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By Wen-long Zhan, Zhe Ning, Jun-hong Zhang, Teng-fei SONG, Zhi-jun He, Qing-hai Pang

In order to investigate the influence of granularity on the gasification property of coke after microwave irradiation, comparison of ordering of carbon structure and internal microstructure of granular coke before and after microwave pretreatment was carried out. It is shown in X-ray diffraction results that the diffraction intensity of the coke sample significantly increased after 40 s irradiation under 264 W microwave power, which indicated the decrease in reactivity of coke.

Mar 1, 2017

By Wei-Tong Du, Zheng-Lei Guo, Yu Wang, Shu-Chao Wang

The influence of bottom blowing a CO2–O2 mixture on the bath temperature of a vanadium extraction converter was studied by using the characteristics of CO2 with weak oxidizing. It was studied in two aspects: oxygen content and temperature. The experiments showed, when the ratio of the mixture of CO2–O2 was 2:8 at 1300 °C, the bottom blowing of the converter inhibited the heating up of the hot metal, thus keeping the temperature below the carbon vanadium transition temperature. At 1360 °C, the sensible heat absorption by CO2 was 1.44 times that absorbed by O2 per mole. Meanwhile, at 1300 °C, 20% CO2 released the chemical heat of 13.58 kJ. So with the increase of the CO2 ratio, the bath temperature was reduced. The research showed that the bottom blowing of a CO2–O2 mixture had an advantageous effect by decreasing the temperature of the vanadium extraction converter.

Mar 1, 2018

By Xueqin Li, Xuewei Lv, Wenchao He, Jie Qiu, Jie Dang

Iron powders are mainly produced by Hoganas process and water atomization process, while both of which have the disadvantages of energy consumption. To obtain iron powders with higher particle sphericity, more uniform particle size distribution and higher proportion of total iron (TFe), a novel method considering of energy conservation was developed in this paper. The hot metal was transformed into granules with air cooling in a rotary disc atomizer, iron powder particles and hot off-gas were collected respectively. It was found that the property of the obtained iron powders was mainly controlled by the flow rate of the hot metal, the diameter of the rotary disc and the rotary speed and the heat of off-gas has a high level of value as well.

Mar 1, 2017

By A. O. Apata, F. V. Adams

The use of rice husk ash as aggregate for foundry sand mould production has been studied. 5 –25wt% rice husk ash was added to the sand mixture. The chemical, physical and mechanical properties measured include: chemical analysis of the rice husk ash, particle size, density, permeability, compatibility mouldability, moisture content, green compression and shear strength, dry compression and shear strength. The result revealed that, addition of rice husk ash to River Niger Silica sand, increased the mouldability, compatibility, grain fineness number, both green and dry strength, slightly decreased the density, permeability and moisture content. The result shows that better properties is achievable by the addition of rice husk ash to River Niger silica sand and can be used to enhance the mould properties of foundry sand.

Mar 1, 2017

By Shaohua Ju, Feng Jiang, Jian Jian, Hongying Xia, Jinhui Peng, Libo Zhang

Microfluidic solvent extraction of zinc from sulfate solution was studied using di-2-ethyl hexyl phosphoric acid, D2EHPA, in sulfonated kerosene as diluent. The influence of different parameters on the extraction of zinc, such as flow rate, temperature, flow rate ratio, extraction concentration, and saponification ratio of extractant were investigated and the conventional and micro fluidic extraction were compared. Under the optimized conditions, micro fluidic extraction efficiency of zinc is up to 97.1%. It is better than that conventional extraction. Therefore, microfluidic solvent extraction can achieve high efficiency and low consumption of extraction process.

Mar 1, 2018

By Kazuki Morita, Ye Wang

In order to optimize the B removal during slag-refining process for solar-grade silicon production, a new process for the removal of B in molten Si was proposed based on the principle of oxidized chlorination and evaporation. B can be generated and evaporated in the form of B-containing gas (BOCl) from molten Si using CaO–SiO2–CaCl2 slag system. Compared with the binary systems of CaO–CaCl2 and SiO2–CaCl2 slag, the ternary slag system CaO–SiO2–CaCl2 showed a better potential (90 pct) for B removal at 1723 K for 2 h. Moreover, the diffusion coefficient (D) of B in the slag was also determined using tube-molten pool method. Through this, it was found that the rate-limiting step of B-removal in the slag refining process is controlled by B transfer in the slag interface and surface.

