摘要
以Ca(OH)_(2)为脱碱剂水热浸出赤泥脱碱,考察了Ca(OH)_(2)掺量、反应温度、液固比对赤泥脱碱率的影响,同时对赤泥脱碱过程进行机理分析和浸出动力学分析。研究结果表明,在Ca(OH)_(2)掺量为60%(质量分数)、反应温度为250℃、液固比为8 mL/g的条件下,赤泥脱碱率可达到96.3%。Ca(OH)_(2)可有效脱除赤泥中的游离碱和结构碱,赤泥中的钙霞石和水钙铝榴石被分解,脱碱渣中新相铁钙榴石(水合的)是主要的衍射峰,并且赤铁矿的衍射峰明显减弱,方解石的衍射峰增强。该脱碱过程受固膜内扩散关键步骤控制,线性相关系数都大于0.97,特征常数n<1,表观活化能为5.20 kJ/mol。
Red mud is a solid waste residue produced in the process of alumina production,which has caused serious environmental pollution,but due to strong alkalinity,it is difficult to utilize resources.In this paper,hydrothermal leaching of red mud with Ca(OH)_(2) as the dealkalization agent was carried out.The effects of the Ca(OH)_(2) dosage,reaction temperature and liquid-solid ratio on the dealkalization rate were investigated.Meanwhile,the mechanim and leaching kinetics of the dealkalization process of red mud were analyzed.The results show that the dealkalization rate of red mud reaches 96.3%under the conditions of the Ca(OH)_(2) dosage of 60%(mass fraction),reaction temperature of 250℃,liquid-solid ratio of 8 mL/g.Ca(OH)_(2) effectively removes free alkali and structural alkali from red mud.The cancrinite and katoite in the red mud are decomposed.New phase andradite(hydrated)in the dealkalized residue is the main diffraction peak.Meanwhile,the diffraction peak of hematite is obviously weakened and the diffraction of calcite is enhanced.The leaching process is controlled by the key steps of diffusion in the solid film.The linear correlation coefficients are all greater than 0.97,the characteristic constant is n<1,and the apparent activation energy is 5.20 kJ/mol.
作者
王涛
李望
朱晓波
燕旭东
WANG Tao;LI Wang;ZHU Xiaobo;YAN Xudong(College of Chemistry and Chemical Engineering,Henan Polytechnic University,Jiaozuo 454000,China;Coal safety production Collaborative Innovation Center,Jiaozuo 454000,China)
出处
《硅酸盐通报》
CAS
北大核心
2022年第7期2368-2375,共8页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金(51904097,51804103)
河南省高等学校青年骨干教师培养计划项目(2019GGJS056)
河南省科技攻关项目(202102310548)
河南理工大学杰出青年基金(J2022-3)。
