Method for preparing glass-ceramics using lithium slag

Abstract

The application provides a method for preparing microcrystalline glass by using lithium residue, and belongs to the technical field of microcrystalline glass. The method can comprise the following steps: removing sulfur-containing substances from lithium residue to obtain material A; pretreating the material A and ingredients to obtain material B, and then drying the material B to obtain a preparation blank; pressing the preparation blank into shape to obtain a microcrystalline glass blank, and finally heat-treating the blank to obtain microcrystalline glass, cutting and polishing the microcrystalline glass to obtain a microcrystalline glass product. The application provides a low-cost raw material for the microcrystalline glass industry while solving the problem of lithium residue treatment, realizes high-value utilization of lithium residue, has the advantages of simple process flow, low energy consumption, green environmental protection and being conducive to industrial promotion, and the prepared microcrystalline glass material has excellent physical and chemical properties and can be used as a mechanical and mechanical material, a building decoration material and the like.

Description

Technical Field

[0001] This invention relates to a method for preparing microcrystalline glass using lithium slag, and belongs to the field of microcrystalline glass technology. Background Technology

[0002] Lithium carbonate, as a key raw material for clean energy batteries, has seen its production capacity increase year by year along with the rapid development of the lithium battery industry. Currently, the main method for extracting lithium carbonate from spodumene is the concentrated sulfuric acid-calcium carbonate method. During this process, lithium carbonate clinker, after leaching, filtration, and washing, produces lithium slag, a byproduct of the process. In recent years, the rapid growth in demand for lithium salts has led to a year-on-year increase in lithium slag stockpiles. Currently, the main methods for disposing of lithium slag are stockpiling and landfilling. Long-term stockpiling not only causes serious pollution to the surrounding environment but also imposes a heavy economic burden on enterprises. Therefore, developing high-value utilization technologies for lithium slag and eliminating the secondary pollution problems caused by its stockpiling has become a popular research topic with significant economic, environmental, and social benefits.

[0003] Microcrystalline glass, a functional material with a large amount of glass phase and microcrystalline phase, is produced by heating a base glass of a certain composition and controlling its crystallization. Due to its combination of the characteristics of glass and ceramics, it has high mechanical strength, high hardness, good wear resistance, strong corrosion resistance, good chemical stability and thermal stability, can adapt to harsh environments, and has many excellent properties that are difficult for conventional materials to achieve. Therefore, it is widely used in production, daily life and national defense and military industries.

[0004] CN106986545A discloses a method for preparing sintered microcrystalline glass using a non-melting process. The specific steps of the method are as follows: Lithium iron phosphate is subjected to acid leaching and filtration to obtain acid leaching solution and acid leaching residue; the obtained acid leaching solution is subjected to lithium precipitation filtration to obtain lithium slag and lithium precipitation solution, and the lithium slag is returned to lithium recovery; the acid leaching residue obtained in the first step and the lithium precipitation solution obtained in the second step are spray dried to obtain iron phosphate powder and mixed sodium salt; the iron phosphate powder and mixed sodium salt obtained in the previous step are granulated with cobalt oxide powder, sodium / potassium feldspar powder and fluorite powder in a dry powder granulator to obtain raw material granules; the raw material granules obtained in the previous step are distributed by a material distribution machine and then sintered to obtain sintered black microcrystalline glass. The method has the following drawbacks: 1. The method mainly utilizes lithium iron phosphate, which is a recycled material from waste batteries. This method cannot be applied to the treatment of lithium mining industrial waste residue; 2. The method requires a particle size of 300 mesh for the ingredients, resulting in high ingredient costs; 3. The method mainly uses sodium / potassium feldspar powder, followed by iron phosphate powder, which also results in high costs. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a method for preparing microcrystalline glass using lithium extraction waste residue from lithium ore.

[0006] The method for preparing microcrystalline glass using lithium slag according to the present invention includes the following steps:

[0007] a. Remove sulfur-containing substances from lithium slag to obtain material A;

[0008] b. Pre-treat the material A and the ingredients to obtain a mixed powder, and then dry the mixed powder to obtain a blank;

[0009] c. Press the blank into shape to obtain a microcrystalline glass blank, and finally heat treat the blank to obtain microcrystalline glass.

[0010] In step a, the precipitant contains OH... - The concentration is 1.5–2.5 mol / L, OH - With CO3 2- The molar ratio is 1.5–2.5; preferably, OH - The concentration is 2 mol / L, OH - With CO3 2- The molar ratio is 2.

[0011] The lithium slag contains 50-60% SiO2, 15-25% Al2O3, 5-8% SO3, and 4-7% CaO.

[0012] Furthermore, the lithium slag has a moisture content of 15% to 25%.

