钕铁硼废料铁渣还原酸浸液氨法制备铁红  

Preparation of iron red from reductive acid leaching solution of NdFeB waste iron residue by ammonia method

作　　者：张丽萍[1,2] 杜浩杰[2] 肖万海 齐涛 王志[3] 王东[2,3] ZHANG Li-ping;DU Hao-jie;XIAO Wan-hai;QI Tao;WANG Zhi;WANG Dong(School of Chemistry and Chemical Engineering,Nanchang University,Nanchang 330031,China;Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341119,Jiangxi,China;Key Laboratory of Green Process Engineering,National Engineering Research Center for Green Recycling of Strategic Metal Resources,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]南昌大学化学化工学院,南昌330031 [2]中国科学院赣江创新研究院,江西赣州341119 [3]中国科学院过程工程研究所,战略金属资源绿色循环利用国家工程研究中心,中科院绿色过程工程重点实验室,北京100190

出　　处：《矿冶》2023年第3期70-77,共8页Mining And Metallurgy

基　　金：江西省清洁生产重点实验室开放基金资助项目(E03MYB0306)。

摘　　要：钕铁硼废料盐酸优溶法提取稀土过程产生大量的铁尾渣中含有少量的稀土和钴等有价金属以及大量的氧化铁,回收再利用价值高。团队前期采用还原酸浸的方法从铁尾渣中提取稀土、钴,可有效解决废渣中稀土残留量高的难题,但是还原酸浸液中含量丰富的硫酸亚铁尚未得到有效利用。含铁量高的废液,一般用来制备颜料级铁红。目前,氨法工艺流程是一种环保型且具有发展前景的工艺。然而,氧化制备γ-FeOOH晶种的窗口窄,易出现混晶和形貌不均匀等问题,对工艺条件的控制较苛刻。过程影响因素复杂,定向诱导结晶调控难,需要进一步分析氧化合成过程。以钕铁硼废料铁尾渣酸浸液为原料,NH_(3)·H_(2)O为沉淀剂,采用空气氧化的方法制备前驱体γ-FeOOH活性晶种。首先,通过氨水调溶液pH值,中和沉淀法除去对晶种形貌影响较大的杂质离子Al^(3+),提高晶种的活性。其次,通过热力学稳定区抑制杂相Fe_(3)O_(4)及α-FeOOH的生成,制备具有单一晶型、针状结构且分散均匀的活性晶种。最后,明确氧化合成铁红的工艺参数条件并探讨合成机理。该工艺可产生附加值产品—颜料级铁红,实现钕铁硼废料铁尾渣还原酸浸液的再利用。The iron residue was produced by the extraction of rare earth by hydrochloric acid from NdFeB waste.The residue contains a small amount of valuable metals such as rare earth and cobalt,and a large amount of iron oxide,which has high recycling value.In the previous study of the group,the method of reducing acid leaching to extract rare earth and cobalt from iron residue was proposed.It can effectively solve the problem of high residual rare earth in the residue.However,the abundant ferrous sulfate in the reduced acid leaching solution has not been effectively reused.Solution of waste with high iron content is generally used to prepare pigment grade iron red.At present,the ammonia process is an environmentally friendly and promising process.However,oxidation preparationγ-FeOOH has a narrow window,which is prone to problems such as mixed crystal and uneven morphology,and the process conditions are strictly controlled.In view of the complex influencing factors of the process and the difficulty in regulating the directional induced crystallization,it is necessary to further analyze the oxidation synthesis process.In this paper,the precursorγ-FeOOH active seeds were prepared by air oxidation method using reductive acid leaching solution from iron residue of NdFeB waste as raw material and NH_(3)·H_(2)O as precipitant.Firstly,the impurity ion Al 3+,which has a great influence on the morphology of the seed,was removed by adjusting the pH value of the ammonia water to improve the activity of the seed.Secondly,the formation of heterogeneous Fe_(3)O_(4)andα-FeOOH was inhibited by the thermodynamically stable region,and the active seeds with needle-like structure and uniform dispersion were prepared.Finally,the process parameters of oxidation synthesis of iron red were clarified and the synthesis mechanism was discussed.The process realizes the regeneration of waste and produces value-added products.

关 键 词：氨法 Γ-FEOOH 晶种 酸浸液 铁红 

分 类 号：TQ138[化学工程—无机化工] TF11[冶金工程—冶金物理化学]