Abstract
The powdered solids trapped in filter sleeves in the aluminium tertiary industry are currently disposed of in secure landfills as a result of environmental considerations. Their classification as a hazardous waste is due to their high aluminium content as metallic aluminium or in compounds such as aluminium nitride. These compounds can react with a very low moisture content to release toxic or hazardous gases such as hydrogen and ammonia. This paper presents a low-cost process for the full recovery of this hazardous waste in three steps leading to the production of two different added-value materials. In the first step, mild acid hydrolysis of the waste is carried out to obtain a concentrated aluminium solution and an inert cake. The following steps consist of hydrotalcite synthesis with the resulting solution, and the production of transparent glasses in the CaO–Al2O3–SiO2 system with the cake. Characterisation of the products obtained indicates that the hydrotalcites can adsorb anionic pollutants (molybdates) in a simple way, while the glasses afford improved optical properties in comparison with those prepared by direct vitrification of the waste.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.