Compared with a conventional Hall-Heroult cell(H-H cell), the interpolar distance of a drained cell can be reduced significantly and the cell voltage and heat produced in the electrolysis will decrease greatly as well, which makes it crucial to achieve a new heat balance in the drained cell. A half anode-cathode slice model of a hypothetical drained cell retrofitted from a 160kA currently used in H-H cell was developed for the thermo-electric calculation and simulation. The results were presented and analyzed and possible approaches for setting up a new heat balance in a drained cell were discussed.

The electronic properties of FeS₂ (100) surface were studied by using a density-functional theory(DFT) method. The very stable (100) surface does not give any significant geometric relaxation and can be regarded as a simple termination of the bulk structure along a plane of cleaved Fe-S bonds. The electronic structure of FeS₂ (100) surface is characterized by surface states in its forbidden zone. The highest occupied and the lowest unoccupied states localize at surface Fe sites. Fe sites are energetically favored over S₂ sites for redox interaction with electron donor or acceptor species on (100) surface.

Sintered samples of nickel ferrite-nickel oxide ceramic, usually used as the ceramic phase of cermet inert anode in aluminum electrolysis, were prepared and characterized. The solubilities of NiFe₂O₄-NiO ceramics were measured using an equilibration technique in the Na₃AlF₆-10%AlF₃-5%CaF₂-5 %Al₂O₃ melts at 960℃. Electrical resistivity was also measured for NiFe₂O₄-NiO ceramic samples prepared using the usual ceramic technique as function of temperature and content of NiO with an improved pyroconductivity test device, consisting of a specially constructed closed furnace and a Potentiostat/Galvanostat, based on the conventional direct current four-probe technique. Results show that, under the experimental conditions, the solubility of Fe from NiFe₂O₄ is 0.06% and Ni from NiFe₂O₄ is 0.008%. The solubility of Fe and Ni from NiFe₂O₄-NiO ceramic is inversely related to each other. The solubility of Ni increases but overall solubility of NiFe₂O₄-NiO ceramics decreases with increasing NiO content. The studied ceramic samples have a semiconductor behavior where electrical resistivity ρ decreases with increasing temperature and the resistivity ρ increases with increasing porosity. The resistivity ρ of NiFe₂O₄-NiO ceramic shows a minimum with increasing the content of NiO at various temperatures.

At the total chamber pressure of 1.01×10¹Pa, Hg, Cd and Zn were distilled at 773-973K from spent zinc-manganese batteries, Pb was volatilized at 1173-1273K while Mn, Cu, Fe and C were remained in the residual. MnO₂ and ZnO were reduced by carbon in spent dry-batteries at 773-1273K. Pure metals including Zn, Cd, Hg and Pb were recovered respectively from their mixed vapor by fractional condensation.

The monoclinic and orthorhombic ordered-rocksalt polymorphs of LiMnO↓2 are of interest as high-capacity cathode materials for rechargeable Li batteries. LiMnO₂ and LiMn_1-xCr_xO₂ were prepared by a high temperature solid-state route. In comparison with undoping Cr orthorhombic LiMnO₂, monoclinic LiMnO₂ was preserved with Cr doping. The volume of m-LiMnO₂ decreasing with increasing Cr confirms that the length of bond around Cr ion decreases with Mn substituted by Cr ion. A phase transformation mechanism was proposed for understanding the structure relationship between the LiMnO₂ and chromium-substituted LiMnO₂ oxides.

The high temperature oxidation resistance of RE-Ni-W-B-B₄C-MoS₂ composite coating, the effects of electrodeposition conditions on the morphologies of the coating and the effect of heat treatment temperature on its hardness, abrasion resistance and phase structure were investigated by using scanning electron microscope(SEM), X-ray diffractometer, microhardness tester and abrasion machine. The results show that the oxidation degree of RE-Ni-W-B-B₄C-MoS₂ composite coating is small when the temperature is lower than 700℃, but it increases sharply when the temperature is higher than 700℃. The hardness of RE-Ni-W-B-B₄C-MoS₂ composite coating increases with increasing heat treatment temperature, it comes up to the maximum value at 400℃, but it decreases gradually if the temperature rises continuously. The most favourable abrasion resistance was attained after RE-Ni-W-B-B₄C-MoS₂ composite coating being heat treated at 400℃. Without heat treating, it is mainly amorphous and partially crystallized, but wholly crystallized after being heat treated at 500℃. RE in the composite coating is in the form of CeO₂ and additions of CeO₂ and B₄C can enhance the thermostability of RE-Ni-W-B-B₄C-MoS₂ composite coating.

The application of photoelectrochemical methods in the inhibition effects for copper corrosion was described. The methods include cyclic voltammetry photocurrent measurements, intensity modulated photocurrent spectrum(IMPS) and laser-scanning photoelectrochemical microscopic method(PEM) which have been applied to the evaluation of inhibitors and inhibition behavior. The inhibition effect of BTA for copper corrosion is better than that of 4CBTA, 5CBTA, CBT-1, PTD, BT-250, CBTME and CBTBE at the same concentration. The inhibition mechanism of the derivatives of BTA with —COOH group(4CBTA, 5CBTA, CBT-1) is different from those with estergroup(CBTME, CBTBE).

Based on the analyses of crystal structures and surface properties of diaspore and kaolinite, an effective diaspore depressant, CPAM(cationic polyacrylamide) polymers was discovered by single minerals tests, separation experiments of artificial mixed minerals, zetapotential and adsorption measurement. The reverse flotation separation on diaspore and kaolinite can be carried out using collector dodecylamine acetate and depressant CPAM under pH5.5-8.5. On the surfaces of diaspore, there are a large amount of active aluminum atoms. They can bond with-C(O)NH₂groups in CPAM and make the -CH₂N⁺(CH₃)₃ groups in CPAM orient toward the outer surfaces of diaspore, which prevents a majority of the dodecylamine cations from adsorbing on diaspore, enhances hydrophilicity of diaspore, and depresses the floatability of diaspore. But for kaolinite, CPAM polymers have little effect on its floatability.

Mixture of CaO and SiO₂ was sintered at 1200 or 1400℃ according to the mole ratio of CaO/SiO₂ of 1 or 2, and then calcium silicate was leached in pure caustic or soda solution. The results indicated that calcium silicate exists much more stably in caustic solution than that in soda solution, and CaO·SiO₂ is more stable than β-2CaO·SiO₂ whether in caustic solution or in soda solution. The increase of sintering temperature favored the stability of calcium silicate in the leaching process. When β-2CaO·SiO₂ was leached in soda solution, the increase of leaching temperature and time resulted in decomposing of more calcium silicate. And when β-2CaO·SiO₂ was leached in caustic solution at high temperature, much 2CaO·SiO₂·H₂O but little CaO·SiO₂·H₂O appeared in slag.

A new type of heat storage materials combining high temperature molten salts phases change latent heat thermal storage materials, PCM with porous metals sensible heat thermal storage materials was developed. The process was expressed as following: firstly, it is necessary to heat up the molten salts phases change materials to molten; and then the porous metals are put into the molten bath; after being held for 1-3h, the composite heat thermal storage materials lumps are taken out of the molten bath and cooled to atmospheric temperature; the last step is to electrodeposit a layer metal coat on the surface of the material lumps. The new type of heat storage material integrates the advantages of both solid sensible heat thermal storage materials and high temperature phases change latent heat thermal storage materials. The metal-base heat storage materials enjoy some favorable characteristics such as higher heat charge-discharge rate, higher heat storage density and better mechanical strength.

Regularities of the initial atmospheric corrosion of zinc sprayed with different amount of NaCl exposed to air at 80% relative humidity and 25℃ were investigated via quartz crystal microbalance in laboratory. The results show that NaCl can accelerate the corrosion of zinc. Mass gain of zinc increases with the exposure time increasing, which can be correlated by using exponential decay function. The relationship between mass gain and amount of NaCl sprayed at a certain exposure time follows a quadratic function. Meanwhile, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and electron dispersion X-ray analysis were used to characterize the corrosion surface and products. Zn₅(OH)₈Cl₂·H₂O and ZnO are the dominant corrosion products, which unevenly distribute on the surface of zinc in the presence of NaCl. A probable mechanism is simply presented to explain the experimental results.

