Method for producing ultra-fine cryolite

A production method and cryolite technology are applied in the production field of ultra-fine cryolite, which can solve problems such as limiting the application of cryolite, and achieve the effects of saving drying costs, easy operation and control, and good economic and social benefits.

Inactive Publication Date: 2008-09-17
河南未来铝业(集团)有限公司
View PDF0 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, less consideration has been given to how to produce cryolite products with smaller particle sizes, which limits the application of cryolite in other fields
However, fine-grained cryolite is needed in the fields of olefin complex agents, pesticides and cosmetic additives, and the existing products can no longer meet the requirements.

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 producing ultra-fine cryolite
  • Method for producing ultra-fine cryolite

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Embodiment one: the production method of ultrafine cryolite, see appendix figure 1 , including the following steps,

[0029] (1) Raw materials and dosage: use Bayer method semen, caustic soda and hydrofluoric acid as raw materials, and the molar ratio of raw materials is Al:Na:F=1:3:6, that is, Al 3+ :Na + :F - =1:3:6;

[0030] Requirements: caustic ratio α of Bayer semen k =1.5~2.0, including Al 2 o 3 140~150g / L, SiO 2 2 o 3 2 SiF 6 The mass percentage of <0.3%.

[0031] (2) Add caustic soda to the Bayer method semen during synthesis, stir while adding to dissolve the caustic soda, and obtain a composite solution after mixing;

[0032] (3) 40% composite solution is added to the synthesis tank earlier, then hydrofluoric acid and the remaining composite solution are gradually added to the synthesis tank under stirring, and the rotating speed is 100 rpm during the stirring, by controlling the feed rate in the feeding process, so that The reaction temperature i...

Embodiment 2

[0035] Embodiment two: the production method of ultrafine cryolite, no longer repeat with the same part of embodiment one, difference is,

[0036] (1) Raw materials and dosage: take Bayer method semen, caustic soda and hydrofluoric acid as raw materials, and the molar ratio of raw materials is Al:Na:F=1:3:5;

[0037] (2) 20% of the composite solution is added to the synthesis tank earlier, stirred, then hydrofluoric acid and the remaining composite solution are gradually added to the synthesis tank under stirring, and the rotating speed is 150 rpm during the stirring, and the feed rate is controlled during the feeding process. , keep the reaction temperature between 50-60°C, and the pH of the reaction solution ≥ 10; stop the reaction after the feeding is completed, control the pH at the end point to 12, and then age the slurry for 20 minutes;

[0038] (3) Filter the aged slurry with a belt filter to obtain a filter cake and filtrate, and dry the filter cake at 300° C. by airfl...

Embodiment 3

[0039] Embodiment three: the production method of ultrafine cryolite, no longer repeat with the same part of embodiment one, difference is,

[0040] (1) Raw materials and dosage: take Bayer process semen, caustic soda and hydrofluoric acid as raw materials, and the molar ratio of raw materials is Al:Na:F=1:2:6;

[0041] (2) 70% of the composite solution is added to the synthesis tank first, stirred, and then hydrofluoric acid and the remaining composite solution are gradually added to the synthesis tank under stirring. During the feeding process, the feeding speed is controlled, and the stirring speed is 120 rpm. , keep the reaction temperature between 40-50°C, and the pH of the reaction solution ≥ 10; stop the reaction after the feeding is completed, and then age the slurry for 30 minutes;

[0042] (3) Filter the aged slurry with a belt filter to obtain a filter cake and filtrate, and dry the filter cake at 200° C. by airflow flashing until the water content is below 0.2% (ma...

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

PropertyMeasurementUnit
particle diameteraaaaaaaaaa
Login to view more

Abstract

The invention discloses a production method for a super fine cryolite, which is characterized in that Bayer process concentrate solution, caustic soda, and hydrofluoric acid are used as raw materials; wherein, caustic soda is added into the Bayer process concentrate solution to obtain complex liquid, which is then added into a synthesis tank together with hydrofluoric acid for reaction, the reaction temperature is 40 to 60 DEG C, and the Ph value is larger than or equal to 10; after adding the materials, ageing is conducted for 20 to 30 minutes; subsequently, after filtering, the filter cake is dried under the temperature of 150 to 300 DEG C until the water content drops below, thus acquiring the finished cryolite. The production method has the advantages that: as the production method is carried out under normal temperature, the process is simple and easy to operate and control; and the heat source comes from heat of reaction, the need for adding a heating apparatus is obviated; by adjusting the parameter like reaction temperature, pH value and the ageing time, the product grain size D 50 is controlled within the range of 1 to 5 Mu m, and shows a desirable normal distribution; the molecular ration of NaF to AlF3 in the product is adjustable between 1.7 and 2.9; the production cost is pretty low yet with little pollution, and the treatment of three wastes, namely, wastewater, waste gas and waste residue, thus facilitating the environmental protection.

Description

1. Technical field: [0001] The invention relates to an aluminum electrolytic flux, in particular to a production method of ultrafine cryolite. 2. Background technology: [0002] Artificial cryolite is mainly used as a flux for aluminum electrolysis, as well as wear-resistant fillers for rubber and grinding wheels, enamel opalescent agents, glass opacifiers, fluxes for welding materials, casting deoxidizers, olefin composite catalysts, pesticides and insecticides And cosmetic additives, etc., of which more than 90% are used for aluminum electrolytic flux. [0003] Traditional artificial cryolite is produced by wet method, such as aluminum hydroxide-hydrofluoric acid-soda ash method, sodium fluorosilicate-aluminum hydroxide-soda ash method, ammonium fluoride-sodium aluminate method, sodium aluminate-hydrofluoric acid -Caustic soda method and other methods, the synthetic cryolite particle size D50 is generally about 15μm, and the moisture content of the filter cake is generall...

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): C01F7/54
Inventor 王志勇李民菁史智慧李高军李淮颜廖学建
Owner 河南未来铝业(集团)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