Recycling of residual sludge from aluminum anodizing in fired clay bricks

Abstract

The article presents the results of research aimed at assessing the possibility to use the waste sludge produced in the aluminium anodizing process as an additive to ceramic masses used in the manufacture of building bricks. The physicochemical characteristics of the sludge were determined and the influence of adding the waste to the raw material mixture on the physical and mechanical properties of fired construction ceramics with a porous body was tested on a laboratory scale. The required test specimens were formed from plastic ceramic masses containing 9 – 50% of the waste. After firing at temperatures ranging from 900 to 1000 o C, the linear shrinkage, apparent density, open porosity, water absorption and compressive strength of the obtained materials were determined. The results of the conducted research indicate that adding up to 23% of the sludge to the mix allows obtaining materials with physical properties similar to those of commercial products. • Effect of aluminium anodizing sludge addition on main properties of fired clay ceramic was investigated. • An addition of up to 23 wt% of the dried aluminium anodizing sludge to the raw material mixture used in the industrial production of building bricks allows obtaining a material with physical properties similar to those of commercial products.