阅读说明：本技术 一种制备翡翠微晶玻璃的方法 (Method for preparing emerald microcrystalline glass ) 是由 郭志超 刘大平 王金龙 刘岩 于 2021-01-21 设计创作，主要内容包括：本发明公开了一种制备翡翠微晶玻璃的方法,属于材料合成技术领域。本发明的技术方案要点为：以硅酸铝纤维,硅酸,碳酸钠为原料,按翡翠NaAlSi-2O-6的分子式中各元素的理论质量分数配比进行配料,通过对配料初期处理,再在高温常压下经过两次烧结制的目标产物。本发明原料使用硅酸铝纤维不仅提供Al、Si、O元素源外,还作为形成结晶物的骨架,硅酸和碳酸钠围绕其反应,致使形成球状枝晶,实现了常压下的NaAlSi-2O-6晶化；常压条件制备解决了传统高温高压实现翡翠结晶方法,降低了制备条件和成本。所的产物结构均匀、半透明,含有非晶玻璃体与晶化的翡翠结晶体混合的翡翠微晶玻璃。(The invention discloses a method for preparing jade microcrystalline glass, and belongs to the technical field of material synthesis. The technical scheme provided by the invention has the key points that: takes aluminum silicate fiber, silicic acid and sodium carbonate as raw materials and takes jade NaAlSi as raw material 2 O 6 The target product is prepared by carrying out batching on theoretical mass fraction ratios of all elements in the molecular formula, carrying out initial treatment on batching and then carrying out twice sintering at high temperature and normal pressure. The raw material of the invention uses the aluminum silicate fiber not only to provide Al, Si and O element sources, but also to be used as a framework for forming a crystal, and silicic acid and sodium carbonate react around the framework to form a spherical dendritic crystal, thereby realizing NaAlSi under normal pressure 2 O 6 Crystallizing; the preparation under the normal pressure condition solves the problem of realizing jadeite under the traditional high temperature and high pressureThe jade crystallization method reduces the preparation condition and the cost. The product has uniform and semitransparent structure and contains emerald microcrystalline glass mixed by amorphous glass and crystallized emerald crystal.)

1. A method for preparing emerald glass ceramics is characterized by comprising the following specific steps:

step S1: preparation of the reaction initial Material

With aluminium silicate fibres Al₂O₃+SiO₂Silicic acid H₂SiO₃Sodium carbonate Na₂CO₃As raw material, according to the jade NaAlSi₂O₆The theoretical mass fraction ratios of each element in the molecular formula (1) are respectively weighed, the weighed aluminum silicate fibers and silicic acid are crushed and mixed, then the mixture is mixed with a sodium carbonate solution dissolved by deionized water, the mixture is stirred to be fully and uniformly mixed, then the mixture is placed in a muffle furnace to be kept at 160 ℃ for 2 hours and then taken out, and the lump materials are crushed, ground and pressed into blocks to finish the preparation of initial materials;

step S2: first sintering

Putting the pressed initial material into a crucible to be sintered in a high-temperature furnace, wherein the sintering conditions are as follows: heating at a rate of 5 ℃/min, keeping the temperature at 1080 ℃ for 300min, cooling to normal temperature, and taking out after cooling;

step S3: second sintering

Taking out the primary sintering product, crushing, grinding, briquetting and sintering in a high-temperature furnace, wherein the sintering conditions are as follows: the heating rate is 5 ℃/min, the temperature is kept at 1080 ℃ for 300min, then the sample is cooled to the room temperature, and the sample is taken out after cooling, thus finishing the preparation of the jade microcrystalline glass.

Technical Field

The invention belongs to the technical field of material synthesis, and particularly relates to a method for preparing jade microcrystalline glass.

Background

The microcrystalline glass is also called as microcrystalline jade or ceramic glass, the atomic arrangement is not regular and different from that of the interior of common glass, the microcrystalline glass is base glass with specific composition, and is subjected to crystallization heat treatment at a certain temperature, so that a large number of micro crystals are uniformly separated out from the glass, and a compact multiphase complex of a microcrystalline phase and a glass phase is formed, and the microcrystalline glass has the dual characteristics of glass and ceramic. This allows the glass-ceramic to integrate a variety of excellent properties, such as: 1) the strength is high, and the mechanical strength is good; 2) the dielectric ceramic has excellent electrical properties, low dielectric loss rate and excellent electrical insulation; 3) the material has good thermal property, low thermal expansion coefficient, good thermal vibration stability and high deformation temperature; 4) the water-resistant and hydration-resistant agent has more stable chemical performance, water resistance, hydration resistance and cation exchange resistance; 5) good processing performance, can be matched with a plurality of materials, and the like. It has been widely used in many fields. The glass ceramics are classified according to the composition of the base glass, and are mainly classified into silicates [ CaMgSi ]₂O₆And CaSiO₃]And aluminosilicate [ LiO ]₂-Al₂O₃-SiO₂System, Al₂O₃-MgO-SiO₂System, Na₂O-Al₂O₃-SiO₂Series, ZnO-Al₂O₃-SiO₂Is a system]Phosphates and fluorosilicates [ KMg₃AlSi₃O₁₀F₂]With the advancement of science and technology and the increasing demand of people on functional materials, the microcrystalline glass materials with more complex components, finer structure and more excellent performance are required.

