A cationic amphiphilic copolymer was synthesized with acrylamide (AM), dimethyl diallyl ammonium chloride (DMDAAC), monomer B by solution copolymerization. Through the orthogonal test, the optimum synthesis condition was obtained as follow: the solid content of the polymerization system is 10%, the pH value is 4.0, the polymerization temperature is 60°C, the concentration of the initiator is 0.06%, and the monomer ratio of m (AM): m (DMDAAC): m (monomer B) is 70:10:20. The copolymer was used for the filtration aiding in the wet process phosphoric acid. The filtration rate of the gypsum slurry is increased by 4.8 times, and the filter cake moisture is reduced by 11.79%, with the addition of PADB. The mechanism of filtration aiding was also researched, which shows that PADB can change the mean diameter of crystals and agglomerate the tiny crystals; PADB can decrease the surface tension of the filter liquor and enhance the hydrophobicity of the gypsum.

A novel copolymer PADA which has two functions of flocculation and surface activity was synthesized in aqueous solution. The copolymer was applied to filtration aiding on wet-process phosphoric acid (WPA). The results show that PADA can increase the filtration rate of the phosphoric acid slurry and decrease the moisture of the filter cake. The mechanism of filtration aiding was studied. PADA neutralizes the surface potential of the phosphogypsum and makes the microcrystal particles flocculate to conglobation, which indicate that electrostatic neutralization and flocculation might be the action modes in the process of filtration aiding. The shortest flocculation time and largest average diameter of floccules can be obtained with the addition of 10 ppm PADA. The average pore size and porosity of the filter cake are enlarged by 0.22 μm and 15.38% respectively with the addition of PADA. The surface contact angle of the phosphogypsum is increased by 3.4° with PADA presence.

A non-ionic copolymer PAMA which has two functions of flocculation and surface activity was synthesized in aqueous solution. The copolymer was also characterized by means of infrared spectroscopic and unclear magnetic. The application performance of PAMA were studied, and the results show that the filtration rate of the phosphoric acid can be increased by about 3.8 times,the water content of the filter cake can be reduced by about 9.8%. Meanwhile, PAMA may increase the cake porosity by 25.82%,increase the mean void area about 7 times ,increase the surface contact angle of phophogypsum by 9.8°and decrease the surface tension by 7.4 mN·m-1 according to the SEM photos and hydrophobic experiment. All this confirms that PAMA is useful for vacuum filter system of wet process phosphoric acid.

The interfacial reactions and thermodynamic properties of the emulsion liquid membrane on separation and concentration of chromium (III) were discussed. Interfacial chemical reaction equations of membrane phase with P204 and mass transfer mechanism of ELM system were determined. The extraction reaction enthalpy is 11.41 kJmol1, while stripping reaction enthalpy is-143.65 kJmol1, were obtained by investigating reaction temperature on the distribution ratio under two different conditions. So extraction is an endothermic process and stripping is an exothermic process. And the main driving force of the separation system is the concentration gradient of hydrogen ion between external and internal phase interface.

The extraction kinetics and mechanism of La (III) by P204-kerosine from phosphoric acid were investigated by constant interfacial cell with laminar flow. The effects of stirring speed, temperature, specific interface area on extraction rate were studied. The results indicated that a plateau region is appeared at the stirring speed of over 115r/min. The extraction apparent activation energy was calculated to be-13.40kJ/mol and the extraction process is controlled by a mixed mechanism of diffusion and chemical reaction. The rate equation of extraction was deduced. Under conditions of 25°C and interfacial area 19.64cm2, the extraction rate constant was 2.08×10-6 m·s-1·. Through the derivation of the reaction mechanism the reaction zone is at the liquid-liquid interface.