Quantum chemical simulation calculation shows that kaolinite is cleaved to produce (001) and (001^-) basal planes. (001) plane is dominant by ［SiO₄］ tetrahedral, which interacted easily with hydrogen ion or other positive ions by electrostatic forces or hydrogen bonding. (001^-) plane is dominant by ［AlO₂(OH)₄］, which interacted easily with high negativity group such as -O-, -N-, F- etc. The apparent zeta potential and surface points of zero charge(PZC) are different for hard and soft kaolinites depending on their crystallinity index (HI). The self-aggregation between edge and basal plane due to the electrostatic interactions may occur at acidic media. The dispersion of kaolinite particles at alkaline media may be attributed to the electrostatic repulsion between basal planes and/or edges. The aggregation or dispersion behavior is revealed by scan electron microscope and the transmittance measurements for the suspension of kaolinite particles.

Selective extraction of zinc from sulfate leach solution of zinc ore was studied. D2EHPA dissolved in 260^＃kerosene was used as extractant. The pH-extraction isotherms show the extraction order of D2EHPA for metals is 
Fe³⁺＞Zn²⁺＞Ca²⁺＞Al³⁺＞Mn²⁺＞Cu²⁺＞Cd²⁺＞Co²⁺＞Ni²⁺＞Mg²⁺(pH0.5). This confirms that Fe³⁺ is preferentially extracted before the extraction of zinc. Extraction experiments were carried out with varying the extractant content, equilibration time, aqueous pH and phase ratio, and the solvent extraction of zinc with sodium salt of D2EHPA were also investigated. Some impurity co-extracted into the zinc loaded organic phase was efficiently removed by scrub, and the Fe³⁺ was hardly stripped from organic phase by sulfuric acid, hence zinc was separated from Fe³⁺ by selective stripping. A pregnant zinc sulfate solution with low contaminants was obtained by selective solvent extraction.

The fibrous nickel oxide particles were prepared by chemical precipitation and pyrolysis method. The NiO precursors were firstly precipitated from nickel ions solution with addition of oxalate salt, and then the final NiO particles were obtained by pyrolysis of the precursor. The effects of the pH value, precipitation temperature, reactant concentration, addition of surfactant on the morphology of the precursor particles were investigated. The crystallinity, purity, morphology of the fibrous NiO were analyzed by XRD and SEM. The fibrous NiO particles with 100-120 in axis/diameter ratio may be produced under the optimal process conditions that are proposed: the Ni²⁺ concentration is 0.5-0.8mol/L, pH value is 8.3-8.9, precipitation temperature is 60-75℃, pyrolysis temperature is 500-600℃. 

The adsorption behavior and mechanism of a novel chelate resin, macroporous phosphonic acid resin(PAR) for Cu(Ⅱ) were investigated. The statically saturated Cu(Ⅱ) adsorption capacity is 168mg/g resin at 298K in HAc-NaAc medium. The Cu(Ⅱ) adsorbed on PAR can be eluted by 1.0-3.0mol/L HCl and the elution percentage reaches 100%. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is 
k=1.64×10^-4s^-1 at 298K. The adsorption behavior of PAR for Cu(Ⅱ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change ΔH, free energy change Δ/G/ and entropy change ΔS of PAR for Cu(Ⅱ) are 11.8kJ/mol, －2.0kJ/mol and 46.4J·mol^-1·K^-1 respectively. The apparent activation energy is E_a=8.0kJ/mol. The molar coordination ratio of the functional group of PAR to Cu(Ⅱ) is about 2∶1. The adsorption mechanism of PAR for Cu(Ⅱ) was examined by chemical method and IR spectrometry. 

