Applied Mechanics and Materials Vols. 217-219

Abstract: This paper studies the construction waste recycled coarse aggregate concrete blocks including waste and brick, through the control of brick in the admixture of recycled coarse aggregate concrete, compound to regenerate waste away in the analysis and research of the brick dosage of recycled concrete performance impact.

Abstract: Weight loss and heat flow during heating process of municipal solid waste incineration (MSWI) fly ash were investigated through the DSC-DTG experiment carried out from 40°C°C to 1400°C°C, with different heating rates (5°C/min, 10°C°C/min, 20°C°C/min) and different atmosphere (N2, Air). Two main weight loss peaks were found at 800°C°C-1000°C°C and 1000°C°C-1200°C0°C for three different samples. Weight loss ingredients were analyzed by comparing the difference of components between fly ash and slag. Then Kinetics parameters of fly ash melting were acquired by Numerical Solution using a C++ program.Introduction

Abstract: Diatomite-based porous ceramics were prepared by hand compression molding under low temperature sintering, using diatomite as raw material, sodium carbonate and polyvinyl alcohol (PVA) as additives. The effects of sintering temperature, addition amount of sodium carbonate and PVA on the properties of porous ceramics were discussed. The prepared porous ceramics were characterized by mercury porosimeter, XRD, SEM and FTIR. And the adsorption of methyl orange by porous ceramics was investigated. The results show that the performances of porous ceramics, such as porosity and crushing strength, change with the addition amount of sodium carbonate and PVA, also the sintering temperature. The optimum formula for preparing porous ceramics used as carrier and filter simultaneously consists of 100 portions of calcined diatomite, 10 portions of sodium carbonate, 150 portions of water, PVA and polyacrylamide (PAM) solution[m(H₂O):m(PVA):m(PAM)=1000:4:4]. When sintered at 900°C, the porosity, crushing strength, average pore diameter and specific surface area of prepared porous ceramics are 71.74%, 4.535MPa, 10.023μm and 230m2/g, respectively. The prepared porous ceramics are composed of tetragonal cristobalite. And the decoloration conversion for methyl orange of prepared porous ceramics can reach 40.43% in 90 min.

Abstract: An effective method was proposed to recycle trimethyl chlorosilane (Me3SiCl) from chlorosilane waste generated by chlorosilane plants to produce hexamethyldisiloxane (Me3SiOSiMe3) and trimethylethoxysilane (Me3SiOEt) through hydrolysis and alcoholysis with ethanol, respectively. And this method had been used successfully in a chemical plant of Hebei Hongxing in North China. The concentration of Me3SiCl in the waste stream varied between 40 wt%~80 wt% mixed with SiCl4, Me2SiCl2, and a smaller amount of 2-MeC5H11 and 3-MeC5H11. Laboratory experiments were performed using simulated wastes in order to obtain optimal operational parameters and validate the feasibility of the method.

Abstract: Based on the high turbidity feature of mine water, Glutinous Rice Starch(St)- Acrylamide(AM) graft polymer cationic flocculant was synthesised by copolymerization with St and AM as materials, ammonium persulfate and sodium hydrogen sulfite as the initiator, 2.3-glycigyl trimethyl ammonium chloride were used as cationic agent. The optimum condition of cation was established through orthogonal experiments: reaction time is 4 hrs, St dosage is 5g, mass ratio of AM and St is 4:1, dosage of initiator is 1.4g, GTA dosage is 2.6g, NaOH dosage is 0.24g, etherification reaction time is 2.5 hrs, reaction temperature is 70°C. The performance of the cationic starch flocculant used as the mine wastewater treating was evaluated.

