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CN-121974717-A - Method for preparing ceramsite from tailings after extracting iron from red mud

CN121974717ACN 121974717 ACN121974717 ACN 121974717ACN-121974717-A

Abstract

The invention discloses a method for preparing ceramsite by utilizing red mud tailings after iron extraction, which comprises the following steps of firstly, separating simple substance iron from the red mud tailings after iron extraction, namely, after deep reduction of the red mud, putting red mud raw materials into a high temperature of 1500-1700 ℃ for melting, and separating liquid simple substance iron and molten tailings; the method for preparing the ceramsite by utilizing the tailings after the red mud is used for extracting iron realizes the full-process resource utilization of the red mud from the iron extraction to the preparation of the ceramsite by utilizing the tailings, changes the traditional stacking or landfill treatment mode of the tailings after the red mud is used for extracting the iron, saves a large amount of land resources, avoids potential harm to the environment, converts the tailings after the red mud is used for extracting the iron into the ceramsite with economic value, fully utilizes the red mud, reduces the pressure of solid waste on the environment, improves the comprehensive utilization rate of the resources, forms a benign resource circulation system and is beneficial to promoting sustainable development.

Inventors

  • LI LAIGUANG
  • GAO JIQIN
  • XIE HAI

Assignees

  • 郑州碳诺科技有限公司

Dates

Publication Date
20260505
Application Date
20250721

Claims (7)

  1. 1. The method for preparing the ceramsite by utilizing the tailings after the red mud is used for extracting iron is characterized by comprising the following steps of: Firstly, separating simple substance iron and tailings after extracting iron from red mud, namely after deeply reducing the red mud, putting a red mud raw material at a high temperature of 1500-1700 ℃ for melting, and separating liquid simple substance iron and molten tailings; secondly, crushing and separating molten tailings, namely conveying the molten tailings from a melting furnace to the upper part of the center of a rotary centrifugal disc through a high-temperature-resistant diversion trench, and throwing the molten tailings out along the diversion trench under the action of centrifugal force and crushing the molten tailings into fine liquid drops; step three, cooling and solidifying the molten tailings, namely solidifying liquid drops into ceramsite under the action of high-speed cooling wind, and collecting the ceramsite by a collecting device; screening and grading, namely screening the collected ceramsite by using a vibrating screen, collecting the qualified ceramsite, and returning the unqualified ceramsite to remelt treatment.
  2. 2. The method for preparing ceramsite by utilizing tailings after extracting iron from red mud as set forth in claim 1, wherein the ceramsite comprises solid ceramsite and hollow ceramsite.
  3. 3. The method for preparing the ceramsite by utilizing the tailings after the red mud is used for extracting iron, as set forth in claim 2, wherein the solid ceramsite is a solid ceramsite with the particle size of 0.5-5mm obtained by directly extruding or dripping molten tailings through a spray nozzle or a die, and the particle size of the ceramsite is controlled by controlling the pore diameter, the extrusion speed or the dripping height of the spray nozzle in the forming process.
  4. 4. The method for preparing ceramsite by utilizing tailings after extracting iron from red mud as set forth in claim 2, wherein the hollow ceramsite is formed by adopting a double-layer spray head or introducing gas into molten tailings.
  5. 5. The method for preparing ceramic particles by utilizing the tailings after the iron extraction from the red mud, as set forth in claim 4, wherein the hollow ceramic particles are granulated by adopting a double-layer spray head, the outer layer of the spray head sprays molten tailings, the inner layer of the spray head sprays gas, and the ceramic particles with a hollow structure are formed under the action of the gas.
  6. 6. The method for preparing ceramic particles by utilizing the tailings after the iron extraction from the red mud, as set forth in claim 4, wherein the hollow ceramic particles are granulated by introducing gas into the molten tailings, and the molten tailings are injected with a proper amount of gas through a gas injection device before entering a forming die, and then the gas expands inside the molten tailings to form the hollow ceramic particles in the forming process.
  7. 7. The method for preparing ceramsite by utilizing tailings after extracting iron from red mud, as set forth in claim 1, wherein the surface of the qualified ceramsite is coated with a protective film.