The viscosities of molten Fe_nO-MgO-SiO₂ and Fe_nO-MgO-CaO-SiO₂ semi-synthetic slags for nickel flash smelting were mearured in the temperature range of 1200-1450℃ by use of a rotational viscometer. The mass ratio of Fe to SiO₂ was fixed at 1.2, calcium oxide and magnesium oxide contents varied in the range of 2%-8% and 9%-12%(mass fraction), respectively. The results show that silicate anions become smaller by increasing CaO content, which results in the viscosity decrease of slag. In the case of addition of MgO the viscosity behaviour is complicated. When MgO content is less than 11%, the viscosity increases with the increase of MgO at all temperatures tested . However, when the MgO content is more than 11%, the viscosity decreases slightly for Fe_nO-MgO-CaO-SiO₂ system. At higher MgO contents, low-viscosity slags can be obtained by adding CaO. As for a given composition, the viscosity decreased with increasing temperature .The higher the temperature, the more MgO can be added before saturation. The effect of Fe₃O₄ on the viscosity is quite significant. The viscosity of slag increases to 300mPa·s at 1300℃ when Fe₃O₄ content varied from 2.84% to 9.53%. The viscosity values are expressed as the functions of temperature and composition. A comparison between Fe_nO-MgO-SiO₂ and Fe_nO-MgO-CaO-SiO₂ systems are also given.

Using ammonium chloride (NH₄Cl) as a chlorinating agent, the effects of chlorinating temperature, chlorinating time and NH₄Cl dosage on chlorination of La₂O₃ and CeO₂, and the thermal decomposition of LaCl₃·7H₂O and CeCl₃·7H₂O were investigated. The results show that 80% of both La₂O₃ and CeO₂ can be chlorinated at 300℃ for 90min, and have no advantage to chlorination of lanthanum and cerium oxides at higher temperature. The thermal decomposition of LaCl₃ and CeCl₃ is carried out to explore the mechanism of chlorinating lanthanum and cerium oxides. At the same time, the chlorination of lanthanum and cerium oxides is not devoted to the HCl decomposed from NH₄Cl, but to NH₄Cl directly taking part in the chlorination of La₂O₃ and CeO₂. The lanthanum and cerium oxides in chlorination firstly form intermediate LaOCl and CeOCl, and then transfer to LaCl₃ and CeCl₃, finally to La₂O₃ and CeO₂, respectively. The thermal decomposition analyses of LaCl₃·7H₂O and CeCl₃·7H₂O further prove the existence of the intermediates LaOCl and CeOCl. Therefore the chlorinating temperature and time should strictly be controlled when the lanthanum oxide and cerium oxide are chlorinated with NH₄Cl. And over-dosage of NH₄Cl should be also applied in the process of chlorination.

A method of melt-oxidation at high temperature is adopted to prepare Ir/IrO_x pH electrode, and different carbonates such as Li₂CO₃, K₂CO₃, Na₂CO₃ and their mixture were used in this process. It is shown that the electrode prepared in carbonate melt has good pH response characteristics, such as stability, sensitivity, response time, and anti-corrosion ability in the solution containing F^-, etc. The hysteresis mechanism was also investigated based on a storage model with a cyclic voltammetry experiment. It is found that the valence of Ir in the oxide film is +4, and the iridium oxide on the surface of the film is co-ordinate with -OH and H₂O from the result of XPS spectra. The mole fraction ratio of Ir to O is 1∶2.1 in the bulk of the oxide, but x(Ir)∶x(O) is 1∶6.78 on the surface of the oxide film by EDX technology. The hydration effect of the thermally prepared iridium oxide was investigated. Therefore, a H⁺ response mechanism is suggested, being much different from the reported theory for thermally prepared iridium oxide electrode, which previously does not take the hydration of oxide into consideration.

The influences of the ratio of the radius of atom A(r_A) to radius of atom B(r_B), electronegativity and electron number were discussed on the Laves phase formation and the characteristics of Zr-based AB₂ type hydrogen storage alloy. An enthalpy model of Zr-based AB₂ alloy was obtained from known data and twelve Zr-based alloys were designed to test the model. The results show that the predicted values are in good agreement with the experimental values. The model can be used for predicting enthalpy values of Zr-based hydrogen storage alloys and settles a foundation for experiments.

Ex-situ electroremediation tests were conducted on the lead-contaminated red soils to find out the optimum condition for the most efficient removal of lead pollution from the red soil, and to examine the relation of the pH of the soil with the electroremediation efficiency. The results show that the electroremediation technology is efficient to remedy Pb contaminated red soils, and the removal efficiency can be enhanced by controlling pH value in the cathode reservoir with HNO₃. The average removal efficiency of Pb is enhanced from 24.5% to 79.5%, and the energy consumption reaches 285kW·h per m³ red soil.

