Glass sintered article and method of making, method of purifying molten salt

Abstract

The application discloses a glass sintered product and a preparation method and a molten salt purification method, and belongs to the ion exchange field. The glass sintered product prepared by designing the components of a glass composition and cooperating with a sintering process has ion absorption function, can purify molten salt, and further has a through-hole honeycomb structure, can realize the exchange between the whole inside and outside of the glass sintered product and lithium ions in the molten salt, increase the effective area of ion exchange, improve the absorption efficiency of lithium ions, quickly and efficiently adsorb lithium ions in the molten salt, and is stable in structure at high temperature, convenient to use, not easy to contaminate the molten salt, and capable of reducing the replacement frequency of the molten salt.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ion exchange, in particular to a glass sintered product and preparation method, and a molten salt purification method. BACKGROUND

[0002] The process of glass chemical strengthening ion exchange usually involves sodium-lithium, potassium-sodium ion exchange. The salt bath used for ion exchange is generally composed of a certain proportion of alkali metal components. During the ion exchange process, the smaller alkali metal cations, lithium ions, continuously diffuse into the salt bath, while the larger alkali metal cations in the salt bath enter the glass. However, as the smaller alkali metal cations, such as lithium ions, continuously diffuse into the salt bath, the composition ratio of the salt bath changes. When the lithium ions exceed the required threshold, the ion strengthening effect of the glass tends to deteriorate, or the product size expansion rate changes, thereby affecting the product yield.

[0003] Currently, to stabilize the composition ratio of the salt bath, sampling detection is often used. When the composition in the salt bath exceeds the threshold, the salt bath is emptied and fresh salt is melted. This method causes the process to stop, affecting production efficiency. Especially for the strengthening of microcrystalline glass, due to its high requirement for lithium ion proportion stability, it may need to be replaced for each furnace, which is not economical.

[0004] Alternatively, phosphates are added to the salt bath to precipitate small cations, but after adding sodium phosphate to the molten salt, it needs to be clarified for a long time before it can be used. Lithium phosphate will make the salt bath turbid, which will adhere to the surface of the strengthened glass and produce defects.

[0005] In addition, a solid purification agent or ion sieve product is also used, but the absorption and treatment time is long, and the composition of such products often contains part of alkaline earth metal ions (such as Ca 2+ , Zn 2+ , Mg 2+ ), which is not stable at high temperatures. Other ions are easily introduced into the molten salt at high temperatures, hindering the ion exchange between K, Na, and Li, thereby affecting the ion exchange efficiency of the product.

[0006] Therefore, there is an urgent need to develop a new product that can quickly and efficiently adsorb lithium ions in molten salt, with high absorption efficiency and stable structure at high temperatures, and is easy to use. SUMMARY

[0007] The main purpose of the present application is to provide a glass sintered product and preparation method, and a molten salt purification method, which can quickly and efficiently adsorb lithium ions in molten salt, with high absorption efficiency and stable structure at high temperatures, and is easy to use, solving the technical problem of rapid purification of molten salt for chemical strengthening.

[0008] To achieve the above object, the present application provides a glass sintered product, which comprises a glass composition and an inorganic binder, wherein the glass composition comprises the following components based on 100% of the total mass of the glass composition:

[0009] SiO2: 30% to 50%,

[0010] Al2O3: 15% to 35%,

[0011] P2O5: 0% to 5%,

[0012] Na2O: 15% to 35%,

[0013] K2O: 0% to 5%.

[0014] In some embodiments of the present application, the content of the inorganic binder is 0.1% to 5% based on 100% of the total mass of the glass sintered product.

[0015] In some embodiments of the present application, the inorganic binder comprises at least one of sodium silicate, sodium phosphate, sodium borate and boric acid.

[0016] In some embodiments of the present application, the shape of the glass sintered product is plate-shaped, and the size of the plate-shaped glass sintered product is greater than or equal to 1cm*1cm.

[0017] In some embodiments of the present application, the thickness of the glass sintered product is 0.5mm to 2mm.

[0018] In some embodiments of the present application, the glass sintered product has a through-hole honeycomb structure.

