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CN-122012922-A - Method for efficiently leaching valuable aluminum in aluminum ash

CN122012922ACN 122012922 ACN122012922 ACN 122012922ACN-122012922-A

Abstract

The invention provides a method for efficiently leaching valuable aluminum in aluminum ash, belonging to the technical field of solid waste disposal and resource utilization. The method comprises the steps of carrying out acid leaching on aluminum ash to obtain acid leaching solution and acid leaching slag, mixing the acid leaching slag with a sintering agent, then sintering to obtain a sintering product, mixing the sintering product with water, leaching under a heating condition, carrying out solid-liquid separation to obtain a leaching solution rich in active aluminum, adding the acid leaching solution into the leaching solution rich in active aluminum until precipitation is generated, and carrying out solid-liquid separation to obtain an aluminum-containing solution with fluorine-chlorine impurities removed, wherein the sintering agent is a mixture of boric acid, sodium hydroxide, sodium chloride and non-aluminum metal powder. The whole process has reasonable and effective design, can realize innocuity and recycling of the aluminum ash, and realize efficient leaching of inert aluminum and active aluminum in the aluminum ash, thereby greatly improving the aluminum leaching rate of the aluminum ash and achieving the purpose of effectively disposing and utilizing dangerous wastes.

Inventors

  • YANG ZHUOQUN
  • LI XIONG
  • LIU YUYI
  • HE DEWEN
  • CHEN WEI
  • OU PENG
  • GONG JINPENG

Assignees

  • 中南大学
  • 湖南蒙拓环境科技有限公司

Dates

Publication Date
20260512
Application Date
20260226

Claims (8)

  1. 1. The method for efficiently leaching valuable aluminum in the aluminum ash is characterized by comprising the following steps of: acid leaching is carried out on the aluminum ash to obtain acid leaching liquid and acid leaching slag; mixing the acid leaching slag and a sintering agent, and sintering to obtain a sintering product; Mixing the sintered product with water, leaching under heating, and carrying out solid-liquid separation to obtain a leaching solution rich in active aluminum; Dripping the acid leaching solution into the leaching solution rich in active aluminum until precipitation is generated, and obtaining aluminum-containing solution with fluorine-chlorine impurity removed after solid-liquid separation; the sintering agent is a mixture of boric acid, sodium hydroxide, sodium chloride and non-aluminum metal powder.
  2. 2. The method of claim 1, wherein the aluminum ash comprises 60-70 wt% of Al 2 O 3 , 10-15 wt% of AlN, 5-15 wt% of Cl, 1-10 wt% of C, 1-10 wt% of Mg, 1-10 wt% of Na, 2-6 wt% of SiO 2 , 1-5 wt% of F, 1-5 wt% of K, and the balance Ca.
  3. 3. The method according to claim 1, wherein the pickling solution used in the pickling is sulfuric acid and/or hydrochloric acid, and the pickling is carried out at a temperature of 20-200 ℃ for 1-2 hours.
  4. 4. The method according to claim 1, wherein the sintering agent comprises 5wt% to 20wt% boric acid, 40wt% to 80wt% sodium hydroxide, 5wt% to 20wt% sodium chloride and the balance non-aluminum metal powder in mass percent.
  5. 5. The method of claim 1 or 4, wherein the metal element in the non-aluminum metal powder is at least one selected from the group consisting of titanium, vanadium, chromium, manganese, iron, nickel, zinc, gallium, rubidium, cesium, francium, zirconium, tungsten, molybdenum, lead, and tin.
  6. 6. The method according to claim 1, wherein the mass ratio of the acid leaching slag to the sintering agent is 1 (0.5-8).
  7. 7. The method of claim 1, wherein the sintering is performed at a temperature of 700-1000 ℃ for a time of 0.5-2 hours.
  8. 8. The method of claim 1, wherein the leaching is at a temperature of 50-100 ℃ for a time of 1-2 hours.

