Molten salt furnace using semi-coke mixture as reducing agent

Abstract

The utility model relates to a molten salt furnace using a semi-coke mixture as a reducing agent, which comprises a furnace body and a top cover matched with the furnace body, a molten salt tank is arranged at the lower part in the furnace body, and the side wall of the furnace body is provided with a lower slag discharge port, a gas inlet, a graphite electrode, an upper slag discharge port, a feeding port and a gas discharge port which are communicated with the molten salt tank. The lower slag discharging opening and the gas inlet are formed in the lower end of the furnace body, the feeding openings are formed in the middle of the furnace body, the gas discharging opening is formed in the upper end of the furnace body, the upper slag discharging opening is formed between the feeding openings and the lower slag discharging opening, the gas outlet end of the gas inlet is conical, and the multiple feeding openings are formed in the side wall of the furnace body in the circumferential direction at intervals. According to the utility model, the gas inlet is not easy to block, the feeding is easy to disperse through the plurality of feeding holes, the feeding is not easy to accumulate in the molten salt tank, the chlorine utilization rate is high, the chlorine content in the subsequent process tail gas is low, the environment protection is facilitated, and the production cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical metallurgy, and particularly relates to a molten salt furnace using a semi-coke mixture as a reducing agent. Background Art

[0002] The main raw materials for producing titanium tetrachloride are generally: titanium-rich materials, calcined coke, and chlorine gas, and the auxiliary material is industrial salt. During the production process, solid materials are fed into the molten salt furnace through the side wall feeding port of the molten salt furnace, and chlorine gas is introduced into the molten salt furnace through the bottom gas supply port. Titanium tetrachloride is generated in the molten salt furnace at a certain temperature. When the existing molten salt chlorination furnace produces titanium tetrachloride, petroleum coke is generally used as a reducing agent. Since the bottom gas pipe of the existing molten salt furnace has a circular tube structure, it is easy to be blocked. The feeding of the molten salt furnace generally adopts single-side feeding. Due to the internal structure characteristics of the furnace, it is not easy to disperse in a region of the molten salt pool, and the reaction is not sufficient. It is more likely to accumulate at the initial stage of the furnace reaction, resulting in a high chlorine content in the tail gas of the subsequent process, causing environmental protection problems. The existing molten salt furnace is not suitable for using a semi-coke mixture as a reducing agent. Content of the Utility Model

[0003] Aiming at the problems existing in the prior art, the purpose of the utility model is to provide a molten salt furnace using a semi-coke mixture as a reducing agent, in which the gas inlet is not easy to be blocked, the feeding is easy to disperse, it is not easy to accumulate in the molten salt pool, the chlorine utilization rate is high, the chlorine content in the tail gas of the subsequent process is low, which is beneficial to environmental protection and reduces production costs.

[0004] To achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The utility model provides a molten salt furnace using a semi-coke mixture as a reducing agent, which includes a furnace body and a top cover cooperating with it. A molten salt pool is arranged at the lower part inside the furnace body. The side wall of the furnace body is provided with a lower slag discharge port, a gas inlet, a graphite electrode, an upper slag discharge port, a feeding port and a gas discharge port communicated with the molten salt pool. The lower slag discharge port and the gas inlet are arranged at the lower end of the furnace body. The feeding port is arranged in the middle of the furnace body. The gas discharge port is arranged at the upper end of the furnace body. The upper slag discharge port is arranged between the feeding port and the lower slag discharge port. The gas outlet end of the gas inlet is conical. A plurality of feeding ports are arranged at intervals along the circumferential direction of the side wall of the furnace body.

[0006] Preferably, the gas outlet end of the gas inlet is flush with the inner side wall of the furnace body.

[0007] Preferably, the number of the feeding ports is 4.

[0008] Preferably, the discharging end of the feeding port is inclined downward, and the inclination angle is 5-10°.

[0009] Preferably, the bottom of the molten salt pool is a cone, and the cone angle is 25-28°.

[0010] Preferably, a plurality of gas inlets are circumferentially arranged at intervals on the side wall of the furnace body, and the cone angle of the gas outlet end of the gas inlet is 40°.

[0011] Preferably, a spray pipe is arranged at the lower end of the top cover.

[0012] Preferably, the spray pipe is a silicon nitride spray pipe.

