Bauxite physical desilication technology and its application

Bauxite, as a mineral mixture mainly composed of aluminum hydroxide, is also called bauxite or high-aluminum bauxite. It is not only a key raw material for alumina production, but also plays an important role in industrial fields such as aircraft materials, high-temperature refractory materials, high-alumina cement, ceramic materials, and artificial corundum.

The presence of silicon and sulfur in bauxite has a significant negative impact on production quality, so the development of effective desilication technology is crucial. This article will discuss several commonly used physical desilication methods, which can remove silicon-containing gangue minerals without changing the mineral properties of bauxite, thereby improving the quality of bauxite.

Graded Desiliconization Technology

The graded desilication technology utilizes the characteristics of the silicon-containing clay minerals in diaspore-type bauxite with low hardness, easy crushing and mudification. The crushed ore is classified by spirals, high-frequency vibrating screens, hydrocyclones and spirals. The processing of equipment such as chutes can remove fine-grained gangue minerals, achieve desilication, and improve the A/S and quality of bauxite. For karst accumulation-type bauxite with high mud content, a desiliconization process of "pre-selection screening-ore washing-crushing, classification and tailing" was developed.

Gravity Desiliconization Technology

In the Zhaotong area of Yunnan, for diaspore-type high-silica bauxite, the bauxite with better monomer dissociation after rough grinding was desiliconized through spiral chute gravity separation, and a "heavy-floating" method was developed. Combined desilicon technology. After one rough and one fine gravity separation and desiliconization treatment, a qualified coarse-grained gravity separation aluminum concentrate with a yield of 44.65%, an aluminum-to-silicon ratio of 7.25, and an alumina recovery rate of 43.83% can be obtained.

Flotation Desilicon Technology

The flotation desilication process is currently one of the most widely used bauxite desilication methods. Depending on whether the foam product is the target mineral, the flotation desilication process can be divided into forward flotation and reverse flotation. This method adopts the sequence of reverse flotation desulfurization and forward flotation desiliconization. The bauxite undergoes reverse flotation desulfurization after primary grinding, and the desulfurized concentrate is ground again and then undergoes forward flotation desiliconization. Ethyl xanthate is used as the collector for reverse flotation desulfurization to obtain silicon-containing bauxite middlings, which are then subjected to forward flotation and desilication after secondary grinding. Saponified fatty acids and naphthenic acids are used as collectors. agent.