Green and environment-friendly method for preparing high-purity quartz sand for drawing pipe by using quartzite and flotation equipment

Abstract

The invention discloses a method and flotation equipment for preparing high-purity quartz sand for a pull pipe in a green and environment-friendly mode through quartzite in the technical field of purification of the high-purity quartz sand, and the method comprises the following steps that S1, a quartzite sample is subjected to impurity removal, and then the colorless and transparent quartzite sample is screened out; s2, carrying out low-temperature roasting and water quenching treatment on the colorless and transparent quartzite sample, airing, and carrying out sand making and screening to obtain first to-be-treated quartz sand; s3, the first to-be-treated quartz sand is subjected to magnetic separation treatment and then subjected to flotation treatment, and second to-be-treated quartz sand is obtained; s4, performing hot-pressing acid leaching on the second to-be-treated quartz sand by adopting phosphoric acid, cleaning, drying and performing dry magnetic separation to obtain high-purity quartz sand; the quartz sand subjected to flotation is subjected to hot-pressing acid leaching through phosphoric acid, serious harm such as bone lesions, tooth injuries and abnormal organ functions cannot be caused to people, and the method is green and environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of high-purity quartz sand purification, specifically to a method and flotation equipment for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner. Background Technology

[0002] High-purity quartz sand is widely used in semiconductor, photovoltaic, fiber optic communication, aerospace, military, and electronic technology fields due to its stable chemical properties, low coefficient of thermal expansion, strong insulation and pressure resistance, and excellent optical and electrical properties. For example, in the semiconductor field, semiconductor device manufacturing equipment requires the extensive use of quartz tubes and quartz flanges made from high-purity quartz sand to ensure the purity and product quality of semiconductor devices.

[0003] Early high-purity quartz sand was mainly prepared using natural crystal as raw material. However, with the increasing depletion of natural crystal, the preparation of high-purity quartz sand using pegmatite, vein quartz, and quartzite as raw materials has gradually become a new development trend. Compared with pegmatite and vein quartz, quartzite has large reserves. In addition, after strong natural metamorphism during the mineralization process, quartzite has a dense structure and easy separation of impurity minerals, which has the potential to prepare 4N5 grade (SiO2 content ≥99.995%) high-purity quartz sand for pipe drawing.

[0004] Typically, the preparation of high-purity quartz sand involves processes such as coarse crushing, roasting and water quenching, sand making, magnetic separation, flotation, acid leaching, and chlorination. Among these processes, acid leaching often uses a mixture of hydrofluoric acid and other acids to remove impurities from the quartz. For example, patent CN202510638560.8 describes using a mixture of hydrofluoric acid, oxalic acid, and hydrochloric acid to leach quartz sand, which effectively removes impurities and produces 4N-grade high-purity quartz sand. However, hydrofluoric acid not only causes serious harm to humans, such as bone diseases, tooth damage, and organ dysfunction, but also causes severe environmental pollution. Therefore, the use of hydrofluoric acid requires not only strict protective measures but also systematic treatment of the acid leaching wastewater, which significantly impacts production efficiency and costs. Summary of the Invention

[0005] The purpose of this invention is to provide a green and environmentally friendly method and flotation equipment for preparing high-purity quartz sand for pipe drawing using quartzite, which solves the problem of the hazards caused by the existing acid leaching method using hydrofluoric acid.

[0006] This invention achieves the above objective through the following technical solution: a method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner, comprising the following steps: S1: Remove impurities from the quartzite sample and then screen out colorless and transparent quartzite samples; S2: After low-temperature roasting and water quenching of colorless and transparent quartzite samples, they are dried and then screened to obtain the first quartz sand to be treated. S3: After the first quartz sand to be treated is subjected to magnetic separation, it is then subjected to flotation to obtain the second quartz sand to be treated. S4: After hot-pressing acid leaching of the second type of quartz sand with phosphoric acid, it is cleaned, dried and dried magnetically tested to obtain high-purity quartz sand.

[0007] Preferably, the method for removing impurities from the quartzite sample in step S1 is to wash the quartzite sample with water to remove the soil and impurity minerals attached to the surface of the quartzite sample.

