Grouting Cement Slurry In The Loose Gravel In The Model Pilot Study

After mining, There are a lot of crushed stones from the roof fall and artificial filled. In the process of pillar winning, the mixture of the adjacent crushed stone is the main reason for the ores' dilution. How to reduce ores' dilution is always the problem in engineering. In this paper, grouting methods are used to improve the performance of the adjacent crushed stone in order to reduce ores' dilution in the process of pillar mining.In the grouting process, The complexity of the crushed stones and the variability of the grout make grouting in crushed stone is affected by many factors. The currently grouting theory can't exactly predict or evaluate the effect of grouting. Therefore, in this paper, the grouting process of cement in the crushed stone is researched, and because of the needs of the research, a series of related research are researched:(1) Indoor tests to study the rheological property of cement grout. With the increase of water-cement ratio, the cement grout will transform from the Newtonian fluid to Bingham fluid; The permeated distance of cement grout will increase, and ultimately tends to a constant; For the high concentration of cement grout, with the water-cement ratio increase, its water-separation propriety have small changes; For the lower concentration of cement grout, its water-separation propriety significantly increase with the raise of water-cement ratio;(2) Crashed stones' proprieties are researched, Studying pipe-line fluid property and derivating vadose formula of the grouting process of cement grout in the crashed stones by pipe-line fluid theory and vadose theory;(3) Made a indoor mini-size simulated grouting devices which can be used to research the relationship between the grouting pressure, injected volume, water-cement ratio and grouting permeating distance etc;(4) Based on established grouting theoretical formula, grouting experiment and technical application to reinforce crashed stones are carried out in pillar winning engineering in Zhuyeshan of Yunnan Tin Corporation, which provides a new approach for the successful solution of ore's dilution.Indoor and field grouting test experiment result proves that capability of crashed stones was improved. This paper provides a new method for study of grouting. It is great importance to study grouting process of cement grout in crashed stones and other cellular material.