Multi-component waste salt melting multi-field controlled phase change graded separation and purification device and use method

Abstract

The present invention discloses a multi-component waste salt melting multi-field controlled phase change graded separation and purification device, comprising an oxidation furnace body, a salt separation and purification tube, a stainless steel plug, a thermoelectric resistance wire, and an electromagnetic induction heating coil. When the device is in use, medical waste salt is loaded into the oxidation furnace body. Under the action of an electric field and a magnetic field, the furnace cavity is rapidly heated to 900° C. to 1500° C., so that the waste salt is melted and a molten salt oxidation reaction is performed. Under multi-field control, the melting point difference of different salts is utilized, and the molten salts from low melting point to high melting point are melted and oxidized in sequence and flow into the salt separation and purification tube under the action of gravity, and solidify above the stainless steel plug in the salt separation and purification tube to form solidification sections with different melting points. After the molten salt oxidation reaction is completed, the stainless steel plug is removed, the thermoelectric resistance wire is started, and the salt separation and purification tube in the central cavity is heated. The solidified molten salt sections are melted in sequence during the heating process and flow out of the salt separation and purification tube under the action of gravity, thereby achieving graded separation of different salts. The device provided by the present invention has low cost, simple operation, and is easy to implement.

Description

Technical Field

[0001] The invention relates to a method and device for grading, separating and purifying multi-component waste salt by melting multi-field regulation phase change, and belongs to the technical field of molten salt multi-field regulation phase change separation and purification. Background Art

[0002] Pharmaceutical waste salt primarily consists of inorganic salts such as sodium chloride, along with small amounts of nitrates, sulfates, and other inorganic impurities. Furthermore, it contains a large amount of harmful, refractory organic matter, producing a strong fishy odor, and is typically disposed of in landfills as hazardous waste. Open-air storage or dumping poses a significant environmental threat. CN105060314A addresses the problem of waste salt being unable to be sold due to the presence of various organic impurities. It also addresses the issue of organic impurities being introduced into hot air and subsequently forming new pollutants. It provides an effective method for condensing molten salt, ultimately yielding qualified, reusable finished salt. CN111003866A provides a waste salt concentration treatment device, which relates to the field of waste salt concentration, including an evaporation mechanism, a gas-liquid separation mechanism, a precipitation mechanism and a condensation mechanism. The invention adopts a new and simple waste salt liquid concentration treatment process, and utilizes single-effect evaporation technology to concentrate and separate waste salts with different boiling points, thereby realizing resource recovery and utilization, and solving the problem of coking waste salt discharge in a simpler and more efficient way. The condensate separated from the waste salt liquid can be used for pre-desulfurization and water replenishment of coal gas in coking production or other places, thereby realizing resource recovery and utilization. When the device is shut down in an emergency, all the solutions in the system can be discharged into the sedimentation tank to ensure that the device does not discharge externally, does not scale, and that the process does not discharge wastewater. The heat source of the evaporation device can be selected from coke oven flue gas, which can save the operating cost of using steam heating.

[0003] The above methods and existing technologies usually use high-temperature methods to recycle and treat pharmaceutical waste salt. The methods often heat the waste salt to 800-1000°C. The energy consumption of high-temperature treatment of waste salt is high, and the waste salt residue is prone to ringing and agglomeration during the treatment process, causing corrosion to equipment. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a multi-component waste salt melting multi-field controlled phase change graded separation and purification device, which includes an oxidation furnace body, a salt separation and purification tube, a stainless steel plug, a thermoelectric resistance wire, and an electromagnetic induction heating coil. Insulation cotton is arranged between the inner shell and the outer shell of the oxidation furnace body, and an insulation box with a central cavity is arranged at the bottom of the oxidation furnace body. One end of the salt separation and purification tube is arranged at the bottom of the furnace body and is connected to the inner cavity of the oxidation furnace body, and the other end passes through the insulation box. The stainless steel plug is inserted into the inner bottom of the salt separation and purification tube, the thermoelectric resistance wire is arranged in the central cavity, the electromagnetic induction heating coil is arranged at the bottom of the oxidation furnace body, and the electromagnet is arranged on the inner side of the oxidation furnace body cavity;

[0005] When the above-mentioned device is used, medical waste salt is loaded into the oxidation furnace body. Under the action of electric field and magnetic field, the furnace cavity is rapidly raised to 900℃~1500℃ (within 10 seconds), so that the waste salt melts and undergoes molten salt oxidation reaction. Under multi-field control, the melting point difference of different salts is utilized, and the molten salt from low melting point to high melting point is melted and oxidized in sequence and flows into the salt separation and purification tube under the action of gravity. It solidifies above the stainless steel plug in the salt separation and purification tube to form solidification sections with different melting points. After the molten salt oxidation reaction is completed, the stainless steel plug is removed, and the thermoelectric resistance wire is started to heat the salt separation and purification tube in the central cavity. The solidified molten salt sections melt in sequence during the heating process and flow out of the salt separation and purification tube under the action of gravity, thereby realizing the graded separation of different salts.

