<p>Raw feed material such as sinter iron which constitutes &gt; 50% in blast-furnace-burden material is one of the potential sources for the alkali content. High-alkali content sinters known to have a detrimental effect on the efficiency and performance of the furnace and leads to increased formation of undesired compounds such as alkali chlorides which not only corrodes the refractory lining but also decreases the burden permeability. To overcome this problem, a novel approach is proposed during sinter-making process, wherein a CO atmosphere is created by combustion of coarse coke breeze to induce strong reduction potential across the sinter bed. The indirect reduction of alkali metals is favored due to strong reduction potential and allowed to pass through the flue gases which effectively help in reducing the alkali content to a significant amount. It is found that the effectiveness of the proposed method is dependent on three different process conditions. In the first case, tube furnace trials indicated that alkali removal rates improve at a CO potential of 10%, primarily through indirect reduction reactions. In the second condition, results from the liquid nitrogen quench pot test revealed that alkali discharge patterns into flue dust significantly influence reaction rates of alkali reduction. Specifically, K₂O contents decreased in zones where sintering was completed but increased in un-sintered regions. Initially, the K₂O content was homogenized throughout the bed at 0.45 wt%. After testing, K₂O content decreased to 0.123 wt% in the sintered zone, while in the lower raw material zone, it increased to 0.745 wt%. In the third condition, with Pot sinter test, it is found that the coarser mean particle size (MPS) of conventional coke (preferable MPS of 2–2.3) resulted in maximum K₂O removal (close to 76% for a 0.55 wt% alkali in sinter base matrix compared to ~ 36% with conventional coke with MPS 1.4–1.7). It is found that the coarser coke has not resulted in any negative effect on quality indices of sinter. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) examination further confirms that lower alkali distribution in hematite and complex silico-ferrite of calcium and aluminum (SFCA) and silico-ferrite of calcium and aluminum-1 (SFCA-1) slag phases, with most of the alkali being discharged into the flue dust without significant reaction.</p> Graphical Abstract <p></p>