Abstract: In order to demonstrate whether tailings cemented filling with high sulfur content can be used in a copper mine in China， the strength variation of high-sulfur tailings filling body was investigated by adopting the tailings filling ratio experiment. The results showed that the high sulphur tailings filling body cracks gradually with the growth of curing age under unclosed environment， and its strength increases first and then decreases gradually. Under closed environment， the filling body does not crack， and its strength increases gradually to a relatively stable level with the growth of curing age. Under unclosed condition， the strength of filling body increases or decreases regularly with the change of slurry mass concentration and lime-sand ratio at the early stage， but it has no obvious variation law with the change of lime-sand ratio or mass concentration at the later stage. Scanning electron microscopy analysis shows that the cracking of high sulfur tailings filling body is mainly caused by the large amount of expansive materials such as ettringite and gypsum in the filling body.

Key words: Backfill, High-sulfur tailings, Proportioning test, Compressive strength, SEM, Ettringite