GONTA-TECHNOLOGY Research and Production Enterprise (Ukraine):

Petrov A. V., Ph. D. in Engineering Sciences, Senior Researcher, Head of Group, avpetrov462@gmail.com

Saint Petersburg State Electrotechnical University (Russia):
Ivanov V. А., Ph. D. in Engineering Sciences, Associate Professor, Associate Professor, 79643867536@ya.ru

The work considers superhigh frequency energy application for high-phosphorus oxide carbonate manganese concentrates dephosphorization in the course of thermal treatment. The main reason preventing phosphorus volatilization in conventional roasting of pelletized manganese concentrate is phosphorus absorption by iron, reduced on silicates, forming strong compound of ferrous phosphide. The performed study shows that manganese concentrates thermal treatment process with superhigh frequency energy application is not identical to heat treatment with application of natural gas. Specific character of internal heating provides for uniform temperature distribution in specimen (pellet), increasing volume, within which chemical reactions take place, with their rate limited by temperature. This permits to provide heating in a controlled narrow temperature range of 950–1100 °С in total volume of material simultaneously. This temperature range lacks sufficient degree of reduction and iron metallization, so, the conditions for strong non-volatile ferrous phosphide compounds formation do not exist. This provides for phosphorus egress in gaseous phase. With that, high rates of heat-mass-exchange processes and deep degree of crystallochemical transformations (dissociation, dehydration and reduction) are achieved for carbonate and oxide concentrates. Decomposition time is reduced to 6–12 min. The technical and processing parameters of the laboratory installations, as well as the results of the experiments, obtained on two laboratory installations with microwave power of 2 and 5 kW are presented in the paper. The installations in questions used magnetrons operating at 2450 MHz frequency. Temperature was controlled by means of pyrometric techniques. Material composition prior to and following treatment was determined by chemical methods.

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