CERTAIN ASPECTS OF AN EFFICIENT HETEROPHASE CHEMICAL PROCESS FOR THE REDUCTION OF PbO₂ UNDER CRE-MODE

It has been demonstrated that under the effect of a chain gas-phase reaction (CRE method) involving hydrocarbon oxidation at reduced temperatures starting from 270 °C and above, lead dioxide (PbO2) undergoes efficient chemical conversions leading to complete reduction. Among the products formed during the heterophase CREconversion at various stages of the process are lead oxides (Pb2O3, Pb3O4, PbO), cerussite (PbCO3), and hydrocerussite (2PbCO3•Pb(OH)2) with diverse crystalline structures. The process rate depends on the volumetric composition of the initial hydrocarbon–oxygen mixture (RHO2), the contact time of the gas-phase reaction (к), temperature (T), and other parameters that determine the intensity of the conjugated chain reaction. The experimental data obtained on the heterophase chemical reduction of PbO₂ under CRE mode unequivocally suggest an effective method for recovering metallic lead from its oxides, achieving a reduction degree of Pb no less than 98.5 %.