[0019] To achieve the above object, the present application further provides a preparation method of the above glass sintered product, which comprises the following steps:

[0020] The corresponding raw materials of the glass composition are weighed, mixed, melted, cooled, formed and ground to obtain a glass composition powder;

[0021] The glass composition powder is bonded with the inorganic binder, and pre-pressed to obtain a sintered embryo;

[0022] The sintered embryo is sintered to obtain a glass sintered product.

[0023] In some embodiments of the present application, the sintering temperature is 500°C to 700°C;

[0024] And / or, the sintering time is 0.2h to 3h.

[0025] In some embodiments of the present application, the glass composition powder has a particle size ranging from 1 μm to 100 μm.

[0026] To achieve the above object, the present application further provides a method for purifying molten salt, comprising the following steps:

[0027] The glass sintered product of the present application is added into the molten salt to purify the molten salt, and the purification is the process of absorbing lithium ions in the molten salt by the glass sintered product.

[0028] In some embodiments of the present application, the content of lithium ions in the molten salt is ≤3000 ppm, based on 100% of the total mass of the molten salt, and the addition amount of the glass sintered product is 0.5% to 3%.

[0029] In some embodiments of the present application, the molten salt is used for ion exchange of lithium-containing glass or lithium-containing microcrystalline glass.

[0030] In some embodiments of the present application, the glass sintered product is heated and kept warm before being added into the molten salt, and the heating temperature is 350°C to 400°C.

[0031] And / or, the glass sintered product is heated and kept warm before being added into the molten salt, and the keeping warm time is 30 min to 90 min.

[0032] In some embodiments of the present application, the reaction temperature of the purification is 430°C to 500°C.

[0033] And / or, the reaction time of the purification is 6 h to 12 h.

[0034] The beneficial effects that can be achieved by the present application are as follows:

[0035] The glass sintered product of the present application has lithium ion absorption function, can purify the molten salt, in addition, the glass sintered product also has a through-hole honeycomb structure, can realize the exchange between the whole inside and outside of the glass sintered product and the lithium ions in the molten salt, increase the effective area of ion exchange, improve the absorption efficiency of lithium ions, can quickly and efficiently adsorb lithium ions in the molten salt, and the structure also has good stability at high temperature, is convenient to use, is not easy to contaminate the molten salt, and is suitable for rapid purification of high-temperature molten salt.

[0036] After the molten salt is purified by the glass sintered product of the present application to absorb lithium ions, the molten salt can be quickly purified and reused; also, the lithium ions replaced in the process of ion exchange can be absorbed simultaneously online, the composition of the molten salt in the production process of chemically strengthened glass is controlled to be stable, which is beneficial to promote the chemical strengthening of the glass and improve the performance of the strengthened glass. BRIEF DESCRIPTION OF DRAWINGS

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the process for preparing glass sintered products according to an embodiment of the present invention.

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0043] This invention provides a sintered glass article comprising a glass composition and an inorganic binder. Based on 100% of the total mass of the glass composition, the glass composition comprises the following components:

[0044] SiO2: 30%–50%,

[0045] Al2O3: 15%–35%,

[0046] P2O5: 0%–5%,

[0047] Na2O: 15%–35%,

[0048] K2O: 0% to 5%.

[0049] In the glass sintered product of the present application:

[0050] SiO2 is a component constituting the glass framework, and can serve as the main body of the glass network structure. If the content is low, it is difficult to form glass, the strain point decreases, the expansion coefficient increases, and the glass stability is poor. Therefore, increasing the content of SiO2 can increase the mechanical strength of the glass, reduce the expansion coefficient, and improve the stability of the glass. However, too high a content of SiO2 can increase the high-temperature viscosity of the glass, which is not conducive to the melting of the glass. Therefore, in order to balance the mechanical strength, expansion coefficient, stability, and high-temperature viscosity of the glass, the content of SiO2 in the present application is 30% to 50%. In some embodiments, the content of SiO2 in the glass sintered product of the present application can be any one of 30%, 31%, 33%, 35%, 38%, 40%, 42%, 45%, 46%, 47%, 48%, 50%, etc., within the range of 30% to 50%.

