Based on the systematic experiment of treating low-concentration lye in the red-mud mound, several key problems in the selection of technological process for industrial trial, such as aluminum precipitation in the process of electrodilalysis, dealuminum with carbon dioxide at low temperature, the selection of the technology for electrodialysis and estimation of benefit of the trial production line, are studied in the paper. For a production line with the handling capacity of 50 m³/h, its annual direct economic benefit can reach RMB 4 million yuan, calculated by 300 working days a year.

A new method for production of ammonium metatungstate (AMT) directly from ammonium tungstate solution—Donnan dialysis method is advanced. Laboratory experiments are conducted by a Donnan dialysis cell with the membrane area of 140 mm ×200 mm. The result shows that the transformation rate of AMT reaches 370 g-WO₃/(m²·h), the recovery ratio of AMT by the Donnan dialysis method is nearly 100%, and the loss of tungsten is less than 0.2%. It has been proved that the Donnan dialysis method is effective for production of AMT.

In order to design the technological process of desalination by electrodialysis for the industrial wastewater of an alumina plant, the limit current density of the industrial wastewater is measured, and the equations of limit current density, voltage drop of the unit membrane pair at the limiting current and desalination ratio at the limiting current were obtained.

The experimental results of producing deionized water for the themoelectric factory from two types of the industrial wastewater of an alumina plant by using membrane technology are reported in this paper. For the treatment of the industrial wastewater with high salinity and pH value, the combination of electrodialysis (ED) and reverse osmosis (RO) is utilized, while for the treatment of the low-salinity wastewater with low pH value, RO is directly used. The research results show that the above-mentioned methods are effective. The technological process of the wastewater treatment with the capacity of 120 tons is designed on the basis of the experimental results.

In the production process of titanium dioxide with sulfuric acid, the contamination of the titanium sulfate solution (the ilmenite leaching solution) in the Fe³⁺ reduction stage by iron scraps is a practical problem because it is difficult to guarantee the quality of the iron scraps. In this research, a new method, called the ion-exchange membrane primary cell method, for reduction of Fe³⁺ in the titanium sulfate solution has been advanced. The positive compartment of the primary cell consists of lead (copper) electrode and the titanium sulfate solution, and the negative compartment consists of iron electrode and acidic FeSO₄ solution. The anion ion-exchange membrane is used as the diaphragm between two compartments. Fe³⁺ in the titanium sulfate solution is reduced by the electric discharge of the primary cell. The effects of temperature, stirring strength of the solution and membrane area on the reduction rate have been investigated. The experimental result shows that the optimum current density can be higher than 100 A/m².

concentrating sulfuric acid by membrane distillation in a flat-sheet direct-contact membrane distillation device with a self-made metal-PTFE composite membrane has been studied. The effect of sulfuric acid concentration of feed, the flowrate and liquor temperature in high-temperature side and low-temperature side on the flux and separation efficiency is investigated. The stability of this composite membrane is also inspected. The experimental results show that the metal-PTFE composite membrane can be used in membrane distillation, and its properties are very stable. It is feasible to concentrate sulfuric acid by membrane distillation with this membrane.

Concentrating sulfuric acid solution by vacuum membrane distillation with flat PEFE membrane is explored. The effects of sulfuric acid concentration, temperature of the feed, the vacuum degree of the vacuum side on the flux of membrane distillation and the separation efficiency of acid are investigated. The results illustrate that the flux of the membrane distillation increases with the rise of feed temperature and the vacuum degree of the vacuum side, but it decreases with the rise of the sulfuric acid concentration of the feed. The separation efficiency of acid is correlated with the flux of membrane distillation; the separation efficiency of the acid can amount to 100% in the process, when operative conditions are properly controlled. It can also been obtained from the experiment that, compared with other methods of membrane distillation, the vacuum membrane distillation can obtain greater distillation flux.

