| 摘要 |
<p>Sodium bisulfite, for use in the acid digestion of wood to produce pulp is obtained for the process by passing calcium bisulfite through a strong cation exchange resin in the sodium form and regenerating the exchanger with sodium chloride. The calcium bisulfite for the process can be obtained in a known manner, for instance, in an acid tower of the sulfite pulp industry or by passing sulfur dioxide through milk of lime. The process avoids environmental pollution caused by the usual discharge into streams of waste calcium salts from the older sulfiting processes and by the release into the atmosphere of sulfur dioxide containing combustion gases.</p> |
