Composition for rock grouting based on insoluble calcium salts for groundwater protection

摘要

Importance to reduce permeability of rocks arises safety of mining operations and protecting the soil and underground water in the area of industrial waste storage with high contents of water-soluble salts. Disadvantage of the existing methods of grouting rocks by soluble salts is either their dissolution with changing of the composition or diluting of the contacting solution. The paper considers the composition of the grouting mixture for the deposition of insoluble calcium salts and its effectiveness in laboratory conditions. The eutonic solution of a four-component KCl-NaCl-CaCl2-H2O system was used as the initial solution, while saturated solutions of sodium sulfate and carbonate, and sulfuric acid were applied as the precipitators. Efficiency of rock grouting was estimated according to the water or solution filtration rate through the rock (sand, sylvinite, and halite) before and after calcium salt crystallization. Laboratory experiments showed that the precipitation of calcium sulfate responds to the challenge of plugging rocks. The paper proposes some recommendations of protective screens at the bed of the salt tailing piles and slurry storage facilities.