Method for extracting aluminium oxide from coal ash

A technology of fly ash and alumina, which is applied in the direction of alumina/hydroxide, alumina/hydroxide preparation, etc., can solve the problems of restricting social and economic benefits, adding treatment procedures, and difficult recovery of waste acid, etc., to achieve durable The effect of low corrosion performance requirements, small amount of residue, and low corrosiveness

Active Publication Date: 2008-02-06
河南华慧有色工程设计有限公司 +1
View PDF0 Cites 46 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the main disadvantage of the acid method is that the reaction equipment used must be acid-resistant, and the recovery of waste acid is relatively difficult; secondly, when leaching alumina, many soluble impurities such as iron and magnesium in fly ash are also removed. Bringing into the solution, need to add post-processing process
These deficiencies will to a certain extent restrict the scale and social and economic benefits of acid extraction of alumina in fly ash

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for extracting aluminium oxide from coal ash

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Grind the fly ash containing 33% of alumina and 49% of silica, mix ore according to the molecular ratio of ammonium sulfate / alumina in fly ash to 5, the sintering temperature is 530°C, the reaction time is 2 hours, and sintering The clinker is dissolved under the condition of 98°C, and the aluminum ammonium sulfate solid obtained after the dissolution liquid is crystallized is decomposed with ammonia gas to obtain the aluminum hydroxide solid, which is washed, filtered and roasted to obtain the alumina product, and the obtained alumina product has impurities The chemical composition is: Fe 2 o 3 : 0.02%, SiO 2 : 0.08%.

Embodiment 2

[0026] Grind the fly ash containing 40% of alumina and 48% of silica, mix ore according to the molecular ratio of ammonium sulfate / alumina in fly ash to 4, the sintering reaction temperature is 500°C, and the reaction time is 2 hours. The sintered clinker is dissolved under the condition of 85°C, and the aluminum ammonium sulfate solid obtained after the dissolution liquid is crystallized is decomposed with ammonia gas to obtain the aluminum hydroxide solid, which is washed, filtered and roasted to obtain the alumina product, and the obtained alumina product The chemical composition of impurities is: Fe 2 o 3 : 0.05%, SiO 2 : 0.05%.

Embodiment 3

[0028] Grind the fly ash containing 38% of alumina and 47% of silica, mix the ore according to the molecular ratio of ammonium sulfate / alumina in fly ash to 4.5, sinter the reaction temperature at 460°C, and the reaction time is 3 hours. The sintered clinker is dissolved under the condition of 90°C, and the aluminum ammonium sulfate solid obtained after the dissolution is crystallized is dissolved and then recrystallized, and then decomposed with ammonia gas to obtain aluminum hydroxide solid, which is obtained after washing, filtering and roasting. Alumina product, the impurity chemical composition of gained alumina product is: Fe 2 o 3 : 0.04%, SiO 2 : 0.04%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a method to extract aluminum oxide from a fly ash, and relates to a technological method which is to extract aluminum oxide from the fly ash and comprehensively utilize the residue after extracting aluminum oxide. The invention is characterized in the method which is as follows: ammonium sulfate is mixed into the fly ash to sintering, and the solid is dissolved to obtain the solution containing aluminum-ammonium sulfate; the solution is crystallized to form solid aluminium-ammonium sulfate; solid aluminium-ammonium sulfate reacts with ammonia gas to obtain aluminium hydroxide and ammonium sulfate, and aluminium hydroxide and ammonium sulfate are washed and filtrated to obtain solid aluminium hydroxide; solid aluminium hydroxide is calcined to obtain aluminum oxide; ammonium sulfate can be circularly used after being evaporated in the liquid phase. The ammonium sulfate which is used by the method of the invention is weak acidic, the corrosiveness on the equipment is small, and the ammonium sulfate can be used circularly. The whole process is easy to industrial application. The requirement of the corrosion resistance on the equipment is low. The amount of the residue is small which is beneficial to the comprehensive utilization of the residue after extracting the aluminum oxide.

Description

technical field [0001] A method for extracting alumina from fly ash relates to a process for extracting alumina from fly ash and comprehensively utilizing the residue after alumina extraction. Background technique [0002] At present, the production of alumina mainly uses bauxite as raw material, and the production methods of alumina are mainly alkaline method, including Bayer method, sintering method and combined method. In recent years, my country's alumina production has continued to grow rapidly and has become the world's second largest alumina producer. However, my country is a country with relatively poor bauxite resources. Currently, the nationally identified and inferred bauxite resource reserves have a significant impact on my country's alumina production. The degree of industrial guarantee is low, so the resource problem has become one of the main problems restricting the sustainable development of my country's aluminum industry. [0003] my country is a big coal c...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/02C01F7/30
Inventor 尹中林范伟东赵卓
Owner 河南华慧有色工程设计有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap