Sedimentation behavior of dispersed particles of clay and silt in acidic and alkaline suspensions of inorganic materials from various volcanic ash soils
Sedimentation behavior of dispersed particles of clay and silt in acidic and alkaline suspensions of inorganic materials from various volcanic ash soils
复制标题
不同火山灰土壤酸性和碱性无机材料悬浮液中粘土和粉砂分散颗粒的沉降行为
DOI：
10.1080/00380768.2004.10408448
复制
发表时间：
2004
影响因子：
2
通讯作者：
T. Honna
中科院分区：
文献类型：
--
作者：
Y. Horikawa;S. Kawachi;T. Honna
摘要用物理和超声波处理过氧化氢预处理过的火山灰土。采用移液管法分别测定了酸性（pH 4）溶液和碱性（pH 10）溶液中悬浮的粘土和淤泥颗粒的量。酸性/碱性悬浮液中粘土的质量比可分为3类：远小于1（G1）、近似等于1（G2）和远大于1（G3）。G1和G2粘土在碱性溶液中均能稳定悬浮，表明粘土颗粒分散在碱性溶液中，颗粒中含有丰富的2：1和2：1：1型层状硅酸盐矿物及其中间级。在酸性溶液中，G2粘土也稳定悬浮，而G1粘土沉降迅速，这表明带负电荷的层状硅酸盐和带正电荷的胶体，如gFe（氢）氧化物之间存在相互作用。G3粘土在酸性溶液中保持悬浮状态，而在碱性溶液中迅速沉降。G3粘土在酸性条件下的分散可以用高铝相的存在引起的相互排斥来解释（Si/Al=约1：2）、伊毛戈兰和连二亚硫酸盐柠檬酸盐可提取组分（DCEC），例如Fe（氢）氧化物和脲基烷类组分，G3粘土在碱性溶液中快速沉降的原因可能是（1）与伊毛戈兰石的相互絮凝作用，（2）水铝英石与DCEC胶体的包覆（和桥接）作用。粉土颗粒的沉降特性与粘土颗粒的沉降特性基本相似。结果表明：（1）G3在碱性悬浮液中的快速沉降和（2）G1在酸性悬浮液中的快速沉降主要是由于粘粒粘附在较大的粉粒表面。
Abstract Various volcanic ash soils pre-treated with hydrogen peroxide were dispersed by physical and ultrasonic treatments. Amounts of clay and silt particles suspended in acidic (pH 4) solution and those in alkaline (pH 10) solution were determined by a pipet method, respectively. The mass ratios of clays in acidic I alkaline suspensions were classified into three categories: much less than unity (G1), approximately equal to unity (G2), and much higher than unity (G3). Both G1 and G2 clays were stably suspended in alkaline solution, indicating that clay particles consisting of abundant layer silicate minerals of the 2 :1 an 2 :1:1 types and their inter grades were dispersed. In acidic solution, G2 clay was also stably suspended, whereas G1 clay settled rapidly, suggesting the existence of an interaction between the negatively charged layer silicates and the positively charged colloids, e.gFe (hydr)oxides. The G3 clay remained suspended in acidic solution, but settled rapidly in alkaline solution, The dispersion of G3 clay under acidic conditions can be explained by mutual repulsion due to the presence of alto phane (Si/Al=about 1 : 2), imogolite, and dithionitet citrate-extractable components (DCEC), e.gFe (hydr)oxides, and allophane-like constituents, The rapid sedimentation of the G3 clay in alkaline solution was attributed to (1) mutual flocculation with imogolite, and probably (2) coating (and bridging) of allophane with the colloids of DCEC. The sedimentation behavior of the silt particles was generally similar to that of the clay particles. It was concluded that rapid sedimentation of the silt particles of (1) G3 in alkaline suspension, and (2) G1 in acidic suspension was mostly due to the adhesion of clay particles onto the surface of larger silt particles.