Iron-deposited TiO₂ was prepared by photo-reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO₂ was deposited with iron, and the optimum n(Fe)/n(Ti) is 0.25%. TiO₂ and iron-deposited TiO₂ are anatase and rutile, and anatase is the dominant crystalline phase. In all samples, the XRD patterns indicate that there are no characteristic peaks of iron to be detected. XPS confirms that Fe³⁺ and Fe²⁺ are present on the surface of 0.5% iron-deposited TiO₂, however they are not susceptible to XRD detection. The thermodynamics analysis shows that the alternative possibility of reduction from the Fe³⁺/Fe²⁺ couple seems plausible, but Fe²⁺ can not be reduced to Fe. The fluorescence intensity weakens after iron is deposited on TiO₂, because iron deposited traps photo-generated electrons and holes. The fluorescence intensity order of TiO₂ and iron-deposited TiO₂, from strong to weak, is in good agreement with that of photocatalytic reactiveness TiO₂ and iron-deposited TiO₂, from low to high.

To realize nonferrous metals deposit mining remotely with mobile robot under unknown environment, parallel evolutionary computing and 3-tier load balance were proposed to overcome the efficiency problem of online evolutionary computing. A system of polar coordinates can be established on remote mining robot with the polar point of current position and the polar axis from the current point to goal point. With the polar coordinate system path planning of remote mining robot can be computed in a parallel way. From the results of simulations and analysis based on agent techniques, good computing quality can be guaranteed for remote mining robot, such as efficiency, optimization and robustness.

The principle of thermal flux being constant in heat-flow-tube and the principle of heat balance were applied to analyze and calculate the steady-state thermal field and the electrolyte-ledge heat transfer coefficient of aluminum reduction cell by finite element method. The calculated results show that the melt-ledge heat transfer coefficient in the 160kA prebaked anode aluminum reduction cell of Guizhou Aluminum Smelter is higher than that of other cells of the same current. It is also found that the electrolyte and metal flow much faster, which may be the results of poor bus bar arrangements. Meanwhile, the calculated results of melt-ledge heat transfer coefficient by heat-flow-tube method are almost in full agreement with the former works. This verifies the applicability of this method.

Rest potentials for the steel ball electrode and the pyrite electrode as well as the combination potentials and the galvanic currents developed in the pyrite-steel ball couple were measured. The data demonstrate that the galvanic couples are going to form between the pyrite particles and the steel balls when they contact with each other. The initial combination potential and the initial galvanic current of the pyrite-ball couple while bubbling with oxygen are greater than those in aeration of air. The combination potential and the galvanic current decrease more quickly with time while bubbling with oxygen than they do in aeration of air. In an experiment of simulating wear differences, a galvanic current, which is smaller than that developed in the pyrite-ball couple, exists between two different ball electrodes in wear degree on the surface of them. Under different grinding time conditions, the equivalent corrosion current density calculated from marked ball wear data by applying Faraday’s law correlates well with those estimated from polarization curves of pyrite and ball electrodes, and the former is always greater than the latter.

Lix984N is intimately related to the dynamic characteristics of phase disengagement in copper solvent extraction because of its interfacial activity. With increasing Lix984N content, the phase disengagement time is prolonged and the mechanism dominating phase disengagement process transfers from sedimentation to coalescence. The rate of droplet coalescence is faster than that of droplet sedimentation in the dense dispersion band when the volume fraction of Lix984N is less than 3.0%. The former almost equaled to the latter at Lix984N content of 3.0% and finally becomes lower than the latter when the volume fraction of Lix984N is more than 3.0%. The relationship between the adhesion force of two equal droplets and physical properties of fluids is deduced, which explains that the change of physical properties of organic phase with Lix984N content can make droplet coalescence more difficult and phase disengagement slower.

Flotation mechanism of kaolinite was investigated through flotation test, SEM analysis and quantum chemical simulation calculation. It is shown that the (001) face of kaolinite easily adsorb cationic collector to exhibit hydrophobicity; the (001^-) face is easily interacted with the reagent carrying the group of high electronegativity (-O-, -N-, F-) to show hydrophilicity. The cationic and anionic polyacrylamide are adsorbed onto the (001^-) face of kaolinite and the flocculation of kaolinite particles may take place; the (001) faces are exposed to interact with cationic collector to be rendered hydrophobicity. Thus, the macromolecules can evidently enhance the flotation of kaolinite in alkaline media.

