A process for preparing alumina ceramic products by low-temperature sintering

A technology of alumina ceramics and alumina powder, which is applied in the field of alumina ceramics, can solve the problems of lower firing temperature, and achieve the effects of lower firing temperature, large surface energy, and energy reduction

Active Publication Date: 2019-04-26
HUNAN FUQIANG SPECIAL CERAMIC MFG CO LTD
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to reduce the firing temperature of alumina ceramics, in the prior art, the raw materials are usually made into micron-sized powders to increase the specific surface area of ​​the powder and improve the point contact of the powder, but this method has limited reduction in the firing temperature

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

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0026] In the preparation process provided by the present invention, firstly, β-alumina powder, dolomite powder and hydrochloric acid are added into the reaction kettle. Wherein, the particle size of the β-alumina powder is preferably 2-8 μm, more preferably 3-5 μm; the dolomite powder is a carbonate mineral, and its chemical composition is CaMg(CO 3 ) 2 The particle size of the dolomite powder is preferably ≤60 μm, more preferably ≤44 μm; the concentration of the hydrochloric acid is preferably 10 to 40 wt%, more preferably 37 wt%; the β-alumina powder and dolomite powder The mass ratio is preferably ≥99:1, more preferably 100:1; the ratio of the molar amount of carbonate radicals in the dolomite powder to the molar amount of hydrogen ions in hydrochloric acid is preferably 1:(1-3), more preferably 1 : 2; the time of the closed reaction is preferably 1~5h, more preferably 2h. During the reaction, the CaMg(CO 3 ) 2 It reacts with hydrochloric acid to form calcium chloride ...

Embodiment 1

[0032] Pour 50kg of β-alumina powder (3-5μm in particle size) and 0.5kg of dolomite powder (44μm in particle size) into the reaction kettle, lock the lid tightly, and stir for 15 minutes; then press the dolomite powder through the stainless steel valve of the reaction kettle The molar ratio of carbonate and hydrogen ions in hydrochloric acid is 1:2 and inject dilute hydrochloric acid (37wt%); start the operation of the reactor, and the chemical reaction between hydrochloric acid and dolomite releases a large amount of heat and gas CO 2 , the pressure in the reactor is raised to 0.05MPa to 0.1MPa, and the flux (calcium chloride and magnesium chloride) penetrates into the micropores of the β-alumina particles due to the effect of the pressure (there are a large number of micropores in the β-alumina particles, Relatively loose), at this time, there is a large amount of surface energy absorbed by the surface and interior of the β-alumina particles; along with the heat release of th...

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
particle diameteraaaaaaaaaa
particle diameteraaaaaaaaaa
Login to view more

Abstract

The invention belongs to the field of alumina ceramics and particularly relates to a process for preparing alumina ceramics through low-temperature sintering. The process comprises the following steps: a) adding a beta-alumina powder, a dolomite powder and hydrochloric acid into a reactor, closing and reacting to obtain the reacted material; b) molding the reacted material to obtain a ceramic body; c) firing the ceramic body, so as to obtain the alumina ceramics. According to the process disclosed by the invention, the traditional process that the firing temperature is reduced by improving thepoint contact manner of the powder is changed, and the combination of physical surface energy of the beta-alumina powder and chemical energy on a flux molecular level is realized, so that the beta-alumina powder obtains great surface energy, the needed energy during firing of the product can be further greatly reduced, and the firing temperature is reduced. Experimental results show that, compared with the traditional process, the process for preparing the alumina ceramics provided by the invention has the advantages that the primary firing temperature can be reduced by 100-150 DEG C, and thesecondary firing temperature can be reduced by 200-250 DEG C.

Description

technical field [0001] The invention belongs to the field of alumina ceramics, in particular to a process for preparing alumina ceramic products by low-temperature sintering. Background technique [0002] Alumina ceramics are a kind of aluminum oxide (Al 2 o 3 ) as the main material, has good conductivity, mechanical strength and high temperature resistance, and has a wide range of uses. Because of its superior performance, alumina ceramics have been more and more widely used in modern society, which can meet the needs of daily use and special performance. [0003] However, Al 2 o 3 It is a high-temperature raw material with a melting point of 2050°C. Therefore, Al 2 o 3 Products with higher content are difficult to burn and consume more energy. Especially for Al 2 o 3 For ceramic products with a flux content of 99wt%, extremely high firing temperatures are required because the flux content is only 1wt%. In order to reduce the firing temperature of alumina ceramics...

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 Patents(China)
IPC IPC(8): C04B35/10C04B35/64
CPCC04B35/10C04B35/64C04B2235/321C04B2235/444C04B2235/5436C04B2235/661
Inventor 张海鹰
Owner HUNAN FUQIANG SPECIAL CERAMIC MFG CO LTD
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