The microcrystalline glass is Na₂O-Al₂O₃-SiO₂Is one of microcrystalline glasses, Na₂O-Al₂O₃-SiO₂The microcrystalline phase of the glass matrix is jadeite microcrystalline (NaAl (SiO)₃)₂). Natural emerald is a chain metamorphic structure silicate derived from metamorphic rock layer, belonging to pyroxene family, is monoclinic system, and belongs to C2/C space group, wherein a = 9.418A and b =8.562 a, c =5.219 a, β =107.58 °, with atomic spacings: Si-O bond distance (Si-O = 1.623A), Al-O bond distance (Al-O = 1.928A), and Na-O bond distance (Na-O = 2.469A). The typical chain silicate of jadeite uses an extended chain to connect two corners of a silicon-oxygen tetrahedron with two adjacent silicon-oxygen tetrahedrons, and metal ions (Na) are passed between different chains arranged alternately⁺、Al³⁺) And (4) connecting. The jade microcrystalline glass reported at present is still in the development stage of laboratories and is not produced commercially.

The microcrystalline glass is prepared mainly by melting method, sintering method, sol-gel method, etc., and also by oxyhydrogen flame spraying technique and chemical catalysis method developed in recent years. The comprehensive performance of the microcrystalline glass is controlled by three factors: the composition of the base glass, the grain size and amount thereof, the nature of the residual glass phase and the volume fraction thereof. The type of crystalline phase of the microcrystalline glass is determined by the composition of the base glass, and the heat treatment temperature determines the latter two factors. By designing different basic glass compositions and formulating different heat treatment temperatures, the microcrystalline glass with different crystalline phase types and specific properties can be obtained. The main problem of preparing the jade microcrystalline glass is the heat treatment process, and the crystallization of the glass matrix to form the jade microcrystalline is difficult.

The method develops the commercial value of the jade microcrystalline glass, explores the condition and the treatment process for converting the jade amorphous glass into the crystal structure, and has decorative value, cultural value, commercial value and scientific research value.

Disclosure of Invention

The invention aims to provide a method for preparing jade microcrystalline glass, which has simple process and low cost.

The invention adopts the following technical scheme for solving the technical problems, and the method for preparing the jade microcrystalline glass is characterized by comprising the following specific steps of:

step S1: preparation of the reaction initial Material

With aluminium silicate fibres (Al)₂O₃+SiO₂Composition mass ratio of Al₂O₃：SiO₂= 48: 50) silicic acid H₂SiO₃Carbonic acidSodium Na₂CO₃As raw material, according to the jade NaAlSi₂O₆The theoretical mass fraction ratios of each element in the molecular formula (1) are respectively weighed, the weighed aluminum silicate fibers and silicic acid are crushed and mixed, then the mixture is mixed with a sodium carbonate solution dissolved by deionized water, the mixture is stirred to be fully and uniformly mixed, then the mixture is placed in a muffle furnace to be kept at 160 ℃ for 2 hours and then taken out, and the lump materials are crushed, ground and pressed into blocks to finish the preparation of initial materials;

step S2: first sintering

Putting the pressed initial material into a crucible to perform sintering treatment in a high-temperature furnace, wherein the sintering conditions are as follows: heating at a rate of 5 ℃/min, keeping the temperature at 1080 ℃ for 300min, cooling to normal temperature, and taking out after cooling;

step S3: second sintering

Taking out the primary sintering product, crushing, grinding, briquetting and putting into a high-temperature furnace for sintering treatment, wherein the sintering conditions are as follows: the heating rate is 5 ℃/min, the temperature is kept at 1080 ℃ for 300min, then the sample is cooled to the room temperature, and the sample is taken out after cooling, thus finishing the preparation of the jade microcrystalline glass.

Compared with the prior art, the invention has the following beneficial effects: the invention develops a brand new process for preparing the jade microcrystalline glass at high temperature and normal pressure; the raw material uses aluminum silicate fiber to provide Al, Si and O element sources and also serves as a framework for forming crystals, silicic acid and sodium carbonate are surrounded by the aluminum silicate fiber to react, so that spherical dendritic crystals are formed, and NaAlSi under normal pressure is realized₂O₆Crystallizing; the preparation under the normal pressure condition effectively solves the problem of the traditional method for realizing the preparation of jade crystal by high temperature and high pressure, and reduces the requirements on the preparation conditions and the preparation cost.

