Study On The Preparation Of Mixed Soil Of Planting Of Mine Solid Waste

The yield and deposition of solid wastes, generated in the mine, are excessive, what is more, the comprehensive utilization efficiency is low and occupation and destruction of land, it would lead the disasters, such as debris flow and land collapse,so it is already become the key factor of menace of ecological environment of mine, at the same time, because of lack of soil source, how to use land sources and how to deal with the solid wastes of mine effectively is now become a difficulty for the mine ecological restoration. "Mixed soil of planting" was a method, it though using the fine particle filled the macrospores between solid wastes, to improve the physicochemical nature of solid waste mine, resulted to improve the site conditions for plant; Using this method had great realistic meaning in the utilization and consumption of mine solid waste, and mine environmental restoration.In this study, waste rock of iron ore from Dushancheng mine area of Laiyuan as the subjects of the research, and mixed by different proportion with tailings produced by study area, mountain leather soil of study area, campus medium loam and heavy loam of Agricultural University of Hebei to be the "Mixed soil of planting". They includes tailings + waste rock(â… type), waste rock + sandy loam(â…¡type), waste rock + medium loam(â…¢type), waste rock + heavy loam(â…£type). The experiment used randomized block design, and did the outdoor pot experiment, planting alfalfa. Though the study of physicochemical nature of mixed soil in different proportion and growth situation of alfalfa, the results showed that:1. Different kinds of fine grained composition had improvement on physical and chemical properties of iron ore waste rock. The improvement effect by heavy loam was the most significant; water storage capacity, the ratio of quality and volume, porosity ofâ… type were superior than the other three categories; water storage capacity, the ratio of quality and volume, porosity of the â…¡type and â…£type had no significant difference; and the moisture content of â…¡type was higher than other three categories; overall, the physical properties ofâ…¡type, â…¢type, and â…£type had little difference.2. The mixing of tailings and sandy loam had no significant effect on the p H of the iron ore waste rock; the mixing of medium loam and heavy loam could not made the p H of the iron mine waste rock dropped below 8.5; the contents of available phosphor and available potassium of all ratios in different periods could all reach 3 or above 3 grade of the classification criterion of national soil nutrient, alkaline hydrolysis nitrogen and organic matter of different ratios were all below 3 grade of the classification criterion of national soil nutrient.3. The incorporation of loam and heavy loam made alfalfa growth better thanâ… type andâ…¡type. Emergence and shoot cap of alfalfa in â…¢type was better than alfalfa in â…£type. The plant height and biomass of alfalfa in â…£type was better than alfalfa in medium loam.4. The growing best proportion of alfalfa in the â…¡type which added the sandy loam, whose quality was the 30% iron ore waste rock was better than alfalfa inâ… type. The growing best proportion of alfalfa in the â…¢type which added the medium loam, whose quality was the 60% iron ore waste rock had no significant difference from â…¡type. The growing best proportion of alfalfa in the â…£type which added the heavy loam, whose quality was the 90% iron ore waste rock had no significant difference from â…¢type.5. When the tailings were added the sandy loam whose quality was the 120% to 180% iron ore waste rock, the growth of alfalfa had no difference from pure tailings. When added the sandy loam, medium loam, and heavy loam whose quality was the 90% to 180% iron ore waste rock, the growth of alfalfa had no difference from corresponding fine ingredients.