Dual-alkali desulfurization process
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I read in relevant materials that in the double-alkali desulfurization process, sodium carbonate is used during startup while sodium hydroxide is used during normal operation. Why can’t sodium hydroxide be used during startup? I would appreciate advice from my friends.
Many hydrometallurgical plants here use one type of alkali, liquid caustic, instead of sodium carbonate.
{:3_57:} Let’s guess together: when starting the reaction, sodium carbonate is used instead of sodium hydroxide. The differences between sodium carbonate and sodium hydroxide are as follows: first, the heat released during the reaction; second, the initial concentration is higher than normal, but the reaction rate should not differ much. Is it because there is a fear that high heat release in the initial stage could lead to the formation of sodium thiosulfite? {:3_53:}