Papers by Keyword: Removal Ratio

Abstract: Electrolytic manganese residues containing a substantial amount of manganese are a potential pollution. Removing water-soluble manganese ions from electrolytic manganese residues by hydrometallurgical process was discussed. In the work, the basic property of the electrolytic manganese residues was analyzed. Based on it, we proposed the suitable method to remove Mn²⁺ from the slag by pollution-free oxidation in alkaline solution. The results shown that the best conditions to remove Mn²⁺ were pH 10.5, temperature 55 °C, the flow rate of hydrogen peroxide 0.50 mL·L^-1·min^-1 and agitation speed 250 r/min. At the optimum condition, the removal ratio of water-soluble Mn²⁺ exceeded 99.9% and the concentration of Mn²⁺ in the final solutions was about 3 mg/L.

Abstract: Solving the housing problem for urban low-income people is one of important issues of the housing policy and urban planning in China. Shanty towns which were left from old days are now the main housing source for low-income populations; therefore, shanty town reconstruction has been taken as a resolution for solving housing problems for low-income people. However, the current land policy, real estate development policy, urban planning laws and regulations are insufficient in solving the shanty town reconstruction difficulties and more likely become barriers of it. A number of indicators such as building density, per capita living space, land prices and floor area ratio are used to determine how successful the shanty town reconstruction being implemented. In this article, a flexible solution on political and regulatory basis for solving shanty town reconstruction difficulties will be proposed by systematically analyzing various economical and technical indicators.

Abstract: In this study, a new method (negative pressure cavitation method, NPC) for metal ions removal from industry waste water has been studied. Under the identical adsorption conditions，we have seen some different effects among static adsorption, shaking adsorption and NPC adsorption. The results are as following: four kind metal ions showed the accordant phenomenon that the sequence of adsorption capacity is NPC adsorption>shaking adsorption>static adsorption. The different metal ions have different improvement of removal ratio. The sequence is Cd>Hg>Pb>Cu. The intercellular pH of absorbed yeast cells increased with the adsorption process from acidic to alkaline. These may suggest that the Candida utilis has certain resistance against heavy metals. The increased pH is also an environment stress response of Candida utilis. So NPC adsorption may have potential values to removal of metal ions.

Abstract: Due to the high grinding speed and the less contact length, there is the super high material strain rate in the contact layer during quick-point grinding process. Based on the principle of micro-damages mechanics, it is the impact process between the workpiece and the grits on the wheel in the process. The weakening effects of the super high strain rate caused by the mechanical impact micro-damages and the adiabatic shearing damage can lower the dynamic strength of the material in contact layer and the micro-plastic pile-up deformation on the ground surface in the process. Therefore, it is possible to improve the surface integrity of the workpiece since the materials removal mechanism is changed in quick-point grinding process. In this paper, the impact performances and the model of quick point grinding process were studied. Based on the above, the model of the ground surface roughness related to the plastic pile-up deformation was established. The effects of the strain rate on the ground surface roughness and the materials removal ratio were analyzed. In addition, the grinding experiment was performed to testify such investigations. It is indicated that quick-point grinding is an impact process assuredly during the removing material process.