Separation technology of high sulfur bauxite

Soviet Union using Southern Ural bauxite removal of sulfide minerals and industrial test of the success of flotation of carbonates. The ore a boehmite and diaspore a 46%, 19.0% calcite, 12% hematite, 6.6% kaolinite and 4% pyrite. The ore is subjected to three-stage crushing and three-stage grinding, and the final grinding grain size is -200 mesh, accounting for 94%. Flotation process: Sulfide is obtained by rough selection, secondary selection and secondary sweeping, respectively, to obtain sulfide concentrate and tailings; the tailings are then floated to carbonate, after secondary selection and secondary sweep. Selected, respectively, carbonate concentrate and bauxite concentrate. The test results are shown in Table 1. The bauxite concentrate is used to produce aluminum by Bayer process, the carbonate concentrate is used for sintering aluminum, and the sulfur concentrate is used as a vulcanizing agent for smelting of nickel oxide ore. The ore is fully utilized.

Table 1 Flotation industry test indicators

The industrial test of the North Ural bauxite mine using the screening-photoelectric picking-flotation combined process has also been successful. The original ore bauxite is mainly diaspore, with an aluminum to silicon ratio of up to 15, but sulfur and carbonate are harmful. The impurity content is high, 1.5% S and 3.5% to 3.6% CO _{2 , respectively} . Sulfur is mainly distributed in pyrite-type ore, and CO ₂ is concentrated in carbonate ore. After crushing ore, most of the sulfur and carbonate are concentrated in the +200mm particle size, and the -200mm grain size has a low impurity content, which can be used to make aluminum by Bayer process. The coarse-grained grade is used for photoelectric beneficiation and flotation. The electro-selected concentrate is used for Bayer's aluminum smelting raw materials, the tailings are desulphurized by flotation, the sulfur concentrate is used as a vulcanizing agent for nickel oxide smelting, and the flotation tailings sintering method is used for smelting aluminum. The process is characterized by simple screening and electro-optic separation using differences in the heterogeneity and optical properties of sulfides and carbonates in the ore.

To this end, in the early 1980s, a 250-300t bass bauxite ore dressing plant was built, mainly dealing with the southern Ural and northern Ural bauxite mines to remove harmful impurities such as sulfides and carbonates. The plant has carried out systematic industrial tests from crushing, pre-selection, grinding, grading and flotation, dewatering and filtration, and has achieved good and reliable technical and economic indicators.