[0051] The Al2O3 component is used to increase the strength of the glass structure. Non-bridging oxygen forms aluminum oxide tetrahedra with Al ions. The volume of the aluminum oxide tetrahedra is larger than that of the silicon oxide tetrahedra, and can produce larger gaps in the glass structure, which is conducive to promoting ion exchange. However, if the content of Al2O3 is too high, the glass is difficult to melt. Therefore, taking into account the above factors, the content of Al2O3 in the glass sintered product of the present application is 15% to 35%. In some embodiments, the content of Al2O3 in the glass sintered product of the present application can be any one of 15%, 18%, 20%, 22%, 25%, 27%, 29%, 30%, 31%, 32%, 34%, 35%, etc., within the range of 15% to 35%.

[0052] The introduced P2O5 can replace SiO2 in the glass to form aluminum phosphate (AlPO4) structure. Aluminum phosphate is composed of tetrahedral coordinated aluminum and phosphorus, and has a larger volume compared with the glass network structure silicon oxide tetrahedra. Moreover, it does not destroy the overall network structure of the glass, and can increase the ion exchange speed. In some embodiments, the content of P2O5 in the glass sintered product of the present application is 0% to 5%, for example, it can be 0%, i.e. no addition, or it can be 0.1%, 0.2%, 0.3%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.6%, 1.8%, 2%, 2.5%, 3%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.7%, 4.8%, 4.9%, 5%, etc., any one of the content values within the range of greater than 0% and less than or equal to 5%. By adding P2O5, the glass sintered product of the present application can further increase the speed and depth of ion exchange.

[0053] The introduced Na2O and K2O are main ions for ion exchange of the glass in a chemical strengthening process. Na2O belongs to a network exoskeleton and plays a fluxing role, which can reduce the glass melting temperature and improve the chemical stability of the glass. K2O mainly plays a fluxing role, which is helpful to reduce the viscosity and improve the melting property of the glass, but if too much K2O is introduced, the ion exchange speed will be hindered. In some embodiments, the content of Na2O in the glass sintered product of the present application is 15% to 30%, for example, it can be any one content value in the range of 15% to 30%, such as 15%, 16%, 17%, 18%, 19%, 20%, 22%, 24%, 25%, 27%, 28%, 29%, 30%, etc. In order to balance the melting property and ion exchange speed of the glass, in some embodiments, the content of K2O in the glass sintered product of the present application can be 0% to 5%, for example, it can be any one content value in the range of 1% to 5%, such as 0%, i.e. no addition, or 0.1%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, etc. By adding an appropriate amount of K2O, the melting effect of the glass is improved.

[0054] The glass sintered product of the present application also introduces an inorganic binder. The inorganic binder can bond the powdered glass composition under low temperature conditions. The inorganic binder can react with the powdered glass powder during high-temperature sintering. Due to the difference in the expansion coefficient and expansion softening point between the glass composition and the inorganic binder, the glass sintered product with a honeycomb structure having through holes can be sintered. The glass sintered product with a honeycomb structure having through holes can exchange lithium ions in the molten salt from the inside and the outside, increase the effective area of ion exchange, and improve the absorption efficiency of lithium ions. The glass sintered product can quickly and efficiently adsorb lithium ions in the molten salt, is stable at high temperature, is easy to use, is not easy to contaminate the molten salt, and can reduce the replacement frequency of the molten salt.

[0055] The present application does not limit the type of inorganic binder. In some embodiments, the inorganic binder includes at least one of sodium silicate, sodium phosphate, sodium borate, and boric acid. The above types of binders can bond the powdered glass composition into a shape under low temperature conditions, and then react with the glass composition through high-temperature sintering to sinter the glass sintered product with a honeycomb structure having through holes.

