Investigations into high temperature separation of antimony from metal oxide varistors
Artikel i vetenskaplig tidskrift, 2017

Very little research has been done into methods for recycling antimony from end of life products. This study investigates separation of antimony from metal oxide varistors (MOVs), where antimony is present between 3 and 5 wt%. In MOVs, antimony is found in spinet (Zn(2.33)Sh(0.67)O(4), Zn7Sb2O12) and pyrochlore (Zn2Bi3Sb3O14) compounds. Due to the low concentration of antimony in MOVs, a leaching pretreatment using dilute sulfuric acid was performed where antimony remained in an insoluble solid. The leaching pretreatment resulted in a more than fivefold increase in the antimony concentration. In order to separate antimony from the MOV leaching residue, it was subjected to a simple thermal treatment and carbothermal reduction at temperatures of 500-1300 degrees C. Results showed that 80% of antimony can be separated from the leach residue by heat treatment at 1100 degrees C, while 85% of antimony can be separated from the leach residue at 1100 degrees C using carbothermal reduction. Once separated, antimony can be recovered from the gaseous phase due to its volatile nature. Results show that antimony recycling from MOVs is a promising source of secondary antimony.

Characterisation

Separation

Antimony

Recycling

Reduction

Författare

Toni Karlsson

Industriell materialåtervinning

Christer Forsgren

Stena Metall Ab

Britt-Marie Steenari

Industriell materialåtervinning

Journal of Cleaner Production

0959-6526 (ISSN)

Vol. 162 474-483

Ämneskategorier

Metallurgi och metalliska material

Miljövetenskap

DOI

10.1016/j.jclepro.2017.06.033