Drawings

FIG. 1 is an optical photograph of a sample prepared according to an embodiment of the present invention;

FIG. 2 is a photomicrograph of a sample prepared according to an embodiment of the present invention taken at (a) magnification (b) magnification of 40 magnification;

FIG. 3 is an XRD pattern of a sample prepared according to an embodiment of the present invention;

FIG. 4 is an SEM image of a sample prepared according to an embodiment of the present invention;

FIG. 5 is a TEM image of a sample prepared by an example of the present invention.

Detailed Description

The present invention is described in further detail below with reference to examples, but it should not be construed that the scope of the above subject matter of the present invention is limited to the following examples, and that all the technologies realized based on the above subject matter of the present invention belong to the scope of the present invention.

Examples

Is made of aluminum silicate fiber (type: SYGX-311, component mass ratio Al)₂O₃：SiO₂= 48: 50) silicic acid (H)₂SiO₃) Sodium carbonate (Na)₂CO₃) As raw material, according to jadeite (NaAlSi)₂O₆) The method comprises the following steps of weighing the theoretical mass fraction ratios of the elements in the molecular formula, and synthesizing a jadeite sample by a high-temperature normal-pressure solid-phase sintering method:

(1) preparation of the reaction initial Material

Firstly, crushing and mixing aluminum silicate fibers and silicic acid, then mixing with a sodium carbonate solution dissolved by deionized water, stirring to fully and uniformly mix, then placing the mixture in a muffle furnace, preserving heat at 160 ℃ for 2 hours, taking out, crushing, grinding and briquetting lump materials to finish preparing an initial material;

(2) first sintering

Putting the pressed initial material into a crucible to be sintered in a high-temperature furnace, wherein the sintering conditions are as follows: heating at a rate of 5 ℃/min, keeping the temperature at 1080 ℃ for 300min, cooling to normal temperature, and taking out after cooling;

(3) second sintering

Taking out the primary sintering product, crushing, grinding, briquetting and sintering in a high-temperature furnace, wherein the sintering conditions are as follows: the heating rate is 5 ℃/min, the temperature is kept at 1080 ℃ for 300min, then the sample is cooled to the room temperature, and the sample is taken out after cooling, thus completing the preparation.

For the test of the prepared product, fig. 1 is an optical photograph of the sample prepared in the example of the present invention, and it can be seen that the sample is uniform, translucent, glass-glossy, and green onion (the color may be caused by impurities of Fe, Cr, Pb, etc. in the raw material).Fig. 2 is optical photographs (a)10 times and (b)40 times of a prepared sample under a microscope, and the sample is observed from the microscope to form a dendritic structure like snowflake. FIG. 3 is an XRD spectrum of a sample prepared by an example of the present invention, and (1) in FIG. 3 is an XRD spectrum of a product obtained by first sintering the starting material, and it can be seen that the sample has a large amount of amorphous state and also has NaAlSi₂O₆The diffraction peak of (2) in fig. 3 is the XRD pattern of the surface layer of the second-time sintered sample, it can be seen that the sample prepared in this patent still has a lot of amorphous glass, and the core XRD pattern of (3) in fig. 3 is the XRD pattern of the second-time sintered sample, it can be seen that there is still much amorphous, but NaAlSi₂O₆The crystalline diffraction peak is stronger. Other physical properties of the prepared sample were measured to determine a refractive index of about 1.61 and a density of 2.86.86 g/cm³The Mohs hardness was about 5.9. In combination with the above analysis, the prepared sample contains a large amount of amorphous state, the raw material uses aluminum silicate fiber as a framework for forming crystals in addition to providing a source of Al, Si and O elements, silicic acid and sodium carbonate are reacted around the amorphous state, and the spherical dendrite is formed, which can be confirmed by the SEM image of fig. 4 of the prepared sample of the embodiment of the invention, and the structural characteristics of the dendrite can be seen from the microscopic view of fig. 4, and the existence of a large number of holes on the material is a reason for the low density and hardness of the prepared sample. Fig. 5 is a TEM image of a sample prepared in accordance with an example of the present invention, in which irregular disordered crystalline grains are observed, and the XRD pattern analysis result is also confirmed, which shows that the prepared product is a mixture of jadeite crystals and glass bodies.

While there have been shown and described what are at present considered the fundamental principles of the invention, its essential features and advantages, the invention further resides in various changes and modifications which fall within the scope of the invention as claimed.