HIGH TEMPERATURE PRETREATMENT USING AN AQUEOUS ALKALINE SOLUTION OF CLAY-LIKE NATURAL MATERIALS CONTAINING AT LEAST ONE VALUABLE FUEL ELEMENT

摘要

High-temperature pretreatment process by means of an aqueous solution for so-called pretreatment of natural materials containing at least one upgradable fuel element, the gangue of which contains argillaceous compounds capable of forming a stable plastic suspension in the presence of water, characterised in that, for the purpose of permitting subsequent easy separations of the aqueous liquid and solid phases, on the gangue, the natural material containing at least one fuel element to be upgraded is brought into contact with an alkaline pretreatment solution containing at least 2.10 g/l of OH- ions and then the medium formed is immediately raised to the minimum pretreatment temperature of at least 120 DEG C in a time of at most 30 minutes taken from the time the natural material is brought into contact with the aqueous pretreatment solution.