Silica–Calcareous Non Fired Bricks Made of Biomass Ash and Dust Filter from Gases Purification

Abstract

From the point of view of saving and conservation of natural resources, the use of alternative components in construction materials is now an international concern. In this work, the valorization of two industrial wastes with no value in the market, biomass ash and exhaust dust filter from gases purification raw materials for the production of sustainable silica–calcareous units by the method of cementation was studied. After characterization of the raw materials, bricks were manufactured by mixing different ratios of residues, biomass ash (100−50 wt%) and dust filter (0–50 wt%) formed by pressure at 10 MPa and cured in water at room temperature for 28 days. The results indicate that as the dust filter content increases, the bulk density and mechanical strength of the silica–calcareous units decrease due to the lower density and high carbonation of the filter dust residue and the higher proportion of cement-based products formed in the pozzolanic reaction. Bricks containing 90 wt% of biomass ash-10 wt% of dust filter meet the criteria established by the regulations with an apparent density of 1471 kg/m3, water absorption of 24.2%, a compressive strength of 18.2 MPa and a thermal conductivity of 0.48 W/mK. In addition, the concentration of heavy metals obtained by leaching of the silica–calcareous ecobricks did not exceed the limits established by EPA 658/2009.