Efficient resource utilization method of red mud

Abstract

The invention discloses an efficient resource utilization method of red mud. The red mud is leached out with diluted hydrochloric acid; the obtained ore pulp is separated with a thickener (or an ore washing tank); overflow (containing suspended solids, namely activated soil) at the upper part is used as a composite water purifying agent product; settling slag at the lower part is subjected to multi-stage thickener (or the ore washing tank) countercurrent washing with the diluted hydrochloric acid having a pH value of 0.5-1; washing liquid is used for diluting concentrated hydrochloric acid andthen used as leaching initial acid; iron ore concentrate products and titanium-rich slag are produced through magnetic separation of the settling slag of the last stage; the titanium-rich slag is circularly leached through sulfuric acid; titanium-rich liquid and sulfuric acid leaching slag are obtained; titanium, scandium and vanadium are recycled from the titanium-rich liquid; residual liquid isused for producing polymeric ferric sulfate aluminum products; and the sulfuric acid leaching slag serves as zirconium, tantalum and niobium extraction raw materials or building material raw materials. The method is simple in production process, low in energy consumption and good in production environment, no waste water or waste residues are discharged in the production process, red mud resources are completely consumed, and remarkable economic benefits can be obtained.

Description

technical field [0001] The invention belongs to the fields of hydrometallurgy and solid waste resource utilization, and in particular relates to a method for efficient resource utilization of red mud. Background technique [0002] Red mud is the solid waste residue produced when bauxite is eluted with high temperature, high pressure and strong alkali, and the solid and liquid are separated. The main components are iron, aluminum, silicon, calcium, sodium, titanium, oxygen and a small amount of scandium, zirconium, vanadium, tantalum , niobium and other rare metals. The mineral components contained in red mud are complex, among which: hematite (α-Fe 2 o 3 ), hydrated garnet [Ca 3 AlFe(SiO 4 )(OH) 8 ], sodium silicate (Na 2 O·Al 2 o 3 1.68SiO2 2 1.73H 2 O), calcium aluminate (Ca(AlO 2 ) 2 ), perovskite (CaTiO 3 ) and other new minerals, as well as goethite (α-FeOOH), diaspore (Al 2 o 3 ·H 2 O), gibbsite (Al 2 o 3 ·3H 2 O), Hydroxysite (Ca(OH) 2 ), calcium c...

AI Technical Summary

Problems solved by technology

Silicon-containing minerals are dissolved by dilute acid to form silicic acid. Due to the low solubility of silicic acid in water, it mainly exists in the pulp in the state of sol, and is easy to condense into silica gel, which makes it difficult to filter the leachate and separate and recover valuable metals. ; When the calcium in red mud reacts with sulfuric acid, the amount of calcium sulfate dihydrate slag produced is 4.3 times that of the calcium content in red mud. Due to the excessive amount of slag, it will have a serious adverse effect on the recovery of valuable metals

In order to overcome the above problems, the recycling process of red mud resources developed in the past is often too complicated, resulting in high product recycling costs, and even recycling costs are much higher than the market price of recycled products, which is not feasible in terms of technology and economy, and there are also secondary problems in terms of environmental protection. Disposal of waste residue and waste water, the industrial technology of large-scale utilization of red mud has not yet made breakthroughs at home and abroad, and most of the red mud can only be stored for a long time

The stockpiling of red mud takes up valuable land resources, and there is a risk of dam failure and the release of alkaline substances to pollute the environment

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