[0013] Furthermore, the method for removing sulfur-containing substances is flotation, which includes roughing and scavenging.

[0014] Furthermore, the coarse selection and the sweep selection each independently incorporate modifiers, inhibitors, and collectors.

[0015] Furthermore, the modifier includes one or more of sulfuric acid, oxalic acid, and calcium carbonate.

[0016] Furthermore, the inhibitor includes one or more of sodium silicate, sodium hexametaphosphate, and copper sulfate.

[0017] Furthermore, the collector includes one or more of dodecylamine, sodium oleate, or benzohydroxyxamic acid.

[0018] Furthermore, in the roughing operation, the dosage of the modifier is 1000-2000 g / t, the dosage of the inhibitor is 2000-3000 g / t, and the dosage of the collector is 50-200 g / t.

[0019] Furthermore, in the scavenging operation, the dosage of the modifier is 200-1000 g / t, the dosage of the inhibitor is 500-1000 g / t, and the dosage of the collector is 20-50 g / t.

[0020] Furthermore, the moisture content of material A is 70% to 85%.

[0021] Furthermore, the ingredients include flux and microcrystalline glass nucleating agent;

[0022] Furthermore, the flux includes one or more of calcium oxide, magnesium oxide, quartz sand, albite, potassium feldspar, and glass powder;

[0023] Furthermore, the microcrystalline glass nucleating agent includes one or more of Ti2O, Zr2O, and P2O5;

[0024] Furthermore, calculated by mass percentage, the flux contains 20%–30% calcium oxide, 20%–30% magnesium oxide, 20%–25% quartz, 20%–25% potassium feldspar, and 5%–10% glass powder.

[0025] Furthermore, the microcrystalline glass nucleating agent contains 30-40% TiO2, 30-40% Zr2O, and 20-30% P2O5;

[0026] Furthermore, in the formulation, the amount of co-solvent is 20% to 30% of the mass of material A, and the amount of microcrystalline glass nucleating agent is 3% to 6% of the mass of material A.

[0027] Furthermore, the pretreatment includes grinding and mixing.

[0028] Furthermore, the particle size of material B is 100-150 μm and the moisture content is 55%-70%.

[0029] Furthermore, the drying process includes spray drying;

[0030] Furthermore, the internal hot air temperature of the spray dryer is 200℃~250℃.

[0031] Furthermore, the pressing and molding process includes the following steps:

[0032] The blank material is evenly spread in the mold, at a pressure of 400–700 kgf / cm². 2 The pressure is maintained for 20–60 seconds, and then the glass preform is demolded to obtain a microcrystalline glass blank.

[0033] Furthermore, the heat treatment includes the following steps:

[0034] The microcrystalline glass preform is heated to 1400–1600°C at a heating rate of 2–5°C / min and held for 1.0–3.0 h to homogenize the glass melt. It is then annealed in a furnace preheated to 600–800°C. The temperature is then increased to 950–1050°C at a rate of 4–7°C / min and held for 1.0–2.0 h to nucleate the glass. The temperature is then increased to 1100–1200°C at a rate of 1–3°C / min and held for 1.5–2.5 h to crystallize the glass. Finally, the glass is allowed to cool naturally in the furnace to obtain microcrystalline glass.

[0035] The beneficial effects of this invention are:

[0036] 1. The method for preparing microcrystalline glass using lithium slag provided by the present invention removes sulfur-containing substances from lithium slag by flotation to obtain material A, thereby solving the problem that sulfur-containing substances seriously affect the firing effect of microcrystalline glass.

[0037] 2. The method for preparing microcrystalline glass using lithium slag provided by this invention removes sulfur-containing substances that can be used as a cement retarder or a main raw material for gypsum building materials.

[0038] 3. The method for preparing microcrystalline glass using lithium slag provided by this invention provides that the lithium metal minerals contained in the lithium slag give the sintered microcrystalline glass low thermal expansion and overall uniformity, and that other harmful components such as heavy metals in the lithium slag are formed as mineralizing components and solidified in the crystal grid as crystalline phases or solid solutions, thereby realizing the glass-microcrystallization and solidification of harmful components in the slag. The prepared microcrystalline glass material has excellent physical and chemical properties and can be used as a mechanical material, building decoration material, etc.

[0039] 4. The method for preparing microcrystalline glass using lithium slag provided by this invention produces microcrystalline glass with properties superior to natural stone, which can be used as high-grade building decoration material, craft carving and functional ceramic material, etc.

[0040] 5. The method for preparing microcrystalline glass using lithium slag provided by this invention has a simple process, low energy consumption, is green and environmentally friendly, and is more conducive to industrial promotion. It is especially suitable for application in the central and western regions where there is sufficient electricity and the ecological environment is relatively fragile.

