METHOD OF PROCESSING SOLID WASTE AND REFUSE FORMED IN ZINC OXIDE-BASED VARISTOR CERAMICS PRODUCTION Russian patent published in 2004 - IPC

FIELD: ceramics. SUBSTANCE: solid waste and refuse are dissolved in mineral acid, after which metal cation mixture is precipitated, washed, dried, and calcined to give oxide forms. In particular, dissolution is carried out in concentrated hydrochloric acid at 50-80 C at liquid phase-to-solid phase ratio (2.9- 3.1):1 l/kg and metal cation mixture comprising Zn, Bi, Sb, Co, Mn, Cr, and Al is precipitated by sodium carbonate aqueous solution at 40-70 C. EFFECT: recovered varistor ceramics material and enabled reuse of recovered powder both in pure form and as additive to production blend prepared from pure oxides. 2 ex