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By Leila Figueiredo de Miranda, Leonardo G. de Andrade e Silva, Anderson dos Santos Mesquita

ThisworkseekstounderstandifPETcompoundswithcarbonblackcan be uses to replace polypropylene and polystyrene for anti-static packaging mate- rials. PETcompoundswerefabricatedcontaining10.0;11.0;12.0and15.0weight % of carbon black with a particle size 325 mesh. We determined the thermome- chanical properties (Dynamic Mechanical Analysis—DMA, Tensile Properties, Fracture Toughness, and Hardness) and Electrical properties of the compounds. In conclusiontheresultsshowthecompoundbased onPETfilledwith 15.0% carbon black might be used in the handling, transportation and storage of electronic components because their mechanical properties, thermal and resistivity are satis- factory for this purpose. (cid:1) (cid:1)

Mar 1, 2018

By J. A. S. Tenorio, A. B. Botelho Junior, I. A. Anes, D. C. R. Espinosa, M. A. Caralho

Recovery of metals from reserves with low grade and from waste with high presence of contamination is a challenge to be overcome. Metals like nickel, cobalt and copper could be recovery from nickel laterite leach waste by many different processes. Among recovery processes that could be applied are ion exchange, solvent extraction and precipitation. The aim of this work was recover copper from liquor of nickel laterite by precipitation using chemical reduction. Copper concentration in liquor was 146 mg L −1 and reducing agent used was sodium dithionite 1 mol L −1. Influence of stirring speed was studied between 0–200 rpm. Results indicated a selective precipitation of copper on solution with others metals at 240 mV. The analyzes were conducted in SEM, energy-dispersive X-ray spectroscopy and XRD, that indicated presence of copper and sulfur.

Mar 1, 2018

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 Haibin Wang, Baojun Zhao, Xueyi Guo, Zhixiang Cui, Zhi Wang

In conventional copper production, anode copper is produced from concentrate in three furnaces in a process that entails four oxidation steps and one reduction step. Three types of slags are produced that require further treatment to recover copper. Dongying Fangyuan Nonferrous Metals recently developed a simplified process which requires only two custom-designed furnaces instead of the conventional smelting, converting and re fining furnaces. The first furnace continuously produces high-grade matte (>75 wt% Cu) that contains little iron (<2 wt% Fe). The liquid matte is continuously fed to the second furnace, which produces anode copper. The new process signi ficantly reduces the capital and operating costs and increases productivity and environmental sustainability. This paper presents fundamental concepts that enable the simpli fied process to be developed. The detailed operations in Dongying Fangyuan Nonferrous Metals are also described.

Mar 1, 2018

By Wei-Tong Du, Yu Wang, Peng-cheng Li, Shu-Chao Wang

CaCO3 thermal decomposition produces CO2 and CaO, and CO2 can be used as a weak oxidant in vanadium extraction. CaO will also affect the vanadium extraction process. This experiment, taking self-blowing and temperature acquisition experiment system, through adding different quality CaCO3, studies the molten iron in the oxidation behavior of C, V and P and its impact, and analysis of CaCO3 decomposition of the heating effect of the molten pool. The result indicates that adding CaCO3 in the vanadium extraction process had no obvious effect on the oxidation of carbon, but partly increased vanadium oxidation which reached more than 90%. Increased CaCO3 additions also increased cooling the molten pool, with a maximum decrease in temperature of 20 K. In addition, the oxidation of P also increased, reaching 40%. The research has proved that CaCO3 can serve to oxidize V and P is effective in vanadium extraction.

Mar 1, 2017

By Yeole Shivraj Narayan, Nunna Nagabhushana Ramesh, Banoth Balu Naik, Alluru Ramya

MicroEDM process is mainly used for producing miniaturized features like microholes on different types of materials that are hard to cut and difficult to machine. One typical application of microEDM process is microhole drilling operation. Choice and utilization of optimum pulse parameters is of utmost importance for achieving superior surface quality and higher machining rates. However, the process is characterized by low machining rates and considerable overcut as compared to conventional EDM drilling. An attempt is made to investigate the effect of pulse parameters on maraging steel 300 alloy during micro EDM drilling. Parameters like pulse on time, pulse off time, voltage and current are explored through 09 experiments replicated thrice using Taguchi method. Machining characteristics like material removal rate and overcut are studied while drilling micro holes of 500 µm diameter using brass electrode. Evaluation of microhardness after microdrilling is also performed. It is found that puls on time and current influenced the machining characteristics. Minimal change is observed int he microhardness of the alloy after microdrilling.

