OPTIMIZATION MODEL AND MICROSCOPIC MECHANISM ANALYSIS OF A MULTI-SOLID WASTE ACTIVATOR

Solid wastes such as slag, fly ash, steel slag, lime, and desulfurization ash were used to prepare a multi-solid waste activator (MSWA) for tailings filling. We constructed a multi-response optimization model, analyzed the significance of MSWA raw materials, and conducted microscopic experiments to explore the hydration mechanism. The above test results showed that: the error of the calculated value of the desired model of multiple responses was less than 2%, which can effectively reflect the proportioning willingness and the significance of raw materials; the TS-3 intention value of the test group was 0.812, and the 3-day strength and expansion were 0.643 MPa and 15.8 cm; the significant factors in 3-day strength term were cement clinker (0.629) and steel slag (0.171), the significant factor of expansion term was fly ash (0.761). The microscopic test showed that: in the OH^- and SO^2-₄ solution provided by slag, C₃S and C₃A in cement clinker and other raw materials rapidly hydrated and released heat, and fly ash could promote hydration and improve the workability of mortar. In the product, C—S—H and AFt were well developed, making the structure compact, thus enhancing the macroscopic mechanical properties of the filling body.