Method and device for producing high-purity quartz sand
Through a multi-step process and circulating water system, combined with flotation agent and pickling technology, the impurities and inclusions in quartz sand were successfully removed, the purity and quality of quartz sand were improved, and the impurity removal problems in the existing technology were solved, so as to achieve The industrial production of high-purity quartz sand.
Patent Information
- Application Number
- CN202411413387.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2024-12-31
AI Technical Summary
The prior art is difficult to effectively remove impurities, especially inclusions, in the production of high-purity quartz sand, resulting in unstable product quality, and the existing processes are not effective in removing gas-rich and micro-size fluid inclusions.
Multi-step processes include cleaning and picking, crushing, roasting water quenching, water grinding, screening, magnetic separation, flotation, precision magnetic separation, pickling, water washing, drying and chlorinated roasting, etc., through the circulation of water and flotation agent Use to gradually remove impurities and inclusions from quartz sand to improve its purity and quality.
It significantly improves the purity and quality of quartz sand, solves the problem of removing impurities, realizes the industrial production of high-purity quartz sand, and meets the needs of high-purity quartz sand in different application directions.
Smart Images
Figure CN119216082A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of quartz sand purification, in particular to a method and a device for producing high-purity quartz sand. Background Art
[0002] High-purity quartz sand refers to a high-purity non-metallic mineral raw material with a certain particle size specification and SiO2 purity higher than 99.9% produced by a series of physical and chemical purification technologies from natural quartz minerals. It is a hard, wear-resistant, and chemically stable silicate mineral; the quality of high-purity quartz is not simply linearly related to the impurity content, but depends on the process mineralogical characteristics of its impurities. The impurity characteristics and contents of different quartz ores are not the same. Therefore, for high-purity quartz raw materials, analyzing its impurity characteristics is the premise for determining the purification process and application direction; inclusions are certain solid minerals or gas-liquid impurities encapsulated in the quartz ore. The type, size, and content of fluid inclusions have a significant impact on the quality of high-purity quartz; but no good progress has been made in removing gas-rich phases and micro-sized fluid inclusions. Summary of the invention
[0003] The purpose of the present invention is to solve the shortcomings of the prior art. A method for producing high-purity quartz sand is provided, comprising:
[0004] Step 1, cleaning and sorting: the crude quartz blocks entering the factory are cleaned by water spraying through a circulating water pool through a conveyor belt. At the same time, the quartz blocks of different specifications and sizes are hammered and sorted manually. According to the sorted quartz stones, they are added to the subsequent processing stages in batches;
[0005] Step 2, crushing: The selected rough quartz blocks are sent to the rod mill through the conveyor belt and crushed into the required size of the product by the rod mill. A small amount of circulating water is added during the crushing process, and a small amount of dust exhaust gas will be generated;
[0006] Step 3, roasting and water quenching: the crushed raw materials enter the water quenching furnace, and are electrically heated to 1000℃ for high temperature roasting. The quartz silicon particles roasted in the water quenching furnace have a particle size between 2-3 cm, which is relatively large and has no fine particles. The roasting furnace is fully closed and does not produce particulate matter. After roasting, the quartz particles enter the matching water tank and are introduced into the running water (without water temperature requirement) to rapidly cool the calcined quartz stone, so that the quartz particles are loose and dissociated for subsequent water grinding. In this process, 40% of the fresh water introduced is lost by evaporation, and 60% of the waste water is reused after sedimentation in the water tank;
[0007] Step 4, water grinding: the loosened and dissociated material with a diameter of 2-3 cm is put into a wet rod water mill and dissociated into fine particles of 50-140 mesh after adding water. During this process, water needs to be continuously introduced (without water temperature requirement) to keep the material hydrated. 5% of the introduced water enters the raw material and 20% is lost.
