模拟拜耳法赤泥的沉降分离性能及吸附机理  

Settling separation performance of red mud from simulative Bayer process and the adsorption mechanisms

作　　者：刘锦伟[1] 胡慧萍[1] 王梦[1] 陈启元[1] 

机构地区：[1]中南大学化学化工学院,湖南长沙410083

出　　处：《轻金属》2015年第4期12-16,共5页Light Metals

基　　金：国家自然科学基金项目(No.51174231);国家自然科学重点基金项目(No.51134007)

摘　　要：本文将我国拜耳法赤泥分解成含钛组分钙钛矿、含硅组分水化石榴石(以水化钙铝榴石物相为主)和含铁组分赤铁矿。在模拟拜耳法溶出条件下,分别合成了赤泥的主要组分钙钛矿、水化钙铝榴石和赤铁矿,并研究了商品聚丙烯酸钠(PAAS)与Hx-600(Cytec,USA)对赤泥中主要组分的沉降性能,并通过FT-IR谱初步探讨了絮凝机理。结果表明,赤泥中的含钛组分钙钛矿,其沉降速度较快,只需添加高分子量的PAAS即可满足工业生产要求;含硅组分水化钙铝榴石与Hx-600、PAAS均未发生化学吸附作用,仅通过物理缠结作用提高了水化钙铝榴石的沉降性能;含铁组分赤铁矿与Hx-600或PAAS发生了化学吸附,Hx-600对赤铁矿的沉降性能优于PAAS,可能由于Hx-600与赤铁矿表面形成的五元环比PAAS与赤铁矿表面形成的四元环更稳定所致。The red mud from Bayer process in China was decomposed into the typical titanium - containing, silicon - containing and iron - containing com- ponents, which were perovskite, hydrogarnet （hydration grossular） and hematite respectively. The main components were correspondingly synthesized un- der the conditions of the simulative Bayer process, and their settling behaviors between commercially available polyacrylate sodium （PAAS） or Hx -600 （Cytec, USA） were studied, respectively. Moreover, the adsorption mechanisms of main components and flocculants were analyzed by FT -IR spectra preliminarily. The results show that the typical titanium -containing component （perovskite） harbored fast settling rate and only PAAS could enhance the settling behavior; the adsorptions of Hx -600 and PAAS on the typical silicon -containing component （hydration grossular） surfaces were assigned to a bridging flocculation ; while the adsorptions of Hx - 600 and PAAS on the typical iron - containing component （hematite） surfaces were belonged to a chemisorption, and a stronger adsorption of Hx -600 （a five -membered ring chelate） than PAAS（ a four- membered ring chelate） on the hematite sur- faces can be estimated, which shed light on the improved flocculation effect of Hx - 600 on the hematite instead of PAAS.

关 键 词：赤泥 一水硬铝石 絮凝 吸附机理 

分 类 号：TD951[矿业工程—选矿]