Colored quartz sand composition is produced by diluting aqueous sodium hydroxide solution, mixing with boric acid and then binder in predetermined ratios, mixing with pigment-coated sand and indirect heating in closed system

摘要

Production of colored sand composition containing numerous quartz sand grains with colored pigment coating involves mixing aqueous sodium hydroxide (NaOH) solution and water in predetermined ratio; mixing with boric acid in predetermined concentration; mixing binder and boric acid-NaOH solution in predetermined ratio; adding coating mixture to pigment-coated grains; and indirect heating in closed system with separate heating and heat-source chambers. An independent claim is also included for the colored sand composition per se.