A novel rare earth complex monomer Tb-Ca-PMDMBA(PMDMBA denotes pyromellitic dianhydride-modified Bisphenol A epoxy acrylate resin) was synthesized for the first time as following procedure. Firstly, Bisphenol A epoxy acrylate resin and Bisphenol A epoxy acrylate resin modified with pyromellitic dianhydride were synthesized from Bisphenol A epoxy resin, acrylic acid and pyromellitic dianhydride through esterification respectively. Their composition is ascertained by the analysis of acidic value and FTIR spectrum. Secondly, the complex monomer Tb-Ca-PMDMBA was prepared by coordinating Tb³⁺, Ca²⁺ with carboxyl groups, and then its fluorescence properties were investigated. The results show that Tb-Ca-PMDMBA complex can emit intense characteristic emission spectrum of Tb³⁺ ion under UV excitation. The fluorescence intensity depends on the content of Tb³⁺ and reaches maximum when the mole ratio of Tb to Ca is 2∶9.

N-decyl-1, 3-diaminopropanes (DNs) were synthesized from alkyl-amine acrylonitrile at ambient pressure. With the synthesized DNs as collectors, the flotation of kaolinite, pyrophyllite and illite was conducted and the results were interpreted in terms of the structure-activity relationship. The DNs are found to be more effective collectors than dodecyl amine, exhibiting the highest recovery over a pH range of 4-6. Among the DNs examined, DN₁₂ shows the highest flotation efficiency. The flotation mechanisms were explained in view of the structures of reagents and aluminium silicate minerals. It is demonstrated that DNs can become new selective collectors for reverse floatation to remove aluminium silicate minerals from bauxite.

Performance comparisons between organic and inorganic zinc-rich paints (ZRPs) were carried out. Electrochemical impedance spectroscopy (EIS) measurements were used to assess the corrosion prevention performance of the ZRP coatings. The results show that during the cathodic protection period the potentials of the epoxy systems are less negative than those of the silicate system. For the zinc-rich ethyl silicate paints, the initial values of the resistance through the binder and the charge transfer resistance associated with zinc dissolution are several orders of magnitude lower than those of the organic zinc paints, while the initial values of the capacitance due to the binder layer between Zn dust and the double layer capacitance for zinc dissolution are several orders of magnitude higher than those of the organic zinc paints. Furthermore, the deterioration with time of capability of the zinc particles in the paint to provide cathodic protection to the steel was interpreted.

A new process for the hydrometallurgy of refractory gold concentrates was presented. The process comprises grinding-leaching, intensified alkaline leaching (IAL), cyanidation and adsorption. In a stirring-type pulverizing-leaching tower mill, the concentrate is ground to ＜35.6μm of 95.5 % while simultaneously leached by NaOH of 12kg/t, then carried out intensified alkaline leaching for 48h by NaOH of 108kg/t in enhanced agitation tanks with the pulp concentration of 40% solids at the environmental temperature of 9.5～13.5℃ and the environmental pressure of 10⁵Pa. The oxidation rate of As is 94.9%, and 47.6% for S. The total consumption of NaOH is only 20% of that theoretically calculated under the conditions of full oxidation at the same oxidation rates of arsenic to arsenate and sulfur to sulfate. The gold leaching rate by NaCN in 24h is increased from 9.2% before pretreatment to 94.2%. The consumption of NaCN is 7.5kg/t, which is one times less than that before pretreatment. The extraction cost of gold is about 422Yuan/t.

Considering importance of study on physics fields and computer simulation for aluminum reduction cells so as to optimize design on aluminum reduction cells and develop new type of cells, based on analyzing coupled relation of physics fields in aluminum reduction cells, the mathematics and physics models were established and a coupled computation method on distribution of electric current and magnetic field, temperature profile and metal velocity in cells was developed. The computational results in 82kA prebaked cells agree well with the measured results, and the errors of maxium value calculated for three main physics property fields are less than 10%, which proves that the model and arithmetic are available. So the software developed can be not only applied to optimization design on traditional aluminum reduction cells, but also to establishing better technology basis to develop new drained aluminum reduction cells.

A process for recovery of RE from Baotou rare earth concentrate was developed by fixing the fluorine and chlorinating RE with ammonium chloride in the ore. The optimum conditions were determined as follows: fixing the fluorine of the ore 80min with the MgO dosage m(ore)/m(MgO)=3∶1 at 600℃; chlorinating the fixed fluorine calcine 80min, with NH₄Cl dosagem(NH₄Cl)/m(ore)=2∶1 at 500℃. The RE recovery reaches 85% under optimum conditions. The products of fixing fluorine with MgO were determined by X-ray diffraction, and the mechanism of fixing fluorine was also discussed. 

