Utilization of sodium sulphate. Commercial sodium sulphate is usually obtained by crystallization and calcination. Processes for utilizing sodium sulphate that have previously been studied or used are mainly the following methods: electrochemical processes, conversion processes, and reduction processes. At present the first two groups of these three appear more advantageous than the reduction processes, which are technically complex and suffer from the formation of waste gases. The lower energy requirements of the conversion processes offer advantages over electrolytic methods. Only comparative cost estimates for the different processes could help one arrive at a sound evaluation.