In the process of sulfuric acid production from pyrite, there is a lot of waste acid produced in fume washing with dilute acid. Acid recovery from this sort of waste sulfuric acid by diffusion dialysis is studied in the paper. The mass transfer dialysis coefficient of sulfuric acid of the membrane AFX is measured, the effect of the flowrate of the feed and ratio of feed to water is investigated, and the two kinds of membrane (AFX and S203) are compared. The results show that diffusion dialysis process can separate the metal cation from sulfuric acid effectively, but it is difficult to separate non-cation impurities as As⁻ and F⁻. The contrast tests of the two membranes show that the dialysis mass transfer coefficient of the membrane AFX is larger, while capacity of the removing impurities of membrane S203 is somewhat better.

By measuring the electrode polarization curves of many kinds of materials and life spans of electrodes through intensifying electrolysis in the process, the appropriate electrode materials for different stages of electrolysis of sodium tungstate solution with membrane have been selected The effects of the electrodes with different shapes on electrolysis have been investigated. The result shows that network electrode is more suitable to electrolysis of sodium tungstate solution.

The functions and system structure of DSA-1 Type direct shear apparatus were described, which is noted for its various functions, advanced techniques of multi-desciplines. The apparatus adopted advanced measuring system and has high accuracy of testing data. It provide a new technical measure for the study of dynamic characteristics of bulk solid.

Redefines the mean Cook distance under the contaminated error model. With the help of the mean Cook distance, the paper discusses the relationship between local influence of small perturbations and high leverage case. A new robust method for the adjustment of geodetic networks is proposed. The suggested method, a generalization of the robust method with the minimum mean Cook distance, is more efficient than the others. The basic feature of the method is that the equivalent weight functions of the robust estimates are determined according to the principle of statistics.

The difficulties of washing during the dressing of kaolin ore have been analyzed, the multistep intermittent washing model has been deduced, and effective methods for dealing with the difficulties were put forward. Experimental results show that the bleaching and washing process was enhanced, the washing time was shortened and the consumption of water was reduced by means of adding flocculant.

The effects of preheating temperature and W powder size on the Self-propagating High-temperature Synthesis (SHS) of Ti-W-C system were studied. Preheated mixtures and the decrease of W powder size can accelerate the formation of (W, Ti) C powders. The uniphase (W, Ti)C (WC:TiC=5:5) powders with 0.32% free carbon were synthesized from Ti, W, C powders by SHS. The powder size of the product was 3–5 µm.

The doping reaction of polyaniline with camphor sulfonic acid (CSAH) in different organic solvents was studied by UV-Vis spectroscopy. The experimental results show that the polaron band of the species was shifted to shorter wavelength when polyaniline was doped with CSAH in N-methyl-2-pyrrolidione (NMP) solvent, while the red shift of polaron band was observed when it was in N, N-dimethylformamide (DMF). It indicates that the influence of different processing solvents on the doping property of polyaniline is greatly different. N-methyl-2-pyrrolidione is a good solvent for polyaniline, polyaniline chain is unfolded in it. The interaction of NMP with CSAH is so strong that the resulting product is apt to dedoping, while the solubility of polyaniline in DMF is relatively low and polyaniline chain is in partly folded state. Thus the doping reaction is kinetically disadvantageous but thermodynamically advantageous.

An approach is proposed to design decentralized state feedback _∞ suboptimal controllers for LTI interconnected large scale systems. The parametrization theorem of decentralized robust state feedback controllers is developed in two steps and the design condition for the feedback gain is in the form of matrix inequalities. An iterative solution algorithm based on linear matrix inequality (LMI) techniques is proposed to obtain the decentralized feedback gain. The given examples are taken to show the application and the convergence of the algorithm.

Presents a control strategy for underactuated mechanical system: the acrobot example, which combines fuzzy control and linear quadratic control. The fuzzy controller designed for the upswing ensures that the energy of the acrobot increases with each swing. After the acrobot enters a neighborhood of the unstable straight-up equilibrium position, a linear quadratic regulator is designed to balance it.

Aimed at the needs of developing the CAI courseware with popularization, the expression ways for hypercard-based information, and the key principles of the development for authoring tools, were discussed. The ideas of the revised hypermedia chaining structure were introduced. The framework of the courseware authoring tool, its function design and the methods of technical realization for system software were also involved.

A new general optimal principle of designing explicit finite difference method was obtained. Several applied cases were put forward to explain the uses of the principle. The validity of the principal was tested by a numeric example.