Methods of Silica Extraction from Hydrothermal Heat Carriers

Abstract

The analysis of methods of extraction of silica and other chemical compounds from hydrothermal heat carriers was done. There were a lot of methods developed for the extraction because of many types of chemical compositions of heat carriers at different hydrothermal fields. The follows methods of silica extraction were analysed: 1) by addition of lime; 2) by addition of other coagulants such as metal salts; 3) by electrochemical coagulation; 4) by ultrafiltration; 5) by using fluidizided beds; 6) membrane filters. One can choose method fit for the heat carrier with definite characteristics. Silica extraction is carried out simultaneuosly with recovery of electrical and heat energy for increasing efficiency of heat carrier using. The examples of extraction of metals, iodine, bromine, sodium chloride, potash, boron, arsenic from the liquid phase of heat carriers and, besides, extraction of CO2 and H2S from gaseous phase were also considered.