Advanced Materials Research Vols. 113-116

Abstract: The iron, residue valuable metal in the zinc-volatile kiln slag, has its own characteristics of complex mode of occurrence, the relative high content and difficult recovery. Based on the differences in magnetism and specific gravity between iron rich part and carbon rich part, integrated to the water waste problem through current dry process to recover iron, ribbon, a complete set of all dry beneficiation process had been developed. It included: microwave drying, coarse crush---pre-screening technology, mid crush---fine crush technology, two parts---three steps magnetic separation to produce Fe powder, four steps magnetic separation and air medium re-election of carbon powder processing steps. Meanwhile, it carried out a reasonable selection for the crush equipment and gravity separation equipment. And it developed a new type of magnetic separation equipment. They enable a more uniform particle size and a higher grade and recovery of Fe and carbon powder, as well as lower energy consumption and higher production efficiency advantages. The zinc-volatile kiln slag is promoted to be a further recycling, finally.

Abstract: Pulverized coals are widely used by injection into the blast furnaces in order to replace expensive cokes. In this paper, a new catalytic combustion promoter, containing manganese dioxide with other oxides (or carbonates) of rare earth metals and alkali earth metals, was developed to enhance the combustion of pulverized coal. The effects of addition amount on the ignition temperature and the combustion efficiency were investigated. With more promoters added, the ignition temperature dropped, whilst the combustion efficiency increased significantly. Industrial test showed that, with the addition of 0.4% of the promoter, the coke consumption reduced to 26.7 kg/tFe (equivalent to 7.5 million US dollars per blast furnace per year), and the carbon contents in the fly ash dropped to from 43.1% to 32.4%, which suggests great economic and environmental benefits.

Abstract: Cu(OH)2 precursor was synthesized by direct precipitation method and CuSO4 and NaOH were used as raw materials. Then, Cu(OH)2 precursor was calcined in muffle furnace at 400°C for 2h in order that CuO particle was obtained. Through the analysis of the factors affecting the CuO, the paper determined the optimum conditions for the synthesis of nano-CuO with the direct-precipitation method. Then the paper analyzed phase composition and crystal structure of samples using XRD and calculated the average grain size of samples by Scherrer formula, and observed and analyzed by TEM to characterize the morphology and particle size of samples. The optimum precipitation conditions are as follows: when the precipitation agent is 3.2:1, reaction time 40min and precipitant concentration 0.6mol.L-1. The average size of CuO particle prepared under the conditions is 18nm and the yield is 96%.

Abstract: The tests on physical and mechanical properties of fiberboards made of wood fiber with ammonium lignosulphonate/urea as filling material are performed according to requirement of EU standards EN 622-2-2004 "Fibreboard-Specifications Part 2: Requirements for hardboard" reveal the reaction mechanism of formaldehyde-free fiberboards with ammonium lignosulfonate /urea as filling material through analysis of characteristics of chemical reactions on ammonium lignosulfonate and urea by FTIR and the chemical reaction analysis of C atom by ESCA. The results show that physical and mechanical properties of fiberboards with ammonium lignosulphonate/urea as filling material have reached the requirement of EU standards EN 622-2-2004, the forming of furan resin, the results of reaction between urea and furfural substances is main reason for the better physical and mechanical properties of lignin-based formaldehyde-free fiberboard.

Abstract: In order to simulate accurately the formation process of the keyhole in laser deep penetration welding. Multiple reflection and Fresnel absorption are implemented simultaneously with the ray tracing technique in the keyhole. With all the governing equations including continuity, momentum and energy equation, the VOF method is adopted to trace the free surface of the molten pool. Simulation results are compared with the experimental ones to verify its validity.

Abstract: Exogenous jasmonic acid (JA) and salicylic acid (SA) can have an important effect on rice allelopathy. Currently, the role of endogenous JA and SA on rice-barnyard grass interaction is largely unknown. In this study, the levels of JA and SA in tissues and their correlation to rice allelochemicals inducing with barnyard grass are analyzed. Rice allelochemicals production was enhanced by coexistence with barnyard grass and allelochemicals of the allelopathic variety, PI312777 were generally higher than those of non-allelopathic variety, Liaojing9. Furthermore, JA contents of two rice varieties were generally greater in roots than in shoots, and differed clearly with tested times. The SA levels of PI312777 were generally higher than those of Liaojing9 in shoots but opposite trend in roots. The contents of total allelochemicals correlated positively with SA (Pearson correlation, r = 0.91, P < 0.001). These results indicate that as the phytohormones, JA and SA play a provable role in chemical communication between rice and barnyard grass and participate in rice-barnyard grass allelopathic interaction. Future studies should determine the signal molecules in root exudates of barnyard grass and their functions.

Abstract: As the main adhesive types in wood-based panel industry，urea-formaldehyde has such shortcomings as high levels of free formaldehyde content and formaldehyde emission of its bonding product. In this experiment, we try to modify urea-formaldehyde resin with keratin through copolymerization reaction. Through the determination of such reaction technology as molar ratio, adding sequence of keratin and adding amount of keratin, we finally synthesized the low toxic urea resin. The results show that the optimum molar ratio is 1.3:1, the adding amount of keratin is 5% and adding keratin after the third feeding of urea is the best choice. By optimizing the synthesis process, we ultimately get the low toxicity modified urea-formaldehyde resin. At the same time, modified urea-formaldehyde resin cost has been reduced because extensive sources of keratin and low cost.

Abstract: Organoclay has a low electrical conductivity and a proper dielectric constant which makes it to be used as a gate insulator. In a dry form, the organoclay exists in aggregates of montmorillonite platelets and very little surface area of the montmorillonite is exposed. For uniform dispersion of the clay aggregated, PA-66 and organically modified Na-montmorillonite (OMMT) were melting blended by using an internal mixer. The crystalline change and effects of intercalation were investigated with X-ray diffraction. Results of thermal properties, micro-structure, surface resistance and crystallization behavior indicated that OMMT had obviously effects on PA-66. DSC results showed that the existent of OMMT had effect on PA-66/OMMT nanocomposites and OMMT content had important effects on the scatter of OMMT in PA-66 matrix.

Abstract: The recycling of crop straw and waste plastic related to environmental pollution control and improvement.In this paper,we study the effects of different kinds of coupling agents on the mechanical properties and the microstructure change of the composite; MAPP、MAPE and TSZ as the coupling agent to enhance the interfacial adhesion between straw fiber and HDPE. The results indicate that: Coupling agents can modify the Straw/HDPE composites’ combined state of the two phases interfaces. MAPE can improve the mechanical properties of composites better than MAPP. Adding TSZ would suppression the two interfaces combination of HDPE and straw, depress the mechanical properties.DMA shows that adding MAPE in the composites, the storage modulus and glass transition temperature increased, the damping performance decreased. SEM shows that after adding MAPE the combination of composites have significantly improved.

Abstract: Three kinds of phenols, namely gallic acid, syringal alcohol and ferulic acid, were selected as laccase natural mediator to investigate the changes of fiber surfaces, morphological properties of fibers, kappa number and physical properties of OCC (Old Corrugated Containers) pulp with laccase/ natural mediator system treatment. It was illustrated that condensation reaction of phenols could be occured by catalytic oxidation of laccase. The results of fiber quality analysis and SEM observation showed that after treated using laccase/ natural mediator system, the resultantly yielded OCC pulp had much smoother surface, larger fibers coarseness, higher kappa number, and the auto-adhesion of fibers could be observed in the fibers. In additon, the wet strength of handsheets, especially the wet ring crush strength, was improved obviously, compared with control sample.