[0008] Preferably, the method of performing low-temperature roasting and water quenching treatment on the colorless and transparent quartzite sample in step S2 is to perform microwave-infrared combined heating and high-pressure water jet water quenching treatment on the colorless and transparent quartzite. The first type of quartz sand to be treated is 40-180 mesh quartz sand.

[0009] Preferably, the magnetic field strength of the magnetic separation in step S3 is 0.6-1.2T.

[0010] Preferably, in step S4, the hot-press acid leaching reaction temperature is 160-200℃, the reaction pressure is 3-8MPa, the reaction time is 5-9h, the phosphoric acid solution concentration is 1-2mol / L, and the liquid-solid ratio is 3:1-6:1.

[0011] Preferably, a flotation device is used to flotate the first quartz sand to be treated after magnetic separation in the above-mentioned method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner. The device includes: a box body, the box body is provided with a box cover, a discharge port and a drive motor, the output shaft of the drive motor extends into the inner cavity of the box body and is connected to a rotating rod, the rotating rod is provided with blades, the rotating rod is provided with an airflow channel, the side wall of the rotating rod is provided with an air hole for communicating with the airflow channel, and the rotating rod is provided with an air pipe for communicating with the airflow channel. The inner cavity of the box is provided with a collection cylinder at the bottom, the bottom of the collection cylinder is provided with a through hole, the bottom of the collection cylinder is provided with a perforated plate, and the rotating rod is detachably connected to the output shaft of the drive motor.

[0012] Preferably, the bottom of the inner cavity of the collecting cylinder is provided with an opening, and a kit is rotatably provided in the opening. The rotating rod is provided with a mounting ring for detachable connection with the kit.

[0013] Preferably, the collecting cylinder is provided with an elastic element for driving the orifice plate to rotate, the inner side wall of the box is provided with a limiting groove and an annular groove, and both the collecting cylinder and the orifice plate are provided with limiting blocks located in the limiting groove.

[0014] Preferably, the bottom of the collecting cylinder is provided with a positioning groove, and the perforated plate is provided with a positioning block for insertion into the positioning groove and an elastic element connected to the positioning block.

[0015] The beneficial effects of this invention are as follows: 1. Using phosphoric acid for hot-press acid leaching of flotation-processed quartz sand will not cause serious harm to humans, such as bone diseases, tooth damage, or organ dysfunction, and is also green and environmentally friendly. 2. This invention employs a microwave-infrared combined heating and high-pressure water jet quenching method for roasting and quenching operations. The use of staged heating and high-pressure water quenching not only effectively removes inclusions but also saves energy. Furthermore, it utilizes quartzite to prepare high-value-added high-purity quartz sand products for pipe drawing, greatly improving economic benefits. It also allows for the comprehensive utilization of substandard quartzite ore and quartz powder without generating solid waste. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the flotation equipment of the present invention; Figure 2 This is a schematic cross-sectional view of the box structure of the present invention; Figure 3 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the middle; Figure 4 This is a schematic diagram of the connection structure between the box body and the box cover of the present invention; Figure 5 This is a schematic diagram of the connection structure between the collecting cylinder and the perforated plate of the present invention; Figure 6 This is a schematic diagram of the perforated plate structure of the present invention.

[0017] In the diagram: 1. Box body; 2. Box cover; 3. Discharge port; 4. Air pipe; 5. Drive motor; 6. Rotating rod; 7. Blade; 8. Air hole; 9. Collection cylinder; 10. Orifice plate; 11. Kit; 12. Mounting ring; 13. Limiting groove; 14. Annular groove; 15. Limiting block; 16. Positioning block. Detailed Implementation

