Design, preparation and performance for low-carbon-dioxide belite–ye’elimite–Q phase clinker using gold mining and alumina industrial solid waste

Low-carbon-dioxide belite–ye’elimite–Q phase clinker (BYQ clinker) was designed and prepared, and its performance was explored in this work to realise the utilisation of gold mining and alumina industrial solid waste and the reduction of carbon dioxide emission. This new system of BYQ clinker was designed based on the investigation involved in the Q phase formation and Q–C4A3$ coexistence. In detail, the effects of temperature and magnesium oxide (MgO) composition on the calcining of the Q phase, the coexistence mechanism of Q phase and C4A3$, as well as the effects of sodium oxide (Na2O) on Q phase and C4A3$ were discussed. The results showed that the Q phase was calcined at 1350°C when the content of magnesium oxide was 3.37–5.37%. The ratio of Q phase/C4A3$ was greater than 1:1 in order to realise the coexistence of Q phase and C4A3$. Also, C4A3$ and Q phase can accommodate some amount of sodium oxide. These findings provide the foundation for the successful preparation of BYQ clinker using 35% gold mining and alumina industrial solid waste, with red mud accounting for 4%. The BYQ clinker was sintered at 1350°C and demonstrated excellent hydration activity, high early strength and a remarkable capability for immobilising heavy metal ions present in industrial solid waste raw materials.