[0056] If the amount of the inorganic binder is too small, it is difficult to bond the powdered glass composition into one body, and the glass is prone to be crushed during sintering, which is not conducive to forming the glass sintered product with the honeycomb structure with through holes. If the amount of the inorganic binder is too large, the bonding force between the powdered glass compositions is too strong, which is not conducive to forming the glass sintered product with the honeycomb structure with through holes during sintering. In some embodiments, the content of the inorganic binder in the glass sintered product is 0.1% to 5%, for example, 0.1%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any value within the range of 0.1% to 5%, based on 100% of the total mass of the glass sintered product. Within the above amount range, the inorganic binder can firmly bond the powdered glass composition together and sinter to form the glass sintered product with the honeycomb structure with through holes through the sintering process; at the same time, the powdered glass compositions will not be too strongly bonded due to the excessive addition of the inorganic binder, which is not conducive to the formation of the honeycomb structure with through holes of the glass sintered product.

[0057] The present application does not limit the shape of the glass sintered product, and in some embodiments, the shape of the glass sintered product includes a plate shape. The plate-shaped glass sintered product has a large specific surface area, which can increase the contact area with lithium ions in the molten salt and quickly absorb lithium ions during the purification process of the molten salt.

[0058] In some embodiments, the size of the plate-shaped glass sintered product is ≥1 cm×1 cm. It can be understood that the above size refers to the area of one side of the glass sintered product.

[0059] In some embodiments, the thickness of the glass sintered product is 0.5 mm to 2 mm.

[0060] The present application also provides a preparation method of the glass sintered product as described above, which comprises the following steps:

[0061] Step S10: weighing the corresponding raw materials of the glass composition, mixing, melting, cooling, shaping, and grinding to obtain the glass composition powder;

[0062] Step S20: bonding the glass composition powder with the inorganic binder and pre-pressing to obtain the sintered embryo;

[0063] Step S30: sintering the sintered embryo to obtain the glass sintered product.

[0064] In some embodiments of step S10, the melting temperature is 1300°C to 1600°C, for example, 1300°C, 1350°C, 1400°C, 1450°C, 1500°C, 1550°C, 1600°C, or any temperature value within the range of 1300°C to 1600°C.

[0065] In some embodiments of step S10, the cooling is to 800-1200℃, for example, to 800℃, 900℃, 1000℃, 1100℃, 1200℃, or any one of the temperature values in the range of 800-1200℃. The cooling is more conducive to the forming of the glass.

[0066] The present application does not limit the specific way of cooling, and the cooling can be performed in a slow cooling manner, i.e., by slowly reducing the temperature of the molten glass to prevent the glass from cracking due to uneven heating.

[0067] The present application does not limit the forming manner of the glass in step S10, and in some embodiments, the formed glass can be obtained by mechanical external force drawing or extrusion forming. The above forming manner is conducive to obtaining a glass product in the form of a sheet or a particle, and the glass product in the form of a sheet or a particle is more conducive to being ground into a glass composition powder, facilitating the bonding of the glass composition powder by an inorganic binder, and being conducive to obtaining a honeycomb structure in the form of a through hole in the sintering stage.

[0068] In some embodiments of step S10, after the cooling and forming process is completed to obtain the formed glass, the formed glass can be further slowly cooled to 300-600℃ before being ground, and then the glass is water quenched under the condition of 0-50℃ to form a particle or is pressed into a sheet, and then subsequent grinding treatment is performed to obtain a glass composition powder. By the method of gradually refining the particle size of the glass, the glass composition powder with uniform particles can be obtained by grinding.

[0069] The glass composition powder obtained by the present application has a small particle size, and the glass composition with a small particle size can be mixed with the inorganic binder more uniformly, the bonding force between the glass compositions is strong, and a glass sintered product with a more stable structure is obtained. Moreover, the glass composition powder and the inorganic binder have a larger contact area, which is conducive to promoting the reaction between the inorganic binder and the glass composition during high-temperature sintering, and obtaining a glass sintered product with a honeycomb structure in the form of a through hole.

[0070] In some embodiments, the particle size of the glass composition powder is in the range of 1-100 μm, for example, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 95 μm, 100 μm, or any one of the particle size values in the range of 1-100 μm. The glass composition with the above particle size range can be uniformly mixed with the inorganic binder, the contact area between the two is increased, the reaction is promoted, a glass sintered product with a stable structure is obtained, and the glass sintered product has a honeycomb structure in the form of a through hole.

