METHOD OF UTILISING SOLAR PONDS FOR EFFECTING CONTROLLED TEMPERATURE CHANGES OF SOLUTIONS PARTICULARLY IN PROCESSES INVOLVING THE DISSOLUTION AND/OR PRECIPITATION OF SALTS

摘要

METHOD OF UTILISING SOLAR PONDS FOR EFFECTINGCONTROLLED TEMPERATURE CHANGES OF SOLUTIONS PARTI-CULARLY IN PROCESSES INVOLVING THE DISSOLUTIONAND/OR PRECIPITATION OF SALTSABSTRACT OF THE DISCLOSUREA method of changing the salt content of asolution is described by including the salt in a non-convective solar pond heated by solar radiation andhaving stable salt-concentration and temperaturegradients increasing from the top to the bottom ofthe pond, the bottom layer of the pond being a sub-stantially saturated solution at a predeterminedtemperature. A feed solution containing the salt isintroduced directly into the bottom layer and iscirculated through the bottom layer. The predeterminedtemperature of the bottom layer is different fromthe initial temperature of the feed solution whenintroduced into the pond bottom layer and is selectedto effect a change in solubility, and thereby a changein the salt content, of the feed solution by causingsalt in the feed solution to be precipitated therefrom,or additional salt to be dissolved therein.Examples are described in which the solarpond is used for the production of sodium sulphate,dehydration of other salts, upgrading of Carnalite,production of potassium chloride, and production ofvarious minerals from the Dead Sea.