Device for preparing selenium dioxide

Abstract

The utility model relates to a device for preparing selenium dioxide, which comprises a crude selenium filter press, a neutralizing washing tank, a neutralizing filter press, a drying melting furnace, a condenser, a crude selenium ingot casting device, a crusher, a forehearth generator, an oxidizing furnace, a product collecting box, a sedimentation collecting box and a buffer tank. The device disclosed by the utility model is high in selenium recycling rate, low in production cost and less in three wastes, can solve the problems of corrosion, short service life and lower selenium recycling rate of equipment for producing selenium dioxide from crude selenium, and achieves the purpose of clean production by recycling wastewater and waste residues.

Description

Technical Field

[0001] This utility model relates to an apparatus for preparing selenium dioxide, specifically belonging to the technical field of selenium dioxide manufacturing equipment. Background Technology

[0002] Currently, the main industrial method for preparing selenium dioxide is the oxygen oxidation method, with the primary raw material being crude selenium produced during the smelting of copper anode slime. In actual production, the crude selenium may contain Cl-. - SO3 2- If acid radicals and H2SeO3 are not recovered and purified beforehand, they will corrode subsequent equipment, severely reducing its service life and increasing the loss rate of selenium in crude selenium, thus reducing its recovery rate. Furthermore, the crude selenium particles produced during copper anode mud smelting are generally less than 0.05 mm in size. Directly feeding them into the oxidation furnace for oxidation is difficult due to their small particle size, making it hard to control the rate and extent of the oxidation reaction, thereby reducing the quality of the selenium dioxide product. Traditional oxygen oxidation methods use high-temperature direct heating of crude selenium to react with oxygen to produce selenium dioxide. However, during this process, a large amount of selenium evaporates, and some selenium does not have time to react with oxygen, resulting in incomplete oxidation and the presence of elemental selenium in the selenium dioxide product, severely affecting its purity. To address these issues, this invention, through the structural design of the selenium dioxide preparation device, effectively solves the problems of equipment corrosion, short service life, and low selenium recovery rate in the production of selenium dioxide from crude selenium. Summary of the Invention

[0003] In view of the above situation, this utility model proposes an apparatus for preparing selenium dioxide. Through the arrangement of the apparatus structure, the problems of corrosion, short service life and low selenium recovery rate of equipment for producing selenium dioxide from crude selenium are solved.

[0004] The apparatus for preparing selenium dioxide according to this utility model consists of a crude selenium filter press (1), a neutralization washing tank (2), a neutralization filter press (3), a drying and melting furnace (4), a condenser (5), a crude selenium ingot casting device (6), a crusher (7), a front furnace generator (8), an oxidation furnace (9), a product collection box (10), a sedimentation collection box (11), and a buffer tank (12).

[0005] Among them, the crude selenium filter press (1) is connected to the feed inlet of the neutralization washing tank (2) via a conveyor belt. The discharge outlet of the neutralization washing tank (2) is connected to the neutralization filter press (3) via a pipe, and then connected to the feed inlet of the drying melting furnace (4) via a conveyor belt. The discharge outlet of the drying melting furnace (4) is connected to the crude selenium ingot casting device (6) via a pipe. The crude selenium ingot casting device (6) is connected to the crusher (7) and the crusher (7) is connected to the front furnace generator (8) via a conveyor belt. The discharge outlet of the front furnace generator (8) is connected to the feed inlet of the oxidation furnace (9) via a pipe. The discharge outlet of the oxidation furnace (9) is connected to the feed inlet of the product collection box (10) via a pipe. The top air outlet of the product collection box (10) is connected to the air inlet of the settling collection box (11) via a pipe. The air outlet of the settling collection box (11) is connected to the air inlet of the buffer tank (12).

[0006] The crude selenium filter press (1) is equipped with a crude selenium raw material inlet, a water inlet, and a filtrate outlet.

[0007] The neutralization washing tank (2) is equipped with a stirring paddle, a caustic soda inlet, and a condensate inlet.

[0008] The filter press (3) is equipped with a filtrate discharge port.

[0009] The drying and melting furnace (4) is connected to the condenser (5), and the condenser (5) is connected to the water inlet of the neutralization and washing tank (2) through a connecting pipe.

[0010] Both the fore furnace generator (8) and the oxidation furnace (9) are equipped with oxygen inlets.

