Z 1368 (OTTO) Zirconyl sulphate, 98%+ Cas no- 7446-31-3 - used in organic synthesis. Z 1368 (OTTO) Zirconyl sulphate, 98%+ Cas no- 7446-31-3 - used in tanning white leather. Z 1368 (OTTO) Zirconyl sulphate, 98%+ Cas no- 7446-31-3 - used as catalyst supports to precipitate proteins and amino acids. It is also useful in chemical analysis. It plays an essential role as an additive for lubricants and as a pigment stabilizer.