Description

Method for preparing ceramsite from tailings after extracting iron from red mud Technical Field The invention relates to the technical field of solid waste recycling, in particular to a method for preparing ceramsite by utilizing tailings after red mud iron extraction. Background With the rapid development of the alumina industry, the bayer process is the mainstream production process, producing about 1.3 million tons of red mud solid waste per year. It is worth noting that the content of ferric oxide in the Bayer process red mud is up to 50%, and the method has remarkable resource recovery value. Although the prior art can realize the extraction of part of iron elements, the tailings after the iron extraction still contain about 35 percent of ferric oxide, and a large amount of secondary waste is generated. At present, how to realize innocent treatment and recycling of the iron-containing tailings becomes a key technical bottleneck for restricting green development of the alumina industry. The existing treatment technology of the tailings after the red mud is used for extracting iron mainly has the outstanding problems that 1, the limitation of traditional landfill disposal is that each ton of tailings occupies 0.5-1.2m2 of land, soluble salts such as sodium, aluminum and the like and long-term infiltration of trace heavy metals are needed, anti-seepage layer maintenance and leachate treatment are needed to be continuously carried out, 2, the technical bottleneck of building material utilization is that the components of the tailings after the red mud is used for extracting iron are complex, the stability is poor, the quality of the manufactured building material is difficult to guarantee, and the application range is greatly limited. At present, a technology which is low in cost and can realize valuable utilization of tailings after iron extraction of red mud is lacking, on one hand, most of the existing treatment technology is complex in flow, large in equipment investment and high in operation cost, so that enterprises face huge economic pressure when treating the tailings, and on the other hand, the potential value of the tailings cannot be fully excavated, so that great waste of resources is caused, and therefore, development of a method which is efficient and low in cost and can realize recycling utilization of the tailings after iron extraction of the red mud is urgent, and the method has important significance for relieving environmental pressure, improving resource utilization rate and reducing treatment cost of the enterprises. Disclosure of Invention The invention aims to overcome the existing defects, and provides the method for preparing the ceramsite by utilizing the red mud tailings after the iron extraction, which is convenient for reducing the treatment cost of the red mud tailings after the iron extraction, can effectively and valuable utilize the red mud tailings after the iron extraction, and can effectively solve the problems in the background art. In order to achieve the above purpose, the present invention provides the following technical solutions: A method for preparing ceramsite by utilizing tailings after extracting iron from red mud comprises the following steps: Firstly, separating simple substance iron and tailings after extracting iron from red mud, namely after deeply reducing the red mud, putting a red mud raw material at a high temperature of 1500-1700 ℃ for melting, and separating liquid simple substance iron and molten tailings; the liquid simple substance iron in the red mud and the molten tailings are separated by utilizing high-temperature melting, so that the tailings after the iron extraction of the red mud can be effectively recycled. Secondly, crushing and separating molten tailings, namely conveying the molten tailings from a melting furnace to the upper part of the center of a rotary centrifugal disc through a high-temperature-resistant diversion trench, and throwing the molten tailings out along the diversion trench under the action of centrifugal force and crushing the molten tailings into fine liquid drops; the molten tailings are separated in a molten state to form a ceramsite shape, so that secondary high-temperature heating is avoided, and energy is saved. Step three, cooling and solidifying the molten tailings, namely solidifying liquid drops into ceramsite under the action of high-speed cooling wind, and collecting the ceramsite by a collecting device; The air cooling is utilized to cool and shape the molten state tailings liquid drops rapidly, thereby accelerating the production rhythm. Screening and grading, namely screening the collected ceramsite by using a vibrating screen, collecting the qualified ceramsite, and returning the unqualified ceramsite to remelt treatment. And screening out the unqualified ceramsite, so as to ensure the quality of the formed ceramsite. As a preferable technical scheme of the invention, the ceramsite comprises solid cera