不同烷基季铵盐对膨润土絮凝性的影响

以四乙基溴化铵((Et)4NB)、一种二价季铵盐(MD膜驱剂)、十二烷基三甲基溴化铵(DTAB)和十六烷基三甲基溴化铵(CTAB)为改性溶剂,考察改性膨润土的分散、絮凝作用和层间含水量,对膨润土用X射线衍射(XRD)、傅立叶红外(FT-IR)和分光光度计等分析表征.结果表明,烷基季铵盐已进入膨润土晶层之间,使膨润土层间含水量降低,而MD膜驱剂改性膨润土含水量最小.烷基季铵盐在高浓度下对膨润土都有一定的絮凝性,膨润土的沉降体积随季铵盐浓度增大出现一个极大值.与(Et)4NB,DTAB和CTAB相比,MD膜驱剂在较低浓度下对膨润土就有较好的絮凝性.膨润土在MD膜驱剂或DTAB溶液中沉降平衡时间较(Et)4NB或CTAB的短.

Study on the flocculability of the bentonite modified by different alkyl quaternary ammonium salts

Bentonite is modified separately using tetraethyl ammonium bromide((Et)4NB),molecular deposition filming flooding agent (MDFFA),dodecyl trimethyl ammonium bromide (DTAB) and hexadecyl trimethyl ammonium bromide (CTAB) as modifying solvents.The modified bentonite is characterized by X-ray diffraction (XRD),Fourier transform infrared spectrometer (FT-IR) and spectrophotometer analysis methods.The results show that,alkyl quaternary ammonium salts enter between the crystal layers of bentonite,which makes the water content between the crystal layers of bentonite decrease.Among the four modifiers,the molecular deposition filming flooding agent (MDFFA) makes the water content decrease the most.The alkyl quaternary ammonium salts of high concentration all have definite flocculation to bentonite,there is a maximum of settling volume of bentonite with increasing of the concentration of alkyl quaternary ammonium salts.Comprised with tetraethyl ammonium bromide((Et)4NB),dodecyl trimethyl ammonium bromide (DTAB) and hexadecyl trimethyl ammonium bromide (CTAB),molecular deposition filming flooding agent (MDFFA) of lower concentration has better flocculation to bentonite.The settling time of bentonite in molecular deposition filming flooding agent (MDFFA) or dodecyl trimethyl ammonium bromide (DTAB) solvent is shorter than in tetraethyl ammonium bromide ((Et)4NB) or hexadecyl trimethyl ammonium bromide (CTAB) solvent.