流态功能纤维回收金的动力学研究

在一高1200mm，直径为40mm的流化床上，分别测定了不同流速下纯金溶液和含金工业废水中金与功能纤维的反应速率，并与静脉试验结果进行了比较。结果表明，流态化条件下的反应速率比静态下的反应速率有明显提高，且随流速增大而增大，说明随着纤维／溶液相对流速的增大，湍流程度加大，纤维表面的浓度边界层减小，且在床中建立起了较一致的温度场。

煤金团聚法回收金机理初探

介绍了煤金团聚法（Coal Cold Agglomeration，CGA）的研究现状，讨论了影响煤金油团聚的几个主要因素，如煤化学、中性油的特性、疏水颗粒间的相互作用等。在此基础上，研究搅拌强度和接触时间对CGA金回收动力学的影响，发现在其他条件不变的情况下，同一矿种在不同的搅拌速度下，金回收动力学速率常数是一定的。筛选出的煤、油混合的聚团很好的无捕收剂捕金能力，金回收率可达77％～86％。进一步实验研究发现添加适量的硫化钠调整剂对含硫化物原生金矿中金有较好的活化作用，金回收率有显著提高，而硫化物的上浮却有所降低。

Investigating the first-order flotation kinetics models for Sarcheshmeh copper sulfide ore

This study was performed in two phases of work.In the first stage,four conventional first-order flotation kinetics models were fitted to the measured recoveries data and the best model were selected.In the second stage,influence of pH,solid concentration,water chemistry and the amount of collector dosage were investigated on kinetics parameters including flotation rate constant and ultimate recovery.The results indicated that that perfectly mixed reactor model and Kelsall model gave the best and the weakest fit to the experimental data,respectively.It was observed that flotation rate constant and ultimate recovery were strongly affected by chemical factors investigated especially water quality.The flotation rate constant decreased with increasing the solids content,while ultimate recovery increased to certain value and thereafter reduced.It was also found that the most values of flotation rate constant and ultimate recovery obtained in dosage of collector are 30 and 40 g/t,respectively.

Recovering of copper with metallic aluminum

The cementation of copper ions from aqueous copper sulfate solutions by using spherical aluminum metal particles was examined. The effects of the experimental parameters on copper cementation were investigated and evaluated. Reaction rate increases with increasing copper concentration, reaction temperature, stirring speed and decreasing pH. It was observed that the reaction follows the first-order kinetics, and progresses according to the diffusion controlling step.

Separation and recovery of copper in Cu-As-bearing copper electrorefining black slime by oxidation acid leaching and sulfide precipitation

A new hydrometallurgical route for separation and recovery of Cu from Cu-As-bearing copper electrorefining black slime was developed. The proposed process comprised oxidation acid leaching of Cu-As-bearing slime and selective sulfide precipitation of Cu from the leachate. The effects of various process parameters on the leaching and precipitation of Cu and As were investigated. At the first stage, Cu extraction of 95.2% and As extraction of 97.6% were obtained at 80 ℃ after 4 h with initial H2 SO4 concentration of 1.0 mol/L and liquid-to-solid ratio of 10 mL/g. In addition, the leaching kinetics of Cu and As was successfully reproduced by the Avrami model, and the apparent activation energies were found to be 33.6 and 35.1 kJ/mol for the Cu and As leaching reaction, respectively, suggesting a combination of chemical reaction and diffusion control. During the selective sulfide precipitation, about 99.4% Cu was recovered as CuS, while only 0.1% As was precipitated under the optimal conditions using sulfide-to-copper ratio of 2.4:1, time of 1.5 h and temperature of 25 ℃.

Adsorption and reduction of platinum(Ⅳ) chloride complex ions on activated carbon

The adsorption kinetics of platinum（IV） chloride complex ions on the activated carbon Norit GF40 was investigated. Experiments were carried out at different initial concentrations of Pt（IV） chloride complex ions, temperature, rate of mixing and pH. It was found that the value of activation energy of the studied process is equal to 19.7 kJ/mol. From the ICP MS analysis it was confirmed that platinum ions （Pt（IV） and Pt（II）） are removed from the solution due to the adsorption and are further reduced to the metallic state. Such mechanism was confirmed by XPS analysis which showed that on the carbon surface three forms of platinum species, i.e. Pt（0）, Pt（II） and Pt（IV）, exist. The presence of platinum in the solution at different oxidation states was also confirmed spectrophotometrically by identification of their characteristic absorption bands. The metallic form of Pt present on the surface of activated carbon was observed in the form of small spherical islands with the diameter not exceeding 500 nm. Those islands consist of smaller, flake-shape particles with a thickness of about 35 nm.

Theoretical Investigation on Internal Leakage and Its Effect on the Efficiency of Fluid Switcher-Energy Recovery Device for Reverse Osmosis Desalting Plant

This work is focused on the theoretical investigation of internal leakage of a newly developed pi lotscale fluid switcherenergy recovery device （FSERD） for reverse osmosis （RO） system. For the purpose of in creasing FSERD efficiency and reducing the operating cost of RO, it is required to control the internal leakage in a low level. In this work, the internal leakage rates at different leakage gaps and retentate brine pressures are investigated by computational fluid dynamics （CFD） method and validating experiments. It is found that the internal leak age has a linear relationship with the retentate brine pressure and a polynomial relationship with the scale of leakage gap. The results of the present work imply that low internal leakage and high retentate brine pressure bring benefits to achieve high FSRD efficiency.

Effect of butanol on flotation separation of quartz from hematite with N-dodecyl ethylenediamine

In order to investigate the effect of butanol on quartz flotation when N-dodecyl ethylenediamine(ND)was used as collector, single mineral flotation and artificial mixed mineral(hematite and quartz were mixed at a mass ratio of 3:2) separation were conducted in the laboratory. Experimental results indicated that addition of butanol could improve the collecting performance of ND on quartz and enhance the floatability of quartz. Best flotation recovery of quartz was obtained when butanol was mixed with ND at a mass ratio of 1:1. Moreover, the molecular structure of alcohols had a significant effect on mineral recovery. Best separation efficiency could be obtained when tert-butanol was added as it had the largest cross-sectional area. Zeta potential measurements indicated that alcohols could strengthen electrostatic adsorption between quartz and collector. Molecular dynamic simulations revealed that co-adsorption of alcohols along with ND had taken place on the quartz surface, and ND/tert-butyl combinations were more easily absorbed on the quartz surface.

Biosolid Application to Agricultural Land a Contribution to Global Phosphorus Recycle： A Review

Phosphorus(P) is an essential nutrient required for plant development.Continuous population growth and rising global demand for food are expected to increase the demand for phosphate fertilizers.However,high-quality phosphate rock reserves are progressively becoming scarce.Part of the increased pressure on P resources could be alleviated by recycling P present in biosolids.Therefore,it is crucial to understand the dynamics of P in biosolid-amended soils,the effects of residual biosolid-borne P in soils,the way in which microorganisms may control P dynamics in biosolid-amended soils and the environmental implications of the use of biosolids as a source of P.Further research is needed to maximize biosolid-borne P uptake by crops and minimize its loss from biosolid-amended soils.The analysis of the microbiological control of P dynamics in biosolid-amended soils indicates interactions of biosolid P with other nutrients such as carbon(C) and nitrogen(N),suggesting that harmonization of the current regulation on the use of biosolids in agriculture,mainly based on total N and pollutant contents,is needed to better recycle P in agriculture.