陕西洋县膨润土的物相分析与改性研究

Modal Analysis and Modification of the Bentonite from Yang County,Shaanxi Province:An Experimental Study

基于X射线粉晶衍射分析、化学成分分析数据,依据物质平衡原理,采用"相混合计算"方法,确定陕西洋县膨润土为钙基膨润土,主要矿物成分有蒙脱石、石英、高岭石、白云母、赤铁矿等。其中蒙脱石的含量为38.5%,晶胞参数为a0=0.5232nm,b0=0.9056nm,c0=1.5511nm,β=89°3'。基于上述物相分析结果,对原矿土进行了提纯实验,以Na2CO3溶液为改性剂,将提纯后的蒙脱石制成改性土。通过10组实验,确定了影响改性效果的主要因素有矿浆浓度、Na2CO3溶液加入量、反应温度和搅拌时间。对改性土的X射线衍射分析证明改性成功,确定了优化改性条件,即在矿浆浓度1.64%(固液比1:60),改性剂Na2CO3溶液(浓度0.67mol/L)的加入量为40mL,反应温度65℃,中速搅拌的条件下,钠化改性效果最好。

The bentonite from Yang County of Shaanxi province was studied in detail for both of the modal analysis and sodium modification possibility. Based On the mass balance principle, the mineral contents of the bentonite were estimated by resolving the phase mixing equation constructed from the data of X-ray diffraction and wet chemical anaysis. The bentonite was mainly composed of montmoriUonite, quartz, kaolinite, muscovite, and hematite, with montmorillonite proportion of roughly 38.5%, and The cell lattice constants as： a0 =0. 5232 nm, b0 =0. 9056 nm, C0 = 1. 5511 nm, andβ =89°03′ To modifying the refined bentonite through 10 sets of parallel experiments with Na2CO3 aqua, it is demonstrated that the factors effecting the quality of sodium-based modification of the bentonite include the mineral syrup concentration, the concentration of Na2 CO3 in the aqua, reaction temperature, and the stirring time. The X-ray diffraction data of the sodium modified bentonite indicated that the sodium-based modification of the bentonite was successful, and herein the optimal modification conditions were experimentally determined, under mid-speed stirring, add 40 mL Na2CO3 aqua, in 1.64% （0.67 moL/L） mineral syrup concentration, and at reaction temperatures around 65 ℃.