尾矿酸浸液制备氢氧化铁过程中施威特曼石的形成与转变

摘要

During the preparation of ferric hydroxide with acid leaching filtrate of tailings, schwertmannite is formed because of the formation of a high SO_4~(2-)and high Fe environment with pH values from 2.8 to 3.8 resulting from the gradual dropping of the lye into the filtrate. Schwertmanntie is a metastable mineral, which is transformed into a more stable goethite (iron hydroxide) with the variation of time and system environment. The influence of pH value, temperature and time on the transformation was investigated, and the results show that, under the condition of 60℃, the transformation process in the solution with pH value of 12 for 36 hours can fully convert the schwertmannite into Fe(OH)_3.%尾矿酸浸液在制备氢氧化铁的过程中,由于逐渐滴加碱液正好形成了pH值为2.8～3.8的高SO_4~(2-)、高Fe环境,因而生成了施威特曼石.施威特曼石是一种亚稳定矿物,随着时间的延长和体系状态改变,它可以转变为更稳定的针铁矿(氢氧化铁).考查了pH值、温度及时间对施威特曼石相转变的影响.结果表明,在60℃条件下,在pH值为12的碱溶液中转化36 h,施威特曼石可完全转变为Fe(OH)_3.