盐酸酸浸二次铝灰制备聚合氯化铝及其性能研究

Preparation of Polyaluminum Chloride by Acid Leaching of Secondary Aluminum Ash with Hydrochloric Acid and Its Properties

摘要: 铝灰是一种危险废物，其主要成分包括铝、氧化铝、氮化铝、氯盐、氟盐等，具有一定的回收价值。本文选取了三种组分不同的铝灰，通过盐酸酸浸的方法回收铝灰中的铝元素，研究了温度、浓度、时间以及液固比对铝浸出率的影响。综合成本考虑，最佳的铝浸出条件为：在10 mL 6 mol/L的盐酸中80℃温度下酸浸3 h，液固比为10 mL/g，铝元素最佳浸出率为59.6%。浸出的铝盐溶液经过调节pH、熟化，制备成聚合氯化铝。最后考察了制备出聚合氯化铝的指标以及对含磷、氟废水的絮凝性能，并对其机理进行了讨论。

Abstract: Aluminum ash is a kind of hazardous waste, and its main components include aluminum, alumina, aluminum nitrification, chloride salt, fluoride salt, etc., which has certain recovery value. In this paper, three kinds of aluminum ash with different components were selected, and the aluminum element in the aluminum ash was recovered by hydrochloric acid leaching method. The effects of temperature, concentration, time and liquid-solid ratio on the aluminum leaching rate were studied. Considering the overall cost, the optimal leaching conditions for aluminum were as follows: acid leaching in 10 mL 6 mol/L hydrochloric acid at 80˚C for 3 h, liquid-to-solid ratio of 10 mL/g, and the optimal leaching rate of aluminum element was 59.6%. The leaching aluminum salt solution was prepared to polymerize aluminum chloride by adjusting pH and aging. Finally, the indexes of the prepared polymeric aluminum chloride and its flocculation performance to wastewater containing phosphorus and fluorine were investigated, and its mechanism was discussed.