Preparation and characterization of permeable bricks from gangue and tailings

- New permeable bricks were prepared by using gangue and tailings.
- Effects of adding new aggregate and sintering temperature were investigated.
- Effects of aggregates content and aggregates size were also investigated.
- Fabrication was simplified without using natural clay and artificial aggregates.

Gangue and tailings are both solid wastes produced by mining processing. In this study, permeable bricks were prepared by partial sintering of aggregates method, using gangue and tailings as aggregates and binder, respectively. The effects of aggregates content, aggregates size, sintering temperature and adding new aggregate on the permeability, apparent porosity, water absorption and mechanical properties of the prepared permeable bricks were systematically investigated. The optimum parameters to prepare the permeable bricks were obtained at 1180-1200 °C for 45 min with 20 wt% tailings, 60-70 wt% gangue and 10-20 wt% waste ceramic. The prepared permeable bricks, with the optimized parameters, have a high permeability (about 0.03 cm/s), exhibiting considerable compressive strength (exceeding 30 MPa). Combined with the macroscopic properties and microstructure analysis of the permeable bricks, the variation of the performance of permeable brick under different factors is studied. The preparation of permeable bricks using gangue and tailings may provide a promising way to reuse mine solid wastes, considering the advantages in both economic and environmental aspects.