Adaptation of the SAVMIN process for mine water treatment

Abstract

Abstract The article presents the thermodynamic substantiation of the necessary and sufficient basicity of calcium aluminates for the formation of the preferred form of ettringite during purification of mine water from sulfate ions, the selection results based on the data obtained and studying the phase composition of aluminothermic slags by X-ray phase analysis of the preferred precipitating reagent. It has been established that mainly basic calcium aluminates are present in the chromium metal production slags, while ferrotitanium and ferrochrome production slags contain up to 35% majenite - 12CaO 7Al2O3, the presence of which in the precipitator increases the feasibility of precipitation from ettringite in the form of calcium mono-hydrosulfoaluminates. The results of the experimental verification of the feasibility and effectiveness of the purification of the model sub-waste water are presented. It is shown that it is possible in principle to reduce sulfates to MAC in mine waters using two-stage sedimentation using ferrotitanium production after liming as a reagent-precipitant of mechanically activated slag.