Semi-fused salt caustic leaching of turkish lignites- sorel cement use for desulfurization

Abstract

Beneficiate from clean fuels, particularly from clean coals, in industrial combustion systems and power stations for energy production is much significantly preferred in our country as well as in the world. İnstead of beneficiation from high quality coals due to lack of the deposits, production of low quality coals and consumption in our country may create some the environmental issues. Low-grade coals withhigh ash ans sulfur should be processed by physical and chemical methods and laterbeneficiated. it has been fundamentally needed that the use of most feasible chemical methods for desulfurization and deashing of the turkish lignites and hard coals since they might not be cleaned by physical methods. In this research, the one commonly used among various chemical methods, semi-fused salt-caustic mixture leaching of several Turkish lignites, for desulfurization and deashing was investigated and discussed for use of marblşe waste fine and sorel cement in salt leaching of Turkish lignites. In this study, semi-fused salt-caustic leaching tests of different types of Turkishh run-off-mine lignites; Aydın Şahinali, Kütahya Gediz, Denizli Çivril, Bolu Mengen, Tunçbilek, Soma Kısrakdere were carried out. Optimum semi-fused leaching conditions and effects of different types of salts were investigated. Magnesia and Sorel cement, NaCl, MgCl2 and KCl were also used as desulfurizing salt agent. Use of Sorel cement (3MgO.MgCl2)- caustic mixture in coal desulfurization were distinctly investigated and discussed. The qualities of processed coal products are ascertained by chemical and standard coal analysis of ASTM 3174-3177. According to the test results, the best semi-fused salt- caustic leaching process and salt mixture was determined.