萤石型铅锌尾矿渣的基质改良与矿山修复应用

以湖南郴州萤石型铅锌矿山建设中产生巨大量级尾矿渣的处置及排土场为研究对象，通过土壤障碍因子鉴别法确定尾矿渣理化性质的缺陷，再采用生化黄腐酸(BFA)、磷酸二氢铵、沸石和有机肥开展相应性能的改性研究，并以改良后的尾矿渣基质作为种植土壤，利用盆栽试验结合中试研究评估改良剂协同植物对尾矿渣的修复效果，提出基于尾矿渣原位基质改良及直接植被的生态修复方法。结果表明：当BFA、磷酸二氢铵、沸石和有机肥的添加量分别为0.5%、0.4%、2%和15%时，尾矿渣的pH值和干密度分别降低25.8%和77.6%,非毛管孔隙度、有机质、水解性氮和有效磷含量分别提升1.49,26.7,9.3,20.9倍。盆栽试验和中试结果表明：牛筋草对氟化物和重金属铅锌的富集与转运能力综合最优；波斯菊是综合富集能力最优的植物，对铅、锌和氟的富集量分别为267.2,432.8,513.2 mg/kg;籽粒苋是综合转运能力最优的植物，对铅、锌和氟的转运系数分别为0.485、1.208、1.810。为达到萤石型铅锌矿山的复垦效果，建议同时种植牛筋草、波斯菊和籽粒苋。

SUBSTRATE AMELIORATION OF FLUORITE-TYPE LEAD-ZINC TAILINGS AND ITS APPLICATION IN MINE RESTORATION

Taking the disposal of huge-scale tailing slag generated in the construction of a fluorite lead-zinc mine in Chenzhou, Hunan province and greening of the dump as the research object, the physical and chemical defects of tailing slag were clarified by soil obstacle factor identification firstly. Then, biochemical fulvic acid (BFA), ammonium dihydrogen phosphate, zeolite and organic fertilizer were used to modify the corresponding properties. After that, a modified tailing matrix was used as the planting soil. Furthermore, a pot experiment in an artificial climate incubator combined with a pilot test in mine was used to evaluate the remediation effect of modifier and plant on tailing slag, and an ecological restoration method based on in-situ matrix improvement and direct vegetation of tailing was proposed eventually. The results showed that when the addition amount of BFA, ammonium dihydragen phosphace, zeolite and organic fertilizer was 0.5%, 0.4%, 2% and 15% respectively, the pH value and dry density of tailings decreased by 25.8% and 77.6% respectively, and non-capillary porosity, organic matter content, hydrolytic nitrogen content and available phosphorus content of tailings improved by 1.49 times, 26.7 times, 9.3 times and 20.9 times, respectively. The results of pot experiment and field pilot test showed that the comprehensive enrichment and transport ability of Eleusine indica to fluoride, lead and zinc, was the highest; Cosmos bipinnata had the best comprehensive accumulation capacity, and the enrichment amounts of lead, zinc and fluorine were 267.2 mg/kg, 432.8 mg/kg and 513.2 mg/kg, respectively; Amaranthus hybridus was the selected plant with the transport coefficients of lead, zinc and fluorine of 0.485, 1.208 and 1.810, respectively. In order to achieve the reclamation effect of fluorite lead-zinc mine, it is necessary to plant Eleusine indica, Cosmos bipinnata and Amaranthus hybridus simultaneously.