铁矿尾砂掺土对土壤几种物理性质的影响

利用铁矿尾砂掺土培养实验，测定金山店铁矿尾砂掺土对其尾矿库边坡覆土即红色石灰土几种物理性质的影响，结果表明，铁矿尾砂掺土使土壤自然容重和压实容重分别增加了4．0％～26．8％和2．6％～24．8％，但与掺砂比例并不呈线性关系．随掺砂比例增加，土壤密度增加了1．7％～20．2％，与掺砂比例呈显著的线性相关．适当的掺砂比例可以显著增加土壤孔隙度．土壤吸湿系数随掺砂比例增加下降了10％～87％，与掺砂比例呈显著的线性负相关．随掺砂比例增加，土壤最大吸水量的变化可分为稳定、急降和缓降3个阶段．综合吸湿水和最大吸水量，适当的掺砂比例可以降低土壤凋萎系数，增加有效水的含量范围，从而能提高土壤抗旱能力．总之，适当比例的铁矿尾砂掺土可以改善土壤的物理性质，调节所用土壤的水、气状况，因此铁矿尾砂的土壤利用可以作为一种铁矿尾砂资源化利用的新技术，最佳掺砂范围应在30％～40％．

Effects of mixing iron ore tailing sands with soil on some soil physical properties

In order to understand the effects of iron ore tailing sands on soil physical properties, an experiment of mixing iron ore tailing sands from Jinshandian tailings pond with calcareous red earth used as covering soil on the slope of Jinshandian tailings pond was conducted and the soil physical properties was determined. The results showed that mixing tailing sands with soil had significant effect on soil physical properties. The bulk density of natural and compacted soil was respectively increased 4. 0%--26.8% and 2.6%--24. 8% by mixing tailing sand with soil, but it did not linearly increased with ratio of sands to soil. Soil density was linearly increased 1.7%-20. 2% with the ratio of sands to soil. Soil porosity was significantly influenced by mixing tailing sands with soil and was increased by proper ratio of sands to soil. Soil hygroscopic coefficient was decreased 10%-87% by mixing sands with soil and was significant negative linearly correlative to the ratio of sands to soil. With the increase of ratio of tailing sands to soil, the maximum water holding capacity was divided into stable, fast decline and slow decline stages. Under integration of soil hygroscopic coefficient and maximum water holding capacity, a proper mixing ratio of tailing sands to soil can decrease the wilting point, increase the range of soil available water and increase soil drought resistance. In summary, the application of iron ore tailing sands to soil is a new technique to use iron ore railings as resource because of its improvement of soil physical properties and regulation of soil water and gas situation and the best mixing rate of iron ore tailings to soil is from 30% to 40%.