.IntroductionIt is well known that inclusions have a great impact on the strength, plasticity, fracture toughness, cutting performance, fatigue property and corrosion resistance of steels. Especially, with the demand for thinner slab, the cleanness is increasingly becoming more significant as a quality criterion[1]. High manganese and carbon steels not only demonstrate high strength but also proper plasticity. There are many problems unsolved for 65Mn steel as a result of the low solidification rate, bad thermal strength, crack sensitivity and low casting temperature[2,3].The superheat of the molten steel has a great impact on the erosion of refractory lining, molten steel fluidity and non-metallic inclusion behavior[4]. The serious erosion situation of ladle lining, nozzle and casting tundish will give rise to more inclusions at a high superheat. Meantime higher superheat will make second dendrite arm spacing coursing and element segregation which lead to inclusion, bubble formation and shrinkage cavity. On the contrary, it is hard for non-metallic inclusions to float up with a low superheat value. Inclusions of 65Mn steel, which produced in different superheat condition by CSP, were studied for the sake of higher slab properties including statistics and EDS analysis."

Jan 1, 2012

Accretions of dust on the walls of the offtakes from furnaces and in the waste heat boiler are a cause of significant operating and maintenance problems in non-ferrous smelters. The dust originates from entrained solids in the gas stream and vaporised species that condense during gas cooling. Control of dust formation is very important for minimising the formation of accretions and reducing the severity of environmental problems caused by toxic species, such as those containing arsenic, in the dust. The present paper discusses the formation of accretions and the condensation of dust in copper smelting from a thermodynamic viewpoint. Changes, in gas composition and the amounts and identities of the condensed species in the dust are calculated using computational thermodynamics. Interactions between dust species to form accretions are considered in the light of appropriate phase equilibria. The results show that the nature of the dust formed varies greatly, depending on the temperature and the amount of oxygen present during cooling. Control of the amount of oxygen is required if offtake and waste heat boiler accretion problems are to be minimised.

Jan 1, 2002

By Arthur G. Hunt

Smelting using the direct-to-blister process commenced at Olympic Dam on 31 July 1988. The unique nature of the Olympic Dam ore body led to the selection of the direct to blister smelting process. Significant improvement in the design of the furnace and the understanding of the fundamentals of the process and its operation has occurred in the 10 years of operation. The paper will discuss the operation of the #1 Smelter and the design, preparation for start up and early operating experience of the #2 Smelter.

Jan 1, 1999

By C. Lupi

The electrorefining of primary copper is a well known technology: in this work copper scrap was directly processed in the same way. he copper and copper alloy scrap was previously pressed by means of a 20 tons apparatus in order to avoid pyrometallurgical operations. The samples obtained in this manner showed a good compactness so that they were used as anodes in the electrorefining tests. The tests were carried out on anodes made by copper scrap, copper alloy scrap and a mixture of the two. The electrorefining tests were performed at both 303 and 333 K, in a perspex cell having a volume of 500 ml using a current density of 250 A/m2. The cathode used was always a sheet of pure copper and the electrolyte composition was 40-50 g/l Cu as CuS04 and 150-200 g/l H2SO4. Current efficiency in the range of 92-97% and specific energy consumption ranging from 0.14- 0.20 kWg of copper were reached in all the tests. The refined copper deposits were analyzed by AAS to verify their purity and observed by SEM to highlight their morphology.

Jan 1, 1998

By Qian Xu, Xionggang Lu, Xingli Zou, Zhongfu Zhou, Shuhua Geng, Hongwei Cheng

Herein we report an electrochemical route from oxides (SiO2, TiO2)/sulfide (MoS2)/carbon mixture precursors to Mo-Si-Ti-C composites in molten salt. The electrochemical process was carried out in molten CaCl2 at 800 °C with a potential of 3.1 V, and a graphite-based anode was used in the electroreduction process. The reaction mechanism and the influences of the stoichiometry of the initial mixture precursor on the morphology and phase composition of the final products were investigated. It has been found that Mo5Si3/MoSi2/Mo3Si/Mo, Mo5Si3/MoSi2/Mo2C/SiC, and Mo5Si3/Mo2C/Ti3SiC2/TiC/Mo composites can be electrosynthesized directly from their oxides/sulfide/carbon mixture. The preliminary experimental results suggest that the electroreduction process can be used for the controllable electrolytic production of alloys/carbide-containing composites from oxides/sulfides/carbon precursors.

Jan 1, 2016

Studies of electric pulse (EP) disintegration were conducted on ores of disseminated precious minerals, 'on platinum-bearing chromitites of the Konder Complex, Russia, on diamond-bearing impactites of the Popigai meteoritic crater, Russia, and on and diamond-bearing metamorphic rocks of Northern Kazakhstan. It was shown that EP disintegration ~s a technology that achieves ideal liberation of disseminated minerals, and is a new efficient method to study accessory minerals.