[0071] The application can sinter the sintered body, and the reaction between the inorganic binder and the glass composition powder occurs during the sintering process. Due to the difference between the expansion coefficients and the expansion softening points of the two, a honeycomb structure with a through-hole shape can be sintered. In some embodiments, the sintering temperature is 500-700 DEG C, for example, the sintering temperature can be 500 DEG C, 550 DEG C, 600 DEG C, 650 DEG C, 700 DEG C, etc. Any one of the temperature values in the range of 500-700 DEG C, under the above sintering temperature conditions, it is beneficial to obtain a glass sintered product with more through-hole honeycomb structure.

[0072] The application does not limit the sintering time, in some embodiments, the sintering time is 0.2-3h, which can be 0.2h, 0.5h, 0.6h, 0.8h, 1h, 1.5h, 1.6h, 1.8h, 2h, 2.2h, 2.5h, 2.8h, 3h, etc. Any one of the time values in the range of 0.2-3h, under the above sintering time conditions, it is beneficial to obtain a glass sintered product with more through-hole honeycomb structure.

[0073] It should be noted that the above restrictions on sintering temperature and sintering time can only meet one of them, or both. When both are met, it is beneficial to obtain a glass sintered product with more through-hole honeycomb structure, and energy is not wasted.

[0074] In some embodiments, the shape of the sintered body is plate-shaped. The plate-shaped sintered body is heated more uniformly during the sintering process, which is beneficial to obtain a honeycomb-shaped glass sintered product with a large number of through-holes and uniform distribution.

[0075] In some embodiments, the thickness of the sintered body is 0.5-2mm, for example, it can be 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 1.9mm, 2mm, etc. Any one of the thickness values in the range of 0.5-2mm, the above thickness range is beneficial to sinter a glass sintered product with through-hole honeycomb structure distributed on the inside and outside, realize the lithium ion exchange between the whole glass sintered product and the molten salt, improve the effective area of lithium ion absorption, and improve the lithium ion absorption efficiency during the purification of the molten salt.

[0076] The application also provides a method for purifying molten salt, which comprises the following steps: adding the glass sintered product of the application to the molten salt to purify the molten salt, and the purification is the process of absorbing lithium ions in the molten salt by the glass sintered product.

[0077] The glass sintered product of the application is used for purifying molten salt, and the main process of purification is to absorb lithium ions in the molten salt, which can maintain the stability of the composition of the molten salt, and the glass is not easy to cause the chemical strengthening effect to be not ideal due to the too high lithium ion concentration in the process of chemical strengthening, which affects the performance of the strengthened glass.

[0078] In some embodiments, the molten salt is used for ion exchange of lithium-containing glass or lithium-containing glass-ceramics.

[0079] In some embodiments, the purification process of the molten salt can be performed after ion exchange of lithium-containing glass or lithium-containing glass-ceramics, and the molten salt can be quickly purified and reused.

[0080] In some embodiments, the purification process of the molten salt can be performed after ion exchange of lithium-containing glass or lithium-containing glass-ceramics, and the molten salt can be quickly purified and reused.

[0081] In some embodiments, the content of lithium ions in the molten salt is ≤3000 ppm, based on 100% of the total mass of the molten salt, and the addition amount of the glass sintered product is 0.5% to 3%. For example, the content of lithium ions in the molten salt can be 3000 ppm, 2500 ppm, 2000 ppm, 1500 ppm, 1000 ppm, 500 ppm, 200 ppm, 100 ppm, 50 ppm, 20 ppm, etc., less than or equal to 3000 ppm, and greater than 0 ppm; and the addition amount of the glass sintered product can be 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.3%, 2.5%, 2.8%, 2.9%, 3%, etc., any one value in the range of 0.5% to 3%. Within the above range of lithium ion content and addition amount of the glass sintered product, the lithium ion concentration in the molten salt can be effectively controlled, and the composition of the molten salt can be stabilized. The addition amount of the glass sintered product can be determined according to the content of lithium ions in the molten salt, so that the lithium ions can be absorbed in large quantities without wasting the glass sintered product.