[0018] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0019] Please see Figure 1 A green and environmentally friendly method for preparing high-purity quartz sand for pipe drawing using quartzite includes the following steps: S1. Raw material screening: The quartzite samples are washed with water to remove the surface soil and impurities such as minerals. Then, they are manually sorted to select colorless and transparent samples for further processing. Colored samples can be sold as quartz for glass. Among them, water washing can be carried out by high-pressure water gun rinsing, stone washing machine washing, etc. S2. Low-temperature roasting and water quenching: Colorless transparent quartzite is subjected to microwave-infrared combined heating and high-pressure water jet quenching, and after drying, it is screened to obtain 40-180 mesh quartz sand. The process involves using microwaves with a power of 20-30 kW / m³ to rapidly heat the quartz to approximately 600-650°C, promoting the transformation of α-quartz to β-quartz. The quartz is then immediately placed in an infrared homogenization zone at 800-850°C, where the increased temperature further promotes the vaporization and expansion of inclusions and other impurities. A 50-60 MPa rotating water jet then impacts the hot quartz exiting the infrared zone, causing instantaneous cooling and the generation of microcracks along the inclusion / quartz interface, releasing the inclusions and impurities. Sand making can be achieved using roller crushers, impact crushers, ball mills, rod mills, etc. Quartz sand with a mesh size of 40 or larger after screening is returned for further sand making, while products with a mesh size of less than 180 can be sold as silica powder. S3. Preliminary impurity removal: Magnetic separation is performed on 40-180 mesh quartz sand to remove iron impurities and possible magnetic minerals introduced by the wear of sand making equipment during the sand making process. Then, the magnetically separated quartz sand is subjected to flotation treatment to further remove impurity minerals. The magnetic separation field strength is 0.6-1.2T. Before flotation, the sample needs to be tested and impurities are removed by flotation according to the type of impurity minerals. If the impurity minerals are silicate minerals, they can be removed by flotation under acidic conditions using amine collectors. If the impurity minerals are iron-containing minerals, they can be removed by flotation under neutral conditions using sodium petroleum sulfonate or oleic acid collectors.

[0020] S4. Hot-press acid leaching: The flotation-processed quartz sand is hot-pressed acid leaching with phosphoric acid. The acid-leached quartz sand is then washed, dried, and magnetically dried to obtain 4N5 grade high-purity quartz sand for pipe drawing. The hot-press acid leaching reaction temperature is 160-200℃, the reaction pressure is 3-8MPa, and the reaction time is 5-9h; the phosphoric acid solution concentration is 1-2mol / L, and the liquid-solid ratio is 3:1 to 6:1.

[0021] It should be noted that by not using hydrofluoric acid for acid leaching, the potential harm to human health and the environment caused by the use of hydrofluoric acid is avoided. At the same time, an environmentally friendly purification process is provided, which can purify quartzite to grade 4N5, making it a high-purity quartz sand for pipe drawing, which greatly increases the added value of the product.

[0022] Example 1

[0023] As a further optimization of Example 1, please refer to Figure 1 and Figure 2 A flotation device includes: a housing 1, a housing cover 2 on the top of the housing 1, the housing 1 and the housing cover 2 being detachably connected (e.g., by bolts or clips), a discharge port 3 on the side wall of the housing 1, and a valve on the discharge port 3; a drive motor 5 on the bottom wall of the housing 1, the output shaft of the drive motor 5 extending into the inner cavity of the housing 1 and connected to a rotating rod 6, the output shaft of the drive motor 5 being detachably connected to the rotating rod 6 (a threaded hole is provided at the end of the output shaft of the drive motor 5, and a screw is provided at the bottom end of the rotating rod 6, the screw being screwed into the inner cavity of the threaded hole, thereby realizing the detachable connection between the output shaft of the drive motor 5 and the rotating rod 6), the rotating rod 6 The side wall of the housing 1 is provided with blades 7; the inside of the rotating rod 6 is provided with an airflow channel, and the side wall of the rotating rod 6 is provided with several air holes 8, which are connected to the airflow channel. The top wall of the housing 2 is provided with an installation hole, and a bearing is installed in the inner cavity of the installation hole. The top of the rotating rod 6 is inserted into the inner ring of the bearing, and an air pipe 4 is inserted into the top of the inner ring of the bearing. The end of the air pipe 4 away from the rotating rod 6 is connected to an external air pump. The bottom of the inner cavity of the housing 1 is provided with a collection cylinder 9, and the bottom of the collection cylinder 9 is provided with a through hole. The bottom of the collection cylinder 9 is provided with a perforated plate 10 (the perforated plate 10 rotates around the axis of the collection cylinder 9), and the holes on the perforated plate 10 coincide with the through hole.