[0008] Step 5, screening: The water-ground quartz silicon is first screened through a vibrating screen to remove coarse particles, and particles above 50 mesh are returned to the water-grinding step, and particles below 50 mesh are further screened through a drum screen. After screening, the coarse particles continue to be water-grinded, and materials that meet the conditions enter the magnetic separation process. The screening process requires continuous water flow (no water temperature requirement) to keep the material in a fluid state, so no waste gas is generated. 20% of the water introduced during screening is lost, and 80% of the waste water is reused after settling in a sedimentation tank. The crushed quartz sand is sent to a high-frequency screen for screening via a conveyor belt. The high-frequency screen is used to remove large-sized quartz blocks that are not completely crushed. The screening of materials in the present invention is carried out in circulating water throughout the entire process, and no waste gas is generated during the process;
[0009] Step 6, coarse magnetic separation: Magnetic separation is one of the effective methods to remove iron impurities in raw materials. Since the hematite, limonite and other minerals contained in the raw materials have weak magnetism, the fine particles after screening enter the permanent magnetic drum magnetic separator and the electromagnetic separator for two magnetic separations to separate the iron and other metal impurities in the materials. Water needs to be passed through the magnetic separation process. The moisture content of the material after magnetic separation is about 12%. The particle size range of the material obtained after screening is 40-200 mesh. It is sent to the factory magnetic separator through a conveyor belt for magnetic separation to preliminarily remove the iron impurities in the quartz sand. The magnetic separation is carried out in circulating water throughout the process, and no waste gas is generated during the process;
[0010] Step 7, flotation: flotation uses multiple flotation machines in series, wherein the flotation agent, sulfuric acid, prepared hydrofluoric acid and water are flotated in a certain proportion, and the flotation uses a multiple series process (fresh water is added to the front part of the flotation machine, and purified water is added to all the back flotation machines). The flotation agent can selectively adsorb on the surface of the particles of the material to be selected, so as to enhance its hydrophobicity and improve its floatability, and firmly adhere to the bubbles and float upward, so as to remove impurities; after filter pressing, the flotation quartz sand with a particle size range of 40 to 200 meshes and a moisture content of 5% is obtained, and finally the flotation agent is located in the upper layer of the solution and enters the wastewater together with the flotation impurities;
[0011] Step 8, precision magnetic separation: The iron content of quartz silicon has a great impact on subsequent deep processing. It is required to reduce the iron content in quartz silicon as much as possible. In order to improve product quality, a flat magnetic separator is set up after drying to further magnetically separate the dried material, separate the iron in quartz silicon, and further improve the purity of quartz silicon. In order to further remove iron impurities in quartz sand, the quartz sand after flotation is dried, and the drying temperature is about 600°C in an electric heating dryer, and then dry magnetic separation is carried out. Dust exhaust gas will be generated during the drying and magnetic separation process;
[0012] Step 9, soaking, pickling and water washing: In order to ensure product quality, the quartz sand after flotation is pickled again to remove debris, water rust, etc. inside the crushed stone after crushing, and to remove impurities in the quartz particles to the maximum extent; hydrochloric acid, sulfuric acid, and hydrofluoric acid are mixed in a mixed acid tank at a ratio of about 6:2:1, and then pure water is added at a ratio of about 3:2 between acid and water. The mixed liquid in the mixed acid tank enters the double cone tank through a pipeline, and the double cone tank is heated to 60°C and soaked for 8 hours before acid discharge. The discharged acid enters the acid return tank for reuse (the alkali metal ions in the quartz silicon react with the acid to generate chloride). The generated chloride adheres to the surface of the quartz silicon, and the outer layer wraps the acid liquid. 80% of the acid liquid exits as free acid liquid that is not adsorbed on the surface of the quartz silicon. A small amount of quartz silicon will exit with the acid liquid. Therefore, a filter cloth is set at the acid removal port to intercept quartz silicon particles. Therefore, there will be no particles in the acid removal. Granular quartz silicon may contain a very small amount of chloride. The deacidified acid in the acid recovery tank is analyzed, and the corresponding new acid is added according to the deacidified acid components before entering the next round of acid soaking (the storage period is about 6-7 days). According to the test results, the deacidified acid that cannot be reused (when the deacidified acid test results show that iron ions ≥100ppm, sodium ions ≥100ppm, calcium ions ≥50ppm, and potassium ions ≥100ppm, the deacidified acid needs to be replaced) is discharged regularly. The deacidified acid is discharged about once a year and treated as hazardous waste. After the deacidification, the material is washed with ultrapure water, mainly to wash away the chloride and acid wrapped on the surface of the quartz silicon. The material is washed twice. In this process, waste gas is generated during the mixed acid process, acid mist waste gas is generated during acid soaking, and waste water is generated during pure water washing. The purpose of acid soaking is to remove iron oxides and other soluble impurities in quartz silicon particles, thereby reducing the iron content in quartz silicon and improving the quality of quartz silicon.