[0082] It should be noted that the above limitation of the content of lithium ions in the molten salt and the addition amount of the glass sintered product is only one example listed by the present application, and is not considered as a limitation of the present application. The glass sintered product of the present application can also be applied to the purification of molten salt with a lithium ion content >3000 ppm, and the addition amount of the sintered product can be increased with the increase of the lithium ion content in the molten salt.

[0083] In some embodiments, the molten salt further contains NaNO3 in a mass percentage of 2% to 40% and KNO3 in a mass percentage of 60% to 98%.

[0084] In some embodiments, the sintered glass product is heated and held at a temperature of 350°C to 400°C before adding molten salt. For example, the heating temperature can be any value within the range of 350°C to 400°C, such as 350°C, 360°C, 370°C, 380°C, 390°C, or 400°C. After heating, the sintered glass product is purified by the molten salt, making it less prone to cracking.

[0085] In some embodiments, the heat preservation time is 30-90 minutes, and can be any time value within the range of 30-90 minutes, such as 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, or 90 minutes. Glass sintered products are less prone to cracking after being heat-preserved and then purified by molten salt.

[0086] In some embodiments, the purification reaction temperature is 430℃~500℃, which can be any temperature value in the range of 430℃~500℃, such as 430℃, 450℃, 460℃, 480℃, 490℃, 500℃, etc.

[0087] In some embodiments, the purification reaction time is 6h to 12h, which can be any time value in the range of 6h to 12h, such as 6h, 7h, 8h, 9h, 10h, 11h, 12h.

[0088] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0089] The inorganic binders used in the following examples and comparative examples are at least one of sodium silicate, sodium phosphate, sodium borate, and boric acid.

[0090] The lithium ion content before and after molten salt purification in the following examples and comparative examples was tested using an atomic absorption spectrophotometer.

[0091] Example 1

[0092] 1. Preparation of sintered glass products

[0093] Step S10: Weigh the glass raw materials according to the composition of the glass sintered products in Table 1, mix the glass raw materials thoroughly, melt them at a temperature of 1300℃~1600℃, then slowly cool them to 800℃~1200℃, and form them into sheet glass by mechanical external force drawing or extrusion molding. Then, slowly cool them to 300℃~600℃, and water quench the sheet glass at 0~50℃ to form granules or press them into sheets. Then grind them into glass composition powder with a particle size of 1μm~100μm.

[0094] Step S20: adding inorganic binder to the glass composition powder, the inorganic binder binds the glass composition powder, and the sintered body is pre-pressed into a plate-shaped sintered body with a size of 1 cm x 1 cm and a thickness of 0.5 mm to 2 mm.

[0095] Step S30: sintering the sintered body at a temperature of 500 ℃ to 700 ℃ for 0.2 h to 3 h to obtain a glass sintered product.

[0096] The preparation conditions are shown in Table 1.

[0097] 2. Molten salt purification experiment

[0098] The five groups of glass sintered products obtained in Example 1 are used to purify the same mass of molten salt under different purification conditions, and the content of lithium ions in the purified molten salt is determined. The purification conditions are shown in Table 1.

[0099] The formula of the molten salt is as follows: 30% NaNO3+70% KNO3 with a mass concentration, and the lithium content is 3000 ppm.

[0100] Table 1

[0101]

[0102]

[0103] As shown in Table 1, the glass sintered product of the present application has an absorption effect on lithium ions, can effectively absorb lithium ions in the molten salt, purify the molten salt, and obtain a purified molten salt with low Li content, which can be used for ion exchange of lithium-containing glass or lithium-containing microcrystalline glass.

[0104] Example 2

[0105] Glass composition 1 and glass composition 5 in Example 1 are used as experimental objects in this example, and glass sintered products are prepared under different conditions. The glass sintered products are used to purify the same mass of molten salt under different purification conditions, and then the content of lithium ions in the purified molten salt is determined. The details are shown in Table 2.

