摘要
还原焙烧—磁选工艺可将赤泥中铁与铝硅组分有效分离,所得直接还原铁产品直接用于炼钢生产,但产出的大量非磁性富铝硅渣难以有效利用。针对某三水铝石型赤泥还原—磁选后的脱铁产物,提出采用一步水热法分离回收铝硅,系统分析了脱铁产物在水热过程中的物相转变、微观形貌和主要组分浸出行为。结果表明:脱铁产物主要组分Na_(1.75)Al_(1.75)Si_(0.25)O_(4)在水热过程中反应速率快,溶出的Al(OH)_(4)^(-)和SiO_(3)^(2-)进一步与CaO反应形成水化硅酸钙,同时生成副产物水钙铝榴石及沸石。通过降低NaOH浓度、反应温度及时间可降低Na_(1.75)Al_(1.75)Si_(0.25)O_(4)的反应速率,抑制水钙铝榴石及沸石的生成。推荐工艺制度为:NaOH总浓度20 g/L(含脱铁产物中Na_(2)O)、钙硅摩尔比0.8、反应温度160℃、反应时间60 min,此时钠、铝浸出率分别为74.00%和62.32%,硅组分转变为托贝莫来石产品。含铝浸出液经碳分后可制备拟薄水铝石产品。
The reduction roasting-magnetic separation method can effectively separate iron and aluminum-silicon components from red mud,and the obtained DRI product can be directly used for steel-smelting.However,a large amount of non-magnetic slag with high aluminum-silica contents is also discharged,which is difficult to use economically.In this paper,a one-step hydrothermal method was used to separate aluminum and silicon from this iron-removed tailing.The phase transformation,morphology and leaching behaviors of main elements of the iron-removed tailing during hydrothermal process were investigated.The results shown that,as the main component in iron-removed tailing,the reaction rate of Na_(1.75)Al_(1.75)Si_(0.25)O_(4),was fast in the hydrothermal process,and the formed Al(OH)_(4)^(-)and SiO_(3)^(2-)reacted with CaO to form C—S—H;and meanwhile,some by-products like hydrogrossularite and zeolite were formed.Reducing the reaction rate of Na_(1.75)Al_(1.75)Si_(0.25)O_(4)could inhibit the formation of these by-products by reducing the NaOH concentration,reaction temperature and time.The recommended process conditions were as follows:the total concentration of NaOH of 20 g/L(including Na_(2)O in iron-removed tailing),the CaO/SiO_(2)molar ratio of 0.8,the reaction temperature of 160℃and time of 60 min,and the leaching ratios of sodium and aluminum were 74.00%and 62.32%,respectively,while the silicon components was trasfrormed into tobermolite.The aluminum-containing leaching solution was then used to prepare pseudo-boehmite product via carbonation process.
作者
阳洋
高德喜
柳佳建
饶明军
罗骏
YANG Yang;GAO Dexi;LIU Jiajian;RAO Mingjun;LUO Jun(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China;College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China)
出处
《金属矿山》
CAS
北大核心
2023年第10期83-93,共11页
Metal Mine
基金
国家重点研发计划项目(编号:2022YFC3900904)。
关键词
拜耳法赤泥
铝硅酸钠
水热法
拟薄水铝石
Bayer red mud
sodium aluminosilicate
hydrothermal method
pseudo-boehmite
