逆流浸取法回收赤泥中的碱

赤泥脱碱现有的方法不足主要表现在：酸法或碱法脱碱会耗费大量的酸或碱，使脱碱成本偏高；简单水洗法脱碱时，副产品中碱浓度较低，不能实现赤泥与碱的综合利用。本文以阴离子型聚丙烯酰胺为絮凝剂，水为浸取剂，采用五级逆流浸取法对赤泥中碱的回收利用进行研究，考察了温度、液固比、浸取速度等因素对碱的浸出率及浓度的影响，得出碱的浸出率与浓度随温度、液固比、浸取速度等因素的变化规律，确定最佳浸取条件为：温度70℃，液固比3∶1，浸取速度15mL/min，在此条件下赤泥中碱的浸出率达89.18%，浓度达到20.38g/L。此方法不仅能将赤泥中的碱有效脱除，同时得到浓度较高的碱溶液，实现赤泥与碱的综合利用。

Recycling alkali from red mud by countercurrent leaching

Deficiencies of red mud dealkalization mainly exist in the high consumption of acid or alkali，high removal cost，low concentration of alkali in simple water washing. Therefore， the comprehensive utilization of red mud cannot be achieved. This research investigated influences of leaching rate and concentration，temperature，liquid-solid ratio，leaching speed and other factors on the alkali，the alkali leaching rate and concentration with temperature，liquid changes to solid ratio，extraction rate and other factors，with anionic polyacrylamide as flocculant，water as extractant，using five stage countercurrent leaching of alkali in red mud recycling. The optimum extraction conditions were determined as the follwing：temperature 70℃，liquid to solid ratio 3∶1，leaching rate of 15mL/min. Under the above conditions，alkali in red mud leaching rate reached 89.71%，concentration reached 20.44g/L.