赤泥、粉煤灰、磷石膏协同高温烧结回收铁铝试验研究
Experimental study on recovery of iron and aluminum from red mud,fly ash and phosphogypsum by high temperature sintering
雷二帅 1金会心 1王尚杰夫 1王正兴 1顾炜1
作者信息
- 1. 贵州大学 材料与冶金学院,贵州 贵阳 550000
- 折叠
摘要
赤泥(RM)、粉煤灰(FA)、磷石膏(PG)这3 种固废具有产生量大、利用率低的特点,长期堆存会对水资源、土壤、空气等产生严重影响.本文提出用磷石膏代替碱石灰CaO,采用高温烧结-碱浸提铝-磁选提铁工艺协同处理3 种固废回收铝、铁,并考察烧结工序工艺条件对铝、铁回收率的影响,得到以下主要结论.在烧结温度1100℃、保温时间30 min、钙比2.0 条件下,铁回收率达到 79.2%、铁品位达到74.5%、铝溶出率达到75.9%;升高烧结温度有利于铁、铝回收,但温度高于1100℃时熟料会出现粘黏阻碍铝的溶出;保温时间对铝铁回收影响较少;CaO与Na2CO3 有助于激活粉煤灰中莫来石的活性,提高铝回收率;磷石膏添加过量时高温下会生成Fe3Ti3O10、Ca3Fe15O25,导致铁品位和铁回收率降低.采用本试验工艺,每消纳1t赤泥、0.5 t粉煤灰、1.5 t磷石膏,可回收75.9%的铝和0.3t铁精矿,而且生产中可实现碱循环,同时生成的2CaO·SiO2 可用来制备硫铝酸盐水泥,整个工艺流程实现了3 种固废绿色协同消纳,有效实现了资源的综合利用.
Abstract
Red mud(RM),fly ash(FA)and phosphogypsum(PG)have the characteristics of large production and low utilization rate,and long-term storage will have a serious impact on water resources,soil and air.In this paper,phosphogypsum is proposed to replace alkali lime CaO,and three kinds of solid wastes are co-treated with high temperature sintering,alkali leaching of aluminum and magnetic separation of iron.The effects of sintering process conditions on the recovery of aluminum and iron are investigated.Under the conditions of sintering temperature 1 100℃,holding time 30 min and calcium ratio 2.0,the iron recovery rate reaches 79.2%,iron grade reaches 74.5%and aluminum dissolution rate reaches 75.9%.Increasing the sintering temperature is conducive to the recovery of iron and aluminum,but the clinker will appear sticky and hinder the dissolution of aluminum when the temperature is higher than 1 100℃.The holding time has little effect on the recovery of aluminum and iron.CaO and Na2CO3 help to activate the activity of mullite in fly ash and improve the recovery rate of aluminum.At high temperature,Fe3Ti3O10 and Ca3Fe15O25 will be formed when phosphogypsum is added in excess,which leads to the decrease of iron grade and iron recovery.Using this test process,every 1 t of red mud,0.5 t of fly ash and 1.5 t of phosphogypsum can recover 75.9%of aluminum and 0.3 t of iron concentrate,and the alkali cycle can be realized in the production.At the same time,the generated 2CaO·SiO2,2CaO·SiO2 and other by-products can be used to prepare sulfoaluminate cement.The whole process realizes the coordinated consumption of three kinds of solid waste,and effectively realizes the comprehensive utilization of resources.
关键词
赤泥/磷石膏/粉煤灰/协同消纳/铝铁回收/高温烧结-碱浸提铝-磁选提铁/资源利用Key words
red mud/phosphogypsum/fly ash/synergistic consumption/aluminium and iron recovery/high temperature sintering-alkali extraction of aluminum-magnetic separation of iron/comprehensive utilization of re-sources引用本文复制引用
出版年
2024
NETL
NSTL
万方数据