The present invention utilizes a high-speed intensive mixer in a fluidizing-type, solid-phase, neutralization reactor to blend solid-state alkali hydroxide with any humic acid sources. The final product is a dry humic acid salt. The purpose of this innovative method is to eliminate a series of complicated unit operations commonly employed by the traditional process. These removed steps may include dissolving caustic soda, mixing in a paste-like formation, extrusion, granulation, drying, and grinding, etc. The invention contributes to a simplified flowsheet, resulting in sharply reduced equipment investment, plant space, and labor and energy costs. All of these factors coupled with increased productivity will drastically lower the overall production cost. Also, the reduction of dust pollution will greatly minimize the impact in environmental protection and safety issues.