Mar 1, 2017

By Jafar Safarian, Gabriella Tranell, Stine Espelien

Hydrometallurgical treatment of silicon is an effective process for the removal of metallic impurities for producing solar grade silicon feedstock. In the present research, the removal of impurities from silicon is studied through the addition of Mg into a commercial silicon, its solidi fication, and acid leaching. The effect of concentration of HCl, temperature and leaching duration on the removal of impurities are studied. It is shown that the impurities such as P, Fe, Al, Ti, Ca, …are effectively removed through the applied method and Mg improves the segregation and the removal of the impurities. Scanning electron microscopy examination of the samples indicates the disintegration and dissolution of Mg2Si phase in acid leaching which causes the chemical and physical removal of the impurities existing in the phases between the silicon grains. It is shown that the leaching process rate can be optimized through the control of the acid leaching conditions.

Mar 1, 2017

By Benjamin Kohler, Amelinda Olson, Marc Snyderman, Chanaka De Alwis, Mike Lewis, James Cox, Matthew Call, Julia Kluck

UTRS Inc. has developed a novel two-step method to extract commercially viable titanium alloys (patent pending no. 20130164167[1]). This approach has proven its potential to produce a variety of titanium alloys (Ti-6Al-4V,Ti Al ,etc.,) x y and has demonstrated a number of advantages over the current commercial titanium production process. Additionally, the UTRS Process operates without producing CO2 and eliminates the use of TiCl. Step 1: Aluminothermic reduction makes available many types of ores that could otherwise not be used. Due to the aluminothermic reduction technique and the composition of the ore,metal extracted from this step will inherently contain non-titanium elements. Step 2: Electro-refining removes undesirable elements from the thermally extracted titanium. This refined metal has a dendritic morphology with a wool-like appearance that is referred to as “titanium wool”. This new morphology of titanium allows it to have a diversity of endproduct types from titanium powder to bulk titanium.

Mar 1, 2017

By Patricia Negrini Siqueira Poveda, Leonardo G. A. Silva

Thermoplastic materials are sensitive to ultraviolet radiation (UV), which can cause structural changes, causing variation in mechanical properties and appearance. UV range between 250 and 400 nm is considered the most aggressive to polymers, and prolonged exposure to it results in breakage and/or crosslinking chains. Light stabilizer additives, blockers or absorbers are added to the polymers for protection in order to extend the life of the final product. The choice of the adequate light stabilizer additive system depends on factors such as resin final application, thickness, geographic location of exposure, presence of fillers in the composition, contact with chemicals, among others. This study evaluates different additive systems: conventional organic, inorganic nanotechnologyc base and the synergy between them when applied to polyethylene considering carbonyl index and UV/VIS results after aging by QUV chamber.

Mar 1, 2017

By H. Y. Sohn, Y. Mohassab, D. Q. Fan, M. Elzohiery

A flash ironmaking process is being developed at the University of Utah in which iron is produced directly from magnetite concentrate. The kinetics of magnetite reduction by a mixture of H and CO gases was determined in the 2 temperature range 1150–1600 °C. Over 90% reduction degree was achieved at a temperature as low as 1250 °C within 4–6 s which is the typical residence time available in a flash reactor. The kinetics results were applied to experimental data obtained in a laboratory flash reactor in which H and CO gas mixtures were 2 produced from in situ partial oxidation of natural gas with oxygen. CFD was used to simulate the laboratory reactor,and the results were in good agreement with the experimental data.

Mar 1, 2017

By Yijun Cao, Shengpeng Su, Guihong Han, Xiangyu Song, Yanfang Huang

Binder is indispensable in the production of iron ore pellets and the quality of pellets seems to be related to the interactions between binders and iron minerals. Humic acid is proved a suitable binder for iron ore pelletizing. In this paper, the interactions between humic acid and iron minerals were investigated by adsorption experiments and molecular dynamic simulations. Adsorption experi- mentalresultsshowthattheadsorptionofhumicacidonhematiteiseasierthanthat on magnetite, and the maximum adsorption capacities of humic acid on hematite and magnetite reach 17.1, 7.39 mg/g, respectively. The results of adsorption iso- therms indicate that the Langmuir model provides the best correlation of the experimental data, while the thermodynamics results demonstrate that the adsorp- tion process is a spontaneous exothermic process. Molecular dynamic simulations reveal that the interaction between hematite and humic acid is stronger than that between humic acid and magnetite. (cid:1) (cid:1) (cid:1)