[0024] It should be noted that after magnetic separation, the quartz sand is added to the inside of tank 1, and then water and reagents (the flotation reagents) are injected into the inside of tank 1. The drive motor 5 works, driving the rotating rod 6 to rotate the blades 7, stirring the mixture inside tank 1. At the same time, the air pump injects air into the airflow channel through the air pipe 4. The gas enters the mixture inside tank 1 through the air hole 8, allowing the ore to come into contact with the high-pressure air and reagents, generating a large amount of foam. This foam adheres the ore particles to the foam, completing the flotation process. The drive motor 5 stops working; the cover 2 is removed from the box body 1, the rotating rod 6 is removed from the output shaft of the drive motor 5, the collection cylinder 9 is moved up to the preset area, the perforated plate 10 is rotated to make the holes of the perforated plate 10 misaligned with the through holes, and the bottom of the collection cylinder 9 is blocked; then the collection cylinder 9 is moved up, and the foam above the inner cavity of the box body 1 is brought out. The foam contains flotation minerals (the collected foam is dehydrated and then screened to obtain the required minerals). Then the discharge port 3 is opened to discharge the remaining objects inside the box body 1.

[0025] It should be noted that after the collecting cylinder 9 moves from the bottom of the box 1 to near the foam area, the orifice plate 10 rotates to seal the bottom of the collecting cylinder 9. Then the collecting cylinder 9 moves upward to carry the foam generated by flotation out of the box 1, which makes it easier to collect the foam generated by flotation and the minerals therein. At the same time, the rotating rod 6 is removed from the inside of the box 1, making it more convenient to collect the foam and the minerals therein.

[0026] In this embodiment, as a further optimization, please refer to... Figure 2 and Figure 3 An opening is provided at the bottom of the inner cavity of the collection cylinder 9 (the opening is located on the axis of the collection cylinder 9). A fitting 11 is rotatably installed in the opening. The fitting 11 passes through the orifice plate 10 and is fitted onto the outer wall of the rotating rod 6. An installation ring 12 is fixedly fitted onto the outer wall of the rotating rod 6. The installation ring 12 and the fitting 11 are detachably connected (e.g., bolts are used to connect the installation ring 12 and the fitting 11). When the rotating rod 6 is moved upward, the installation ring 12 pulls the fitting 11, the collection cylinder 9 and the orifice plate 10 upward together, which facilitates the movement of the collection cylinder 9 and eliminates the need to drive it separately, thus improving work efficiency.

[0027] In this embodiment, as a further optimization, please refer to... Figure 4 and Figure 5 An elastic element (such as a spring) is provided between the collecting cylinder 9 and the orifice plate 10 to drive the orifice plate 10 to rotate. A limiting groove 13 and an annular groove 14 are provided on the inner wall of the housing 1. The limiting groove 13 is vertically positioned, and the annular groove 14 is located above the limiting groove 13 and the two are connected. Limiting blocks 15 are provided on the side walls of both the collecting cylinder 9 and the orifice plate 10. The two limiting blocks 15 are located in the inner cavity of the limiting groove 13, restricting the orifice plate 10 and preventing it from rotating. After the perforated plate 10 moves up a certain distance (the collecting cylinder 9 approaches the foam area at the top of the inner cavity of the box 1), the limiting block 15 moves out of the limiting groove 13 and enters the inner cavity of the annular groove 14. The restriction on the limiting block 15 disappears, and under the action of the elastic element, the perforated plate 10 rotates, causing the holes of the perforated plate 10 to be misaligned with the through holes, thus sealing the bottom of the collecting cylinder 9. This achieves automatic rotation of the perforated plate 10, so that the bottom of the collecting cylinder 9 is automatically sealed when it approaches the foam.

[0028] It should be noted that when the collection cylinder 9 is installed inside the box 1 for reuse, the limiting block 15 of the perforated plate 10 is inserted into the limiting groove 13, and then the collection cylinder 9 is rotated so that the limiting block 15 on the collection cylinder 9 is aligned with the limiting groove 13. Then the collection cylinder 9 is moved down so that the limiting block 15 of the collection cylinder 9 is also inserted into the limiting groove 13, thereby resetting the collection cylinder 9.