Mar 1, 2018

By Weizhi Zeng, Michael L. Free, Shijie Wang

Copper electrorefining is an old technique that is generally performed in electrolytic cells with a bottom inlet and top outlet that are convenient for electrolyte flow control. Nevertheless, this configuration cannot effectively direct electrolyte flow to the regions between electrodes, which results in weak convection and inadequate delivery of chemical species and additives. In this article, we discuss the innovations in electrore fining cell design to improve electrolyte flow for better cathode quality and simulation of fluid flow field and particle movements based on finite element modeling method. The resulting fluid flows in cells can transport suspended slime particles to the cathode, where they can be incorporated as impurities. The concentration of suspended slime particles is inversely related to slime adhesion, which is strongly influenced by slime particle sintering, and sintering is dependent on temperature and slime particle composition. Thus, the combination of innovative fluid flow and slime particle sintering can play important roles in improving cathode quality.

Mar 1, 2017

By Sergio N. Monteiro, Artur C. Pereira, Foluke S. de Assis

Jute fibers are among the lignocellulosic with great potential for use in polymer composites. In this work, polyester matrix composites incorporated jute fabric were investigated for their flexural behavior. Specimens with up to 30% in volume of jute fabric were bend-tested until rupture. The results showed an increase in both the composite mechanical strength, principally to a polyester composite reinforced with 30% in volume of jute fabric. A fractograph analysis by SEM disclosed a moderate adhesion mechanism between the jute fabric and the polyester matrix. This mechanism is apparently responsible for the improved performance of the composites.

Mar 1, 2018

By S. N. Monteiro, N. A. Cerqueira, E. B. Zanelato, J. Alexandre, M. T. Marvila, B. C. Mendes, A. R. G. Azevedo, G. C. Xavier

Mortar is a widely used building material and has its application in buildings in extremely vulnerable environments and susceptible to degradation, such as facades. The objective of this work was to evaluate the loss of mechanical resistance to compression and flexure and the loss of mass of the mortars with effluent sludge from paper industry, when exposed to saline environments. The specimens were done with 0, 5, 10 and 15% of incorporation in lime paste and subjected to saline mist equipment that sprays salt solution in cycles simulating natural degradation conditions using literature data. It can be concluded that mortars with a15%incorporation obtained a significant loss of mass and a decrease in their mechanical resistance, which impairs their use in civil construction and influence in other properties of the material, with a level of incorporation of 10% the results within Brazilian standards.

Mar 1, 2018

By Coida D. S. Renata, Gerald Okwuchi Onyedika, Moura E. B. Esperidiana, Graca Valenzuela-Diaz, Martin Chidozie Ogwuegbu, Francisco R. Valenzuela-Diaz, Amauche Cyprian Achusim-Udenko

This work aims to incorporate Mgbee clay, vegetal fibre (Costus afer) in recycled low density polyethylene (rLDPE). The incorporation of clay and vegetal fibre in rLDPE was carried out using a twin screw extruder machine and the nanocomposites were obtained. The nano composites were characterized by the Young’s modules test, tensile tests, bending test, XRD, SEM, DSC, and TG and other properties evaluated. The results of morphological and thermal properties showed a good interaction between the clay, and rLDPE as compared to neat rLDPE.

Mar 1, 2017

By Ian Buterbaugh, Calvin Lo, Tomoko Sano, Brendan Koch, James Catalano, Timothy Walter

In this research, two grades of alumina, one at nominally 85% composition and the other at 99.5% were characterized. Microstructural and phase characterization was conducted using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-ray Diffraction, and micro-computed X-ray tomography. It was determined that the Knoop hardness values were influenced by the porosity in the 85% composition. Quasi-static compressive tests and high strain rate compression experiments were conducted to determine the influence of the microstructure to the compressive properties. It was observed that the overall compressive strengths increased with strain rate. Although the Knoop hardness values were much lower in the 85% alumina due to the porosity, the compressive strength at both quasi-static and dynamic strain rates were not significantl lower than those of the 99.5% composition.