Jan 1, 1991

By Ulrich Kerney

In 1996, bath smelting technology for lead recovery from concentrates and secondary materials was introduced in Nordenham to replace the common sinter plant/shaft furnace operation. Since start-up, a continuous improvement of equipment and operation lead to a steady increase of capacity and plant availability. The decision to skip the reduction stage for slag treatment now allows the treatment of 200000 t/a feed materials with a secondary fraction of up to 70 %. The main feed source for the furnace is automotive battery recycling, which offers oxide paste and metallics to be molten under oxidizing conditions in the lance fired furnace. The lead bullion is transferred to the refinery, where copper, silver and other impurities are removed. Silver is recovered as doré quality. All loopings are recycled to the BSF. Inert feed material is collected in a so-called lead concentrate of metallurgical origin, the primary slag, which is sold. It is rather a valuable feed material for further processing than a slag The off-gas is cooled in a flux-flow system, entering then an electrostatic dust precipitator. Having passed a further washing and cooling system, SO2 is oxidized and collected and sold as concentrated sulphuric acid. The presentation will cover a review of the start-up phase, the development of significant production parameters over the last years and actual production routes and figures. A comparison of environmental data between new and old applied technology is made.

Jan 1, 2006

By Yamei Han, Jiang Du, Jinhui Peng, Mengbi Fu, Libo Zhang, Zhengfu Zhang

"A continuously pilot synthesis by microwave-heating was used in preparing the cathode material LiNi113Co113Mn11302 for Li-ion battery, which used Ni1/3Co1/3Mn1/3(0H)2 and LizC03 as raw materials. Decomposition of the raw materials and synthesis of LixNi113Co113Mn11302 would be fmished in single roasting process. In addition, using microwave-heating would reduce the reacting time largely. Furthermore, the yield of LixNi1/3Co1/3Mn1/302 synthetized in single roasting process was 50 kg. Meanwhile, the effects of Li:(Ni+Co+Mn) molar radio (Li:(Ni+Co+Mn)=l.06, 1.075, 1.09, 1.15) was studied in this paper. XRD, SEM and EIS were used in characterizing the cathode material. The results showed that the best Li:(Ni+Co+Mn) molar radio was 1.075. It was found that the LiNi113Co113Mn11302 synthetized with Li:(Ni+Co+Mn)=l.075 had homogenous distribution of particles and ideal layered structure. The galvanostatic charge-discharge(O. l C, 2. 75-4.3V, vs. Lt /Li) tests showed that the initial discharge capacity of the LixNi113Co113Mn11302 was 159.5mAh·g-1, and the discharge capacity was 157.6mAh·g·1after10 cycles.IntroductionRecently, as the cobalt was expensive and the restriction of dynamic power, the commercial cathode Li2Co02 which was expensive, toxic, and high pollution had exposed its defects[1·2l. Since T.Ohzuku[3l first reported the layered LiNi113Co113Mn11302, this material had high reversible capacity and caused the attentions of researchers[4l. Its reversible capacity was l 60mAh/g and 200mAh/g in the voltage range of 2.75-4.3V[5-61. But for the present, preparing LiNiwCowMnw02 by traditional had lots of disadvantages, such as the long heating time, the high cost and the volatizing of lithium and so on[7-9l. According to these, traditional prepatation wasn't good for sustainable development and energy conservation."

Jan 1, 2013

By Emilia Visileanu, Eftalea Carpus

"Ecological economic policy shall be understood as the sum of political, economical and environmental measurements aimed at the entire economy dematerialization and the dematerialization shall be ""imposed"" since the designing stage of goods and services"". European textile and clothing industry with a long leading tradition in terms of innovation, fashion and creativity, continues to be one of Europe's major industrial sectors. Textile industry affects the environment by high consumption of water, energy and chemicals, as well as by the large amount of waste it generates as a result of using a large number of chemicals and technological processes.Textile waste prevention, reduction and ecological exploitation require the implementation of new management and education tools.Introduction“Europe must learn from the experience of global economic and financial crisis ""- this was the conclusion of the European Commission that has elaborated a ten-year strategy designed to reinvigorate the economy and make possible a growth which is ""intelligent, sustainable and favorable to inclusion"", by a better coordination of national and European policies.Adapting infrastructure and logistics that encourage the marketing of ""sustainable"", ""fair traded"" and ""green"" products as well as other special „green” products will facilitate the movement towards dematerialization and eco-efficiency among producers."

Jan 1, 2012