The mineralogical characteristics of three kinds of gibbsitic high-iron bauxite and the effects of various digestion conditions on the enrichment and separation of iron minerals were investigated. The results show tha...The mineralogical characteristics of three kinds of gibbsitic high-iron bauxite and the effects of various digestion conditions on the enrichment and separation of iron minerals were investigated. The results show that adding an appropriate organic reductant such as glycerol can promote the digestion of concomitant diaspore, boehmite and alumogoethite as well as the conversion of goethite to hematite in the reductive Bayer digestion. Processing Bauxite A with A/S of 25.41 can directly produce qualified iron concentrates(TFe>56%) by the reductive Bayer digestion, and thus realize the zero red mud discharge. For Bauxite B and Bauxite C with A/S of 7.82 and 3.35, the iron recoveries of 65.13% and 79.13% can be achieved with the corresponding TFe of 52.05% and 50.16% in the iron concentrates by gravity separation, respectively, resulting in the red mud discharge reduction of ~50% or above.展开更多
Bauxite residue(BR),a by-product of the industrial production of alumina,has raised environmental concerns in the last decades,due to the presence of high amounts of alkali and various heavy metal ions.Limited studies...Bauxite residue(BR),a by-product of the industrial production of alumina,has raised environmental concerns in the last decades,due to the presence of high amounts of alkali and various heavy metal ions.Limited studies on the application of abandoned BR with massive consumption have been reported.In this study,the possibility of the revegetation using ryegrass growing on BR was discussed mainly through the growth indications and transfer of heavy metal ions in BR and plants.In the pot trails,ryegrass was seeded on BR,de-alkali BR,with(DBRO)or without(DBR)organic fertilizer,respectively.The results indicated that the remediation of bauxite residue can be achieved through de-alkali with acid neutralization.Elemental analysis indicated that the elements,except for Fe,Mn and Pb,were stable in plant roots,and ryegrass could hardly absorb Cd.But,some heavy metals such as Cu enriched in plants,which should be noted in revegetation on bauxite residue.展开更多
基金Project(2019M652799)supported by China Postdoctoral Science FoundationProject(51604309)supported by the National Natural Science Foundation of China。
文摘The mineralogical characteristics of three kinds of gibbsitic high-iron bauxite and the effects of various digestion conditions on the enrichment and separation of iron minerals were investigated. The results show that adding an appropriate organic reductant such as glycerol can promote the digestion of concomitant diaspore, boehmite and alumogoethite as well as the conversion of goethite to hematite in the reductive Bayer digestion. Processing Bauxite A with A/S of 25.41 can directly produce qualified iron concentrates(TFe>56%) by the reductive Bayer digestion, and thus realize the zero red mud discharge. For Bauxite B and Bauxite C with A/S of 7.82 and 3.35, the iron recoveries of 65.13% and 79.13% can be achieved with the corresponding TFe of 52.05% and 50.16% in the iron concentrates by gravity separation, respectively, resulting in the red mud discharge reduction of ~50% or above.
基金Projects(51704329,51705540)supported by the National Natural Science Foundation of ChinaProject(2018JJ3671)supported by the Hunan Provincial Natural Science Foundation,China+1 种基金Project(2015CX005)supported by the Innovation Driven Plan of Central South University,ChinaProject(B14034)supported by the National 111 Project,China
文摘Bauxite residue(BR),a by-product of the industrial production of alumina,has raised environmental concerns in the last decades,due to the presence of high amounts of alkali and various heavy metal ions.Limited studies on the application of abandoned BR with massive consumption have been reported.In this study,the possibility of the revegetation using ryegrass growing on BR was discussed mainly through the growth indications and transfer of heavy metal ions in BR and plants.In the pot trails,ryegrass was seeded on BR,de-alkali BR,with(DBRO)or without(DBR)organic fertilizer,respectively.The results indicated that the remediation of bauxite residue can be achieved through de-alkali with acid neutralization.Elemental analysis indicated that the elements,except for Fe,Mn and Pb,were stable in plant roots,and ryegrass could hardly absorb Cd.But,some heavy metals such as Cu enriched in plants,which should be noted in revegetation on bauxite residue.
