Electrostatic Separation of Fine Particles in Vibrated Fluidized Beds
Very fine particles which cannot be fluidized by means of a flowing gas alone because of entrainment may be effectively individualized and retained in the bed through a combination of gas at low rate flow and mechanical vibrations of selected frequency and amplitude. A mixture of very fine particles may be fluidized and successfully separated and/or concentrated by means of electrostatic fields. Results are presented of a factorial experiment in which the conditions of temperature, humidity, and voltage were investigated for the separation of a (50-50 by weight) synthetic mixture of iron and glass powder of particle size ranging from 15-45¿m. A new and highly efficient particle collection mechanism is introduced, and mathematical models of the process are presented as part of the optimization work.
Electrostatic Separation of Coal Macerals
Present threats of energy shortages have placed an increasing importance on coal as a fossil fuel. Government restrictions on the maximum permissible S02 content in coal burning plant effluents have necessitated sulphur reduction processes. By using an apparatus developed by the researchers at the University of Western Ontario, it has been demonstrated that constituent macerals of the coal may be successfully triboelectrified and then separated in electrostatic fields. The electrification and separation of the pyrite maceral from coal by means of dilute phase fluidization and electric fields is discussed. Some results are also presented on the separation of the vitrinite, fusinite, exinite, and micrinite macerals as well as of coal fractions with high ash content. The results show the effectiveness of the triboelec-trification of the macerals in contact with one another and with the material used in the construction of the separator.
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.