Sintayehu Nibret (PhD)Tujuba Tamiru2024-09-032024-09-032024-06https://etd.aau.edu.et/handle/123456789/3464Valorization of byproducts from chemical manufacturing is critical for reducing environmental impact advocating circular economy. High silica filter cake from Awash Melkasa Chemical Factory (AMCF) is disposed in landfills after producing aluminum sulfate. This study aimed to produce amorphous precipitated silica from byproduct of Awash Melkasa Chemical Factory and explore its potential as rubber filler in tire industry. Filter cake byproduct from Awash Melkassa Chemical factory was calcinated at a controlled temperature of 550 ℃ for 3 hours, followed by the extraction of amorphous silica using sol-gel technique. To characterize phase composition, chemical structure, morphology, and surface area of the as prepared silica filler, XRD, FTIR, SEM, BET, AAS, and XRF were employed. Silica with purity of 92.50% was obtained and tested as reinforcing rubber filler in tire industry. Curing characteristics of natural rubber compound filled with filter cake silica and commercial silica were examined with Rheo-line moving die and Mooney viscometer. Compound reinforced with filter cake silica has shorter curing time than compound filled with commercial silica due to finer particle size and high surface area revealed by SEM and BET respectively. Filter cake silica filled rubber compound showed better mechanical properties, compared to commercial silica reinforced rubber compounds. The lower Mooney viscosity of filter cake reinforced rubber compound makes filter cake reinforced rubber compound easier to process compared to commercial silica reinforced compounds. Morphology analysis of filter cake silica shows it is fine, and better filler for rubber applications in tire industries. Commercial silica has lower specific gravity and has less reinforcing ability in rubber compound, while filter cake silica filler has higher specific gravity that makes better reinforcing filler in rubber compounds. Therefore, amorphous silica from filter cake is potential filler in tire industry and the use of filter cake silica filler is a potential solid waste management in Awash Melkasa Chemical Factory and related industries.en-USfilter cake silicasol-gel techniquerubber fillerrubber curing characteristicsMooney viscosityThesis