CN-117985938-B - Preparation and application of hollow glass bead precursor particles with core-shell structure

Abstract

The invention discloses a preparation method and application of hollow glass bead precursor particles with a core-shell structure, which comprises the steps of mixing water glass with water, removing sodium ions in the water glass with cation exchange resin to obtain a silicic acid aqueous solution, dissolving metal nitrate and boric acid into a saturated aqueous solution, adding the saturated aqueous solution into the silicic acid aqueous solution under magnetic stirring to obtain a uniformly doped transparent mixed solution, and carrying out spray drying to obtain the hollow glass bead precursor particles with the core-shell structure. According to the invention, larger-size air holes are formed in the precursor particles in advance, so that hollow glass bead precursor particles with a core-shell structure are obtained, the foaming and balling time can be effectively shortened, the particles with incomplete foaming are reduced, and the yield and performance of the hollow glass beads are improved. The invention adopts molecular water glass as main raw material, completes partial silicate formation and crosslinking reaction in the process, replaces the bonding aggregation of particles prepared by the traditional soft chemistry method by chemical bonding action, and enhances the compressive strength of precursor particles.

Inventors

• SHI ZHAOHUA
• LI BO
• LIU DAOYIN
• FU ZHENJIN
• ZHOU XIAOYAN
• FAN ZHIHENG
• LI FANG
• LIU YAHUI
• LIU LEI

Assignees

• 中国工程物理研究院激光聚变研究中心
• 中钢集团马鞍山矿院新材料科技有限公司
• 东南大学
• 西南科技大学

Dates

Publication Date

20260505

Application Date

20240130

Priority Date

20240123

Claims (6)

1. 1. The preparation method of the hollow glass bead precursor particles with the core-shell structure is characterized by comprising the following steps of: Firstly, mixing water glass with water, and removing sodium ions in the water glass by using cation exchange resin to obtain a silicic acid water solution, wherein the modulus of the water glass is 3.1-3.4, the mass volume ratio of the water glass to the water is 1 g:3-5 mL, the cation exchange resin is macroporous strong acid styrene type cation exchange resin D001, and the mass ratio of the cation exchange resin to the water glass is 1.5-2.5:1; Dissolving metal nitrate and boric acid into a saturated aqueous solution, and adding the saturated aqueous solution into the silicic acid aqueous solution obtained in the first step under magnetic stirring to obtain a uniformly doped transparent mixed solution, wherein the metal nitrate is lithium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate, aluminum nitrate and sodium nitrate; and thirdly, spray drying the transparent mixed solution obtained in the second step to obtain hollow glass microsphere precursor particles with a core-shell structure.
2. 2. The method for preparing hollow glass bead precursor particles with a core-shell structure according to claim 1, wherein in the second step, the magnetic stirring speed is 500-700 rpm.
3. 3. The method for preparing core-shell hollow glass bead precursor particles according to claim 1, wherein in the second step, the amount of boric acid is calculated according to the mass ratio of B 2 O 3 in the target hollow glass beads.
4. 4. The method for preparing core-shell hollow glass bead precursor particles according to claim 1, wherein in the second step, the amount of the metal nitrate is calculated according to the mass ratio of the corresponding oxides in the target hollow glass beads.
5. 5. The method for preparing hollow glass bead precursor particles with a core-shell structure according to claim 1, wherein in the third step, the air inlet temperature of spray drying is 180-400 ℃, the feeding rate is 5-10%, the air inlet quantity is 60-80%, and the air flow rate is 500-700L/h.
6. 6. Use of hollow glass bead precursor particles of core-shell structure prepared by the preparation method of any one of claims 1 to 5 in the preparation of hollow glass beads.

Description

Preparation and application of hollow glass bead precursor particles with core-shell structure Technical Field The invention belongs to the technical field of preparation of hollow glass bead precursor particles, and particularly relates to preparation and application of hollow glass bead precursor particles with a core-shell structure. Background The hollow glass microsphere is hollow spherical glass powder with the diameter of micron, and has the advantages of low density, high strength, good environmental stability and easy dispersion. The glass material components of the hollow glass beads can be endowed with the functions of corrosion resistance, radiation resistance, heat insulation, sound insulation, insulation and the like by design and control, so that the hollow glass beads are widely applied to the tip technical fields of aviation, deep sea and the like and the civil fields of petrochemical industry and the like. The industrial preparation process of the hollow glass microsphere mainly comprises two stages, namely, preparing precursor particles and foaming the precursor particles into balls at high temperature. Wherein the nature of the precursor particles prepared in the first stage has a decisive influence on the efficiency of the second stage foaming to form balls and on the product properties. The main stream industrial production method of the precursor particles is a glass powder method, and the process is that quartz sand, limestone, boric acid and other raw materials are uniformly mixed and then melted into glass liquid at high temperature (1200-1400 ℃), and then water quenching, drying and crushing treatment are carried out to obtain precursor particle powder with a given composition. The other is a soft chemistry method, silica micropowder, inorganic salt, foaming agent and stable dispersant are dispersed in water according to a certain proportion to form slurry, then the slurry is sprayed and dried to obtain precursor particles, and all components of the precursor particles prepared by the method are aggregated into particles under the bonding action of the stable dispersant, and all components have no chemical bonding action, so that the precursor particles have lower strength and metal salt is easy to separate out. The method is characterized in that the heat transfer, mass transfer and morphology evolution in the precursor particle balling process are analyzed through a hydrodynamic simulation method, the whole precursor particle balling process can be divided into 4 stages of packaging, foaming, refining and cooling solidification, wherein the foaming stage can be divided into 4 processes of bubble nucleation, bubble growth, bubble coalescence and bubble integration, and the precursor particles undergo the evolution from solid particles, porous particles, core-shell particles to hollow microspheres. The precursor particles obtained by the glass powder method and the soft chemistry method are solid particles, and have the problem of incomplete foaming in the high Wen Bo balling process. Disclosure of Invention It is an object of the present invention to address at least the above problems and/or disadvantages and to provide at least the advantages described below. To achieve these objects and other advantages and in accordance with the purpose of the invention, there is provided a method for preparing hollow glass bead precursor particles of a core-shell structure, comprising the steps of: Step one, mixing water glass with water, and then removing sodium ions in the water glass by using cation exchange resin to obtain a silicic acid aqueous solution; Dissolving metal nitrate and boric acid into a saturated aqueous solution, and adding the saturated aqueous solution into the silicic acid aqueous solution obtained in the step one under magnetic stirring to obtain a uniformly doped transparent mixed solution; and thirdly, spray drying the transparent mixed solution obtained in the second step to obtain hollow glass microsphere precursor particles with a core-shell structure. Preferably, in the first step, the modulus of the water glass is 3.1-3.4, and the mass volume ratio of the water glass to the water is 1 g:3-5 mL. Preferably, in the first step, the cation exchange resin is macroporous strong acid styrene type cation exchange resin D001. Preferably, in the first step, the mass ratio of the cation exchange resin to the water glass is 1.5-2.5:1. Preferably, in the second step, the magnetic stirring rotation speed is 500-700 rpm. Preferably, in the second step, the amount of boric acid is calculated according to the mass ratio of B 2O3 in the target hollow glass beads. Preferably, in the second step, the metal nitrate includes lithium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate, aluminum nitrate and sodium nitrate. Preferably, in the second step, the amount of the metal nitrate is calculated according to the mass ratio of the corresponding oxide in the target hollow