Harnessing biochar as a resource for carbon and climate management has gained considerable attention in recent times. However, biochar mineralization has been shown to release carbon dioxide into the atmosphere. Biochar releases dissolved organic matter into the soil, accelerating the metabolism of bacteria and resulting in CO2 emissions. The mechanisms and applications of minerals and other metal compounds to improve the chemical resistance of biochar have been widely studied. Nevertheless, the effectiveness of co-pyrolyzing these minerals has yet to be fully considered. The interaction of mineral aggregation to organic matter and its effects on biochar chemical resistance still needs to be investigated. As an Earth-abundant element, soil minerals such as Kaolinite can modify biochar’s physical and chemical properties, as shown in previous studies on pyrolyzing or dissolving organic matter with Kaolinite. This study focuses on the significance of integrating alkaline additives and soil clay minerals prior to pyrolysis on the chemical mineralization and physical protection of biochar derived from common agricultural residues, maple wood branches, and wheat straw. As a result, the modified biochar through alkaline cation and soil minerals can promote the biochar chemical oxidation resistance by decreasing the carbon loss to 6% in maple wood biochar and 8% in wheat straw biochar. Our work shows that this chemical resistance to oxidation is contributed by physical coating on biochar from Kaolinite by the bridging effects of Ca2+ ions that facilitate the building of a non-swelling alumina-silicate mineral coating to biochar's surface and pores. The mineral’s elements were bound to the biochar surface more than three times compared to the calcium-exclusive groups, and increased pore filling by enhanced Kaolinite concentration was found. Additionally, CaCl2 reveals the effects of catalyzing pyrolysis to enhance aromatization. The chemical bonding results indicated that co-pyrolyzing CaCl2 and Kaolinite can increase the biochar aromaticity and reduce volatile matter contents, marked by a 25-28% aromatic carbon bonds increase and a 16-24% decrease in aliphatic carbon bonds. The 8-31% reduction of thermogravimetric loss indicated the limited volatile matter and easily oxidized carbon content in the modified biochar. Furthermore, adding alkaline metal may cause differing effects based on the lignocellulosic composition of the biomass. The addition of CaCl2 induces around 4-18% production of bio-oil in maple wood biochar, such as the increase of carbon-oxygen and carbon-hydrogen bonds, but promotes the shift of carbon-oxygen bonds from calcium and aluminum bonding with oxygen groups on biochar. The variation of the chemical bondings evidences the advanced bridging effect by Ca2+ to produce a chemically resistant biochar. These fundamental studies unlock new insights into enhancing biochar chemical oxidation recalcitrance in natural soils.