[0041] 6. The method for preparing microcrystalline glass using lithium slag provided by the present invention can reduce the stockpiling of lithium slag, thereby reducing the occupation of land resources, reducing the harm of lithium slag to the environment, and realizing the high-value utilization of lithium slag. Attached Figure Description

[0042] Figure 1 This is the process flow of the method for preparing microcrystalline glass using lithium slag according to the present invention. Detailed Implementation

[0043] The method for preparing glass-ceramics using lithium slag includes the following steps:

[0044] a. Remove sulfur-containing substances from lithium slag to obtain material A;

[0045] b. Pre-treat the material A and the ingredients to obtain material B, and then dry material B to obtain the blank;

[0046] c. Press the blank into shape to obtain a microcrystalline glass blank, and finally heat treat the blank to obtain microcrystalline glass.

[0047] Preferably, the lithium slag contains 50-60% SiO2, 15-25% Al2O3, 5-8% SO3, and 4-7% CaO.

[0048] Preferably, the lithium slag has a moisture content of 15% to 25%.

[0049] Preferably, the method for removing sulfur-containing substances is flotation, which includes roughing and scavenging, with modifiers, inhibitors and collectors added independently in each of the roughing and scavenging processes.

[0050] Preferably, the modifier includes one or more of sulfuric acid, oxalic acid, and calcium carbonate;

[0051] Preferably, the modifier is sulfuric acid;

[0052] Preferably, the inhibitor includes one or more of sodium silicate, sodium hexametaphosphate, and copper sulfate;

[0053] Preferably, the inhibitor is sodium silicate;

[0054] Preferably, the collector includes one or more of dodecylamine, sodium oleate, or benzohydroxyxamic acid.

[0055] Preferably, the collector is sodium oleate.

[0056] Preferably, in the roughing operation, the amount of sulfuric acid used is 1000-2000 g / t, the amount of sodium silicate used is 2000-3000 g / t, and the amount of sodium oleate used is 50-200 g / t; in the scavenging operation, the amount of sulfuric acid used is 200-1000 g / t, the amount of sodium silicate used is 500-1000 g / t, and the amount of sodium oleate used is 20-50 g / t.

[0057] Optionally, the sulfuric acid dosage in the roughing operation can be any value between 1000 g / t, 1250 g / t, 1500 g / t, 1750 g / t, 2000 g / t, or 1000-2000 g / t; the sodium silicate dosage can be any value between 2000 g / t, 2250 g / t, 2500 g / t, 2750 g / t, 3000 g / t, or 2000-3000 g / t; and the sodium oleate dosage can be any value between 50 g / t, 100 g / t, 150 g / t, 200 g / t, or 50-200 g / t. The amount of sulfuric acid used in the scavenging operation can be any value between 200 g / t, 400 g / t, 600 g / t, 800 g / t, 1000 g / t or any value between 200 and 1000 g / t; the amount of sodium silicate used can be any value between 500 g / t, 600 g / t, 700 g / t, 800 g / t, 900 g / t, 1000 g / t or any value between 5000 and 1000 g / t; and the amount of sodium oleate used can be any value between 20 g / t, 30 g / t, 40 g / t, 50 g / t or any value between 20 and 50 g / t.

[0058] Preferably, the moisture content of material A is 70% to 85%;

[0059] Optionally, the moisture content of material A can be 70%, 75%, 80%, 85%, or any value between 70% and 85%.

[0060] Preferably, the ingredients include a flux and a microcrystalline glass nucleating agent;

[0061] Preferably, the flux includes one or more of calcium oxide, magnesium oxide, sodium feldspar, potassium feldspar, and glass powder;

[0062] Preferably, the co-solvent contains 20%–30% calcium oxide, 20%–30% magnesium oxide, 20%–25% quartz, 20%–25% potassium feldspar, and 5%–10% glass powder, calculated by mass percentage.

[0063] Optionally, the amount of the co-solvent, calculated as a percentage by mass, can be any value between 20%, 22%, 24%, 26%, 28%, 30%, or 20%–30% of the mass of material A; the content of calcium oxide can be any value between 20%, 22%, 24%, 26%, 28%, 30%, or 20%–30%; and the content of magnesium oxide can be any value between 20%, 22%, 24%, 26%, 28%, 30%, or 20%–30%. The content of sodium feldspar can be any value between 20% and 30%, and the content of potassium feldspar can be any value between 20%, 21%, 22%, 23%, 24%, 35%, or between 20% and 25%. The content of potassium feldspar can be any value between 20%, 21%, 22%, 23%, 24%, 35%, or between 20% and 25%. The content of glass powder can be any value between 5%, 6%, 7%, 8%, 9%, 10%, or between 5% and 10%.