[0013] Preferably, the liquid outlet end of the spray pipe is a conical round opening.

[0014] Preferably, multiple circles of round holes are arranged along the circumferential direction of the spray pipe on the side wall of the liquid outlet end of the spray pipe, and the positions of two adjacent circles of round holes are staggered.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] (1) The present utility model adopts the method of adding materials simultaneously through multiple feeding ports at different positions, so that the added materials are more dispersed and uniform, and are in more sufficient contact with chlorine gas, reducing the amount of chlorine gas mixed into the titanium tetrachloride gas. The dissolved amount of chlorine gas in the crude titanium tetrachloride in the cold system is small, and the chlorine content in the process tail gas is reduced from 5000PPm to within 1000ppm. This is not only beneficial to environmental protection, but also improves the utilization rate of chlorine gas and reduces production costs.

[0017] (2) The gas outlet end of the gas inlet of the present utility model is a conical opening, which can increase the chlorine gas flow rate and reduce the blockage of the air inlet. The gas outlet end of the gas inlet of the present utility model is flush with the inner side wall of the furnace body and is at the boundary between the high-temperature molten salt and the refractory material. The chlorine gas flow rate increases by about 20% at this position, which can further reduce the blockage risk of the gas inlet.

[0018] (3) A silicon nitride spray pipe is arranged at the lower end of the top cover of the present utility model. This silicon nitride spray pipe is corrosion-resistant, can reduce the number of maintenance times, and makes the operation of the furnace more stable. Currently, metal spray washing pipes are commonly used in the industry. This spray pipe is easily corroded after contacting with high-temperature chlorine gas in the molten salt furnace and needs to be frequently replaced. Online replacement will affect the temperature inside the furnace, causing the temperature to rise and the reaction to be unstable. Description of the Drawings

[0019] Figure 1 is a schematic diagram of the overall structure of the molten salt furnace of the present utility model;

[0020] Reference numerals: 1. Spray pipe, 2. Lower slag discharge port, 3. Upper slag discharge port, 4. Feeding port, 5. Gas discharge port, 6. Spray pipe, 7. Top cover, 8. Graphite electrode, 9. Gas inlet, 10. Molten salt pool. Detailed Embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0022] Referring Figure 1 , this embodiment provides a molten salt furnace using a semi-coke mixture as a reducing agent, including a furnace body 1 and a top cover 7 cooperating therewith. A lower slag discharge port 2, a gas inlet 9, a graphite electrode 8, an upper slag discharge port 2, a feeding port 4, and a gas discharge port 5 are provided on the side wall of the furnace body 1. A molten salt pool 10 is provided in the lower part of the furnace body 1. The lower slag discharge port 2, the gas inlet 9, the graphite electrode 8, the upper slag discharge port 3, the feeding port 4, and the gas discharge port 5 are all communicated with the molten salt pool 10. The lower slag discharge port 2 and the gas inlet 9 are provided at the lower end of the furnace body 1. The feeding port 4 is provided in the middle of the furnace body 1. The gas discharge port 5 is provided at the upper end of the furnace body 1. The upper slag discharge port 3 is provided between the feeding port 4 and the lower slag discharge port 2. A plurality of feeding ports 4 are provided at intervals along the circumference of the furnace body 1. The gas outlet end of the gas inlet 9 is conical. The mass percentage of semi-coke in the semi-coke mixture is: 30-50%. The distance from the feeding port 4 to the bottom of the furnace body 1 is: 6400-6500 mm. The inner diameter of the upper part of the furnace body 1 is 5200-5400 mm.

[0023] In this embodiment, during the feeding process, by feeding through a plurality of feeding ports 4 simultaneously, the added materials are more dispersed and uniform, making contact with chlorine more sufficient, reducing the amount of chlorine mixed into the titanium tetrachloride gas, and reducing the dissolution amount of chlorine in the crude titanium tetrachloride in the cold system. This is not only beneficial to environmental protection but also improves the utilization rate of chlorine and reduces production costs. In this embodiment, the gas outlet end of the gas inlet 9 is also set as an inwardly converging conical port to increase the outflow speed of chlorine, reduce the blockage of the gas inlet, and prevent affecting the production process.

