Studies on the Technology of Direct Causticizing Process by Ferric Oxide Part 2 Properties of White Liquor and Black Liquor in Alkaline Pulping

Properties of white liquor in Direct Causticizing process by ferric oxide and behavior of inorganic impurities which were leached from iron ore and accumulated in white liquor were investigated.Iron ore was reused 20 times in Direct Causticizing reaction and residual inorganic impurities were measured. About 66% of Al2O3 and only 5% of SiO2 is leached at the first cycle. NaCl, Na2SO4, KCl and K2CO3 has very little influence on Direct Causticizing reaction between Fe2O3 and Na2CO3.