To investigate the effect of minerals in brown coal on CO yield in a CO2 atmosphere, we impregnated pickled coal with nitrate and quartz to simulate the mineral content and assessed their impact on CO yield during gasification. It demonstrated that the reaction of Ca2+ and Fe3+ forming CaFe2O4 enhanced the CO yield. In the 100 % CO2 atmosphere, pickled coal containing CaFe2O4 produced five fold the amount of CO as after-pickling coal. The effect of minerals on CO generation under the CO2 atmosphere was explored by adding specific amounts of 1.96 wt% Ca, 1.80 wt% Fe, 6.83 wt% Al, 0.53 wt% Mg, and 11.64 wt% Si to acid-washed brown coal. The results show that the addition of Ca2+ contributes to the enhancement of CO, whereas the combined addition of Ca2+ and Fe3+ increases CO yield. CaFe2O4 enhances CO yield for two reasons: firstly, it is oxidized by CO2 to produce CO; secondly, CaFe2O4 can further react with CO2 to form Ca2Fe2O5, Ca2Fe2O5 then reacts with carbon in the brown coal to generate CO. This study has significant implications for the utilization of brown coal resources.