物理改良对采矿伴生黏土水分和养分保持能力的影响

Effects of Physical Improvement on Water and Nutrients of Mining Associated Clay

采矿伴生黏土由于物理结构差、有效养分低等问题难以促进植被的建植,因此需要对采矿伴生黏土进行改良。分析利用采矿伴生黏土作为表土替代材料的可能。选择易于取得的沙土对采矿伴生黏土进行物理改良,试验发现物理改良工艺应为沙土和黏土充分混合,按1∶1比例混合沙土与黏土形成的土壤其水分入渗速率与表土最为相似,并且是黏土的2.74倍,能够有效防止积水;同时,混合的物理改良工艺对钾元素迁移的控制能力与表土最为相似。确定沙土与黏土混合的最佳配比为1∶1,混合后土壤基质为砂质黏土,与某地区表土(壤质黏土)最为相近。通过水分蒸发试验发现,按1∶1的比例混合沙土与黏土其保水效果优于按其他比例混合得到的土壤。利用沙土改良的采矿伴生黏土可作为露天矿排土场的表土替代材料,并且可促进采矿伴生黏土的资源化利用和排土场的生态恢复。

The mining associated clay is difficult to promote the establishment of vegetation due to its poor physical structure and low effective nutrients,so it is necessary to improve the mining associated clay.The possibility of using mining associated clay as a substitute for topsoil was analyzed.The sand soil which is easy to obtain was selected to improve the physical property of mining associated clay.It is found that the physical improvement process should be that sand and clay are fully mixed,and the soil formed by mixing sand and clay with the ratio of 1∶1 has the most similar water infiltration rate with the topsoil,and is 2.74 times of the clay,which can effectively prevent accumulation.At the same time,the control ability of the mixed physical improvement process to the potassium element migration is the most similar to that of the topsoil.It is determined that the best ratio of sand and clay is 1∶1,and the soil matrix after mixing is sandy clay,which is the most similar to the surface soil(loamy clay)in the soil triangle.Through the experiment of water evaporation,it is found that the water conservation effect of1∶1 of sand and clay is better than that of other mixing soil.Therefore,using sand to improve the mining associated clay has the potential to become the surface soil substitute material of the open-pit waste dump,promoting the utilization of clay resources and the ecological restoration of the waste dump.