煤矸石酸渣制备白炭黑的实验研究

Study on Preparation of White Carbon Black from Coal Gangue Acid Leaching Slag

白炭黑是橡胶、塑料、涂料等化工制品的重要填料,煤矸石制取白炭黑是其高附加值利用手段之一。利用煤矸石提铝后的酸渣,制备低模数水玻璃,经新鲜酸渣提模,制取与工业水玻璃模数(n≈3.6)相近的高模数水玻璃。以二氧化碳为沉淀剂,经碳化反应制取白炭黑。采用单因素实验和正交实验相结合,确定出最佳的工艺条件:(1)煤矸石酸渣制备高模数水玻璃:提模时间1.0 h、提模温度60℃及液固比为4∶1;(2)高模数水玻璃制备白炭黑:反应温度80℃、反应时间2.5 h、水玻璃密度1.075 g/mL、水玻璃模数3.3、搅拌速率为350 r/min、二氧化碳浓度为20%。所制白炭黑质量好,吸油值2.2 mL/g,白度90%以上,纯度85%以上。

White carbon black is one of important padding in rubber, plastic and coating etc, and it is high value-added utilization to preparation white carbon black from coal gangue. Coal gangue acid slag produces low-modulus sodium silicate, and after improving its modulus, high modulus sodium silicate have been prepared that whose properties are similar with industrial sodium silicate. With the high modulus sodium silicate as raw materials, carbon dioxide for precipitation agent, the technology of preparing white carbon is explored. Combination of single factor and orthogonal experiments, the results indicate that the optimum process conditions are as follows：（ 1 ） improve-modulus time , temperature and loquid-solid ratio are respectively 1.0 h,60 ℃ ,1：4 for preparation of high modulus sodium silicate; （2） for carbonation reaction, the reaction temperature and time, sodium silicate density and modulus, stirring rate,CO2 concentration are respectively 80 ℃ ,2.5 h, 1. 075 g/mL,3.3,350 r/min,20%. Under the optimized process condition, the whiteness can reach more product requirement, oil absorption value, whiteness and purity are respectively 2.2 mL/g, 〉90%, 〉 85%.