Verwertung von Natriumsulfat

Abstract

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.

Acid Gas Capture at High Temperatures Using Molten Alkali Metal Borates

“…Once up-concentrated, the sulfurous compounds could be further refined and purified under ambient conditions and made into marketable products. Many options exist, − including some at high temperatures, which would minimize thermal losses. However, it is likely that the value of lithium relative to all other species will dictate the treatment method.…”

Recycling of Sodium Sulfate by High Temperature Metathesis with Hydrogen Chloride

“…As the demand for sodium sulfate in the western industrial nations has decreased over the last decade, selling sodium sulfate has become increasingly difficult. [1,2] Both dumping (due to high dumping costs) and disposal as wastewater are neither economically nor ecologically acceptable options. Recycling processes are thus attracting increasing industrial interest.…”

“…One of the potentially interesting conversion processes is the metathesis of sodium sulfate with hydrogen chloride. Combined with the alkali chloride electrolysis and the hydrogen chloride synthesis it enables the conversion of sodium sulfate into caustic soda and sulfuric acid: [1,2] metathesis: Na 2 SO4 + 2 HCl 2 NaCl + H 2 SO 4 (…”