[0006] The stainless steel plug is fixed by a fixing clip fixed to the bottom of the thermal insulation box.

[0007] The inner diameter of the salt separation and purification tube is 7-9 mm, the length is 250-300 mm, and the distance between the thermoelectric resistance wire and the bottom of the oxidation furnace cavity is 120-180 mm.

[0008] The salt separation and purification tube is sheathed with an insulation tube; the insulation cotton and the insulation tube are made of refractory materials, and the electromagnetic induction heating coil and the electromagnet are made of metal materials such as aluminum, copper, iron, nickel, tin and other conventional conductor composite materials that can be induction heated.

[0009] Beneficial effects of the present invention:

[0010] The present invention utilizes the physical and chemical properties of the molten salt itself. When flowing through the salt separation and purification tube, the molten salt naturally condenses to form a frozen plug. After completing the molten salt oxidation experiment, the center of the salt separation and purification tube is heated to melt the naturally condensed frozen plug, forming a molten salt passage, thereby realizing the discharge of the molten salt, solving the leakage problem that is prone to occur in the existing molten salt oxidation process. In addition, the typical single-component molten salt melting multi-field controlled phase change graded separation and purification technology and equipment provided by the present invention are low-cost, simple in preparation process, and easy to obtain. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the oxidation furnace structure of the present invention;

[0012] In the figure: 1-salt separation and purification tube; 2-central cavity; 3-stainless steel plug; 4-inner shell; 5-insulation cotton; 6-outer shell; 7-insulation box; 8-thermoelectric resistance wire; 9-insulation tube; 10-fixing clamp, 11-electromagnetic induction heating coil; 12-electromagnet. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solutions and advantages of the present invention more understandable, the present invention is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention;

[0014] Example 1: Figure 1 As shown, the device used in this embodiment includes an oxidation furnace body, a salt separation and purification tube 1, a stainless steel plug 3, a thermoelectric resistance wire 8, and an electromagnetic induction heating coil 11. Insulation cotton 5 is provided between the inner shell 4 and the outer shell 6 of the oxidation furnace body. An insulation box 7 with a central cavity 2 is provided at the bottom of the oxidation furnace body. One end of the salt separation and purification tube 1 is provided at the bottom of the furnace body and communicates with the inner cavity of the oxidation furnace body, and the other end passes through the insulation box 7. An insulation tube 9 is provided on the outer surface of the salt separation and purification tube 1. The inner diameter of the salt separation and purification tube 1 is 8 mm, the length is 271 mm, and the material is Inconel 625; the stainless steel plug 3 is inserted into the inner bottom of the salt separation and purification tube 1, the thermoelectric resistance wire 8 is provided in the central cavity 2, the electromagnetic induction heating coil 11 is provided at the bottom of the oxidation furnace body, and the electromagnet 12 is provided inside the inner cavity of the oxidation furnace body; the stainless steel plug is fixed by a fixing clip 10 fixed to the bottom of the insulation box;

[0015] The distance between the thermoelectric resistance wire 8 and the bottom of the oxidation furnace chamber is 181 mm; the length of the stainless steel plug 3 inserted into the salt separation and purification tube 1 is 90 mm; the insulation cotton 5 and the insulation tube 9 are both conventional refractory materials;

[0016] When the above device is used, the stainless steel plug 3 is inserted into the salt separation and purification tube 1 and fixed with a stainless steel fixing clip; 100g of medical waste salt containing sodium sulfate (884℃), potassium sulfate (1067℃) and calcium sulfate (1297℃) are loaded into the oxidation furnace body. Under the action of the electric field and magnetic field (2.0T), the furnace chamber temperature gradually rises from 900℃ to 1300℃, so that the multi-component waste salts are melted in turn and undergo molten salt oxidation reaction. Under multi-field control, the melting point difference of different salts is utilized, and the molten salts from low melting point to high melting point are melted and oxidized in turn and flow into the salt separation and purification tube under the action of gravity. The molten salt solidifies in the molten salt tube above the stainless steel plug in the salt separation and purification tube (the temperature of the salt separation and purification tube 1 is 72°C at this time), and solidified segments of sodium sulfate, potassium sulfate, and calcium sulfate are formed from bottom to top. After the molten salt oxidation reaction is completed, the stainless steel fixing clamp 10 is released to fix the position of the stainless steel plug 3, the stainless steel plug is removed, and the thermocouple 8 is started to heat the salt separation and purification tube in the central cavity. The temperature gradually rises from 900°C to 1300°C. The solidified molten salt segments melt in sequence during the heating process and flow out of the salt separation and purification tube under the action of gravity, thereby realizing the graded separation of sodium sulfate, potassium sulfate, and calcium sulfate. Example 2

