Valorization of Silica Enriched Industrial Byproduct for Partial Replacement of Cement Clinker and Synthesizing of Zeolite Based Catalyst for Polyethylene Cracking

Abstract

With increasing urbanization industries waste, CO2 emission and energy audit are some of huge challenge to the world. Awash Melkassa is chemical factories in Ethiopia that discharge silica enriched byproducts during aluminum sulfate manufacturing. This waste is dumped inside industry compound in huge landfill. These have been a challenge for the factory. Therefore this byproduct was valorized for application of cement sector as partial replacement of cement clinker and catalysts sector for synthesis of zeolite based catalysts for PE degradation. This silica enriched Industrial byproduct was valorized by first altering crystalline nature to amorphous phase by calcination with immediate quenching with various temperatures. Highly amorphous phase had been achieved by 600 oC calcination with immediate quenching. With the successful achievement of amorphous chemical factory waste (CFW), cement clinker had been partially replaced by amorphous CFW with (5, 10 and 15%) by weight, proportions. The blaine air permittivity test, chemical analysis, compressive strength test, flexural strength test, setting time and soundness test result were in total agreement with standard of ordinary portland cement. Initial setting time increased with replacement compare with benchmark. This was due to the increasing content of Al2O3. 10% CFWB replacement had showed maximum compressive strength with 120% strength index. Fineness of clinker blend had showed significant effect on 2days curing of cement rather than 28 days curing. With 15% replacement 5.65*104 KJ/Qtl energy is saved that reduced production cost by $71,568. In addition to saving energy and cost it has reduced CO2 emission by 105 Qtl. It was concluded that the partial cement clinker replacement using activated CFW have a great influence on Strength of cement mortar, the reduction of CO2 emission and energy saving in cement manufacturing. On the other hand Nano Zeolite Y had been synthesized successfully from activated CFW by gel formation, aging, hydrothermal treatment and drying with gel composition of 13.2 Na2O. Al2O3. 11SiO2.263H2O. The XRD, SEM, FTIR, PSA and BET results was obtained from the analysis totally agreed with the standards. Aging temperatures, duration of aging and Na2O/SiO2 ratio were chosen as room temperature, 12 hr and 0.8, respectively. The performance of synthesized Zeolite Y also was evaluated by degradation temperature shifted from 398 oC to 334 oC at 95% weight loss (T5), with HDPE-30Z which implies that breakdown temperature reduced by 64 oC compared to pure HDPE.