Mar 1, 2018

By Ahmet Haxhiaj, Bajram Haxhiaj

Based on the placement of lead and its consumption in industry branches, the paper deals with the composition of lead in the massive of Kopaonik. Removal, tenuity and grinding of galenit. The paper in particular treats the flotation process, and also treats physico-chemical bases of reagents in the process, as well as decanting, drying, filtering and storage of concentrates. Verification of the chemical composition of Pb concentrates with Pb, Zn, Bi, As, Sb, In, Au, Ag, etc. It is special that in Kopaonik massive the ratio of Pb: Zn composition is 1.4:1.0 and during the flotation lead is inclined to go with pirotines concentrate more than is allowed. We are strongly focused to maximally decrease the Pb amount that goes with pirotine concentrates and wastes. The paper as such gave the first effects in optimizing of these parameters with positive effects in flotation process in Trepca.

Mar 1, 2018

By Joseph Hamuyuni, Dmitry Sukhomlinov, Pekka Taskinen, Mari Lundström

The standard thermodynamic properties of the compound Ca2CuO3 were determined electrochemically by the Electromotive Force (EMF) method. The ternary phase Ca2CuO3 was synthesized from the pure oxides CaO and CuO at CaO saturation using a ceramic route. The EMF measurements were performed over a temperature range 973 T/K 1124. The standard Gibbs energy of formation of the ternary compound Ca2CuO3 was determined using the EMF technique as: DfðoxÞGCa2CuO3 ¼ 21:88422:92 103 T: ð1Þ

Mar 1, 2017

By Jinsheng Wang, Xueming Lv, Wei Lv, Junyi Xiang, Xuewei Lv, Chenguang Bai

In this study, microwave heating was used to dry the nickel laterite which contains plenty of free water, crystal water and hydroxy water. The results showed that compared with the conventional drying process, the microwave drying greatly improved the drying efficiency of nickel laterite. The whole microwave drying process can be divided into three stages according to the drying rates, namely, the rising stage, stable stage and declining stage. The effects of microwave power output and particle size were also studied in the range of 0.8–2.0 KW microwave power and 3–6 cm of particle size. The results showed that the drying time significantly decreased with the increase of microwave power and decrease of particle size. The phases transition of the sample during the microwave drying process were also discussed.

Mar 1, 2018

By Ruixuan Zhang, Yan Li, Shusen Cheng

The measurement of raceway temperature in the blast furnace is a critical issue, which is very significant for judgment of, prediction and diagnosis of the racewa yburning state. This paper deals with mathematical models by Monte Carlo method to approximately simulate the radiation heat transfer in the race-way and establish matrix equations using CCD cameras, which are solved to obtain the three-dimensional temperature field. Due to the existence of fluctuation error, CCD camera measurement error and others,this is analyzed and random error is added in the measurement data to demonstrate the effectiveness and stability of the reconstructed temperature field. The results show that the reconstructed three-dimensional temperature field of the raceway is very close to the exact temperature.

Mar 1, 2017

By Lingling Zhang, Daqiang Cang, Guizhou Zhao

Pilot trial ofthe detoxification ofchromium slag in cyclonefurnace and the preparation of glass-ceramics were investigated in a power plant in China. 10wt.%chromiumslagweremixedwithpulverizedbituminouscoalandlimestone as the raw materials of the cyclone furnace. Cr(VI) in chromium slag was reduced toCr O insidethecyclonefurnace.Themeltwaswater-quenchedintofritandthen 2 3 fired into glass-ceramics with a laboratory ceramicrollerkiln. The preparation and crystallization behavior of glass-ceramics were investigated with differential ther- mal analysis (DTA), physical and mechanical properties testing, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optimal flexural strength exceeding 90 MPa were achieved in firing temperature zone of 1170–1200 °C. Anorthite (CaAl Si O ) and diopside [Ca(Mg, Fe)Si O ] can be identified in the 2 2 8 2 6 glass-ceramicsandCaAl Si O isthepredominantcrystalphase.Fineparticleswith 2 2 8 average diameter of 200 nm distributed uniformly in the glass-ceramics. Granular crystals are intensively interconnected and constituted a crystal skeleton soaked in theglassmatrix.LeachingtoxicitytestdetectedCr(VI)of0.016and0.010 mg/Lof the water-quenched frit and glass-ceramics, respectively. This method provides an effective and comprehensive technique for the detoxification and utilization of chromium slag at low cost and large-scale. (cid:1) (cid:1)