[0011] Both the product collection box (10) and the sedimentation collection box (11) are equipped with selenium dioxide discharge ports at their bottoms.

[0012] The buffer tank (12) is provided with a wastewater outlet at the bottom and a waste gas outlet on the side of the tank.

[0013] The beneficial effects of this utility model are as follows: By combining a neutralization washing tank, a drying melting furnace, and a condenser, this utility model removes acid ions from crude selenium and collects and returns the condensate to the selenite system for reuse. This reduces the corrosion of downstream equipment by the material, extends the equipment's service life, and the condensate is reused in the neutralization washing tank. A pre-furnace generator is installed before the oxidation furnace to perform the first stage of oxidation on the crude selenium, followed by a second stage of oxidation in the oxidation furnace, ensuring complete oxidation of the crude selenium and high purity and yield of selenium dioxide. A settling collection box allows for the sedimentation and recovery of selenium dioxide from the waste gas generated during the secondary oxidation process. Wastewater generated by the buffer tank is returned to the selenite system for reuse, effectively improving the selenium recovery rate. This utility model device has a high selenium recovery rate, low production cost, and minimal waste. It solves the problems of corrosion, short service life, and low selenium recovery rate in crude selenium to selenium dioxide production equipment. The recycling of wastewater and waste residue achieves the goal of clean production. Attached Figure Description

[0014] Figure 1 : Schematic diagram of the apparatus for preparing selenium dioxide according to this invention;

[0015] The components include: 1. Crude selenium filter press; 2. Neutralization and washing tank; 3. Neutralization filter press; 4. Drying and melting furnace; 5. Condenser; 6. Crude selenium ingot casting device; 7. Crusher; 8. Fore-furnace generator; 9. Oxidation furnace; 10. Product collection box; 11. Settling collection box; 12. Buffer tank. Detailed Implementation

[0016] Example 1

[0017] The apparatus for preparing selenium dioxide according to this invention consists of a crude selenium filter press (1), a neutralization washing tank (2), a neutralization filter press (3), a drying and melting furnace (4), a condenser (5), a crude selenium ingot casting device (6), a crusher (7), a fore furnace generator (8), an oxidation furnace (9), a product collection box (10), a sedimentation collection box (11), and a buffer tank (12).

[0018] Among them, the crude selenium filter press (1) is connected to the feed inlet of the neutralization washing tank (2) via a conveyor belt. The discharge outlet of the neutralization washing tank (2) is connected to the neutralization filter press (3) via a pipe, and then connected to the feed inlet of the drying melting furnace (4) via a conveyor belt. The discharge outlet of the drying melting furnace (4) is connected to the crude selenium ingot casting device (6) via a pipe. The crude selenium ingot casting device (6) is connected to the crusher (7) and the crusher (7) is connected to the front furnace generator (8) via a conveyor belt. The discharge outlet of the front furnace generator (8) is connected to the feed inlet of the oxidation furnace (9) via a pipe. The discharge outlet of the oxidation furnace (9) is connected to the feed inlet of the product collection box (10) via a pipe. The top air outlet of the product collection box (10) is connected to the air inlet of the settling collection box (11) via a pipe. The air outlet of the settling collection box (11) is connected to the air inlet of the buffer tank (12).

[0019] The crude selenium filter press (1) is equipped with a crude selenium raw material inlet, a water inlet, and a filtrate outlet. The neutralization and washing tank (2) is equipped with a stirring paddle and a caustic soda inlet and a condensate inlet. The filter press (3) is equipped with a filtrate outlet. The drying and melting furnace (4) is connected to the condenser (5), and the condenser (5) is connected to the water inlet of the neutralization and washing tank (2) through a connecting pipe. The fore-furnace generator (8) and the oxidation furnace (9) are both equipped with oxygen inlets. The bottom of the product collection box (10) and the settling collection box (11) are both equipped with selenium dioxide outlets. The bottom of the buffer tank (12) is equipped with a wastewater outlet, and the side of the tank is equipped with a waste gas outlet.

