Quartz sand chlorination device and chlorination method

Abstract

The invention provides a quartz sand chlorination device and a chlorination method.The quartz sand chlorination device comprises a chlorination heat preservation box, a spiral pipe is arranged in the chlorination heat preservation box, a heating device and a heat preservation device are arranged in a gap between the chlorination heat preservation box and the spiral pipe, the spiral pipe is provided with an air inlet and an air outlet, and one end of the spiral pipe is sequentially communicated with a feeding device, a draught fan and a condensation bin; the other end of the air outlet is communicated with the discharging device; and the air outlet is communicated with the condensing bin. The quartz sand chlorination device is communicated with the condensation bin and the fan through the gas outlet, chlorine and hydrogen chloride gas can be recycled, waste gas emission is reduced, the environment is protected, and the chlorine production cost is reduced; compared with a three-section type chlorination purification furnace, the quartz sand chlorination device has the advantages that the space utilization rate is increased, and the occupied space is reduced; according to the quartz sand chlorination device, a boiling flow method can be realized through the fan, so that quartz sand in the spiral pipe is suspended in chlorine for chlorination reaction, and the chlorination efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of quartz sand purification, in particular to a quartz sand chlorination device and a chlorination method. Background Art

[0002] High-purity quartz sand (SiO2 purity ≥99.99%) is a core raw material for high-end industries such as semiconductors, optical fiber, and photovoltaics. Its quality directly impacts the performance of end products. Traditional purification processes include flotation, pickling, high-temperature calcination, and purification. Chlorination is a key step in this process. This process involves the high-temperature reaction of HCl and Cl2 gases with impurity elements (such as Al, Fe, K, and Na) in the quartz sand to produce gaseous chlorides, achieving deep impurity removal.

[0003] However, existing chlorination furnace equipment and processes still face the following technical bottlenecks: Most chlorination furnaces use a static or unidirectional flow reaction mode, resulting in insufficient contact between the quartz sand and the chlorine gas, leading to a low reaction rate. For example, Chinese invention patent publication number CN119034645A discloses a three-stage chlorination purification furnace using high-purity quartz sand. Although this patent implements a staged process, the heat exchange efficiency during the preheating stage is insufficient, requiring a long time to heat the material, increasing energy consumption and space utilization, and the chlorination effect is not high. Toxic gases such as HCl and Cl2 generated during the chlorination process can easily cause environmental pollution if not fully recovered. Although the existing technology incorporates a closed collection device, the gas utilization rate is low. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to improve the chlorination efficiency of quartz sand and the gas utilization rate.

[0005] The present invention solves the above technical problems through the following technical means:

[0006] A first aspect of the present invention provides a quartz sand chlorination device, comprising a chlorination insulation box, a spiral tube arranged in the chlorination insulation box, a heating device and a heat preservation device arranged in the gap between the chlorination insulation box and the spiral tube, an air inlet and an air outlet arranged in the spiral tube, one end of the spiral tube being connected to a feeding device, a fan and a condensation bin in sequence, the other end of the spiral tube being connected to a discharging device, and the air outlet being connected to the condensation bin.

[0007] Beneficial effects: The quartz sand chlorination device of the present invention is connected to the condensation bin through the gas outlet, and can realize the recycling of chlorine and hydrogen chloride gas generated by the reaction, reduce waste gas emissions, protect the environment, and reduce the cost of chlorine production; compared with a three-stage chlorination purification furnace, the quartz sand chlorination device of the present invention improves space utilization and reduces occupied space; the quartz sand chlorination device of the present invention can realize the "boiling flow method" through the fan, so that the quartz sand in the spiral tube is suspended in the chlorine to carry out a chlorination reaction, thereby improving the chlorination efficiency.

[0008] Preferably, the heating device comprises a U-shaped silicon carbon rod, and the U-shaped silicon carbon rod is fixed on the outside of the spiral tube.

[0009] Preferably, a heat-insulating device is provided on the outside of the spiral tube, the heat-insulating device is heat-insulating cotton, and the U-shaped silicon carbon rod is fixed between the heat-insulating cotton and the spiral tube.

[0010] Preferably, the heating device comprises a straight silicon carbon rod, and the straight silicon carbon rod is fixed inside the spiral tube.

