A procedure to cover sand grains from individual coatings formed by a virtually termoinforceable resin. (Machine-translation by Google Translate, not legally binding)

摘要

A process for coating the sand grains of individual coatings formed by a solid and non-sticking, virtually thermoset resin, characterized in that the sand is mixed with an initially thermoplastic phenol-formaldehyde resin and with an amount of hexamethylene tetramine sufficient to finally carry the resin to the thermoset state while the mixture is still hot, in order to evenly distribute the resin that is in a liquid or molten state; and of uniformly coating the grains of sand; the mixture is cooled after partial reaction with the resin to a point below its modified melting point resulting from the treatment, in order to block the subsequent conversion reaction and to solidify the virtually thermosetting resin coating that is deposited on the sand grains. ; the mixing operation is continued during cooling to solidification to break up the agglomerates contained in the mixture; finally, the resin-coated sand particles are recovered without releasing any dust, which flow freely and are stable to conservation. (Machine-translation by Google Translate, not legally binding)