[0020] Example 2

[0021] The crude selenium material is added to a crude selenium filter press (1) for filtration. The filtrate is returned to the selenite system for reuse. The filtered crude selenium is then transferred to a neutralization and washing tank (2) for neutralization with caustic soda and followed by water washing. The washing process ends when the pH of the crude selenium washing solution reaches neutrality. During the neutralization and water washing process, acidic substances (mainly Cl) carried in the crude selenium are removed. - SO3 2- Selenite (H2SeO3) undergoes a neutralization reaction with sodium hydroxide, preventing corrosion of the equipment in subsequent processes and extending its service life. The saline wastewater generated from the neutralization wash is returned to the selenite system for recycling, improving the efficiency of selenium recovery.

[0022] After neutralization and washing, the crude selenium is filtered by a filter press (3), and the filtrate is returned to the selenite system. It is then transferred to a drying and melting furnace (4), where the drying temperature is set at 110°C and the melting temperature is set at 217°C. The water vapor generated during the drying and melting process is condensed by a condenser (5) and returned to the neutralization and washing tank (2) through a condensate pipe (8) for reuse as washing water, thus reducing the cost of production water.

[0023] The molten crude selenium material is cast into crude selenium ingots. After cooling, the crude selenium ingots are crushed into small pieces and placed in the front furnace generator (8) for melting and sublimation. Oxygen is used for the first stage of oxidation reaction, in which part of the selenium is oxidized into selenium dioxide. The unoxidized selenium continues to undergo the second stage of oxidation reaction in the oxidation furnace (9). Afterward, the selenium dioxide product enters the product collector (10) through the pipeline. The high-temperature waste gas generated during the oxidation reaction process carries some selenium dioxide into the settling collection box (11) and the buffer tank (12). After being absorbed by water in the buffer tank (12), it is returned to the selenite system for continued recycling. The waste gas is discharged through the pipeline.

Claims

1. An apparatus for preparing selenium dioxide, characterized in that: The device consists of a crude selenium filter press (1), a neutralization washing tank (2), a neutralization filter press (3), a drying and melting furnace (4), a condenser (5), a crude selenium ingot casting device (6), a crusher (7), a fore furnace generator (8), an oxidation furnace (9), a product collection box (10), a sedimentation collection box (11), and a buffer tank (12). Among them, the crude selenium filter press (1) is connected to the feed inlet of the neutralization washing tank (2) via a conveyor belt. The discharge outlet of the neutralization washing tank (2) is connected to the neutralization filter press (3) via a pipe, and then connected to the feed inlet of the drying melting furnace (4) via a conveyor belt. The discharge outlet of the drying melting furnace (4) is connected to the crude selenium ingot casting device (6) via a pipe. The crude selenium ingot casting device (6) is connected to the crusher (7) and the crusher (7) is connected to the front furnace generator (8) via a conveyor belt. The discharge outlet of the front furnace generator (8) is connected to the feed inlet of the oxidation furnace (9) via a pipe. The discharge outlet of the oxidation furnace (9) is connected to the feed inlet of the product collection box (10) via a pipe. The top air outlet of the product collection box (10) is connected to the air inlet of the settling collection box (11) via a pipe. The air outlet of the settling collection box (11) is connected to the air inlet of the buffer tank (12).

2. The apparatus for preparing selenium dioxide according to claim 1, characterized in that: The crude selenium filter press (1) is equipped with a crude selenium raw material inlet, a water inlet, and a filtrate outlet.

3. The apparatus for preparing selenium dioxide according to claim 1, characterized in that: The neutralization washing tank (2) is equipped with a stirring paddle, a caustic soda inlet, and a condensate inlet.

4. The apparatus for preparing selenium dioxide according to claim 1, characterized in that: The filter press (3) is equipped with a filtrate discharge port.

5. The apparatus for preparing selenium dioxide according to claim 1, characterized in that: The drying and melting furnace (4) is connected to the condenser (5), and the condenser (5) is connected to the water inlet of the neutralization and washing tank (2) through a connecting pipe.

6. The apparatus for preparing selenium dioxide according to claim 1, characterized in that: Both the fore furnace generator (8) and the oxidation furnace (9) are equipped with oxygen inlets.

7. The apparatus for preparing selenium dioxide according to claim 1, characterized in that: Both the product collection box (10) and the sedimentation collection box (11) are equipped with selenium dioxide discharge ports at their bottoms.

8. The apparatus for preparing selenium dioxide according to claim 1, characterized in that: The buffer tank (12) is provided with a wastewater outlet at the bottom and a waste gas outlet on the side of the tank.

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