Mar 1, 2018

By D. A. Hayman, J. D. Steenkamp, G. M. Denton

Design of furnace containment systems can be based on one of two design philosophies: Insulating or conductive lining designs. In insulating lining designs, management of the compatibility between refractory materials and process materials (typically liquid metal and/or slag) is an important criterion for furnace design, and an important process parameter to control during furnace operation. In conductive lining designs, management of the integrity of the layer of frozen material (freeze lining) on the interface between the liquid process material, and the refractory lining, is important. For example in ferrochromium production, both lining design philosophies are applied. The work presented here discusses the significance of lining design philosophy in the context of ferrochromium production.

Mar 1, 2017

By Duclerc Fernandes Parra, Vijaya Kumar Rangari, Washington Luiz Oliani, Ademar Benevolo Lugao, Nilton Lincopan

Due to its versatility and low cost, polypropylene (PP) is one of the most widely used polymers in the world, consequently in research and development of new products. The polypropylene modified was prepared by gamma irradiation in acetylene at 12.5 kGy dose, technical polymer also known as high-melt-strength-polypropylene (HMSPP). It was mixed with montmorillonite (MMT) clay and silver nanoparticles (AgNPs) for bactericide activity. HMS-Polypropylene-clay-silver nanocomposites were manufactured using twin-screw extruders. Those materials were prepared by a melt mixing process via twin screw extrusion with a wide range of processing conditions. The polypropylene nanocomposites (PPNC) surfaces were exposed to gamma-radiation (60Co) source in presence of nitrogen as inert atmosphere at 1; 3; 5; 10; 20 and 50 kGy doses for modified the surfaces in order to enhance biocide activity. The samples surfaces were characterized by Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX) and evaluated by determination of bactericide effects. The results indicate the formation of structures predominantly intercalated of HMSPP nanocomposite. Contact tests for antibacterial activity of the hybrid polymer were applied against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. The irradiations on the samples surfaces were insufficient to promote activity on contact biocide tests.

Mar 1, 2018

By Neale R. Neelameggham, Brian R. Davis

Organic agriculture is using natural materials such as degrading plant matter to replenish soils. This includes use of naturally degraded plant components such as peat, humus and weathered brown coals. Another important natural organic matter which has not been applied in agriculture thus far has been the black coal, Here we show that reversing the coal formation reaction by combined hydro-oxidation principles of biochemical engineering in natural conversion methods in an accelerated fashion. The modified coal soil additive can convert arid lands into farm lands for the future to sustain the population growth. In addition, the development of this new use of black coal will revive economically deprived areas from phasing out coal in the USA and Europe. This will show how the Stored energy in coal can be made renewable in helping plant growth under the soil to facilitate above ground photosynthesis.

Mar 1, 2018

By Z. Jing, C. Jun

High-purity Bi2O3 was prepared via extraction-preparation stripping method use BiCl3 leaching solution. Parameters such as oxalic acid concentration, phase ration, aging duration, feeding duration, were examined for their effect on the size and morphology of precipitate. The precipitate was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analysis, differential scanning calorimetry and thermal gravity analysis (DSC-TGA) and infrared spectroscopy analysis (FT-IR). Bi2O3 was characterized by elements analysis, particle size analysis and scanning electron microscopy (SEM). Bi2O3 product of 680 nm was obtained using 15 g/L oxalic acid, 1/1 phase ration, 0 min aging duration, 0 min feeding duration and calcinating at 500 °C for 2 h.

Mar 1, 2018

By Wenxuan Xu, Shusen Cheng, Guolei Zhao

According to cross beam temperature measuring data of stock surface gas flow in blast furnace production process, using zoning method to deal with stock surface gas flow cross beam temperature measuring data, the evaluation system of stock surface gas flow distribution in radial direction and circumferential direction was established. Central index, platform index and edge index were proposed to evaluate stock surface gas flow distribution in radial direction, global uniform index and local uniform index were proposed to evaluate stock surface gas flow distribution in circumferential direction. Combined with actual production of 5500 m3 blast furnace and typical morphology of stock surface gas flow distribution,the strength of stock surface gas flow distribution was divided into five grades to provide guidance for the optimization of blast furnace operation.

