内蒙古自治区通辽市奈曼旗的天然矿物麦饭石可应用于水质净化及环境修复等多领域。风化作用改变麦饭石的理化性质，进而影响其对重金属的吸附性能。针对奈曼旗南部山区麦饭石产地的不同深度样品开展风化程度鉴定、重金属吸附实验，并结合理化性质表征进行防控机制探析。研究表明，奈曼旗麦饭石主要受物理风化作用影响，根据表观特征、化学蚀变指数和风化系数（Kf）可判断深层样品为微风化状态，表层样品为中等—强风化状态。风化作用使得表层麦饭石中石英和斜长石晶体破坏，比表面积增加66.81%，3.6~4.0 nm的孔径占比从12.36% 增加到40.05%，碱性元素流失，零点电位明显左移，从7.09 移至小于2.00。深层麦饭石更易吸附地下水中的阴离子型重金属特征污染物铬，理论最大吸附量为0.90 mg/g；表层麦饭石更有利于对土壤中阳离子型重金属特征污染物镉的吸附，理论最大吸附量为5.57 mg/g。吸附过程的表面扩散、中孔内扩散和微孔内扩散3 个阶段均在24 h 内达到平衡。麦饭石对重金属的多分子层吸附以静电作用为主，也包括表面羟基络合等。自然地质风化作用造成麦饭石零点电位左移等理化性质改变，由此产生对土壤—地下水中特征重金属的综合防控能力，研究为奈曼旗麦饭石在地下水水质净化方面的可持续开发利用提供了理论依据。

Abstract: Chinese Maifanite, a natural mineral from Naiman Banner, Tongliao City, Inner Mongolia Autonomous Region, has potential applications in water purification, environmental remediation, healthcare, and agricultural improvement. Weathering processes alter the physicochemical properties of Maifanite, thereby influencing its heavy metal adsorption performance. This research systematically investigated Maifanite samples collected from different depths in the southern mountainous mining area of Naiman Banner, conducted comprehensive analyses including weathering degree assessment, heavy metal adsorption experiments, and prevention and control mechanism studies combining physicochemical characterization. The research reveals that Naiman Banner Maifanite primarily undergoes physical weathering. Based on macroscopic characteristics, Chemical Index of Alteration CIA, and weathering coefficient Kf , deep-layer samples were identified as slightly weathered, while surface samples exhibited moderate to strong weathering. Weathering increased the specific surface area of Maifanite by 66.81%, reduced pores smaller than 3.6 nm, and increased pores between 3.6~4.0 nm from 12.36% to 40.05%. Additionally, weathering caused the destruction of quartz and plagioclase crystals, leaching of alkaline elements (Na, Mg, Si, K, Ca). The zero potential point shifted markedly from 7.09 to below 2. Notably, deep-layer Maifanite demonstrated preferential adsorption toward anionic chromium (Cr) -a characteristic groundwater contaminant-with a maximum theoretical adsorption capacity of 0.90 mg/g. Conversely, surface-weathered Maifanite exhibited enhanced adsorption capacity for cationic cadmium (Cd) -a typical soil pollutant-reaching 5.57 mg/g. The adsorption process, comprising three distinct stages (surface diffusion, mesopore diffusion, and micropore diffusion), achieved equilibrium within 24 hours. Multilayer heavy metal adsorption mechanisms were predominantly governed by electrostatic interactions with additional contributions from surface hydroxyl complexation. In conclusion, natural geological weathering induces significant physicochemical modifications in Maifanite, including the observed zero potential point shift, which collectively enhance its capacity for comprehensive heavy metal prevention and control in both soil and groundwater systems. This research provides crucial theoretical foundations for the sustainable development and utilization of Naiman Banner Maifanite in groundwater purification applications.