Description

Method for efficiently leaching valuable aluminum in aluminum ash Technical Field The invention relates to the technical field of solid waste disposal and resource utilization, in particular to a method for efficiently leaching valuable aluminum in aluminum ash. Background The aluminum ash is dangerous solid waste generated in the process of smelting, processing, casting and regenerating the raw aluminum alloy, and has the double characteristics of dangerous solid waste and valuable resources. The aluminum ash is dangerous solid waste generated in the original aluminum smelting process, and also belongs to the class of aluminum ash. The aluminum ash is mainly composed of Al 2O3, alN, slag forming salt compounds and mixtures of fluorides. The difference of raw materials in the electrolytic aluminum process can cause larger fluctuation of the components of aluminum ash, and the mass of each component generally comprises 20% -80% of Al 2O3%, 5% -20% of silicon, magnesium, iron and calcium oxides, 5% -15% of potassium and sodium chlorides, and 1% -5% of fluorine in a fluoride form. In the production process of electrolytic aluminum, aluminum ash is generated along with aluminum ash, and the aluminum ash can be classified into white aluminum ash and black aluminum ash according to different treatment degrees. The white aluminum ash is white due to no carbon and alumina. The black aluminum ash contains 1% -20% of carbon, so the color is black, and the black aluminum ash belongs to aluminum ash slag. Besides, the aluminum ash also contains waste residues generated in the aluminum alloy production and recovery production processes. Compared with the aluminum ash, the metal aluminum content in the aluminum ash is obviously increased, and the contents of aluminum nitride, fluoride and chloride are obviously reduced. The aluminum and the alloy products thereof are widely applied to daily life of people and various fields, and the recovery treatment of secondary aluminum resources (namely aluminum industrial waste residues and waste aluminum products) is an important measure for realizing sustainable development of the aluminum industry. Researchers at home and abroad have carried out a great deal of research on the treatment of aluminum ash and have made a certain research progress. Most of the researches have focused on the extraction mechanism of AlN and activated aluminum, and there are few researches on the extraction of inert aluminum, and the researches therein have not focused on the efficient extraction of inert aluminum. AlN and active aluminum are easy to dissolve in acid-base solution, and inert aluminum is difficult to dissolve in acid-base solution, and is difficult to leach out completely even under the high-temperature high-pressure acid-base solution. Since aluminum ash is included in hazardous waste, aluminum industry processing costs are increasing and it is difficult to utilize the aluminum ash as a resource. So the aluminum ash is mainly deposited and buried in the aluminum-smelting enterprises at present, and the potential environmental pollution risk exists. Therefore, it is necessary to find an economical and green aluminum ash harmless and recycling treatment process. Disclosure of Invention In view of the above, the present invention aims to provide a method for efficiently leaching valuable aluminum in aluminum ash. The method provided by the invention is environment-friendly, and improves the aluminum leaching rate of the aluminum ash. The invention converts aluminum nitride into ammonia gas and then into ammonium ions, and realizes the purposes of greatly reducing the corrosiveness of aluminum ash products, effectively disposing and utilizing dangerous wastes and promoting the healthy development of the aluminum industry. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides a method for efficiently leaching valuable aluminum in aluminum ash, which comprises the following steps: acid leaching is carried out on the aluminum ash to obtain acid leaching liquid and acid leaching slag; mixing the acid leaching slag and a sintering agent, and sintering to obtain a sintering product; Mixing the sintered product with water, leaching under heating, and carrying out solid-liquid separation to obtain a leaching solution rich in active aluminum; Dripping the acid leaching solution into the leaching solution rich in active aluminum until precipitation is generated, and obtaining aluminum-containing solution with fluorine-chlorine impurity removed after solid-liquid separation; the sintering agent is a mixture of boric acid, sodium hydroxide, sodium chloride and non-aluminum metal powder. In the preferred embodiment of the invention, the aluminum ash comprises 60-70wt% of Al 2O3, 10-15wt% of AlN, 5-15wt% of Cl, 1-10wt% of C, 1-10wt% of Mg, 1-10wt% of Na, 2-6wt% of SiO 2, 1-5wt% of F, 1-5wt% of K and the balance of Ca. The aluminum a