Co-benefits of CO2 emission reduction and sintering performance improvement of limonitic laterite via hot exhaust-gas recirculation sintering

Abstract

The poor sintering performance of limonitic laterite hinders its utilization. Hot exhaust-gas recirculation sintering was conducted to improve its sintering performance and intensification mechanism was revealed. Evaluating sinter indices in systematical sinter pot tests were substantially improved with tumble index and productivity increased by 18.01% and 7.22% respectively and solid fuel rate lowered by 13.71%, further proved by extensive industrial application. Effective CO2 emissions reduction and huge economic benefits were realized. The improvement of thermodynamic conditions converted sinter microstructure from large thin-wall pores into small thin-wall or large thick-wall pores. The amount of silico-ferrite of calcium and alumina in sinter pot tests and industrial application was increased from 8.78% to 18.61% and 21.25% respectively. Grains aggregation and growth of hercynite and close adhesion between solid phases and liquid bonding phases were achieved. Hot exhaust-gas recirculation sintering of limonitic laterite contributed to dramatically improving sinter performance and reducing CO2 emission.