TREATMENT OF PACKING MATERIAL

摘要

PROBLEM TO BE SOLVED: To remove harmful substances and impurities from the sand or gravel of minerals and rock used as a packing material (agent) for a water purifying device. SOLUTION: The sand or gravel of minerals and rock used as a packing material for a water purifying device is heated to 700-1,100 deg.C until a moment immediately before the surface of the sand or the gravel is vitrified. Then the surface of the sand or the gravel is grounded and washed with water and dried. Thereby harmful substances and impurities can be removed from the sand or the gravel of the minerals and the rock and clean and safe drinking water can be supplied.