oa Characterization And Application For Qatalum'S First Cut Spent Spot Lining

Spent spot lining (SPL) is a graphite/ceramic waste that is produced from the aluminum industry. The rate of SPL production is expected to increase worldwide by 500,000 tons per year. SPL is considered as a hazardous material since it contains many contaminants e.g. fluorides, cyanides, lead and chromium in addition to flammable gases when it comes in contact with water e.g. ammonia, phosphine, hydrogen and methane. Hydrogen and methane accounts for approximately 99 percent of gases generated. These gases are released slowly for significant lengths of time which could present an explosion hazard in confined or poorly ventilated spaces. Furthermore, the SPL contaminants can diffuse to the water ground during storage. The aims of this work are to (i) design and verify a full analysis protocol for the SPL and (ii) find a suitable application for consuming the SPL waste. SPL was collected from Qatalum, grinded using a ball miller and then washed with water, conc. HNO3 and finally with conc. NaOH. The evolved gases in each stage were collected in gas collection bags and analyzed using gas chromatography. Also, the eluents from the different washing steps were collected for the induced coupled plasma (ICP) analysis to determine the concentration of the different trace metals. Furthermore, a qualitative analysis for the anions was done. Part of the graphite was transformed into graphene which later was was functionalized in two different ways to add acidic and basic moieties on its surface to trap basic and acidic gases, respectively which are evolved during the washing and chemical treatment of the SPL.