[0064] Preferably, the microcrystalline glass nucleating agent includes one or more of Ti2O, Zr2O, and P2O5;

[0065] Preferably, the amount of the microcrystalline glass nucleating agent is 3% to 6% of the mass of material A, calculated as a percentage by weight.

[0066] Preferably, the microcrystalline glass nucleating agent contains 30-40% TiO2, 30-40% Zr2O, and 20-30% P2O5 by mass percentage.

[0067] Optionally, the amount of the microcrystalline glass nucleating agent can be any value between 3%, 4%, 5%, 6% or 3% to 6% of the mass of material A; the TiO2 content can be any value between 30%, 32%, 34%, 36%, 38%, 40% or 30% to 40%; the Zr2O content can be any value between 30%, 32%, 34%, 36%, 38%, 40% or 30% to 40%; and the P2O5 content can be any value between 20%, 22%, 24%, 26%, 28%, 30% or 20% to 30%.

[0068] Preferably, the pretreatment includes mixing and grinding;

[0069] Preferably, the material B has a particle size of 50–150 μm and a moisture content of 55%–70%.

[0070] Optionally, the particle size of material B can be any value between 50μm, 100μm, 150μm, or 50-150μm, and the moisture content of material B can be any value between 55%, 60%, 65%, 70%, or 55%-70%.

[0071] Preferably, the drying includes spray drying;

[0072] Preferably, the internal hot air temperature of the spray dryer is 200℃~250℃.

[0073] Optionally, the internal hot air temperature of the spray dryer can be any value between 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, or 200°C to 250°C.

[0074] Preferably, the pressing and molding step includes:

[0075] The blank material is evenly spread in the mold, at a pressure of 400–700 kgf / cm². 2 The pressure is maintained for 20–60 seconds, and then the glass preform is demolded to obtain a microcrystalline glass blank.

[0076] Alternatively, the pressure can be 400 kgf / cm². 2 500kgf / cm 2 600kgf / cm 2 700kgf / cm 2 Or 400 kgf / cm 2 ~700kgf / cm 2 The pressure holding time can be any value between 20s, 30s, 40s, 50s, 60s, or any value between 20s and 60s.

[0077] Preferably, the heat treatment steps include:

[0078] The microcrystalline glass preform is heated to 1400–1600°C at a heating rate of 2–5°C / min and held for 1.0–3.0 h to homogenize the glass melt. It is then annealed in a furnace preheated to 600–800°C. The temperature is then increased to 950–1050°C at a rate of 4–7°C / min and held for 1.0–2.0 h to nucleate the glass. The temperature is then increased to 1100–1200°C at a rate of 1–3°C / min and held for 1.5–2.5 h to crystallize the glass. Finally, the glass is allowed to cool naturally in the furnace to obtain microcrystalline glass.

[0079] Optionally, the glass melt homogenization heating rate can be any value between 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, or 2℃ / min to 5℃ / min; the glass melt homogenization temperature can be any value between 1400℃, 1450℃, 1500℃, 1550℃, 1600℃, or 1400℃ to 1600℃; the glass melt homogenization time can be any value between 1.0h, 1.5h, 2.0h, 2.5h, 3.0h, or 1.0h to 3.0h; the furnace annealing temperature can be any value between 600℃, 700℃, 800℃, or 600℃ to 800℃; and the microcrystalline glass nucleation heating rate can be 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, or 1400℃ to 1600℃. The glass-ceramic heating rate can be any value between 4℃ / min and 7℃ / min, and the nucleation temperature can be any value between 950℃, 1000℃, 1050℃, or 950℃ and 1050℃. The glass-ceramic nucleation time can be any value between 1.0h, 1.5h, 2.0h, or 1.0h and 2.0h. The glass-ceramic crystallization heating rate can be any value between 1℃ / min, 2℃ / min, 3℃ / min, or 1℃ / min and 3℃ / min. The glass-ceramic crystallization temperature can be any value between 1100℃, 1150℃, 1200℃, or 1100℃ and 1200℃. The glass-ceramic crystallization time can be any value between 1.5h, 2.0h, 2.5h, or 1.5h and 2.5h.

[0080] The embodiments of the present invention will be described in detail below with reference to specific examples. However, those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the embodiments, conventional conditions apply.