Different researchers often attained scattered kinetic results for the same leaching process. Usually, the difference is ascribed to the variation in mineral resource, chemical composition and, accuracy of experimental methods, while less attention is paid to the sample processing history. The present study shows that processing history of pyrite sample can cause great changes in its physico-chemical properties. Crushing, grinding and milling lead to an increase of the leachability of pyrite and the leaching becomes less temperature dependence owing to the decreasing of apparent activation energy of the reaction. The activation energy for its leaching in H₂SO₄-HNO₃ solution is depressed from 73.9 to 47.5kJ/mol after being activated through vibrating milling for 40min. On the contrary, aging causes the reverse change owing to the release of extra inner energy stored during mechanical treatments. Thus activity of pyrite will decrease towards its original value. Surely the processing history of concentrate sample should be taken into consideration when studying the kinetics of leaching reaction.

Based on the infrared characterization of methyl orange adsorption on TiO₂ surface and the titration of TiO₂, the triple layer model of methyl orange adsorption on TiO₂ was established according to electric double theory. The software FITEQL3.1 was applied to calculate the distribution of organic adsorption on TiO₂ surface by introducing dummy components to help to overcome mathematical difficulties. It is shown that the chem. -adsorption species of methyl orange have a great adsorption amount. The adsorption constants of three kinds of surface complexation expressed as SOH⁺org^-,SOH₂org₂ and SOHorg^- are 5.98, 17.57 and -4.2, respectively.

The adsorption and photocatalytic degradation of phenol in water were investigated in a cylindrical borosilicon glass photoreactor with a cooling water jacket using TiO₂/ACF as photocatalyst. A 15W UV lamp(254nm) was used as central light source. The effects of the temperature and initial concentration of phenol solution on adsorption and photocatalytic process were studied, and the comparison of adsorption, photolysis and photocatalysis was conducted. The results show that the classical model of Langmuir gives a good description of the adsorption of phenol on TiO₂/ACF and low temperature can improve the adsorption of phenol on photocatalyst; increasing temperature can increase the photocatalytic degradation rate of phenol; and the adsorption enhances the photocatalytic removal of phenol.

Considering the fact that there is much coal ash in the municipal solid waste (MSW) in some cities of China, the feasibility of composting in this situation was studied and the effect of content of the coal ash on the composting process and some basic relative technological parameters were investigated. The values of the moisture, the total organic matter, the content of coal ash, the C/N ratio and the ventilation were suggested to be 50%-60%, 40%-60%, 40%-60%, (25∶1)-(35∶1) and 0.05-0.20m³/(min·m³), respectively.

The derivative of charge and discharge curves (dt/dE vs E plot) can be used to describe the charge and discharge process more exactly. The dt/dE—E plots of nickel hydroxide electrode at different charge/discharge rates and intermittent discharge experiment are discussed. Though the dt/dE—E plot is affected by many factors, it clearly has intrinsic relation with the nature of active material such as conductivity and thermodynamic potential of active material, which changes with the state of charge. The dt/dE—E plot can also be applied to other electrochemical active materials, especially to those having several phases during charge or discharge.

The dehydration and hydration processes of magnesium chloride hydrates were studied by means of frontal chromatography analysis, calorimetry, thermogravimetry and chemical analysis. The mathematical imitation for the adsorption isotherms of MgCl₂·4H₂O and MgCl₂·2H₂O at different temperatures indicates that Boltzmann Function is the ideal equation to describe those adsorption isotherms. Its adsorption heat is -13.06kJ/mol and -16.11kJ/mol, respectively. The adsorption equilibrium constants are also given. From the data obtained, there is a thermodynamical possibility to use partial dehydrated magnesium chloride hydrates as an absorbance to clean water vapor contained in bischophite dehydration equipment and let the protection gas HCl recycle in the fluid bed reaction system.