Mar 1, 2018

By Jiongtian Liu, Guihong Han, Shuzhen Yang, Yanfang Huang

Binder, as a necessary functional material of electrode in lithium ion battery, has a vital influence on the electrochemical performance. The humics, coupled with polyacrylamide (PAM) and sodium carboxymethyl cellulose (CMC), were used as a water-soluble binder for LiFePO4 (LFP) cathode using in lithium ion battery. The techniques of cyclic voltammetry (CV) and galvanostatic charge-discharge were conducted to evaluate the performance of humics binder in LFP electrode. The reversible specific capacity of LFP (HA + PAM + CMC) electrode can reach to 142 mAh g−1 after 50th cycling (100 mAh g−1) on conditions of raw materials with 1 wt% PAM addition, humics and CMC with a mass ratio of 3:1 in binder, and the raw materials mixed in an interval order. Humics has the potential to be used as a novel, eco-friendly and high-efficient binder for lithium-ion battery.

Mar 1, 2018

By R. Padilla, I. Gonzalez, M. C. Ruiz, J. Salgado

The mining companies in Chile are increasingly using chloride salts and/or sea water in the sulfuric acid leaching of copper minerals. For this reason, the effect of chloride ions on the solvent extraction equilibria was investigated. Copper extraction isotherms were determined at 25 and 35 °C for aqueous solutions containing 6 g/l of Cu, 7 g/l of Fe, chloride ion concentrations of 0, 60 and 110 g/l, and a pH of 2.0. The organic phases were 20% v/v solutions of a ketoxime (LIX 84-IC) or a salicylaldoxime (LIX 860 N-IC). It was determined that the presence of chloride in the aqueous solution had a large negative effect on the extraction equilibria for both extractants, particularly the ketoxime. Therefore, as the chloride ion concentration increases, an efficient use of the extractant would become more difficult. An increase in the temperature from 25 to 35 °C positively affected the extraction equilibria for these extractants.

Mar 1, 2017

By Manuela Castaneda, Henry A. Colorado

This paper is about the use and stabilization of iron oxide based powders with arsenic contents coming from the purification of water. Cement paste samples with 0.0, 2.5, 10 and 20wt% of waste were fabricated by mixing mechanically all components. There are two main positive impacts of using this waste, first, this waste is produced in large amounts worldwide, and therefore the stabilization has a significant impact for the environment. Second, the waste can be used as an admixture and filler for cement, and therefore reduce the amount of cement in the concrete, which has a major impact in the CO2 footprint since cement industry produces a lot of this gas. Compressive strength and density tests were tested after 28 days. Microstructure was analyzed with scanning electron microscopy and x-ray diffraction. Results show that compressive strengths greater than 20 MPa were obtained and the samples had calcite, portlandite and ettringite phases.

Mar 1, 2018

By Daniel K. Lindberg, Fiseha Tesfaye

To reduce the use of fossil fuels and increase self-sufficiency in energy, nowadays, there is an increasing interest to produce heat, power and transportation fuels from renewable resources. Solid biomass is one of the most important renewable energy sources for meeting this target. However, fouling, slagging, and corrosion threaten long-term operation availability and costs of biomass power plants. Slags accumulated on the surfaces of superheaters, which decrease thermal efficiency, often constitute a considerable percentage of complex inorganic phases. However, thermodynamic properties of the complex inorganic phases and their combined effect, which will help to deal with the slag related problems during high-temperature biomass combustion processes, are not well known. In the present paper, thermodynamic properties of K-, Ca-, and Na-based inorganic phases and their mixtures under different gas conditions are both critically reviewed and experimentally studied. The obtained results are presented and discussed.

Mar 1, 2017