摘要
The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.
利用XRD、ICP-OES、TG/DSC、SEM、TEM和穆斯堡尔(Mössbauer)光谱研究来自俄罗斯阿尔汉格尔斯克地区Severoonezhsk铝矿中铝土矿的化学和矿物组成,发现该铝土矿的含铁矿物包括铝针铁矿(α-Fe_(1−x)Al_(x)OOH)、铝赤铁矿(α-(Fe_(1−x)Al_(x))_(2)O_(3))、正方铝针铁矿(β-Fe_(1−x)Al_(x)O(OH,Cl))和铬铁矿(FeCr_(2)O_(4))。在温度为100℃、HCl浓度为10%,固液比为1:10及浸出时间为60 min的条件下,盐酸浸出铝土矿的铁浸出率为82.5%,而铝的损失不到铝土矿中总铝含量的4.5%。铁浸出过程的动力学分析表明,温度为90~100℃时,扩散是浸出过程的速率限制环节。铝土矿浸出渣含有微量的α-Fe_(1−x)Al_(x)OOH和β-Fe_(1−x)Al_(x)O(OH,Cl),大部分铁呈FeCr_(2)O_(4)形态。除铁氧化物外,铝土矿盐酸浸出渣中铬和钙氧化物的含量也显著降低。含氯化铁的浸出液含有稀土元素(REE):6.8 mg/L Sc、4.1 mg/L Ce和2.3 mg/L Ga。
基金
Ministry of Science and Higher Education of the Russian Federation(scientific topic No.0137-2019-0023).
