Method for efficiently recycling ferro-aluminium from bauxite tailings and synchronously preparing high siliceous residues

Abstract

The invention relates to a method for efficiently recycling ferro-aluminium from bauxite tailings and synchronously preparing high siliceous residues, and belongs to the technical field of waste comprehensive utilization and mineral resource processing. The method comprises the following steps: drying and grinding bauxite tailings, adding concentrated sulfuric acid, uniformly mixing, making into spheres, then heating and calcining, continually adding concentrated sulfuric acid during the calcining process, adding cleaning solution and leaching calcined bauxite tailings spheres, filtering, and gaining filter liquor, namely acid leaching initial liquid, gaining filter residue from filter cake to gain filter residue, namely high siliceous residue, and taking the gained cleaning solution as leaching agent of bauxite tailings spheres for next calcining to use; neutralizing the acid leaching initial liquid by grinding tailings, filtering, and gaining filter liquor, namely solution containing aluminum sulfate and ferric sulfate. The method realizes enrichment and edulcoration of silicon, and the recycle of silicon from the acid leaching residue or the preparation of silicate products is facilitated.

Description

technical field [0001] The invention relates to a method for synchronously preparing high silicic acid slag by recycling aluminum and iron from bauxite dressing tailings, and belongs to the technical fields of waste comprehensive utilization and mineral resource processing. Background technique [0002] Bauxite is a multi-mineral mixture mainly composed of gibbsite, diaspore and other hydrous alumina minerals, and also contains kaolinite, opal, hematite and other components. The mineral raw material of aluminum cement, the chemical formula is Al 2 o 3 ·nH 2 O is mainly used to produce alumina, which accounts for more than 90% of the world's total bauxite production. [0003] The vast majority of bauxite in my country belongs to the diaspore type with high aluminum, high silicon and low iron, and more than 80% of the bauxite has an aluminum-silicon ratio between 5 and 8, so the more economical conventional Bayer can not be used. production of alumina. According to the cha...

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Problems solved by technology

The above patents provide a new technical method for preparing chemical products from low-grade bauxite or bauxite tailings, but there are problems such as low recovery rate of leachate or large amount of residues, etc. Therefore, the present invention proposes bauxite tailings The method of high-efficiency recovery of aluminum and iron from ore and synchronous preparation of high silicic acid slag, its technical characteristics are: the tailings are not thermally activated, after drying and grinding, 98% sulfuric acid is directly added to form balls, and they are roasted in a fixed bed device at 250-300 °C 0.5~1h, add concentrated sulfuric acid directly from the top of the material during the roasting process, the acid mist is discharged after being absorbed by the alkali; the roasted product is directly added with washing liquid to dissolve the acid-soluble matter, and the yield of iron and aluminum can reach 99% and 97%

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