During the precipitation of gibbsite from supersaturated sodium aluminate solution, the main aluminum containing species in solution will transform from tetrahedral ［Al(OH)₄］^- to sixfold octahedral ［(H₂O)₂Al-(OH)₄］^-. In order to elucidate the mechanisms responsible for above transformation, the formation Gibbs free energy as well as frontier orbits of a wide range of aluminum species are studied by ab initio method at B3LYP/6-31G** level. Based on theoretical calculation results, thermodynamic possibility and coordination possibility for aluminate ion transforming from ［Al(OH)₄］^- to ［(H₂O)₂Al(OH)₄］^- are analyzed and thermodynamic permitted reaction pathways are extracted. It is found that ［Al(OH)₄］^- can not react directly with H₂O to carry out the variation of coordination number. Transformation of tetrahedral ［Al(OH)₄］^- to octahedral ［(H₂O)₂Al(OH)₄］^- is involved in two reaction pathways, one is realized by neutral ［Na(H₂O)⁺₄·Al(OH)^-₄］ acting mediator, the other is carried by neutral ［(H₂O)Al(OH)₃］. Though there is a strong thermodynamic trend for the transformation of ［Al(OH)₄］^- to［(H₂O)₂Al(OH)₄］^-,the practical transformation is very slow. Thus, it can be concluded that there is a great kinetic resistance during the transformation from ［Al(OH)₄］^- to ［(H2O)₂Al(OH)₄］^-.

Electrochemical behavior of chemical-mechanical polishing of copper with oxide passive film was studied by electrochemical measurement technologies. Dependences of polarization curves and electrochemical parameters, the rate of formation or removal of passive film of copper on film modifier KClO₃ were investigated. The rules of dependences of corrosion potentials and corrosion current densities on polishing pressure and rotation rate were obtained. It is discovered that the rates of formation and removal of passive film of copper are enhanced, while the polishing pressure and rotation rate are reduced. The experiments show that the CMP processes decrease Tafel slope, increase electron transfer coefficient of anode reaction and decrease the activation energy of corrosion reaction of copper, thereby the corrosion processes are accelerated. The results indicate that CMP slurry recipe, which is composed of NaAc-NaOH medium, using KClO₃ as passive film modifier and nano-sized γ-Al₂O₃ as abrasive, is feasible and reasonable. The technological conditions are 100r/min, 16kPa.

The stage-efficiency of a single-stage prototype (d70) centrifugal extractor and the cascade is tested by HNO₃-Nd³⁺ and 30%TRPO-kerosene system. The experimental results of the single-stage centrifugal extractor show that the carryover of the two phases decreases with increasing ratio of the two flow rate and rotation rate and the stage efficiency increases with not only decreasing total flow rate but also increasing rotor speed. However, the experimental results of the cascade show that the average stage efficiency of the cascade increases with not only decreasing total flow rate but also increasing rotor speed in both three-stage mode and two-stage mode.

The solutions of poly(acrylic acid)(PAA), poly(acrylic acid sodium)(PAANa) were coated on aluminium fins by roll coating method. The coatings with different crystallinity were obtained by varying baking time and temperature. Their surface crystallinity and surface tension were measured, and their spreading speed constant and equilibrium contact angle were tested also. The correlation of surface crystallinity, surface tension, spreading speed constant and surface hydrophilicity was discussed. It is demonstrated that surface tension and spreading speed constant increase, while equilibrium contact angle declines with increasing surface crystallinity of coatings, that is to say, the hydrophilicity of coatings is improved with surface crystallinity of coatings increasing.

The modified PVA-CA blend ultrafiltration membranes were prepared by phase inversion from the casting solutions consisting of polyvinyl alcohol(PVA), cellulose acetate(CA), acetic acid, alkali metal chloride and water. The effects of different concentration of alkali metal chloride on the properties of membranes were investigated. The results show that when the mass fraction of the salt in the casting solution is not greater than 1%, the property of rejection of the alkali metal salt modified ultrafiltration PVA-CA blend membrane has little change compared with that of the unmodified PVA-CA blend membrane, but the permeation flux is much greater than that of the unmodified membrane under the same operation condition. When the mass fraction of the salt is greater than 1.5%,the permeate flux increases much greater than that of the unmodified membrane, but the property of rejection of the modified ultrafiltration membrane decreases greatly. The results also show that the contact angle of the salt modified PVA-CA blend UF membrane decreases but the swelling in water increases with the increment of the mass fraction of alkali metal salts. Furthermore, the NaCl modified PVA-CA blend membrane has a slightly lower swelling and a little smaller contact angle of water than the KCl modified PVA-CA blend membrane does when the mass fraction of salts is the same.