Bioleaching of marmatite with a culture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans in high concentration of iron was studied, the results show that the zinc leaching rate of the mixed culture is faster than that of the sole Thiobacillus ferrooxidans, the increasing iron concentration in leaching solution enhances the zinc leaching rate. The SEM analysis indicates that the chemical leaching residues is covered with porous solid layer of elemental sulfur, while elemental sulfur is not found in the bacterial leaching residues. The primary role of bacteria in bioleaching of sphalerite is to oxidize the chemical leaching products of ferrous ion and elemental sulfur, thus the indirect mechanism prevails in the bioleaching of marmatite.

The process of cobalt removal from zinc sulphate solution using rude antimony trioxide as an additive was investigated. The rude antimony trioxide was produced in treatment of copper and lead anode mud and its main components are antimony trioxide, antimony arsenate and lead antimonate. Using the rude antimony trioxide as the additive of cobalt removal can not only decrease operation cost of purification but also find out a new way for utilization of the rude antimony trioxide. The effects of temperature, dosage of zinc dust, the rude antimony trioxide, copper ion and solution pH on removal of cobalt were studied. And experimental data using the rude Sb₂O₃ as additive were compared with those using Sb₂O₃. The results indicate that using rude Sb₂O₃ as additive, cobalt concentration in solution could be decreased from 24mg/L to below 1mg/L under about the same conditions as using Sb₂O₃.

A method based on controlling the complexation-precipitation equilibrium of metal ions was proposed to selectively recover nickel and copper from hydroxide sludge formed by lime neutralization of acid mine drainage(AMD). Ethylenediamine(EDA) and ammonium sulfate were chosen as complex reagent and precipitating reagent, respectively, to dissolve target metal hydroxides from sludge and limit useless metal ions in the pregnant solution. Results from both synthetic and natural samples show the excellent selectivity for the target metals(copper and nickel) against Fe(Ⅱ), Ca(Ⅱ) and Mg(Ⅱ), 99% recovery of Cu(Ⅱ) and Ni(Ⅱ) and shorter leaching time can be reached by this process, and the resultant solution can be used for direct electrowinning. The optimum operating conditions are: pH=9~11, ρ(EDA)=40g/L, ammonium sulfate 50g/L, leaching time 5h(for natural sample) and 2.5h(for synthetic sludge), liquid to solid ratio being 4 with mechanical stirring at room temperature.  

A kind of photoelectrode was innovated by anodising titanium mesh in H₂SO₄ solution and photo-reduced in HAuCl₄ solution and named Ti/Au-TiO₂ mesh electrode. The structural and surface morphology of the Ti/Au-TiO₂ mesh was examined by X-ray diffraction, laser Raman spectra, scanning electronic microscopy(SEM) and X-ray photoelectron spectroscopy respectively. The results indicate that its crystal structure, morphology and the size of pore are affected greatly by gold deposition. XPS measurement shows that the valence band of Ti/TiO₂ has two peaks: a wide one at 4.97eV and a narrow one at 6.61eV, which correspond mainly to π(nonbonding) and σ(bonding) O.2p orbitals. The emission intensity of O 2p orbitals becomes stronger and the width of the valence band increases with the increase of Au content. And the emission of nonbonding shifts toward lower binding energy and that of bonding O 2p orbitals shifts toward higher binding energy. The photoelectrocatalytic(PEC) oxidation of humic acid(HA) was investigated in terms of TOC. The PEC oxidation efficiency of Ti/Au-TiO₂ mesh with optimal content of gold is higher than that of Ti/TiO₂ mesh. It is suggested that the recombination of electrons and holes is hindered owing to gold deposition. The investigation shows that PEC oxidation is a convenient way to mineralize organic matter for water treatment.

In the process of heterogeneous photo-catalytic degradation, the reaction rate depends strongly on the property of organic binding on the surface. It is important to identify the adsorption of organic compounds on TiO₂ surface to understand the mechanism of degradation and proper kinetics expression. The infrared spectroscopy was used to analyze the methyl orange adsorption on TiO₂ surface in aqueous solutions in different pH ranges. The variation of the surface complexation of methyl orange formed on the TiO₂ surface in different acid and basic media was discussed. And the adsorption amounts were also qualitatively analyzed. Methyl orange has strong, weak and little adsorption on the TiO₂ surface in acid, basic and near neutral solution, respectively.

