Aluminate Solution Viscosity

With the development of national economy, the alumina industry has expanded to such an extremely large nonferrous metallurgy calling that the total output amount of alumina in China has exceeded 6 million tons in 2003, concomitant with which is the desirable progress gained in the critical technologies concerning alumina production. But there are still some blankness existing in the fundamental theories involving the process of alumina production such as the properties and structure of sodium aluminate solutions, which awfully obstruct the technology innovation and the craftwork breakthrough of alumina production.Viscosity is an important physical property of sodium aluminate solution, so researching the viscosity of sodium aluminate solution is one of the vital approaches to explore the structure of sodium aluminate solution and modify some relevant parameters of production procedure. This thesis systematically analyze the viscosity of sodium aluminate solution and its influential factors from several aspects as follows:1. The viscosity of sodium aluminate solution is determined by its structure. It's the change of the solution structure that leads to the variation of viscosity. A variety of experimental phenomena in this research can be satisfactorily explained by the theory of polymeric ions, hydrogen bond and electrolytical solution.2. As to pure sodium alumnate solution, factors such as temperature, concentration and caustic ratio etc. exert significant influences on its viscosity. The results of experimentation indicate that the viscosity assumes a high value at low temperature, high concentration, caustic ratio and supersaturation and vice versa. Multiple linear regression on the experimental data make clear the quantitative relationship between viscosity and the temperatue, concentration and caustic ratio of sodium aluminate solution:a-Caustic ratio of solution A - Concentration of alumina, g/L3. The solution viscosity got elevation with the increase of silicon index, which can be mainly ascribed to the formation of large alumino-silicate ions as a result of ion interchange between A1(OH)4-and SiO2(OH)2, both with similar tetrahedron structure. But the increase extent decline in high silicon index due to a weak occurence of this effect.4. The addition of some additives ameliorates the viscosity of sodium aluminate solution to some extent. The combination of surfactant and aluminate anions alter the congregate status of ions, which promote the variation of the ion structure and hence the viscosity of sodium aluminate solution. Hydration is the main mechanism of nonionic surfactant and inorganic salt to impose influence on the surrounding environment of aluminate ions and innervate the variation of solution viscosity.