Progress on the Use of an Information-Technology-Based Method in Low-Waste Technologies for Aluminum Production

Resumo

The use of information-technology-based methods is substantiated and a method based on systems analysis is developed with the use of computer models to optimize the conditions and parameters of the operations in aluminum production. The method of minimizing the Gibbs free energy of a thermodynamic system is used to create an algorithm which determines the order of metastable equilibrium of the components in the production process and the dynamics of the mobile heterogeneous phases. The physicochemical laws that govern structural changes in the composition of the condensed phases and the equilibrium phases are examined in relation to the cryolite ratio (NaF/AlF₃). The results make it possible to correct the cryolitealumina melt (electrolyte) and predict the volume of emissions and waste products. A method of measuring and stabilizing the characteristic temperatures is also developed. The optimum conditions and parameters for the use of fluoride salts (fluoroaluminates) and the recycling of fluorine compounds and impurities in “dry” gas-cleaning and electrolysis are determined. Fluorine-bearing wastes are grouped in three different classes based on the proportions of the main phases and the impurities that are present. Thermochemical methods are proposed for their waste-free processing to obtain additional products and process additives that can serve as valuable components in the production of alumina and aluminum. Improved technologies for cleaning gases and recycling wastes can help make more thorough use of raw materials and reduce emissions of harmful substances during aluminum manufacturing.