Study On The Suppression Of Pisha Sandstone By Polyquaternium Clay Stabilizer

Pisha sandstone is mainly distributed in the boundaries of Shanxi,Shaanxi,Henan and Inner Mongolia provinces.Because Pisha sandstone would collapse when immersed in water,local soil erosion is very serious,the ecological environment is harsh and the local residents live in dire straits.In this paper,Polyquaternium clay stabilizer is applied to improve the feature of collapse in water.The method is not only non-toxic,environmental and economical,but also can reduce soil erosion and increase organic content in soil,resulting in growth of plants.First,the mineral composition and properties in water were studied by experiments.The mineral composition of Pisha sandstone included quartz,feldspar,carbonate and montmorillonite;the weathering degree of red Pisha sandstone was higher than that of white Pisha sandstone;the dry saturated water absorption,collapse form and free expansion rate experiments indicated that Pisha sandstone belonged to a weak expansive rock with poor cementing property.Second,red and white montmorillonites were extracted from Pisha sandstone through wet purification.The results showed that the value of methylene blue adsorbed,swelling volume,particle size and cation exchange capacity(CEC)of red and white montmorillonites were 32.42g/100 g and 38.00g/100 g,3.25ml/g and 3.53ml/g,21.08μm and 15.7μm,113.51mmol/100 g and 119.62mmol/100 g,respectively.Optical microscope images showed that quartz and feldspar contents decreased distinctly in purified montmorillonite,meanwhile,the main oxide included SiO2、Al2O3、Fe2O3 and CaO.Third,the chemical structure of cationic clay stabilizer-LYPO and cationic polymer flocculant-LYPW were analyzed by FTIR,indicating that two products were both quaternium high polymer.Forth,purified montmorillonite was modified using LYPO and LYPW,and Zeta potential,XRD,FTIR,TG/DTG and SEM were applied to character the chemical properties and microstructure.Results suggested that the LYPO and LYPW had a positive effect on the inhibition of volume swelling,the optimum dosage of two type stabilizers were both 0.8 wt%.In addition,pH had no impact on the inhibition of volume swelling.Fifth,the collapse form of Pisha sandstone in water with different mass fractions of stabilizer was investigated.Compared with unmodified sample,the modified Pisha sandstone sample performed more slow collapse.Moreover,collapse rate of the modified sample with LYPW was lower than that of the modified sample with LYPO.