Electroreduction of Co(Ⅱ) to Co in acetami de-urea-NaBr melt at 353K is irreversible in one step. α and D are determined as 0.23 and 2.24×10^-7cm²·
s^-1. Y(Ⅲ) is not reduced to Y alone, but can be inductively codeposited with Co(Ⅱ). The amorphous Y-Co alloy film was obtained by potentiostatic electrolysis. The content of yttrium in the yettrium-cobalt deposits changes with the cathode potential, molar ratio of Y(Ⅲ)/Co(Ⅱ) and the electrolysis time, and can reach 83.93%.  
附件:yw2002-06-40

By partial and general dissection of large prebaked alumina electrolysis cells, the macro appearance, chemical composition and phase variations were studied employing actual observations and measurements on the cells together with X-ray diffraction phase analysis and scanning electron microscopy of samples from different locations. According to the practical production, a chemical reaction model of aluminum reduction cell failure was set up in order to reduce the incidence of cell failure and extend pot service life.

Through the study by electronic probe it was found that many new cracks and holes appear on the surface of gold-bearing arsenopyrite crystal oxidized by Thiobacillus ferrooxidans, which are along with some directions. Then the selective bio-oxidation model of gold-bearing arsenopyrite was set up. The selective bio-oxidation resulting from the submicro-battery effect of gold/ arsenopyrite mineral pairs naturally forms in the gold-bearing arsenopyrite crystal. Thiobacillus ferrooxidans has priority to oxidize the place of gold-rich and oxidizes selectedly along with the crystal border, crystal face and crack. The bacteria oxidation process of gold-bearing arsenopyrite is divided into three stages: the first stage is the surface oxidation, the second stage is restraining oxidation and the third stage is the filament oxidation, bacteria oxidize along with cracks of arsenopyrite.

The effect of 20kHz ultrasound on alumina hydrate precipitation from seeded sodium aluminate solution was studied. Compared with alumina hydrate precipitation without treatment of ultrasound, the precipitation time is reduced from 30h to 15h when the precipitation ratio is 45% under 20kHz ultrasound. Furthermore, agglomeration is increased and the growth rate of alumina hydrate is increased under 20kHz ultrasound by comparing the crystal size distribution and the SEM photographs. As a result, the average size of alumina hydrate is increased by 3.7μm. The structure of product is not changed according to the results of X-ray powder deflection. 

Wavelet transforms(WT) are proposed as an alternative tool to overcome the limitations of fast Fourier transforms(FFT) in the analysis of electrochemical noise(EN) data. The most relevant feature of this method of analysis is its capability of decomposing electrochemical noise records into different sets of wavelet coefficients(distinct type of events), which contains information about the time scale characteristic of the associated corrosion event. In this context, the potential noise fluctuations during the free corrosion of commercial aluminum alloy LY12 in sodium chloride solution was recorded and analyzed with wavelet transform technique. The typical results show that the EN signal is composed of distinct type of events, which can be classified according to their scales, i.e. their time constants. Meanwhile, the energy distribution plot(EDP) can be used as “fingerprints” of EN signals and can be very useful for analyzing EN data in the future. 

The cyclic voltammetry, current-time curve at potential step and potential-time curve of galvanostatic method were used to investigate the electrochemical behavior of Er(Ⅲ) in ErCl₃-LiClO₄-DMF(N, N-dimethylformamide) system on Pt and Cu electrodes. Results indicate that the electroreducation of Er(Ⅲ) to Er(0) is irreversible on Pt and Cu electrodes, the diffusion coefficient and electron transfer coefficient of Er(Ⅲ) in 0.01mol/L ErCl₃-0.1mol/L LiClO₄-DMF system at 303K are 1.96×10^-6 cm²·s^-1 and 0.081 respectively. The Er metal film was prepared by galvanostatic electrolysis on Cu electrode in ErCl₃-LiClO₄-DMF system at 40A·m^-2(current density). The deposites composed of Er over 95%(mass fraction) were obtained.

Sintered zinc-aluminum coating (SZAC) was prepared using zinc flakes, aluminum flakes and CrO₃ as main raw materials. The corrosion behavior of SZAC in 3.5%NaCl solution was studied by means of SEM, EDS, EIS and so on. Results indicate that aluminum corroded in advance of zinc to produce speculate or spherical substances, which attaches to SZAC and adds mass to it. Corrosion production passivates metal powders in SZAC, causes E_corr of SZAC to increase gradually, and causes the arising of the third time constant in EIS, which corresponds to the insulation of corrosion production.

