煤矿开采造成土地沉陷、土壤环境破坏和农田养分流失，采用不同材料充填复垦是目前中国东部矿区修复沉陷土地的常用方法。钾作为作物生长发育的关键元素，探究其在复垦土壤中的有效性十分必要。为了研究不同填充材料复垦土壤中钾的有效性及其影响因素，文章选择以煤矸石(MGS)、湖泥(HN)、黄河砂(HHS)为填充材料的复垦土壤为研究对象，采用X射线衍射仪(XRD)、傅里叶红外光谱仪(FTIR)、电子显微镜(SEM)以及比表面及孔隙度分析仪(BET)对复垦土壤进行表征分析，利用吸附等温线试验和连续流液法吸附、解吸动力学实验测定并通过相应模型描述复垦土壤对钾的吸附、解吸特征。结果表明：不同材料充填复垦土壤的矿物组成、官能团组成、微观形貌、表面结构均与正常耕地存在差异。3种材料充填复垦土壤XRD图谱中伊利石的衍射峰以及FTIR曲线中由伊利石引起的—OH等特征峰均减弱，复垦土壤表面更加光滑，比表面积和孔体积更小；所有充填复垦土壤各吸附、解吸参数均低于正常耕地(ZC)，MGS充填复垦土壤吸附能力最强，其最大吸附量可达7.90～15.00 mg/g，HHS充填复垦土壤吸附能力最弱，其Q_m仅2.66～3.91 mg/g。复垦土壤解吸能力差异不大，均处于较低水平，煤矸石充填复垦土壤填充层(MGST)的平衡解吸量(Q_e4)最高，为4.40 mg/g，黄河砂充填复垦土壤填充层(HHST)的 Q_e4最低，为1.81 mg/g；复垦土壤的吸附参数(最大吸附量、平衡吸附量)与含水量、土壤质地(粉粒、砂粒)、阳离子交换量、表面特征(比表面积、孔体积、平均孔径)显著相关；解吸参数(平衡解吸量)与含水量、黏粒、阳离子交换量显著相关。研究表明，矿区典型材料的充填会降低复垦土壤钾的有效性，这主要与复垦土壤对钾的吸附、解吸能力有关。MGS、HN由于其比表面积、黏粒含量、阳离子交换量较大具有较高的吸附量，但由于其伊利石和—OH含量较高，以不可逆吸附为主，可以通过研磨、筛分减小填充材料粒度及适当提高pH来改良；HHS由于比表面积、黏粒含量、阳离子交换量较小具有较低的吸附量和解吸量，可以通过复垦时掺加黏土及利用秸秆等富含—OH的材料煅烧制备适宜充填复垦的HHS材料来改良。

Coal mining causes land subsidence, soil degradation, and nutrient depletion in agricultural areas. Filling and reclamation with various materials is a common method for restoring subsided land in the eastern mining areas of China. It is essential to explore potassium availability in reclaimed minesoils, as Potassium is a critical element for crop growth and development. To investigate the potassium availability of reclaimed minesoils and their influencing factors, we select the reclaimed minesoils filled with coal gangue (MGS), lake mud (HN), and Yellow River sand (HHS) as the research samples. X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and specific surface and porosity analyzer (BET) are used to characterize the reclaimed soil. And determine the adsorption and desorption kinetics of the reclaimed soil through adsorption isotherm experiments and continuous-flow liquid method, and describe using the corresponding models. The results showed that the mineral composition, functional group composition, microscopic morphology, and surface structure of reclaimed minesoils filled with various materials differed from normal cultivated soil (ZC). The XRD patterns and FTIR curves of the reclaimed minesoils showed weakened diffraction peaks of illite and characteristic peaks of —OH groups caused by illite. Additionally, the surface of the reclaimed mine soils appeared smoother, and the specific surface area and pore volume were smaller than ZC. The adsorption-desorption parameters of reclaimed minesoils are lower than those of ZC. The MGS exhibits the largest adsorption capacity, with a maximum adsorption capacity (Q_m) of 7.90−15.00 mg/g, while the HHS exhibits the lowest adsorption capacity, with a Q_m of only 2.66−3.91 mg/g. The differences in desorption capacities of reclaimed minesoils are insignificant, as they all remain relatively low. The equilibrium desorption capacity (Q_e4) of the reclaimed minesoils filling layer filled with coal gangue (MGST) is the largest, reaching 4.40 mg/g. The Q_e4 of the reclaimed minesoils backfilling layer filled with Yellow River sand (HHST) is the lowest, only 1.81 mg/g. The adsorption parameters, including maximum adsorption capacity and equilibrium adsorption capacity, of the reclaimed minesoils showed significant correlations with water content, soil texture (silt, sand), cation exchange, and surface characteristics (specific surface area, pore volume, and average pore size). The desorption parameter (equilibrium desorption) exhibited significant correlations with water content, clay content, and cation exchange. Studies show that filling typical materials will reduce the potassium availability in reclaimed minesoils, which is mainly related to the adsorption and desorption capacity of reclaimed minesoils potassium. MGS and HN exhibit greater adsorption capacity due to their larger specific surface area, clay content, and cation exchange capacity. However, they are mainly irreversible adsorption due to their high illite and —OH content, which can be mitigated by grinding and sieving the filling materials to reduce particle size and adjusting the pH appropriately; HHS has a lower adsorption and desorption capacity due to its small specific surface area, clay content, and cation exchange capacity, which can be improved by adding clay to reclamation and using —OH-rich materials such as straw to calcine and prepare HHS materials suitable for filling and reclamation.