[0106] Comparative Example 1

[0107] Comparative Example 1 is prepared by referring to the preparation method of glass composition 1 in Example 2, except that no inorganic binder is added in Comparative Example 1.

[0108] The glass sintered product obtained in Comparative Example 1 is used to purify the same mass of molten salt by referring to the molten salt purification conditions of glass composition 1 in Example 2, and the content of lithium ions in the purified molten salt is determined. The details are shown in Table 2.

[0109] Comparative Example 2

[0110] Glass composition 1 and glass composition 5 in Example 1 were directly melted at 1300-1600℃ to form plate-shaped glass products, and the same mass of molten salt was purified by the glass products, and the lithium ion content in the purified molten salt was measured, as shown in Table 3.

[0111] The formula of the molten salt used in Example 2 and Comparative Examples 1-2 is as follows: 30% mass concentration of NaNO3+70% of KNO3, and the lithium content is 3000ppm.

[0112] Table 2

[0113]

[0114] Table 3

[0115]

[0116] As shown in Table 2, the glass composition of Example 2 has a good absorption effect on lithium ions in the molten salt, and can purify the molten salt. The glass sintered product of Comparative Example 1 does not contain inorganic binder, and the glass sintered product obtained by sintering the glass composition does not have a rich honeycomb structure with through holes, and has a poor absorption efficiency of lithium ions.

[0117] As shown in Table 3, the glass product of Comparative Example 2 is not sintered and does not have a honeycomb structure with through holes, and has a poor absorption effect on lithium ions.

[0118] The above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A glass sintered article, characterized by, The glass sintered product comprises a glass composition and an inorganic binder, wherein the glass composition comprises the following components based on 100% of the total mass of the glass composition: SiO2: 30%-50%, Al2O3: 15%-35%, P2O5: 0%-5%, Na2O: 15%-35%, K2O: 0%-5%; The content of the inorganic binder is 0.1%-5% based on 100% of the total mass of the glass sintered product; The inorganic binder comprises at least one of sodium silicate, sodium phosphate, sodium borate, and boric acid; The glass sintered product has a honeycomb structure with through holes.

2. The glass sintered article of claim 1, wherein, The glass sintered product has a plate shape, and the size of the glass sintered product with the plate shape is greater than or equal to 1 cm*1 cm.

3. The glass sintered article of claim 1, wherein, The thickness of the glass sintered product is 0.5 mm-2 mm.

4. A method of making the glass-ceramic article of any one of claims 1 to 3, wherein the method comprises: The method comprises the following steps: The raw materials corresponding to the glass composition are weighed, mixed, melted, cooled, shaped, and ground to obtain a glass composition powder; The glass composition powder is bonded with the inorganic binder, and a sintered embryo is obtained by pre-pressing; The sintered embryo is sintered to obtain a glass sintered product.

5. The method of making a glass-ceramic article according to claim 4, wherein The sintering temperature is 500°C-700°C; And / or, the sintering time is 0.2 h-3 h.

6. The method of making a glass-ceramic article according to claim 4, wherein The particle size of the glass composition powder ranges from 1 μm to 100 μm.

7. A method of purifying a molten salt, characterized by, The method comprises the following steps: The glass sintered product according to any one of claims 1-3 is added to molten salt to purify the molten salt, wherein the purification is a process in which the glass sintered product absorbs lithium ions in the molten salt.

8. The molten salt purification method according to claim 7, wherein The content of lithium ions in the molten salt is less than or equal to 3000 ppm based on 100% of the total mass of the molten salt, and the addition amount of the glass sintered product is 0.5%-3%.

9. The molten salt purification method according to claim 7, wherein The molten salt is used for ion exchange of lithium-containing glass or lithium-containing microcrystalline glass.

10. The molten salt purification method according to claim 7, wherein The glass sintered product is heated and kept before being added to the molten salt, and the heating temperature is 350°C-400°C; And / or, the glass sintered product is heated and kept before being added to the molten salt, and the keeping time is 30 min-90 min.

11. The molten salt purification method according to claim 7, wherein The reaction temperature of the purification is 430°C-500°C; And / or, the reaction time of the purification is 6 h-12 h.

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