Molecular dynamics simulations of the xCaO-(1-x)SiO₂ melts (x varying with the composition of melt) were performed to achieve some structural information. It is found that the first peak positions of Si-Si, Si-O and O-O partial radial distribution functions RDFs(3.165, 1.612 and 2.6 )agree very well with those of x-ray diffraction experiments. The discovered relation of coordinate number N_Si-Si(r₀) with the molar ratio of CaO is linear and the slope is -0.05617. The average bond lengths of Si-O_b and Si-O_nb are 1.6275~1.630 and 1.595~1.60, respectively. Both distribution curves of the angles O-Si-O and Si-O-Si show one peak. For the distribution of angle O-Si-O the positions of the peaks are just a little less than the typical tetrahedral angle 109.5°. And for angle Si-O-Si the positions of peaks fluctuate in the range from 148° to 151°. At last, the distribution of five Si-O tetrahedra was obtained and discussed.

An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed. Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite. The effects of the rough degree of rock surface, cutting angles, and static thrust on the cutting capacity of PDC in very hard rock were investigated and analyzed. The results show that the single mode of rotary drilling using PDC cutters is not applied for very hard rocks.

With aniline and salicylaldehyde as main materials, a new collector for wolframite slime was synthesized. In a pulp of natural pH value, this collector can collect wolframite effectively. Its selectivity is similar to that of benzyl arsenic acid and better than that of sodium oleate. With this collector, a wolframite rough concentrate with grade 30.12% WO₃ and recovery 91.50%, and a concentrate with grade 58.66% WO₃ and recovery 85.00% were obtained respectively from a wolframite ore containing 4.08% WO₃.

Extraction of copper from bacterial leach solution using Lix984 had been perform ed. It was found that the main factors influencing extraction yield of copper are the phase ratio and the concentration of extractant, following the pH of solution and extraction time and the order of factors influencing the separation rate is the pH of solution, the concentration of extractant, the extraction time and the phase ratio. The best conditions obtained by the orthogonal tests are as follows: the extractant concentration 4%, extraction time 3min, phase ratio 1:1, pH of solution 2.

A new type of catalytic material for purification of automobile exhaust, Cu-Mn-Ce-O/γ-Al₂O₃, has been studied. The factors affecting its catalytic activity, such as calcination temperature and the period of calcinations and so on have been investigated. Its catalytic activity after SO₂-poisoning was deter mined in a fixed-bed reactor by exposing the sample to the atmosphere of 160mL/min SO₂/air. The study reveals that the catalyst has shown high catalytic activities for the conversion of NH₃ oxidation by NO after sulfate. The conversion of NO reduction over the sulfated catalyst is somewhat higher than that over the fresh catalyst except that the optimum temperature has increased about 100℃. Also at the optimum process for the experiment, the selective catalytic oxidation of CO by NO is over 76% and the conversion of NO reduction is over 80% by NH₃.

Y and P zeolites were synthesized hydrothermally from natural stellerite under different conditions and were characterized via XRD and FT-IR. The results show that the higher crystallinity of Y zeolite can be obtained in hydrothermal system with low alkalinity, low Ca²⁺/Na⁺ ratio, and high SiO₂/Al₂O₃ ratio. The lattice space of the samples decreases as crystallization time increases. P Zeolite is prompted under condition of higher alkalinity and higher Ca²⁺/Na⁺ ratio. The intensity and number of bands in the range of 400cm^-1～900cm^-1 increases with reaction time. Bands at 680cm^-1, 760cm^-1 and 860cm^-1 corresponding to Y zeolite appear during the crystallization stage. Most of these bands shift to higher wavenumbers when SiO₂/Al₂O₃ ratio increases generally. In the hydrothermal system with reverse condition above, bands at 600cm^-1, 420cm^-1～470cm^-1 hardly change as the crystallization time increases and the main crystal phase of P zeolite is obtained.

A systematic experiment relating to the electrochemistry of oxygen ion transport in slag has been studied in lab. An equivalent circuit has been used to describe ion transfer between metal and slag in this paper and a kinetic model with electrochemical characteristic representing oxygen ion immigration has been worked out. The different experimental phenomena can be explained generally by this model. It can be seen that the theoretical results are in good agreement with experiments. The comparison of experimental data with model calculation proved that the electrochemical model is right.