Method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio by utilizing calcium sulfate dihydrate

A technology of calcium sulfate dihydrate and calcium sulfate hemihydrate, applied in chemical instruments and methods, single crystal growth, single crystal growth, etc., can solve the problems of product purity, low aspect ratio, high requirements, etc., and achieve product added value High, extended raw material range, efficient and thorough removal effect

Active Publication Date: 2021-02-05
郑州中科新兴产业技术研究院 +1
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In the existing technology for preparing calcium sulfate whiskers, the reaction of calcium salts with higher purity and sulfuric acid/sulfate is mostly used, and the requirements for the purity of raw materials are relatively high; In the technology of whiskers, most of them only go through s

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 preparing calcium sulfate hemihydrate whiskers with high aspect ratio by utilizing calcium sulfate dihydrate
  • Method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio by utilizing calcium sulfate dihydrate
  • Method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio by utilizing calcium sulfate dihydrate

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0033]Example 1

[0034]In this embodiment, the method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio using power plant desulfurized gypsum as a raw material, the specific steps are as follows:

[0035](1) Fine grinding / removal of impurities: According to the ratio of liquid to solid ratio of 1, mix desulfurized gypsum and 10% sodium hydroxide solution into the stirring mill for fine grinding, control the fine grinding time to 0.5h, and discharge the material Particle size D90<200 mesh;

[0036](2) Acid leaching and impurity removal: filter the slurry obtained in step (1), and adjust the liquid-to-solid ratio to 1 in dilute hydrochloric acid with a concentration of 10% in the solid phase to control the reaction temperature. The temperature is 50℃, and the leaching time is 1h, so that the carbonate, oxide and other impurities in the raw materials can be further removed by reaction;

[0037](3) Oxidation and impurity removal: solid-liquid separation of the purified raw ...

Example Embodiment

[0042]Example 2

[0043]In this embodiment, the method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio using natural gypsum as a raw material, the specific steps are as follows:

[0044](1) Fine grinding / impurity removal: According to the ratio of liquid to solid ratio of 1.5, mix natural gypsum and 15% sodium hydroxide solution into the stirring mill for fine grinding and impurity removal. The fine grinding time is controlled to be 1h. Material size D90<200 mesh, fully remove impurities such as alumina and silica in the raw materials;

[0045](2) Acid leaching and impurity removal: filter the slurry obtained in step (1), and adjust the liquid-solid ratio to 2 in dilute hydrochloric acid with a concentration of 10% in the solid phase, and perform acid leaching and impurity removal process to control the leaching time It is 2 hours to fully remove the impurity components such as carbonate and iron oxide in the raw materials;

[0046](3) Oxidation and impurity removal:...

Example Embodiment

[0051]Example 3

[0052]In this embodiment, the method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio using titanium gypsum as a raw material, the specific steps are as follows:

[0053](1) Fine grinding / removal of impurities: According to the ratio of liquid to solid ratio of 1, mix natural gypsum and 10% sodium hydroxide solution into the ball mill for fine grinding, control the fine grinding time to 0.5h, and the discharge particle size D90<200 mesh;

[0054](2) Acid leaching to remove impurities: take the slurry obtained in step (1) for solid-liquid separation, add 10% dilute sulfuric acid to the solid phase at room temperature, adjust the liquid-solid ratio to 2, and perform acid leaching to remove impurities During the process, the leaching time is controlled to 2h, so that the impurity components such as carbonate and oxide in the raw material can be further removed by reaction;

[0055](3) Oxidation and impurity removal: solid-liquid separation of the purified...

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
Diameteraaaaaaaaaa
Lengthaaaaaaaaaa
Diameteraaaaaaaaaa
Login to view more

Abstract

The invention provides a method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio by using calcium sulfate dihydrate. Calcium sulfate dihydrate is used as raw material and finely ground in lye; then, the obtained slurry is subjected to solid-liquid separation Acid leaching is carried out under acidic conditions to remove impurities such as carbonates and oxides contained in it; secondly, the oxidation of strong oxidants is used to remove pigments, organic substances and other impurities through oxidation; After deep impurity removal and purification, the calcium sulfate dihydrate is washed, filtered, and slurried to make a calcium sulfate dihydrate slurry with a certain concentration, and a certain proportion of crystal form regulator is added, and finally the crystal form is carried out under hydrothermal conditions. After conversion, the obtained product is filtered and dried to obtain the calcium sulfate hemihydrate whisker product. The invention has the advantages of simple process, wide source of raw materials, low cost, large length-to-diameter ratio and uniform grain size of the obtained whiskers, which can be used as fillers and reinforcing agents in industries such as papermaking, plastics and rubber, and has high added value of products.

Description

technical field [0001] The invention relates to the technical field of preparation of calcium sulfate whiskers, in particular to a method for preparing calcium sulfate hemihydrate whiskers with high aspect ratio by utilizing calcium sulfate dihydrate. Background technique [0002] With the rapid development of my country's infrastructure and economy, the discharge of various chemical gypsum is increasing day by day. However, there is a lack of corresponding effective technology for the utilization and treatment of chemical gypsum, so in-situ accumulation is mostly used in the actual production process. Long-term accumulation not only wastes a lot of land, but also the harmful substances in gypsum will cause serious pollution to the environment, which not only brings a huge burden to the enterprise, seriously hinders the development of the enterprise, but also has a serious impact on the local ecological environment. [0003] As an inorganic whisker material, calcium sulfate ...

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
IPC IPC(8): C30B7/10C30B29/46C30B29/62
CPCC30B7/10C30B29/46C30B29/62
Inventor 田登超郭强李永利李申邵大伟
Owner 郑州中科新兴产业技术研究院
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