Elective culture of bacteria on pyrrhotite was researched, and the selected bacteria were tested on bioleaching of marmatite and zinc sulfide ore. The results show that the microorganism cultured on pyrrhotite with various S/Fe ratios is a mixed culture of thiobacillus ferrooxidans and thiobacillus thiooxidans, of which the integral activity and the oxidation capability of Fe²⁺ and S are enhanced. With the high Fe and low S content of pyrrhotite, the oxidation capacity of ferrous ion is improved; on the contrary, the oxidation capacity of sulfur is advanced. The bioleaching capacity of bacteria cultured on marmatite is better than that of the bacteria cultivated by conventional methods.

Utilizing the dissipative structure theory, the evolutionary process of vibrating liquefaction in saturated granules was analyzed. When the irreversible force increases to some degree, the system will be in a state far from equilibrium, and the new structure probably occurs. According to synergetics, the equation of liquefaction evolution was deduced, and the evolutionary process was analyzed by dynamics. The evolutionary process of vibrating liquefaction is a process in which the period doubling accesses to chaos, and the fluctuation is the original driving force of system evolution. The liquefaction process was also analyzed by fractal geometry. The steady process of vibrating liquefaction obeys the scaling form, and shows self-organized criticality in the course of vibration. With the increment of the recurrence number, the stress of saturated granules will decrease rapidly or lose completely, and the strain will increase rapidly, so that the granules can not sustain load and the “avalanche” phenomenon takes place.

Based on the difference of microscopic properties between MoS₄^2- and WO₄^2-, a series of new reagents, CuS, NiS, CoS, PbS, HgS, as well as ZnS, were developed for separation of molybdenum from tungstate solution. GPT(Generalized Perturbation Theory) calculation reveals they are more reactive with MoS₄^2- than WO₄^2-. In laboratory test, CoS, NiS and CuS can remove more than 99.3%Mo. PbS and FeS are also effective for precipitation of Mo, but HgS and ZnS are almost useless. Taking environment and economy factors into consideration, CuS is chosen as the most suitable reagent.

The effect of mechanical treatment on pyrite and molybdenite was studied. After mechanically activated for 40min under the same condition, the apparent activation energy for leaching reaction of layer-structured molybdenite in HNO₃-H₂SO₄ solution becomes 6.0kJ/mol lower than that for untreated one; while for isotropic pyrite, this value is 18.3kJ/mol. Pyrite seems to be more sensitive towards mechanical activation. Resorting to the difference in crystal structure, it is considered that anisotropic molybdenite may obviate violate mechanical action through inter-layer slippage, while isotropic pyrie can not. So the action may damage pyrite crystal and produce large amount of lattice imperfection. Consequently, more mechanical energy is absorbed by pyrite crystal. So it is one-sighted to consider the mechanical activation effect according to only crystal lattice energy. Crystal structure, isotropy or anisotropy, is an important parameter which affects a lot.

A gold leaching process by using oxidation products of elemental sulfur in alkaline solutions was proposed and investigated. A gold concentrate and a residue from an arsenic refractory gold concentrate by acidic oxidation leaching were tested. The residue contains 16.3% elemental sulfur and no more elemental sulfur was added in tests. For the concentrate elemental sulfur was added before leaching tests. The leaching ratio of gold depends mainly on the initial equivalent ratio of elemental sulfur to hydroxyl ions, the consumption of oxygen and the reaction temperature in the process. Analysis of the experimental results shows that thiosulfate is the majority complexing reagent for gold in the process. Over 90% gold was leached from the residue and 82%-87% from the concentrate by using this process.

On the base of filtering composite additives in laboratory, the industrial property-modified prebaked carbon anodes containing composite additives were prepared in factory. The performance tests show that this kind of anodes not only have the same excellent physical performance as common (contrasting) ones used in aluminum electrolysis production at the present time, but also have better chemical and electrochemical performance than that of the common ones. Furthermore, the industrial preparation of the property-modified prebaked anode lays the foundation of electrolysis test. It can be forecasted that property-modified anodes will have good behavior in aluminum electrolysis production.