[0024] Preferably, the gas outlet end of the gas inlet 9 is flush with the inner side wall of the furnace body 1 and is located at the boundary between the high-temperature molten salt and the refractory material. The chlorine flow rate here can be increased by 20%, effectively reducing the blockage of the air inlet.

[0025] Preferably, there are 4 feeding ports 4.

[0026] Preferably, the discharging end of the feeding port 4 is inclined downward, and the inclination angle is 5-10°, so as to ensure that the materials fed from the feeding port 4 can smoothly flow into the molten salt pool without being too fast and causing impact. The inner diameter of the feeding port 4 is preferably designed to be 160 mm.

[0027] Preferably, the bottom of the molten salt pool 10 is conical, and the cone angle is 25-28°, which can ensure that too much heat does not accumulate at the bottom of the molten salt, so as to make the heat of the molten salt uniform.

[0028] Preferably, four gas inlets 9 are arranged at intervals along the circumferential direction of the side wall of the furnace body 1, and the cone angle of the gas outlet end of the gas inlet 9 is 40°.

[0029] Preferably, a spray pipe 6 is arranged at the lower end of the top cover. The spray pipe 6 is preferably a silicon nitride spray pipe, which is corrosion-resistant, can reduce the number of repairs, and make the furnace operate more stably. The liquid outlet end of the spray pipe 6 is a conical round opening, which can increase the water pressure, make the water flow disperse evenly, and cool evenly; a plurality of circles of round holes can also be arranged along the circumferential direction of the spray pipe 6 on the side wall of the liquid outlet end of the spray pipe 6, and the positions of two adjacent circles of round holes are staggered, and the water flow ejected can form multiple layers to enhance the cooling effect. The number of silicon nitride spray pipes can be determined according to requirements.

[0030] Preferably, the graphite electrode 8 uses an ultra-high power graphite electrode as the electrode for heat preservation and heating, and the resistivity is less than 5.2 μΩ·m to ensure that the temperature of the internal molten salt is 700-750°. The outer end of the electrode is cooled by the way of circulating water in the copper water tank.

[0031] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A molten salt furnace using a semi-coke mixture as a reducing agent, characterized in that, It includes a furnace body (1) and a top cover (7) cooperating with it. A molten salt pool (10) is arranged at the lower part inside the furnace body (1). A lower slag discharge port (2), a gas inlet (9), a graphite electrode (8), an upper slag discharge port (3), a feeding port (4) and a gas discharge port (5) which are communicated with the molten salt pool (10) are arranged on the side wall of the furnace body (1). The lower slag discharge port (2) and the gas inlet (9) are arranged at the lower end of the furnace body (1). The feeding port (4) is arranged in the middle of the furnace body (1). The gas discharge port (5) is arranged at the upper end of the furnace body (1). The upper slag discharge port (3) is arranged between the feeding port (4) and the lower slag discharge port (2). The gas outlet end of the gas inlet (9) is conical. A plurality of feeding ports (4) are arranged at intervals along the circumferential direction of the side wall of the furnace body (1).

2. For a molten salt furnace using a semi-coke mixture as a reducing agent according to claim 1, the gas outlet end of the gas inlet (9) is flush with the inner side wall of the furnace body.

3. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 1, characterized in that, There are 4 feeding ports (4).

4. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 1, characterized in that, The discharge end of the feeding port (4) inclines downward, and the inclination angle is 5-10°.

5. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 1, characterized in that, The bottom of the molten salt pool (10) is a cone, and the cone angle is 25-28°.

6. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 1, characterized in that, A plurality of gas inlets (9) are arranged at intervals along the circumferential direction of the side wall of the furnace body (1), and the cone angle of the gas outlet end of the gas inlet (9) is 40°.

7. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 1, characterized in that, A spray pipe (6) is arranged at the lower end of the top cover (7).

8. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 7, characterized in that, The spray pipe (6) is a silicon nitride spray pipe.

9. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 7, characterized in that, The liquid outlet end of the spray pipe (6) is a conical round opening.

10. A molten salt furnace using a semi-coke mixture as a reducing agent according to claim 7, characterized in that, A plurality of circles of round holes are arranged along the circumferential direction of the spray pipe (6) on the side wall of the liquid outlet end of the spray pipe (6), and the positions of two adjacent circles of round holes are staggered.

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