广西田东某钙基膨润土钠化改型试验

我国膨润土多为钙基膨润土,其蒙脱石含量相对较低,难以用于高黏度、低滤失量的泥浆用膨润土产品的开发。为此,在对广西田东县某钙基膨润土原土进行提纯的基础上,采用碳酸钠为钠化剂对钙基膨润土进行钠化改型研究,考察了矿浆浓度、碳酸钠用量、钠化温度、钠化时间对钠化后膨润土性能的影响。结果表明:随着矿浆浓度、碳酸钠用量、钠化时间的增加,钠化膨润土的600 r/min和300 r/min黏度均呈现先增加后减少的趋势;滤失量则随着矿浆浓度的增加而增加,随着钠化时间的增加呈现先减少后增加的趋势;随着矿浆浓度的增加,动塑比先增加后减少;钠化温度的增加并不能使钠化膨润土的黏度值增大,反而增大了滤失量;在矿浆浓度为5%、碳酸钠用量为4%、钠化温度为25℃、钠化时间为20 min条件下,获得的钠化膨润土的泥浆性能最佳,其600 r/min黏度值达26 m Pa·s、动塑比为0.181 Pa/(m Pa·s)、滤失量为17.6 m L。

Sodium Modification Study on a Ca-based Bentonite from Tiandong,Guangxi

Because most of bentonites are calcium-based bentonites in China,and the content of montmorillonite is rela-tively low,it is difficult to use raw bentonite in the development of bentonite slurry with high viscosity and low filtration loss. Based on the purification of acalcium-based raw bentonite in Tiandong,Guangxi,modification of calcium-based bentonite by so-dium carbonate was studied. Effects of slurry concentration,sodium carbonate dosage,modification temperature and time on the properties of Na-bentonite were investigated. The results showed that the 600 r/min and 300 r/min viscosity of Na-bentonite in-creased firstly and then decreased with the increase of the slurry concentration,dosage of sodium carbonate and modification time. While the filtration loss increased with the increase of the slurry concentration,and it appeared to be the trend of firstly decrease and then increase with increasing modification time. With increase of slurry concentration,the dynamic plastic ratio increased firstly and then decreased. Viscosity of Na-bentonite was not increased by increasing the modification temperature, while filtration loss would be increased. Under the conditions of slurry concentration of 5%,sodium carbonate amount of 4%, modification temperature of 25 ℃ and modification time of 20 min,600 r/min viscosity of the prepared bentonite reached 26 mPa·s,dynamic plastic ratio was 0. 181 Pa/( mPa·s) ,and filtration loss was 17. 6 mL.