The Bayer dissolving method for the diaspore type high-iron bauxite: A case study of the ore from Xianrenyan rock in Zunyi

Abstract：In the past, the adding of aluminum and reducing of iron or the separation of aluminum from iron should be adopted as the first step in the application of high iron bauxite, as indicated by most previous literatures. This paper describes physical and chemical characteristics of the diaspore type high iron bauxite in the ore bed of Xianrenyan Rock in Zunyi. The samples of XCK5 and XCK4 of high iron bauxite were collected, the former is characterized by Al2O3 53.61%，A/S 7.63，and Fe2O3 21.96%, whereas the latter is characterized by Al2O3 51.71%, A/S 7.16，and Fe2O3 24.89%. The Bayer dissolution test shows that the XCK5 has absolute dissolution rate 83.98% and relative dissolution rate 96.65%, chemical alkali consumption 57.9 kg(NaOH)/t（Al2O3）, whereqs the XCK4 shows absolute dissolution rate 80.02%, relative dissolution rate 93.01%, and chemical alkali consumption 34.9 kg(NaOH)/t（Al2O3）. The test also reaches good result in red mud settlement. Therefore, the process chain of the application of high iron bauxite can be considerably shortened in that it is not necessary to add aluminum and reduce iron or separate aluminum from iron first before the application. The result obtained by the authors provides a new way for this kind of ore applications and researches.