Abstract: In this paper, strengthened oxygen delignification of NaOH-AQ pulp of fast growing poplar with low kappa number (Kappa number 13.5, viscosity 851ml/g, brightness 37%ISO) was introduced. By changing different conditions of strengthened oxygen delignification: alkali dosage, temperature, time, oxygen pressure and assistant agent, etc., and detecting and analyzing the pulp kappa number, viscosity, brightness and delignification of the lignin after strengthened oxygen delignification, conditions better suitable for strengthened oxygen delignification of NaOH-AQ pulp was obtained: pulp consistency 10%, alkali dosage 2.5%, H2O2 dosage 3%, MgSO4 dosage 0.5%, oxygen pressure 0.6Mp, temperature 100°C, time 60min; under the conditions, the brightness of the pulp reached 77.2%ISO , pulp viscosity was 748ml/g, the pulp yield was 95%. This provided an experimental and feasible reference for TCF bleaching of NaOH-AQ pulp of fast growing poplar with low kappa number.

Abstract: A kind of composite grinding aids was developed of expanded perlite and grinding aids M-1,and the effect of grinding on it was analyzed by cement powder fineness, specific surface area, laser particle size analysis, SEM image and cement mortar strength performance test. The composite grinding aids have outstanding grinding effect, which shield surplus electric charge, prevent the agglutination between particles, increase the standard water consumption, and decrease the condensation time. Furthermore, the influence of cement properties were tested, and results indicate that the total testing standards meet JC/T667-2004 of grinding aids.

Abstract: The optimal decoloring conditions for glutamate supernatant in orthogonal experiment are: 15g/l bentonite concentration, 2h decoloring time, and 40°C decoloring temperature. VMD technology can concentrate glutamate supernatant filtrate from 2.01% to 5.35%, and bring down flux from 6.71 L/m2h to 1.94L/m2h, at a concentration rate of 1.72 times. The glutamic acid concentration in supernatant fluid is enriched from 2.03% to 5.16%, and flux attenuated from 5.47 L/m2h to 1.91 L/m2h. As glutamic acid concentration in supernatant increases, membrane flux gradually decreases. Analysis of water production in glutamate supernatant membrane distillation and the meteorological chromatograms of glutamic acid filtrate prove that the difference between water-yielding peak time of supernatant fluid and that of the filtrate is less than 0.1 min. The volatile substances during water production are from glutamic acid filtrate and are of the same matter. Therefore, the product water in supernatant fluid membrane distillation can be reused to improve water production efficiency.

Abstract: In this article we study the reclamation technology of alkaline phenol formaldehyde resin bonded sand. We find that there are a lot of evaporation components in the alkaline phenol formaldehyde resin bonded sand, and they can be effectively removed by drying or baking. The loss of ignition of the sand before and after the mechanical regeneration can be reduced by the baking of alkaline phenol formaldehyde resin bonded sand; it also can improve the stripping rate of the reclaimed sand. The acid demand value of the reclaimed sand increases with the increasing of temperature and reaches the maximum at 500°C, when the alkaline phenol formaldehyde resin bonded sand is baked below 500°C, and then the acid demand value of the regenerated sand reduces when the baking temperature increases. The tensile strength of alkaline phenol formaldehyde resin bonded sand mixed by the regenerated sand obtained by the 360°C baking and mechanical regeneration is higher than that of the sand mixed by the regenerated sand obtained by other methods in the case that the service time and the molding sand mixed by the base sand are the same, and has the best casting process performance.

Abstract: Fabrics of cellulose fibers such as cotton, ramie and viscose were buried in activated sludge, the biodegradability of cellulose fibers and their fabrics were studied. And the relations between degradation rates, morphological structure and crystal structure of these fibers and degradation time were analyzed. The results indicated that, under the same conditions, degradation rate of viscose fiber was higher than that of cotton and ramie fibers. With the increase of degradation time, breakage to the fabrics occurred, meanwhile, fibers showed an increase of surface roughness and displayed a lot of tiny cavities and cracks. In the process of degradation, these cellulose fibers of cotton, ramie and viscose all formed new diffraction peaks near the place of 2θ=26.5°, in addition, the degrees of crystallinity of these fibers were fluctuated.