[0011] Beneficial effect: The present invention improves the heating rate and reduces energy consumption by using a U-shaped silicon carbon rod in combination with a straight silicon carbon rod for surrounding heating.

[0012] Preferably, the air inlet and the air outlet are both inclined, with an inclination angle of 30-60°.

[0013] Beneficial effect: The present invention arranges the air inlet and the air outlet at an angle, wherein the air inlet is arranged at an angle to reduce pressure, which is beneficial for the fan to send gas into the chlorination insulation box; the air outlet is arranged at an angle to reduce pressure and make better use of gas discharge.

[0014] Preferably, the air outlet is provided in plurality, and the inclination angles of the plurality of air outlets are the same.

[0015] Beneficial effects: The present invention provides multiple gas outlets to reduce flow pressure, facilitate the separation of quartz sand from gas, and accelerate the recycling of chlorine and hydrogen chloride gases.

[0016] Preferably, the discharging device is a storage tank, and a dust removal device is provided above the storage tank; the dust removal device is an air suction device.

[0017] Beneficial effect: The dust removal device of the present invention is provided to prevent the dust of the chlorinated quartz sand from spreading. Since the chlorinated quartz sand may contain a small amount of chlorine and hydrogen chloride gas, the dust removal device is provided with an air suction device to absorb the dust and gas in the chlorinated quartz sand through the air suction device.

[0018] Preferably, the air inlet is arranged between the feeding device and the fan; the air outlet is arranged between the chlorination insulation box and the discharging device.

[0019] Beneficial effect: The present invention arranges the air inlet between the feeding device and the fan, which is conducive to the mixing of chlorine and quartz sand for chlorination reaction, and then suspends the quartz sand in the chlorine through the fan to efficiently complete the chlorination reaction.

[0020] Preferably, the feeding device is a feeding hopper.

[0021] Preferably, the condensation bin is connected to a treatment box and is provided with a valve, and the treatment box contains alkali solution.

[0022] Beneficial effect: When the reaction is finished, nitrogen is introduced through the air inlet to discharge the gas in the device into the processing box, so that the gas reacts with the alkali solution to ensure production safety.

[0023] A second aspect of the present invention provides a quartz sand chlorination method, using the above-mentioned quartz sand chlorination device, comprising the following steps:

[0024] The heating device heats the spiral tube to 1200-1300°C, and then a fan is used to feed quartz sand and chlorine gas in a mass ratio of 1:2.2-2.6 into the spiral tube for a chlorination reaction. The gaseous chloride and hydrogen chloride generated by the reaction or unreacted chlorine gas enter the condensation bin through the gas outlet. The gaseous chloride sublimates into a solid and deposits in the condensation bin when cooled, while the hydrogen chloride and chlorine gas are fed back into the chlorination insulation box by the fan for a reaction. After the reaction is completed, the chlorinated quartz sand flows out through the discharging device.

[0025] Preferably, the wind speed of the fan is 15 to 22 m / s, and the reaction time is 50 to 60 min.

[0026] Beneficial effects: The quartz sand chlorination device of the present invention can react impurities such as Al, Fe, K, and Na in the quartz sand with chlorine through a chlorination method, generate corresponding chlorides for desublimation and removal, effectively purify the quartz sand, and improve the chlorination efficiency; the chlorine and hydrogen chloride gases in the reaction process are recycled by a fan, thereby improving the gas utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of the quartz sand chlorination device in the embodiment;

[0028] Figure 2 2 is a schematic structural diagram of a U-shaped silicon carbon rod in an embodiment;

[0029] Figure 3 Schematic diagram of the structure of the spiral tube in the embodiment. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0031] In the description of the invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the invention; in addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. It should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] according to Figure 1-3 As shown, this embodiment 1 provides a quartz sand chlorination device, which includes a chlorination insulation box 10, wherein a spiral tube 11 is provided in the chlorination insulation box 10, one end of the spiral tube 11 is connected to the feeding device, the fan 20 and the condensation bin 50 through a pipeline in sequence, and the other end is connected to the discharging device through a pipeline, a first valve (not shown) is provided between the fan 20 and the feeding device, the other end of the condensation bin 50 is connected to the treatment box 70 and is provided with a second valve (not shown), the treatment box 70 contains alkali solution, and the feeding device is a feed hopper 30.

