Study on the System and Reaction Mechanism of Desulphurisation Ash Curing Dry Discharge Tailings

Desulphurisation ash is used as curing agent to cure dry discharge tailings. Through holding time, forming pressure, desulphurisation ash dosage, and material concentration of four single-factor test, the strength change rule of cured body under different curing system is analysed, and the reasons are briefly analysed from the microscopic point of view by means of XRD and SEM. And a large-scale demonstration project of tailings hardening and ecological restoration was carried out at a tailings disposal site. The results show that: when the mass ratio of desulphurisation ash and tailings is 20:80, the concentration is 80%, the forming pressure is 20 MPa, and the holding time is 40 s; the 56d compressive strength of the cured body can reach 7.93 MPa; the main hydration products are AFt and AFm; this study not only makes the tailings get good disposal, but also provides a kind of idea for the ecological restoration of the mine.