CN-121380576-B - Process for extracting iron and aluminum from high-iron red mud

Abstract

The invention provides a process for extracting iron and aluminum by utilizing high-iron red mud, which comprises the following steps of firstly mixing the high-iron red mud, a reducing agent and a complexing agent to prepare a mixture, then sequentially carrying out iron extraction and aluminum extraction on the mixture to obtain waste residues, and finally carrying out building material treatment on the waste residues to obtain the composite admixture for building materials. The process not only effectively improves the recovery rate of iron and aluminum in the high-speed rail red mud, realizes the recycling of resources and reduces the influence on the environment, but also can improve the added value of products, prepare the composite admixture for building materials with good physical and chemical properties, realize the comprehensive recycling and recycling of the high-speed rail red mud and finally achieve the purpose of 100% recycling of the red mud.

Inventors

• DAI WENBIN
• CHEN XUEGANG
• Qi yongfeng
• CHEN XI
• WANG SHUXIAO
• DING CHONG

Assignees

• 中国恩菲工程技术有限公司
• 中国有色工程有限公司

Dates

Publication Date

20260508

Application Date

20251224

Claims (6)

1. 1. The process for extracting the iron and the aluminum by using the high-iron red mud is characterized by comprising the following steps of: Step S1a, mixing high-speed rail red mud, a reducing agent and a complexing agent to prepare a mixture, wherein the mass ratio of the high-speed rail red mud to the reducing agent to the complexing agent in the mixture is 100 (25-40) (25-55), the complexing agent comprises lime, industrial soda ash and fluorite, the mass ratio of the lime to the industrial soda ash to the fluorite is 5-15) (25-60) (1-5), and the reducing agent comprises at least one of semi-coke, anthracite, lignite, coke, carbon-containing fly ash and waste graphite electrode; Step S2a, namely carrying out smelting reduction on the mixture to obtain metal iron liquid and slag, step S2b, adopting a pretreatment agent to remove impurities and carry out casting treatment on the metal iron liquid to obtain pig iron and pretreated slag, and carrying out cooling treatment on the slag through a water quenching process to obtain water quenching slag, wherein in step S2c, the water quenching slag and a first leaching agent are mixed for first wet grinding to obtain a first aluminum-containing leaching solution and first waste slag; In the step S2b, the mass ratio of the pretreatment agent to the molten metal is (0.05-3) 100, wherein the pretreatment agent comprises at least one of high-speed rail red mud, lime, caC 2 , industrial sodium carbonate, calcined dolomite and fluorite, and in the step S2c, the first leaching agent comprises at least one of industrial caustic soda, industrial sodium carbonate and sodium aluminate; And step S3a, mixing the first waste residue with the pretreatment residue, and then drying and grinding to obtain the composite admixture for the first building material, wherein the mass ratio of the first waste residue to the pretreatment residue is 10 (1-3).
2. 2. The process for extracting iron and aluminum from high-iron red mud according to claim 1, wherein in the step S2a, the temperature of the melting reduction is 1500-1650 ℃; and/or in the step S2c, the mass ratio of the first leaching agent to the water quenching slag is (2-15) 100; And/or, in the step S2c, the liquid-solid ratio in the first wet grinding process is (0.2-0.4): 1.
3. 3. The process for extracting iron and aluminum from high-iron red mud according to claim 1, wherein, The step S2c further comprises extracting alumina from the first aluminum-containing leaching solution by an alumina extraction process.
4. 4. A process for extracting iron and aluminum from high-iron red mud according to any one of claims 1 to 3, The average particle size of the reducing agent is 1-10 mm; And/or the average particle size of the complexing agent is 1-6 mm.
5. 5. A process for extracting iron and aluminum from high-iron red mud according to any one of claims 1 to 3, wherein step S1 further comprises aging the mixture for 6 to 24 hours.
6. 6. A process for extracting iron and aluminum from high-iron red mud according to any one of claims 1 to 3, wherein the water content of the high-iron red mud is 10-30 wt%, and the average particle size is less than or equal to 3mm; And/or the mixture is a spherical mixture, and the granularity of the spherical mixture is 10-30 mm; And/or, the high-iron red mud comprises the following components in percentage by mass Fe 2 O 3 54~68%,SiO 2 2~10%,CaO 0.2~5%,Al 2 O 3 3~19,TiO 2 1.2~8%,Na 2 O 0.6~5%.

