can't read?
Zirconium silicate, also zirconium orthosilicate, (ZrSiO4) is a chemical compound, a silicate of zirconium. It occurs in nature as the zircon, a silicate mineral. Zirconium silicate is also sometimes known as zircon flour.
Z 1360(OTTO) Zirconium silicate, 98%+ Cas no 10101-52-7 - used for manufacturing refractory materials for applications where resistance to corrosion by alkali materials is required.