[0081] The lithium slag used in this embodiment of the invention is mainly composed of quartz, calcite, gypsum, corundum, pyrophyllite, and kaolinite, and its main elemental composition is shown in Table 1 below:

[0082] Table 1

[0083] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[SO3]]> CaO <![CDATA[Fe2O3]]> <![CDATA[Na2O]]> <![CDATA[K2O]]> <![CDATA[Li2O]]> <![CDATA[P2O5]]> MgO <![CDATA[TiO2]]> 56.77 22.13 5.53 4.84 1.18 0.83 0.57 0.51 0.26 0.23 0.14

[0084] Example 1

[0085] Preparation of microcrystalline glass using lithium slag:

[0086] (1) Provide lithium slag to be treated. The initial moisture content of the lithium slag is 20.18% and the SO3 content is 5.46%. Then, the lithium slag is scrubbed.

[0087] (2) The scrubbed lithium slag was pretreated by flotation to remove sulfur-containing substances. The flotation process included "roughing and scavenging", with modifiers, inhibitors, and collectors added independently for roughing and scavenging respectively. The modifier added in both roughing and scavenging was sulfuric acid, with a dosage of 1500 g / t in roughing and 500 g / t in scavenging; the inhibitor added in both roughing and scavenging was sodium silicate, with a dosage of 2000 g / t in roughing and 500 g / t in scavenging; the collector added in both roughing and scavenging was sodium oleate, with a dosage of 100 g / t in roughing and 50 g / t in scavenging. The resulting material A had a moisture content of 75% and a sulfur trioxide content of 0.6%.

[0088] (3) Material A is directly mixed with the ingredients in a ball mill for wet milling. The ingredients include flux and microcrystalline glass nucleating agent. The amount of flux added is 30% of the dry basis mass of material A. The flux includes a compound mixture of calcium oxide, magnesium oxide, sodium feldspar, potassium feldspar and glass powder. The mass fraction of calcium oxide in the compound mixture is 30%, the mass fraction of magnesium oxide is 25%, the mass fraction of sodium feldspar is 20%, the mass fraction of potassium feldspar is 20%, and the mass fraction of glass powder is 5%. The amount of microcrystalline glass nucleating agent added is 6% of the dry basis mass of material A. The microcrystalline glass nucleating agent includes a compound mixture of Ti2O, Zr2O and P2O5. The mass fraction of Ti2O in the compound mixture is 40%, the mass fraction of Zr2O is 40%, and the mass fraction of P2O5 is 20%. After wet milling, material B is obtained. The particle size of material B is 150 μm and the moisture content is 70%.

[0089] (4) The wet-milled material B enters a spray dryer for drying and granulation. The hot air temperature for spray drying is 250℃, resulting in a preform. The preform is then evenly spread in a mold and pressed at 700 kgf / cm³. 2 The pressure is maintained for 60 seconds, and then the glass preform is demolded to obtain a microcrystalline glass blank.

[0090] (5) The microcrystalline glass preform is placed in a kiln for high-temperature firing. First, it is heated to 1600℃ at a rate of 5℃ / min and held for 3.0h to homogenize the glass melt. Then, it is transferred to a furnace preheated to 800℃ for annealing. Next, the temperature is increased to 1050℃ at a rate of 7℃ / min and held for 2.0h to allow nucleation. Then, the temperature is further increased to 1200℃ at a rate of 3℃ / min and held for 2.5h to allow crystallization. Finally, it is allowed to cool naturally in the furnace to obtain microcrystalline glass. The main crystalline phase of the fired microcrystalline glass product is diopside, with secondary crystalline phases including calcium magnesium feldspar, perovskite, and quartz. Performance tests were conducted on the microcrystalline glass product, and the measured bulk density was 2.68 g / cm³. 3 It has a water absorption rate of 0.12%, a compressive strength of 158 MPa, an acid resistance of 98.8%, and an alkali resistance of 97.6%.

[0091] Example 2

[0092] Preparation of microcrystalline glass using lithium slag:

[0093] (1) Provide lithium slag to be treated. The initial moisture content of the lithium slag is 24.63% and the SO3 content is 7.58%. Then, the lithium slag is scrubbed.

[0094] (2) The scrubbed lithium slag is pretreated by flotation to remove sulfur-containing substances. The flotation process includes "roughing and scavenging", and modifiers, inhibitors and collectors are added independently for roughing and scavenging respectively. The modifier added in roughing and scavenging is sulfuric acid, with a modifier dosage of 2000 g / t in roughing and 100 g / t in scavenging; the inhibitor added in roughing and scavenging is sodium silicate, with an inhibitor dosage of 1000 g / t in roughing and 200 g / t in scavenging; the collector added in roughing and scavenging is sodium oleate, with a collector dosage of 150 g / t in roughing and 50 g / t in scavenging. The resulting material A has a moisture content of 70% and a sulfur trioxide content of 0.7%.