Description

Process for extracting iron and aluminum from high-iron red mud Technical Field The invention relates to the technical field of mineral processing and metal smelting, in particular to a process for extracting iron and aluminum by utilizing high-iron red mud. Background Red mud is a solid powdery waste produced after alumina is extracted from bauxite, and is mainly produced by three ways of a Bayer process, a sintering process and a combination process. The main chemical components of the red mud are SiO 2、Al2O3、CaO、Fe2O3、Na2O、TiO2 and the like, the red mud has strong alkalinity (pH is more than or equal to 12), the alkaline soil and the polluted groundwater can be realized after long-term stacking, and the comprehensive utilization of the heavy metal toxicity and the radioactivity in the red mud in various fields is greatly restricted. In order to solve the serious environmental pollution caused by red mud, the harmless, the reduction, the recycling and the industrialization of the red mud are important solving approaches, thereby not only meeting the ecological civilization construction, but also guaranteeing the safe supply of resources. At present, the four technical directions of comprehensive utilization of red mud are firstly to extract valuable metals (iron, aluminum, rare metals and the like), secondly to prepare building materials (cement, bricks, roadbed materials, rock wool and the like), thirdly to apply to the field of environmental protection (purifying agents, absorbing agents and the like for waste gas and sewage treatment), and thirdly to apply to soil amendments. Wherein, valuable metals are extracted from the red mud and building materials are prepared at the same time, which is an optimal route for simultaneously realizing large consumption and full excavation of economic value of the red mud. The red mud produced is mainly divided into high-iron red mud (Fe 2O3 is usually more than 30%) and low-iron red mud (Fe 2O3 is usually less than 30%) according to the variety of bauxite. The high-iron red mud is rich in iron resources, and has high content of aluminum, sodium and other elements remained, so that the high-iron red mud is a potential iron and aluminum composite mineral resource. If the content of the residual aluminum, sodium and other components in the red mud is increased after the iron resource is extracted, the red mud can be further extracted, and valuable components and potential values of the red mud are fully excavated. At present, aiming at a high-iron red mud iron extraction recovery route, the original red mud is directly subjected to magnetic separation to obtain iron concentrate, but due to the characteristics of small red mud particles, low magnetic substance content and the like, the direct magnetic separation can have the problems of low iron recovery rate, low iron grade, low iron concentrate yield, large tailings discharge, low utilization rate and the like. In the eddy stirring reduction technology disclosed in the prior art, large-scale eddy stirring heating equipment is expensive, high in investment, high in electricity consumption, high in production and operation cost and difficult in equipment maintenance, and eddy is formed by adopting an electromagnetic induction mode. In addition, the components are directly regulated in the molten slag to meet the requirements of cement clinker, and the overall chemical components can meet the requirements of the clinker, but the overall chemical components exceed the optimal firing temperature of the traditional clinker, so that the clinker minerals are coarse in crystallization, the progress of hydration reaction of the clinker can be inhibited, the cement quality is influenced, the energy consumption is high, and the economy is poor. In addition, it is reported that red mud is treated by a cupola furnace to smelt molten iron, and raw materials such as aluminum ash and desulfurized gypsum are added into the red mud, but the smelted molten iron has high sulfur content and the quality of the molten iron is affected. And the aluminum content in the slag is high, so that the slag is sticky, and normal smelting of the cupola furnace is not facilitated. In addition, the use of the cupola furnace consumes a large amount of expensive coke, and the cupola furnace is a national obsolete smelting furnace type, so that the environment friendliness is poor. Therefore, the technology, economy, policy and the like are still insufficient. In view of this, the present application has been made. Disclosure of Invention The invention mainly aims to provide a process for extracting iron and aluminum by utilizing high-iron red mud, which aims to solve the problems that the high-iron red mud recovery process in the prior art is low in iron recovery rate, low in iron grade, low in aluminum recovery rate, high in tailings alkali content, unfavorable for building material production and application, incapable of realizing 100% recycling of red