[0017] The device of this embodiment is the same as that of embodiment 1. When in use, 100 g of medical waste salt containing sodium sulfite (912°C), sodium fluoride (997°C), magnesium fluoride (1261°C), and calcium fluoride (1402°C) is loaded into the oxidation furnace body. Under the action of the electric field and magnetic field (3.0T), the furnace chamber temperature gradually rises from 912°C to 1402°C, causing the waste salt to melt and undergo molten salt oxidation reaction. Under multi-field control, the melting point difference of different salts is utilized, and the molten salts from low melting point to high melting point are melted and oxidized in sequence and flow into the salt separation and purification tube under the action of gravity. The non-ferrous metals in the salt separation and purification tube are heated and cooled. The upper part of the stainless steel plug solidifies (the temperature of the salt separation and purification tube 1 is 78°C at this time), and solidified sections of sodium sulfite, sodium fluoride, magnesium fluoride, and calcium fluoride are formed from bottom to top. After the molten salt oxidation reaction is completed, the stainless steel fixing clamp 10 is released from the position fixation of the stainless steel plug 3, the stainless steel plug is removed, and the thermocouple 8 is started to heat the salt separation and purification tube in the central cavity, and the temperature gradually rises from 900°C to 1402°C. The solidified molten salt sections melt in sequence during the heating process and flow out of the salt separation and purification tube under the action of gravity, thereby achieving the graded separation of sodium sulfite, sodium fluoride, magnesium fluoride, and calcium fluoride.

[0018] The above description is merely a preferred embodiment of the present invention. Given that those skilled in the art can make appropriate changes and modifications to the above embodiments, the present invention is not limited to the specific embodiments described above. Some modifications and changes to the present invention should also fall within the scope of protection of the claims of the present invention.

Claims

1. A multi-component waste salt melting multi-field controlled phase change fractionation separation and purification device, characterized in that: The invention comprises an oxidation furnace body, a salt separation and purification tube (1), a stainless steel plug (3), a thermoelectric resistance wire (8), and an electromagnetic induction heating coil (11); a heat-insulating cotton (5) is arranged between the inner shell (4) and the outer shell (6) of the oxidation furnace body; a heat-insulating box with a central cavity (2) is arranged at the bottom of the oxidation furnace body; one end of the salt separation and purification tube (1) is arranged at the bottom of the furnace body and is connected to the inner cavity of the oxidation furnace body; the other end passes through the heat-insulating box (7); the stainless steel plug (3) is inserted into the inner bottom of the salt separation and purification tube (1); the thermoelectric resistance wire (8) is arranged in the central cavity (2); the electromagnetic induction heating coil (11) is arranged at the bottom of the oxidation furnace body; and the electromagnet (12) is arranged on the inner side of the cavity of the oxidation furnace body; When the above-mentioned device is used, medical waste salt is loaded into the oxidation furnace body. Under the action of the electric field and magnetic field, the furnace cavity is rapidly raised to 900℃~1500℃, causing the waste salt to melt and undergo a molten salt oxidation reaction. Under multi-field control, the melting point differences of different salts are utilized, and the molten salts from low melting point to high melting point are melted and oxidized in sequence and flow into the salt separation and purification tube under the action of gravity. They solidify above the stainless steel plug in the salt separation and purification tube to form solidification segments with different melting points. After the molten salt oxidation reaction is completed, the stainless steel plug is removed, and the thermoelectric resistance wire is started to heat the salt separation and purification tube in the central cavity. The solidified molten salt segments melt in sequence during the heating process and flow out of the salt separation and purification tube under the action of gravity, thereby realizing the graded separation of different salts.

2. The multi-component waste salt melting multi-field controlled phase change fractionation separation and purification device according to claim 1, characterized in that: The stainless steel plug is secured by a retaining clip (10) fixed to the bottom of the insulated box.

3. The multi-component waste salt melting multi-field controlled phase change fractionation separation and purification device according to claim 1, characterized in that: The inner diameter of the salt separation and purification tube is 7-9 mm and the length is 250-300 mm.

4. The multi-component waste salt melting multi-field controlled phase change fractionation separation and purification device according to claim 1, characterized in that: The distance between the thermoelectric resistance wire (8) and the bottom of the oxidation furnace chamber is 120-180 mm.

5. The multi-component waste salt melting multi-field controlled phase change fractionation separation and purification device according to claim 1, characterized in that: The salt separation and purification tube (1) is sheathed with an insulation tube (9).

6. The multi-component waste salt melting multi-field controlled phase change fractionation separation and purification device according to claim 1, characterized in that: The thermal insulation cotton (5) and the thermal insulation pipe (9) are refractory materials.

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