| 摘要 |
<p>PURPOSE:To recover Na2CO3 from the waste slag containing CaCO3, at a low cost, in high yield, with easy control of the Z-value, by adding sodium sesquicarbonate to the slag. CONSTITUTION:The waste slag containing CaCO3 and produced by the desulfurization or desulfurization and dephosphorization of molten iron with CaCO3 is sent to the dissolution tank 1, added with sodium sesquicarbonate (a mixture of sodium bicarbonate and sodium carbonate and having a Z-value of 0.6-0.7) and water or hot water so as to obtain the extracted CaCO3-containing solution having a Z-value of 0.50-0.65, and filtered (2) to remove the residue. The obtained CaCO3-containing aqueous solution is added with NaOH to adjust the Z- value to 0.50-0.60, and Na2CO3 is recovered by concentrating and evaporating the mixture.</p> |