Nanosized SnO₂ powders were prepared by sol-gel process using inorganic salt as a precursor. The tin oxide powders obtained at different calcinating temperatures (300-700℃) were investigated by means of X-ray diffraction(XRD), infrared spectrum (IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA) and transmission electron microscopy (TEM) as well. The results indicate that well-crystallized nanosized SnO₂ powders with a structure of rutile and uniform size about 10nm can be obtained when the calcinating is carried out at 550℃ for 3h using the method. The electrochemical properties of nanosized SnO₂ powders as anode material for lithium ion batteries were also studied in detail. The results show that nanosized SnO₂ is a candidate of anode material for lithium ion batteries with reversible capacity more than 372mA·h/g after ten cycles and low voltage for Li⁺ intercalation and de-intercalation.

Mathematical model for mass transfer of chemical reactions on the surface of the smelting bath pit in oxygen top-blown smelting furnace was put forward. Additionally, one of two mathematical models for mass transfer of chemical reactions forming copper matte in smelting bath and the other for parameters of smelting process were developed. The verification tests were simultaneously carried out in a pilot scale furnace and the experimental results show that these mathematical models are convincing. Thus, these numerical models are reliable to simulate pyritic smelting process for copper-nickel mineral in oxygen top-blown furnace.

In order to clarify the respective role of the UV light, catalyst, external bias as well as their combined effects on the photodegradation process and to clarify the photocatalytic mechanism under different experimental conditions, a series of experiments were conducted in a shallow pond photoreactor with an effective volume of 100mL using TiO₂/Ti thin film prepared by anodization as photocatalyst. A 300W UV lamp(E_max=365nm)was used as side light source. The effect of light intensity on photocatalysis was also conducted. The results show that photocatalytic oxidation is an effective method for phenol removal from waters. The degradation rate can be improved by applying an anodic bias to the TiO₂/Ti film electrode, phenol can not be decomposed under only 365nm UV light irradiation even in the presence of hydrogen peroxide. In the range of our research, the phenol removal rate can be described in terms of pseudo-first order kinetics.

The effect of several collectors and their dosage on the flotation characteristics of the synthetical fersmite at different pH values, the collecting strength and selectivity of several representative collectors were investigated. The experimental results indicate that diphosphonic acid is a good collector for fersmite and recovery of fersmite ranges from 83.27% to 85.10% when the pulp pH value is at 2.5-5.0 and the dosage is 20mg/L. The rank sequence of selectivity for several collectors is as follows: diphosphonic acid > benzyl arsonic acid >α-styrolphosphonic acid>alkyl hydroximic acid (C_7-9) > cyclic alkyl hydroximic acid. At the same time, Infrared Absorption Spectrum (IAS) and X-ray Photoelectron Spectroscopy (XPS) were used to detect and analyze the action mechanism of diphosphonic acid on fersmite. IAS results show that the characteristic absorption peak relating to P=O as well as P—O vibration occurs between wave number 1178cm^-1, 1142cm^-1, 1087cm^--1 and 934cm^-1, and diphosphonic acid is adsorbed on the surface of fersmite. XPS results indicate that the binding energy of P2p peak of fersmite treated by diphosphonic acid is increased by 3.85eV. It is proved that the adsorption is mainly chemical adsorption.

On the basis of serial laboratory research and industrial test, the mechanism of saving energy and reducing carbon consumption of property-modified prebaked anode in aluminum electrolysis was discussed. It is considered that the anodic over voltage is affected by the concentration of carbon monoxide surrounding anode. The property-modified prebaked anode can restrain the production of carbon monoxide. The reason of reducing carbon consumption was also analyzed, the result shows that besides physical action, chemical action also exists in the process where additives change the reaction rate of anodes.