A mathematical model of multistage and multiphase reactions in flash smelting furnace, which based on the description of chemical reactions and reaction rate, is presented. In this model, main components of copper concentrate are represented as FeS₂ and CuFeS based on experiment, intermediate products are assumed to be S₂ and FeS, and the final products are assumed as FeS, FeO, SO₂, Cu₂S, FeO and FeO(SiO₂)₂. The model incorporates the transport of momentum, heat and mass, reaction kinetics between gas and particles, and reactions between gas and gas. The k-ε model is used to describe gas phase turbulence. The model uses the Eulerian approach for the gas flow equations and the Lagrangian approach for the particles. The coupling of gas and particle equations is performed through the particle source in cell(PSIC) method. Comparison between the model predictions and the plant measurements shows that the model has high reliability and accuracy.

The Navier-Stokes equation with the “k-ε” two-equation turbulence model was employed to describe three-dimension flow of melt in aluminum electrolysis cells. For a 160kA cell with two current risers, the source, i.e. the electromagnetic force, in the momentum equations was solved based on the simulation results of magnetic and temperature fields. Numerical simulation on the three-dimension steady-state flow of melt was carried out. The results obtained about the velocities of molten metal on different planes, the metal/bath interface shape and the electromagnetic force distribution, were analyzed. An iron rod dissolution technique, which is based on the rate of dissolution of iron rods inserted into the melt, was used to measure the velocities of metal pad. The simulation and measurement show that there are two interaction vortexes in horizontal direction. The predictions are in well agreement with the measured results for flow pattern and velocities. It is worthwhile that in the three-dimension simulation, there is also a little change of metal velocities from level to level due to the difference of horizontal current on each level.

Based on the thermodynamic calculation, the mole ratio of CaO to SiO₂, temperature and A/S of bauxite have a profound influence on the mole ratio of 2CaO·SiO₂ to CaO·SiO₂ in sinter. CaO·SiO₂ and β-2CaO·SiO₂ appear stable in caustic solution but unstable in soda solution, and CaO·SiO₂ is more stable than β-2CaO·SiO₂ under the same leaching condition. Compared with the conventional sinter, the rate of alumina extraction of the new sinter is large and the secondary reaction is restricted in the leaching, which might be mainly due to the more content of CaO·SiO₂ in sinter and better stability of CaO·SiO₂ in leaching.

The effects of temperature, nickel concentration and current density on the current efficiency and the electrolyzer voltage were investigated in the process of electrowinning nickel. The results show that the current efficiency is above 90% under the various experimental conditions, and the electrolyzer voltage is less than that of traditional electrolyzer system. Therefore, the optimized parameters, i.e. temperature of 50℃, current density of 400A/m², are determined. It is also elucidated that anodic product is high valent nickel compound in the process of electrodeposition in terms of X-ray diffraction and chemical analysis. The amount of solid product formed on the electrode surface decreases with an increase in ammonium chloride concentration by cyclic voltammetry analysis. It is also indicated that the anodic gas species are mainly composed of nitrogen by vapor phase chromatograph.

The vaporization kinetics of antimony trisulfide in argon fluid was studied with thermogravimetry at 873-1173K. A theoretical model was developed to calculate the overall rate constant and the mass transfer coefficient in gas phase. The experimental results show that the vaporization rate is enhanced with increasing temperature and argon flow-rate. The evaporation rate is mainly controlled by mass transport in the gas phase. The apparent activation energy for the process is found to be 55.54kJ/mol. It is demonstrated that the mass transfer coefficient in gas phase is decreased with increasing temperature.

The rare earth Zr catalyst, whose carrier was Al₂O₃, was prepared by coprecipitation with Zr(NO₃)₂, Al(NO₃)₃, and(NH₂)₂CO as the raw materials. The obtained catalyst was used to reform the waste plastic cracking product. As the Zr content in the catalyst increases, the yields of gasoline, gas, and the rate of carbon deposition increase, but the yields of diesel and heavy oil decrease. The optimum Zr content of the catalyst is 5%. At 290℃, with this most suitable catalyst, the yield of liquid fuel oil is the highest, about 86.10%, and research octance number(RON) of the gasoline is 92.15.

As for the leaching-resistant zinc residues, the silver leaching rate can be over 98% through the process of pressurized preoxidation and thiourea leaching. Compared with the method of extracting the silver directly from the leaching-resistant zinc residues, the silver leaching rate is greatly improved. The optimum preoxidation conditions are: particle size range 40-60μm, oxygen partial pressure 10⁶ Pa, temperature 80-90℃, pH=1.0, and leaching time 5h. After pretreatment, the time of thiourea leaching silver is shortened to 1.5h, and the thiourea consumption is reduced greatly. The oxidation mechanism and the thiourea leaching kinetics were also explored.