Research On Chemical Stabilizing-soil Technology Applied To Discarded Tailings Dam

As the mobility of discarded tailings dam surface is stronger and structural stability is worse, abandoned tailings are easy to occur "Wind Yang" phenomenon. Meanwhile tailings also be washed away easily to cause water erosion phenomenon. That not only causes soil, water and atmospheric environmental damage, even causes serious influence for people’s health and life. Therefore it is very necessary to carry out chemical stabilizing-soil technology research based on discarded tailings dam.Based on collecting, consulting relevant literature and field investigations, this paper reviewed the stabilizing-soil technology and discarded tailings dam, and put forward some determination methods of stability powder materials. Combined with the existing conditions of the laboratory, new types of compound additives were developed and determined soil stability. In this paper, the main research contents and results in this paper are as follows:(1) The present situation of discarded tailings dam and the advance of chemical stabilizing-soil technology were discussed. And combined with one discarded tailings dam, some related research work was carried out.That provides some reference for the research of chemical stabilizing-soil technology applied to discarded tailings dam in future.(2) Some kinds of determination methods of soil stability were put forward, including the unconfined compressive strength, lateral restraint compressive strength, indirect tensile strength (crack resistance), anti-water erosion, sieving analysis, microanalysis, etc. The soil stability was characterized from qualitative analysis to quantitative analysis. Finally, the effective measure of soil stability testing program was determined considering advantages and disadvantages of all methods and the conditions of the laboratory.(3) According to the appropriate materials and ratio, the comprehensive effect of various chemical additives was discussed. Finally, the three compound additives were determined:(C3H7O8Na)n+CaCl2; PAM+Na2SiO3+Al2(SO4)3; CMC+Na2SiO3+C2H2O4. (4) By the orthogonal design, three kinds of compound additives were mixed to the soil and243standard samples were formed. The three indexes of the unconfined compressive strength, water stability and indirect tensile strength were analysed after14days maintenance, and ultimately the best proportion of them are:A2B2, A2B2C3, A3B3.(5) The unconfined compressive strength of mixture with the optimal proportion of the compound additives and trail dam’s soil was researched after3,7,14,28days maintenance. Results show that:in a month, the structure strength of stabilized soil will be stronger as the time was extended; the stable effect of Compound additive-2is the most, the second is Compound additive-1, the stable effect of water is worst; the stable effect of trail dam’s soil mixed with the ordinary soil is higher than that of single trail dam’s soil. At the same time, the change of particle size of soil separately addedd three kinds of compound additives and water was analysed using sieving analysis and SEM.(6) The efficiency and cost of three kinds of compound additives and water were dicussed with economy analytical method. No matter effects or cost, the compound additive-2is the best choice. Finally, this paper discussed the stabilization/solidification mechanism of chemical stabilizing-soil, which will make people understand chemical stabilizing-soil technology profoundly.