[0013] The reaction involved is mainly the oxidation reaction of HCl and iron to generate ferric chloride soluble in water. Reaction equation: Fe2O3+6HCl=2FeCl3+3H2O. The generated ionic chloride is washed with pure water to separate the ionic chloride from the quartz silicon and enter the wastewater, thereby achieving the purpose of purifying the quartz silicon. After the acid bubble is completed, the quartz sand is filtered and then washed with pure water several times until it is clean. The entire pickling and water washing process is carried out in the pickling equipment, which effectively reduces the volatilization of acidic gases and does not contact with the outside world to avoid the introduction of impurities. The main purpose of this process is to remove metal oxides in the quartz sand components and improve the purity of the quartz sand;
[0014] The reaction equations involved in flotation and pickling are:
[0015] SiO2+6HF=H2SiF6+2H2O
[0016] Al2O3+6HF=2AlF3↓+3H2O
[0017] Fe2O3+12HF=2H3FeF6+3H2O
[0018] Al2O3+3H2SO4=Al2(SO4)3+3H2O
[0019] Fe2O3+3H2SO4=Fe2(SO4)3+3H2O
[0020] Step 10, drying: the particle size of the washed quartz sand is in the range of 50 to 180 meshes, and the moisture content is 8%. It is first pre-dried to remove most of the moisture and then fine-dried before packaging. The drying temperature is about 600°C in an electric heating rotary drum dryer to further remove moisture from the surface of the quartz sand, reduce the moisture content of the quartz sand, and improve the quality of the quartz sand;
[0021] Step 11, chlorination roasting: the dehydrated material is heated to 800°C for drying, and then enters the chlorination furnace and is heated to 1000°C. Waste gas is generated in this process; the main principle of the drying chlorination furnace: the method of removing lattice impurities mainly includes the chlorination roasting process. Chlorination roasting uses the gradient of chemical potential between the surface and the interior of the quartz mineral to promote the diffusion of inclusions inside the quartz silicon. The alkali metals, alkaline earth metals and residual inclusions on the surface of the quartz particles react with hydrogen chloride at high temperature to generate gaseous chlorides. The main metal ions removed by hydrogen chloride gas are iron ions and aluminum ions. The main reactions are: Fe2O3+6HCl=2FeCl3+3H2O, Al2O3+6HCl=2AlCl3+3H2O. The high-temperature airflow takes away the chlorides of these impurity elements, thereby achieving the purpose of deep purification;
[0022] Step 12: Packaging and warehousing: The particle size of the high-purity quartz sand after drying ranges from 50 to 180 meshes. It passes through the outlet pipe of the dryer and directly enters the packaging barrel or ton bag for packaging and warehousing.
[0023] The present invention adopts the above technical scheme, which has significant technical advantages and can effectively remove impurities in mineral raw materials. It not only solves the outstanding problems of high impurity content, difficult removal of inclusions, and failure to reach the inner layer of sand in the quartz crucible in the current industry, but is also conducive to the industrial promotion and application of the device. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic diagram of the process of the present invention.
[0025] In the figure: 1-quartz ore selection area, 2-crusher, 3-wet rod water mill, 4-screening machine, 5-roasting furnace, 6-coarse magnetic separator, 7-flotation machine, 8-dryer, 9-precision magnetic separator, 10-pickling tank, 11-pre-dryer, 12-chlorination furnace, 13-product packaging area. DETAILED DESCRIPTION
[0026] Combination Figure 1 The present invention provides a high-purity quartz sand production device, including: flotation process and pickling process reagent components and specifications; wherein the flotation technology is characterized by the control of reagent composition ratio and added amount.
[0027] The quartz ore selection area 1 is connected to the entrance of the crusher 2 through a conveyor belt;
[0028] The outlet of the wet rod mill 3 is connected to the inlet of the screening machine 4 through a pipeline, and the large particles exceeding 200 mesh are returned to the crusher 2 for further crushing. The loosened and dissociated material with a diameter of 2-3 cm enters the wet rod mill for dissociation into fine particles of 50-140 mesh after adding water. This process requires continuous introduction of water (without water temperature requirement) to keep the material hydrated. 5% of the introduced water enters the raw material and 20% is lost.