[0033] like Figure 3 As shown, a vertically placed spiral tube 11 is provided inside the chlorination insulation box 10. The spiral tube 11 is made of 4N8 high-purity quartz sand, which can prevent impurities in the spiral tube 11 from contaminating the quartz sand.

[0034] The spiral tube 11 is provided with a heating device, which includes a U-shaped silicon carbon rod 13 (such as Figure 2 As shown) and a straight silicon carbide rod 12, the straight silicon carbide rod 12 is fixed inside the spiral tube 11, the U-shaped silicon carbide rod 13 is fixed on the outside of the spiral tube 11, a plurality of U-shaped silicon carbide rods 13 are arranged on the outside of the spiral tube 11 from top to bottom, and the outside of the spiral tube 11 is further provided with insulation cotton 14, and the U-shaped silicon carbide rod 13 is arranged between the insulation cotton 14 and the spiral tube 11.

[0035] The spiral tube 11 is provided with an air inlet 15 at the bottom, with an angle of 45° between the air inlet 15 and the pipe. The air inlet 15 is used to introduce chlorine or nitrogen. The feeding device is used to add quartz sand. The air inlet 15 is located between the feeding device and the fan 20, which facilitates the mixing of chlorine and quartz sand before the chlorination reaction. The fan has a wind speed of 15 to 22 m / s. The quartz sand is intermittently driven forward in the spiral tube 11 due to the fluid mechanics, so that the quartz sand is suspended in the chlorine and the chlorination reaction is completed efficiently.

[0036] The spiral tube 11 is provided with a gas outlet 16 at the top, and there are multiple gas outlets 16. In this embodiment, there are three gas outlets 16, which reduce the pressure of the gas flow, are beneficial to the separation of quartz sand and gas, and accelerate the recycling of chlorine and hydrogen chloride gases. The angle between the gas outlet 16 and the pipeline is 45°, and it is inclined to further reduce the flow pressure and be more conducive to the discharge of gas.

[0037] The gas outlet 16 is provided between the chlorination insulation box 10 and the discharge device, and the spiral tube 11 is connected to the discharge device vertically downward after the gas outlet 16 is provided. This design is for the purpose of facilitating the discharge of the chlorinated quartz sand.

[0038] The discharging device is a storage tank 40. In order to prevent the dust of the chlorinated quartz sand from spreading, since the chlorinated quartz sand may contain a small amount of chlorine and hydrogen chloride gas, a dust removal device 60 is provided on the top of the storage tank 40. The dust removal device 60 is an air suction device that can absorb dust and gas in the chlorinated quartz sand.

[0039] The gas outlet 16 is connected to the condensation chamber 50 through a pipeline. The temperature inside the condensation chamber 50 is room temperature. When the gaseous chloride enters the condensation chamber 50 through the gas outlet 16, it is cooled and sublimated, and directly changes from gas to solid and is deposited in the condensation chamber 50. The chlorine and hydrogen chloride gases are sent back to the chlorination insulation box 10 through the fan 20 for recycling.

[0040] The chlorination method of the quartz sand chlorination device of this embodiment is as follows:

[0041] In this embodiment, the spiral tube 11 is heated to 1200° C. using a U-shaped silicon carbide rod 13 and a straight silicon carbide rod 12. Quartz sand is then added to a feed hopper 30. The air inlet 15 is connected to a chlorine gas pipe. The mass ratio of quartz sand to chlorine is controlled to be 1:2.4, and the chlorination reaction is carried out in the chlorination insulation box 10. In this embodiment, the quartz sand and chlorine are fed into the spiral tube 11 of the chlorination insulation box 10 by a fan 20. The average wind speed of the fan is 20 m / s. The fan 20 intermittently transports the quartz sand into the spiral tube 11, so that the quartz sand is suspended in the chlorine gas for reaction, and the chlorination reaction is efficiently completed. The reaction time is 60 minutes.

[0042] The gaseous chloride, hydrogen chloride gas and unreacted chlorine generated during the reaction are transported to the condensation chamber 50 through the gas outlet 16. The gaseous chloride is condensed into solid and deposited in the condensation chamber 50, while the hydrogen chloride gas and chlorine gas are sent back to the spiral tube 11 through the fan 20 to react.

[0043] When the reaction is finished, the chlorinated quartz sand flows into the dust removal device 60 through the pipeline, absorbs the dust and gas in the chlorinated quartz sand, and further flows into the storage tank 40 for storage.