[0095] (3) Material A is directly mixed with the ingredients in a ball mill for wet milling. The ingredients include flux and microcrystalline glass nucleating agent. The amount of flux added is 20% of the dry basis mass of material A. The flux includes a compound mixture of calcium oxide, magnesium oxide, sodium feldspar, potassium feldspar and glass powder. The mass fraction of calcium oxide in the compound mixture is 25%, the mass fraction of magnesium oxide is 20%, the mass fraction of sodium feldspar is 25%, the mass fraction of potassium feldspar is 20%, and the mass fraction of glass powder is 10%. The amount of microcrystalline glass nucleating agent added is 3% of the dry basis mass of material A. The microcrystalline glass nucleating agent includes a compound mixture of Ti2O, Zr2O and P2O5. The mass fraction of Ti2O in the compound mixture is 30%, the mass fraction of Zr2O is 40%, and the mass fraction of P2O5 is 30%. After wet milling, material B is obtained. The particle size of material B is 100 μm and the moisture content is 60%.

[0096] (4) The wet-milled material B enters a spray dryer for drying and granulation. The hot air temperature for spray drying is 150℃, resulting in a preform. The preform is then evenly spread in a mold and pressed on a press at 400 kgf / cm³. 2 Hold under pressure for 20 seconds, then demold to obtain a microcrystalline glass preform.

[0097] (5) The microcrystalline glass preform is placed in a kiln for high-temperature firing. First, it is heated to 1400℃ at a rate of 2℃ / min and held for 1.0h to homogenize the glass melt. Then, it is transferred to a furnace preheated to 600℃ for annealing. Next, the temperature is increased to 950℃ at a rate of 4℃ / min and held for 1.0h to allow nucleation. Then, the temperature is further increased to 1100℃ at a rate of 1℃ / min and held for 1.5h to allow crystallization. Finally, it is allowed to cool naturally in the furnace to obtain microcrystalline glass. The main crystalline phase of the fired microcrystalline glass product is diopside, with secondary crystalline phases including calcium magnesium feldspar, perovskite, and quartz. Performance tests were conducted on the microcrystalline glass product, and the measured bulk density was 2.63 g / cm³. 3 It has a water absorption rate of 0.16%, a compressive strength of 127 MPa, an acid resistance of 97.9%, and an alkali resistance of 98.1%.

[0098] Example 3

[0099] (1) Provide lithium slag to be treated. The initial moisture content of the lithium slag is 20.17% and the SO3 content is 6.58%. The lithium slag is then scrubbed.

[0100] (2) The scrubbed lithium slag is pretreated by flotation to remove sulfur-containing substances. The flotation process includes "roughing and scavenging", and modifiers, inhibitors and collectors are added independently for roughing and scavenging respectively. The modifier added in roughing and scavenging is sulfuric acid, with a modifier dosage of 2000 g / t in roughing and 500 g / t in scavenging; the inhibitor added in roughing and scavenging is sodium silicate, with an inhibitor dosage of 2000 g / t in roughing and 500 g / t in scavenging; the collector added in roughing and scavenging is sodium oleate, with a collector dosage of 100 g / t in roughing and 30 g / t in scavenging. The resulting material A has a moisture content of 75% and a sulfur trioxide content of 0.5%.

[0101] (3) Material A is directly mixed with the ingredients in a ball mill for wet milling. The ingredients include flux and microcrystalline glass nucleating agent. The amount of flux added is 25% of the dry weight of material A. The flux includes a compound mixture of calcium oxide, magnesium oxide, sodium feldspar, potassium feldspar and glass powder. The mass fraction of calcium oxide in the compound mixture is 30%, the mass fraction of magnesium oxide is 20%, the mass fraction of sodium feldspar is 20%, the mass fraction of potassium feldspar is 20%, and the mass fraction of glass powder is 10%. The amount of microcrystalline glass nucleating agent added is 5% of the dry weight of material A. The microcrystalline glass nucleating agent includes a compound mixture of Ti2O, Zr2O and P2O5. The mass fraction of Ti2O in the compound mixture is 40%, the mass fraction of Zr2O is 30%, and the mass fraction of P2O5 is 30%. After wet milling, material B is obtained. The particle size of material B is 50 μm and the moisture content is 50%.

[0102] (4) The wet-milled material B enters a spray dryer for drying and granulation. The hot air temperature for spray drying is 150℃, resulting in a preform. The preform is then evenly spread in a mold and pressed at 500 kgf / cm² on a press. 2 The pressure is maintained for 40 seconds, and then the glass preform is demolded to obtain a microcrystalline glass blank.