Mar 1, 2017

By Camille Fleuriault

Continuous development of lead recycling technologies has driven the increasing contribution of secondary lead in battery manufacturing over the years. This review presents and compares the different technologies available for pyrometallurgical processing of secondary lead materials. Smelting is most often achieved in reverberatory, blast, rotary or electric arc furnaces, using single or two stage routes. Thermal re fining is the most common technique used for the production of lead and its alloys. Some improvements in battery breaking technologies and emission control have also specifically contributed to improve the performance of the smelting and refining units. Recycling lead is facing the challenge of increasing production while meeting more and more stringent regulations. This review will also include an analysis of the current secondary lead market as well as an economic outlook for the years to come in regards to rapidly changing environmental standards.

Mar 1, 2018

By O. M. Popoola, A. P. I. Popoola, D. O. Okanigbe, A. A. Adeleke

The physical, chemical, mineralogical and morphological characteristic of the waste copper smelter dust (CSD) from Palabora Copper (PTY), Limpopo, South Africa, has been reported in the open literature. The bulk of this material falls within the −53 μm particle size fraction with a copper weight percent of 18.02 as determined with the XRF. The high presence of reactive gangue minerals such as mullite (42.97 wt%) and quartz (11.45 wt%) necessitates that the waste CSD be first upgraded of its copper value in the falcon gravity concentrator before subsequent hydrometallurgical treatment. As an initial step, a sample preparation was carried out to make the sample amenable to both real density determination and copper upgrade experiment, thus resulting in 97% of the particles passing the 300 μm sieve aperture (d97 = 300). The laser particle size analyzer (LPSA) was used to analyze the d97 = 300 and the results showed a %change from 90.82% to 95.59%, with a real density of 2.830 for the waste CSD. The result of the copper upgrade showed that test 8 with treatment combination of 80 rpm and 4.5 l/min gave the highest % copper grade of 1.37 which is still less than the %grade of copper in the feed (1.49%). It thus lead to the recommendation that another type of centrifugal separator that will allow the introduction of the feed as slurry so that the pulp density and feed rate can factored into the whole upgrade experiment, consequently reducing the significant amount of losses and the chances of an improved grade and recovery of copper from this waste CSD.

Mar 1, 2018

By Dong-Wei Li, Tao Zhang, Diao Jiang, Zhou Wang

The feasibility of simultaneous vanadium extraction and phosphorus removal from vanadium-containing hot metal was demonstrated with laboratory experimental investigation.The effect of CaO addition on the distribution behavior of vanadium, phosphorus between basic vanadium slag and semi-steel as well as the influence of basicity on the leaching behavior of vanadium, phosphorus was particularly studied. Results show that vanadium oxidation ratio slightly decreases with the increase of basicity, but phosphorus oxidation ratio rapidly increases with the increase of basicity. The leaching of roasted vanadium slag with various CaO contents indicated that the optimal slag basicity for extracting vanadium was 1.5. The maximum leaching efficiency of vanadium could reach 84.02% and the sequence of vanadium leaching efficiency by using different leaching reagents was: 160 g/L Na2CO3 > 100 g/L NaHCO3 > 400 g/L (NH4)2CO3 > 5% H2SO4.

Mar 1, 2017

By Xudong Liu, Ganghua Fu, Yufeng Guo, Wei Chen, Yujia Tan, Tao Jiang

Willemite is usually found in high-silicon oxide zinc ore and zinc metallurgical secondary resources but without effective extraction method yet. In this study, zinc was extracted from willemite by sodium salt roasting and ammonia-leaching process based on the idea of zinc phase reconstruction. The effects of Na2CO3 dosage, roasting temperature and roasting time on phase transformation and zinc leaching rate were studied, respectively. The results show that Zn2SiO4 was transformed into ZnO or Na2ZnSiO4 during roasting process. After roasting at 800 °C for 2.5 h at ratio of n(Na2CO3)/n(Zn2SiO4) = 2.5:1, willemite was thoroughly transformed into ZnO. The zinc leaching rate of the roasted sample was 97.62% in NH4Cl–NH3–H2O leaching system, which increased by 91.57% compared with zinc leaching rate of 6.05% when willemite was directly leached in NH4Cl–NH3–H2O system.

Mar 1, 2017