[0044] At this time, close the first valve, open the second valve, and introduce nitrogen through the air inlet 15 to discharge the gas in the quartz sand chlorination device into the processing box 70. The gas further reacts with the alkali solution to ensure production safety.

[0045] The quartz sand chlorination device of this embodiment can react impurities such as Al, Fe, K, and Na in the quartz sand with chlorine through a chlorination method to generate corresponding chlorides for desublimation and removal, thereby effectively purifying the quartz sand and improving the chlorination efficiency. The chlorine and hydrogen chloride gases in the reaction process are recycled by a fan, thereby improving gas utilization.

[0046] Comparative Example 1

[0047] This comparative example provides a quartz sand chlorination method. This comparative example uses the quartz sand chlorination device of Example 1. Compared with Example 1, this example is different in that the wind speed of the fan is 35 m / s.

[0048] Table 1 is the analysis results of impurity content after chlorination of quartz sand

[0049] Fe Na K Al Example 1 <0.05ppm <0.06ppm <0.09ppm 15ppm Comparative Example 1 0.3ppm 0.35ppm <0.42ppm 15ppm

[0050] According to the data in Table 1, only appropriate wind speed can remove impurities such as Al, Fe, K, and Na in quartz sand, while inappropriate wind speed will not produce ideal impurity removal effect.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A quartz sand chlorination device, characterized in that: The invention comprises a chlorination heat preservation box (10), wherein a spiral tube (11) is provided in the chlorination heat preservation box (10), a heating device and a heat preservation device are provided in the gap between the chlorination heat preservation box (10) and the spiral tube (11), and the spiral tube (11) is provided with an air inlet (15) and an air outlet (16). One end of the spiral tube (11) is connected to a feeding device, a fan (20) and a condensation bin (50) in sequence, and the other end is connected to a discharging device, and the air outlet (16) is connected to the condensation bin (50).

2. The quartz sand chlorination device according to claim 1, characterized in that The heating device comprises a U-shaped silicon carbon rod (13), and the U-shaped silicon carbon rod (13) is fixed on the outside of the spiral tube (11).

3. The quartz sand chlorination device according to claim 2, characterized in that A heat preservation device is provided on the outside of the spiral tube (11), wherein the heat preservation device is heat preservation cotton (14), and the U-shaped silicon carbon rod (13) is fixed between the heat preservation cotton (14) and the spiral tube (11).

4. The quartz sand chlorination device according to claim 1 or 2, characterized in that The heating device comprises a straight silicon carbon rod (12), and the straight silicon carbon rod (12) is fixed inside the spiral tube (11).

5. The quartz sand chlorination device according to claim 1, characterized in that The air inlet (15) and the air outlet (16) are both inclined, with an inclination angle of 30-60°.

6. The quartz sand chlorination device according to claim 5, characterized in that There are multiple air outlets (16), and the inclination angles of the multiple air outlets (16) are the same.

7. The quartz sand chlorination device according to claim 1, characterized in that The discharging device is a storage tank (40), and a dust removal device (60) is provided above the storage tank (40); the dust removal device (60) is an air suction device.

8. The quartz sand chlorination device according to claim 1, characterized in that: The air inlet (15) is arranged between the feeding device and the fan (20); and the air outlet (16) is arranged between the chlorination insulation box (10) and the discharging device.

9. The quartz sand chlorination device according to claim 1, characterized in that: The condensation bin (50) is communicated with a treatment box (70) and is provided with a valve, and the treatment box (70) contains alkali solution.

10. A quartz sand chlorination method, characterized in that: The quartz sand chlorination device according to any one of claims 1 to 9 comprises the following steps: The spiral tube (11) is heated to 1200-1300° C. by a heating device, and then quartz sand and chlorine are fed into the spiral tube (11) at a mass ratio of 1:2.2-2.6 by a fan (20) for chlorination reaction. The gaseous chloride, hydrogen chloride and unreacted chlorine generated by the reaction enter the condensation chamber (50) through the gas outlet (16). The gaseous chloride sublimates into a solid when cooled and is deposited in the condensation chamber (50), while the hydrogen chloride and chlorine are fed into the spiral tube (11) again by the fan (20) for reaction. After the reaction is completed, the chlorinated quartz sand flows out through the discharge device.

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