[0103] (5) The microcrystalline glass preform was placed in a kiln for high-temperature firing. First, it was heated to 1500℃ at a rate of 4℃ / min and held for 2.0h to homogenize the glass melt. Then, it was transferred to a furnace preheated to 700℃ for annealing. Next, the temperature was increased to 1000℃ at a rate of 5℃ / min and held for 1.5h to allow nucleation. Finally, the temperature was increased to 1150℃ at a rate of 2℃ / min and held for 2.0h to crystallize the glass. The glass was then allowed to cool naturally in the furnace to obtain microcrystalline glass. Performance tests were conducted on the microcrystalline glass product, and the measured bulk density was 2.66 g / cm³. 3 It has a water absorption rate of 0.11%, a compressive strength of 148 MPa, an acid resistance of 98.5%, and an alkali resistance of 98.2%.

[0104] Comparative Example 1

[0105] (1) Provide lithium slag to be treated, with an initial moisture content of 20.17% and an SO3 content of 6.58%;

[0106] (2) The lithium slag is directly mixed with the ingredients in a ball mill for wet grinding. The ingredients include flux and microcrystalline glass nucleating agent. The amount of flux added is 25% of the dry weight of the lithium slag. The flux includes a compound mixture of calcium oxide, magnesium oxide, sodium feldspar, potassium feldspar and glass powder. The mass fraction of calcium oxide in the compound mixture is 30%, the mass fraction of magnesium oxide is 20%, the mass fraction of sodium feldspar is 20%, the mass fraction of potassium feldspar is 20%, and the mass fraction of glass powder is 10%. The amount of microcrystalline glass nucleating agent added is 5% of the dry weight of material A. The microcrystalline glass nucleating agent includes a compound mixture of Ti2O, Zr2O and P2O5. The mass fraction of Ti2O in the compound mixture is 40%, the mass fraction of Zr2O is 30%, and the mass fraction of P2O5 is 30%. After wet grinding, material B is obtained. The particle size of material B is 50 μm and the moisture content is 50%.

[0107] (4) The wet-milled material B enters a spray dryer for drying and granulation. The hot air temperature for spray drying is 150℃, resulting in a preform. The preform is then evenly spread in a mold and pressed at 500 kgf / cm² on a press. 2 The pressure is maintained for 40 seconds, and then the glass preform is demolded to obtain a microcrystalline glass blank.

[0108] (5) The microcrystalline glass preform is placed in a kiln for high-temperature firing. First, it is heated to 1500℃ at a rate of 4℃ / min and held for 2.0h to homogenize the glass melt. Then, it is transferred to a furnace preheated to 700℃ for annealing. Next, the temperature is increased to 1000℃ at a rate of 5℃ / min and held for 1.5h to allow nucleation. Then, the temperature is further increased to 1150℃ at a rate of 2℃ / min and held for 2.0h to crystallize. Finally, it is allowed to cool naturally in the furnace to obtain microcrystalline glass. The main crystalline phase of the fired microcrystalline glass product is diopside, with secondary crystalline phases including calcium magnesium feldspar, perovskite, and quartz. Performance tests were conducted on the microcrystalline glass product, and the measured bulk density was 2.53 g / cm³. 3 It has a water absorption rate of 0.28%, a compressive strength of 86 MPa, an acid resistance of 96.2%, and an alkali resistance of 96.3%.

[0109] Comparative Example 2

[0110] (1) Provide lithium slag to be treated. The initial moisture content of the lithium slag is 20.17% and the SO3 content is 6.58%. The lithium slag is then scrubbed.

[0111] (2) The scrubbed lithium slag is pretreated by flotation to remove sulfur-containing substances. The flotation process includes "roughing and scavenging", and modifiers, inhibitors and collectors are added independently for roughing and scavenging respectively. The modifier added in roughing and scavenging is sulfuric acid, with a modifier dosage of 2000 g / t in roughing and 500 g / t in scavenging; the inhibitor added in roughing and scavenging is sodium silicate, with an inhibitor dosage of 2000 g / t in roughing and 500 g / t in scavenging; the collector added in roughing and scavenging is sodium oleate, with a collector dosage of 100 g / t in roughing and 30 g / t in scavenging. The resulting material A has a moisture content of 75% and a sulfur trioxide content of 0.5%.

[0112] (3) Material A is directly mixed with the ingredients in a ball mill for wet milling. The ingredients include a flux, which is added at 25% of the dry basis mass of material A. The flux includes a compound mixture of calcium oxide, magnesium oxide, sodium feldspar, potassium feldspar and glass powder. The mass fraction of calcium oxide in the compound mixture is 30%, the mass fraction of magnesium oxide is 20%, the mass fraction of sodium feldspar is 20%, the mass fraction of potassium feldspar is 20%, and the mass fraction of glass powder is 10%. After wet milling, material B is obtained. The particle size of material B is 50 μm and the moisture content is 50%.