[0029] The inlet of the roasting furnace 5 is connected to the outlet of the screening machine 4 through a pipeline, and the temperature of the roasting furnace is controlled to be 1000°C for high temperature roasting. The particle size of the quartz silicon entering the water quenching furnace is between 2-3 cm;
[0030] The inlet of the coarse magnetic separator 6 is connected to the outlet of the roasting furnace 5. Since the hematite, limonite and other minerals contained in the raw materials have weak magnetism, the fine particles after screening enter the permanent magnetic drum magnetic separator and the electromagnetic separator for two magnetic separations to separate the iron and other metal impurities in the materials. Water needs to be introduced into the magnetic separation process. The moisture content of the material after magnetic separation is about 12%. The particle size range of the material obtained after screening is 40-200 mesh. It is sent to the factory magnetic separator through a conveyor belt for magnetic separation to preliminarily remove the iron-containing impurities in the quartz sand. The entire magnetic separation process is carried out in circulating water, and no exhaust gas is generated during the process;
[0031] The inlet of the flotation machine 7 is connected to the outlet of the coarse magnetic separator 6 through a pipeline. The flotation adopts multiple flotation machines in series, wherein the flotation agent, sulfuric acid, prepared hydrofluoric acid and water are flotated in a certain proportion. The flotation of the present invention adopts a multiple series process (fresh water is added to the front part of the flotation machine, and purified water is added to the back part of the flotation machine). The flotation agent can selectively adsorb on the surface of the particles of the material to be selected, so as to enhance its hydrophobicity and improve its floatability, and firmly adhere to the bubbles and float up, so as to achieve the effect of removing impurities. After pressure filtration, the flotation quartz sand with a particle size range of 40 to 200 mesh and a moisture content of 5% is obtained. Finally, the flotation agent is located in the upper layer of the solution and enters the wastewater together with the flotation impurities;
[0032] The inlet of the dryer 8 is connected to the outlet of the precision magnetic separator 9, and the quartz sand after flotation is dried by the electric heating dryer at a drying temperature of about 600°C, and then dry magnetic separation is performed. Dust exhaust gas will be generated during the drying and magnetic separation process.
[0033] The inlet of the pickling tank 10 is connected to the outlet of the precision magnetic separator 9. It is mainly used to wash away the chloride and acid solution wrapped on the surface of the quartz silicon. The cleaning is performed twice. This process produces waste gas generated during the mixed acid process, acid mist waste gas generated during acid immersion, and waste water generated during pure water cleaning. The purpose of acid immersion is to remove iron oxides and other soluble impurities in the quartz silicon particles, thereby reducing the iron content in the quartz silicon and improving the quality of the quartz silicon;
[0034] The inlet of the pre-dryer 11 is connected to the outlet of the pickling tank 10. The particle size of the quartz sand after pickling is 50-180 meshes and the moisture content is 8%. It is first pre-dried to remove most of the moisture and then fine-dried before packaging. The electric heating rotary drum dryer is dried at a temperature of about 600°C to further remove moisture from the surface of the quartz sand, reduce the moisture content of the quartz sand, and improve the quality of the quartz sand.
[0035] The inlet of the chlorination furnace 12 is connected to the outlet of the drying machine 11. After drying, it enters the chlorination furnace and is heated to 1000°C. The high-temperature airflow takes away the chlorides of these impurity elements, thereby achieving the purpose of deep purification;
[0036] The entrance of the product packaging area 13 is connected to the outlet of the chlorination furnace 12. The high-purity quartz sand after drying has a particle size range of 50-180 meshes, and directly enters the packaging barrel or ton bag through the dryer outlet pipe for packaging and storage.
[0037] Although the specific implementation modes of the present invention have been introduced in conjunction with the embodiments, this does not limit the scope of protection of the present invention. Those skilled in the art should understand that it should be clear to those skilled in the art that these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection of the present invention.
Claims
1. A high-purity quartz sand production device, characterized in that: The quartz ore selection area is connected to the crusher inlet through a conveyor belt; the outlet of the wet rod water mill is connected to the screener inlet through a pipeline; the inlet of the roaster is connected to the screener outlet through a pipeline; the inlet of the coarse magnetic separator is connected to the roaster outlet; the inlet of the flotation machine is connected to the coarse magnetic separator outlet through a pipeline; the inlet of the dryer is connected to the precision magnetic separator outlet; the inlet of the pre-dryer is connected to the pickling tank outlet; the inlet of the chlorination furnace is connected to the dryer outlet; the inlet of the product packaging area is connected to the chlorination furnace outlet.