[0029] In this embodiment, as a further optimization, please refer to... Figure 6 The bottom wall of the collection cylinder 9 is provided with a positioning groove, and the bottom of the orifice plate 10 is provided with a guide hole. A positioning block 16 is slidably provided in the guide hole, and an elastic element (such as a spring) is installed between the positioning block 16 and the guide hole. After the elastic element drives the orifice plate 10 to rotate, the positioning block 16 is aligned with the positioning groove. Under the action of the elastic element, the positioning block 16 moves upward and inserts into the positioning groove, which limits the orifice plate 10 so that it will not rotate automatically and avoids leakage at the bottom of the collection cylinder 9.

[0030] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner, characterized in that, Includes the following steps: S1: Remove impurities from the quartzite sample and then screen out colorless and transparent quartzite samples; S2: After low-temperature roasting and water quenching of colorless and transparent quartzite samples, they are dried and then screened to obtain the first quartz sand to be treated. S3: After the first quartz sand to be treated is subjected to magnetic separation, it is then subjected to flotation to obtain the second quartz sand to be treated. S4: After hot-pressing acid leaching of the second type of quartz sand with phosphoric acid, it is cleaned, dried and dried magnetically tested to obtain high-purity quartz sand.

2. The method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner according to claim 1, characterized in that, The specific method for removing impurities from the quartzite sample in step S1 is to wash the quartzite sample with water to remove the soil and impurity minerals attached to the surface of the quartzite sample.

3. The method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner according to claim 1, characterized in that, The specific method for performing low-temperature roasting and water quenching treatment on the colorless and transparent quartzite sample in step S2 is to perform microwave-infrared combined heating and high-pressure water jet water quenching treatment on the colorless and transparent quartzite. The first type of quartz sand to be treated is 40-180 mesh quartz sand.

4. The method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner according to claim 1, characterized in that, The magnetic field strength for magnetic separation in step S3 is 0.6-1.2T.

5. The method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner according to claim 1, characterized in that, In step S4, the hot-press acid leaching reaction temperature is 160-200℃, the reaction pressure is 3-8MPa, the reaction time is 5-9h, the concentration of the phosphoric acid solution is 1-2mol / L, and the liquid-solid ratio is 3:1-6:

1.

6. A flotation device for flotating the first batch of quartz sand to be treated after magnetic separation in the method for preparing high-purity quartz sand for pipe drawing using quartzite in a green and environmentally friendly manner as described in any one of claims 1-5, characterized in that, include: The box (1) is provided with a box cover (2), a discharge port (3) and a drive motor (5). The output shaft of the drive motor (5) extends into the inner cavity of the box (1) and is connected to the rotating rod (6). The rotating rod (6) is provided with blades (7). An airflow channel is opened in the rotating rod (6). An air hole (8) for communicating with the airflow channel is provided on the side wall of the rotating rod (6). An air pipe (4) for communicating with the airflow channel is provided on the rotating rod (6). The inner cavity of the box (1) is provided with a collection cylinder (9), the bottom of the collection cylinder (9) is provided with a through hole, the bottom of the collection cylinder (9) is provided with a perforated plate (10), and the rotating rod (6) is detachably connected to the output shaft of the drive motor (5).

7. A flotation device according to claim 6, characterized in that, The bottom of the inner cavity of the collecting tube (9) is provided with an opening, and a kit (11) is rotatably provided in the opening. The rotating rod (6) is provided with a mounting ring (12) for detachable connection with the kit (11).

8. The flotation device according to claim 7, characterized in that, The collecting cylinder (9) is provided with an elastic element for driving the orifice plate (10) to rotate. The inner side wall of the box (1) is provided with a limiting groove (13) and an annular groove (14). The side walls of the collecting cylinder (9) and the orifice plate (10) are both provided with limiting blocks (15) located in the limiting groove (13).

9. A flotation device according to claim 8, characterized in that, The bottom of the collecting cylinder (9) is provided with a positioning groove, and the perforated plate (10) is provided with a positioning block (16) for inserting into the positioning groove and an elastic element connected to the positioning block (16).

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