[0113] (4) The wet-milled material B enters a spray dryer for drying and granulation. The hot air temperature for spray drying is 150℃, resulting in a preform. The preform is then evenly spread in a mold and pressed at 500 kgf / cm² on a press. 2 The pressure is maintained for 40 seconds, and then the glass preform is demolded to obtain a microcrystalline glass blank.

[0114] (5) The microcrystalline glass preform is placed in a kiln for high-temperature firing. First, it is heated to 1500℃ at a rate of 4℃ / min and held for 2.0h to homogenize the glass melt. Then, it is transferred to a furnace preheated to 700℃ for annealing. Next, the temperature is increased to 1000℃ at a rate of 5℃ / min and held for 1.5h to allow nucleation. Then, the temperature is further increased to 1150℃ at a rate of 2℃ / min and held for 2.0h to allow crystallization. Finally, it is allowed to cool naturally in the furnace to obtain microcrystalline glass. The main crystalline phases of the fired microcrystalline glass product are anorthite and quartz. Performance tests were conducted on the microcrystalline glass product, and the measured bulk density was 2.58 g / cm³. 3 It has a water absorption rate of 0.22%, a compressive strength of 121 MPa, an acid resistance of 97.3%, and an alkali resistance of 97.6%.

[0115] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading the specification of the present invention, those skilled in the art may make some modifications or improvements based on the present invention, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A method for preparing microcrystalline glass using lithium slag, characterized in that, It is prepared by the following steps: The sulfur-containing substances in the lithium slag are removed to obtain material A; Material A and the ingredients are pretreated to obtain a mixed powder, which is then dried to obtain a blank. The ingredients include a flux and a microcrystalline glass nucleating agent. The amount of flux is 20% to 30% of the dry weight of material A, and the amount of microcrystalline glass nucleating agent is 3% to 6% of the dry weight of material A. The blank is pressed into shape to obtain a microcrystalline glass blank, and finally the blank is heat-treated to obtain microcrystalline glass. In step b, the flux contains 20%–30% calcium oxide, 20%–30% magnesium oxide, 20%–25% quartz, 20%–25% potassium feldspar, and 5%–10% glass powder by mass; the microcrystalline glass nucleating agent contains 30%–40% TiO2, 30%–40% ZrO2, and 20%–30% P2O5 by mass. The heat treatment described in step c includes the following steps: heating the microcrystalline glass preform to 1400-1600℃ at a heating rate of 2-5℃ / min and holding it at that temperature for 1.0-3.0h to homogenize the glass melt; then annealing it in a furnace preheated to 600-800℃; then heating it to 950-1050℃ at a heating rate of 4-7℃ / min and holding it at that temperature for 1.0-2.0h to nucleate it; then heating it to 1100-1200℃ at a heating rate of 1-3℃ / min and holding it at that temperature for 1.5-2.5h to crystallize it; and then naturally cooling it in the furnace to obtain microcrystalline glass.

2. The method for preparing microcrystalline glass using lithium slag according to claim 1, characterized in that, The lithium slag described in step a has a SiO2 mass fraction of 50-60%, an Al2O3 mass fraction of 15-25%, an SO3 mass fraction of 5-8%, a CaO mass fraction of 4-7%, and a lithium slag moisture content of 15-25%.

3. The method for preparing microcrystalline glass using lithium slag according to claim 1, characterized in that, The method for removing sulfur-containing substances from lithium slag in step a is flotation, which includes roughing and scavenging. Each of the roughing and scavenging processes involves the independent addition of a modifier, inhibitor, and collector. In the roughing process, the modifier dosage is 1000-2000 g / t, the inhibitor dosage is 2000-3000 g / t, and the collector dosage is 50-200 g / t. In the scavenging process, the modifier dosage is 200-1000 g / t, the inhibitor dosage is 500-1000 g / t, and the collector dosage is 20-50 g / t. The moisture content of material A is 70%-85%.

4. The method for preparing microcrystalline glass using lithium slag according to claim 1, characterized in that, The pretreatment in step b includes grinding and mixing, wherein the mixed powder has a particle size of 100~150μm and a moisture content of 55%~70%, and the drying includes spray drying.

5. The method for preparing microcrystalline glass using lithium slag according to claim 4, characterized in that, The internal hot air temperature of the spray dryer is 200℃~250℃.

6. The method for preparing microcrystalline glass using lithium slag according to claim 1, characterized in that, The pressing and molding process described in step c includes: evenly spreading the preform material in a mold, and pressing it at a pressure of 400~700 kgf / cm³. 2 Hold under pressure for 20-60 seconds, then demold to obtain a microcrystalline glass preform.

7. The microcrystalline glass prepared by the method for preparing microcrystalline glass using lithium slag as described in any one of claims 1-5.

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