Adsorptive properties of MgCO₃–CaCO₃ Sargasso treated in air and deficient of oxygen

The paper considers the process of thermal treatment in the air of Sargasso algae containing magnesite (MgCO₃), calcite (CaCO₃), and complex carbonates of the MgCO₃·nCaCO₃ type. It has been established that the decomposition of MgCO₃ begins at T_tr = 400 °C: MgCO₃ → MgO + CO₂, the dissociation of calcite begins at 600 °C: CaCO₃ → CaO + CO₂, and the low-temperature decomposition of MgCO₃·nCaCO₃ from 400 °C leads to the additional formation of MgCO₃ and CaCO₃ and a subsequent increase in the content of MgO and CaO with increasing processing temperature. The Sargasso algae treated at T_tr = 600 °C and t_tr = 15 min. and crushed into a powder has good adsorption properties to remove dyes from water and crude oil from the water surface. After T_tr = 600 °C and t_tr = 15 min. of waste mixture oil-adsorbent under conditions of oxygen deficiency is accompanied by the formation of a secondary adsorbent consisting of carbonates and carbon.