2. The preparation method of the present invention is characterized in that: Step 1: Cleaning and sorting: the rough quartz blocks are washed, hammered and sorted through a conveyor belt and sprayed with water in a circulating water pool; Step 2, crushing: the selected rough quartz blocks are sent to the rod mill through the conveyor belt; Step 3, roasting and water quenching: the crushed raw materials enter the water quenching furnace, and are electrically heated to 1000°C for high temperature roasting in the water quenching furnace; Step 4, water grinding: the loosened and dissociated material with a diameter of 2-3 cm is put into a wet rod water mill and dissociated into fine particles of 50-140 mesh after adding water; Step 5, screening: the water-ground quartz silicon is first screened to remove coarse particles, and the particles above 50 mesh are returned to the water-grinding step, and the particles below 50 mesh are further screened by the drum screen. After screening, the coarse particles are further water-ground, and the qualified materials enter the magnetic separation process; Step 6, coarse magnetic separation: Magnetic separation is one of the effective methods to remove iron impurities in raw materials; Step 7, flotation: flotation is carried out by connecting multiple flotation machines in series, wherein the flotation agent, sulfuric acid, prepared hydrofluoric acid and water are used for flotation in a certain proportion; Step 8, precision magnetic separation: after drying, a flat magnetic separator is set to further magnetically separate the dried material to separate the iron in the quartz silicon, thereby further improving the purity of the quartz silicon; Step 9, pickling and water washing: In order to ensure product quality, the quartz sand after flotation is pickled again to remove debris, water rust, etc. inside the crushed stone after crushing, and to remove impurities in the quartz particles to the maximum extent; Step 10, drying: the particle size of the washed quartz sand ranges from 50 to 180 meshes, and the moisture content is 8%. It is first pre-dried to remove most of the moisture and then fine-dried before packaging. The drying temperature is about 600°C in an electric heating rotary drum dryer to further remove moisture from the surface of the quartz sand and reduce the moisture content of the quartz sand. Step 11, chlorination roasting: the dehydrated material is heated to 800°C and dried, and then enters the chlorination furnace and is heated to 1000°C. Waste gas is generated in this process; Step 12: Packaging and storage: The particle size of the high-purity quartz sand after drying ranges from 50 to 180 meshes. It passes through the discharge pipe of the dryer and directly enters the packaging barrel or ton bag for packaging and storage.
3. The method according to claim 2, characterized in that: The particle size of the quartz silicon entering the water quenching furnace for calcination in step 3 is between 2 and 3 cm.
4. The method according to claim 2, characterized in that: The fine particles screened in step 6 enter a permanent magnetic drum magnetic separator and an electromagnetic separator for two magnetic separations to separate metal impurities such as iron in the material. Water needs to be introduced into the magnetic separation process. The moisture content of the material after magnetic separation is about 12%. The particle size range of the material obtained after screening is 40-200 mesh. It is sent to the factory magnetic separator via a conveyor belt for magnetic separation to preliminarily remove iron impurities in the quartz sand.
5. The method according to claim 2, characterized in that: In the step 7, the flotation adopts a multiple-unit series process (fresh water is added to the front part of the flotation machines, and purified water is added to all the back flotation machines). The flotation reagent can be selectively adsorbed on the surface of the particles of the material to be selected, so as to enhance its hydrophobicity and improve its floatability, and firmly adhere to the bubbles and float upward, so as to remove impurities. After filter pressing, the flotation quartz sand with a particle size range of 40-200 mesh and a moisture content of 5% is obtained. Finally, the flotation reagent is located in the upper layer of the solution and enters the wastewater together with the flotation impurities.
6. The method according to claim 2, characterized in that: In the step 8, the quartz sand after flotation is dried by an electric heating dryer at a drying temperature of about 600° C., and then dry magnetic separation is performed.
7. The method according to claim 2, characterized in that: In step 9, hydrochloric acid, sulfuric acid and hydrofluoric acid are mixed in a mixed acid tank at a ratio of about 6:2:1, and then pure water is added at a ratio of about 3:2 between acid and water. The mixed liquid in the mixed acid tank enters a double cone tank through a pipeline, and the double cone tank is heated to 60° C. and soaked for 8 hours before draining the acid.