Industrial sodium-based waste salt resource utilization device

Abstract

The utility model particularly relates to an industrial sodium-based waste salt resource utilization device which is characterized by comprising a waste salt dissolving and purifying device, a nanofiltration device, a sodium sulfate saline water blending tank, a sodium sulfate and ammonium chloride double decomposition device and a freezing crystallization device which are connected in sequence, the water producing end of the nanofiltration device is connected with a first sodium chloride brine blending tank and a second sodium chloride brine blending tank through pipelines, and the outlet end of the first sodium chloride brine blending tank is connected with the feeding end of a sodium chloride and ammonium bicarbonate double decomposition device; the ammonium chloride discharging end of the sodium chloride and ammonium bicarbonate double decomposition device is connected with the feeding end of the sodium sulfate and ammonium chloride double decomposition device through a pipeline, and the discharging end of the second sodium chloride brine blending tank is connected with the feeding end of the ionic membrane electrolytic cell through a pipeline; and a sodium chloride outlet end of the sodium sulfate and ammonium chloride double decomposition device is respectively connected with the first sodium chloride brine blending tank and the second sodium chloride brine blending tank. The device has the advantages of environmental protection and high resource conversion rate.

Description

A device for the resource utilization of industrial sodium-based waste salt Technical Field

[0001] This utility model belongs to the field of industrial waste salt resource utilization technology, specifically relating to an industrial sodium-based waste salt resource utilization device. Background Technology

[0002] Industrial sodium-based waste salt (sodium-containing industrial waste salt) refers to waste containing large amounts of sodium during industrial production processes. This waste salt typically originates from industries such as chemical processing, salt production, and metal processing, and its main components include sodium chloride, sodium sulfate, and sodium carbonate. Traditionally, the primary method for treating industrial waste salt is stockpiling. However, because this waste salt is usually highly corrosive and toxic, stockpiling poses a serious threat to the environment.

[0003] To address this problem, those skilled in the art have developed industrial waste salt treatment devices. For example, the utility model patent technology entitled "An Industrial Waste Salt Pyrolysis System," authorized by the Chinese Patent Office on June 21, 2022, with publication number CN216779827U, includes a feeding crushing and grinding device, a screw conveyor, a pyrolysis reactor, a screw discharge device, a pyrolysis gas combustion chamber, and an air heat exchanger. The pyrolysis reactor further includes a feeding nozzle, a pyrolysis gas outlet, a hot flue gas nozzle, and a discharge port. The hot air channel in the feeding nozzle is connected to the air heat exchanger. While the above technology treats industrial waste salt through pyrolysis and has achieved some success, it suffers from a low resource conversion rate. Summary of the Invention

[0004] The purpose of this utility model is to provide an industrial sodium-based waste salt resource utilization device, which couples multiple industrial waste salt treatment technologies and processes to produce a variety of products and efficiently utilize industrial sodium-based waste salt.

[0005] This utility model is achieved through the following technical solution:

[0006] A device for the resource utilization of industrial sodium-based waste salt is characterized by comprising, in sequence, a waste salt dissolving and purification device, a nanofiltration device, a sodium sulfate brine mixing tank, a sodium sulfate and ammonium chloride double decomposition device, and a freeze crystallization device. The sodium sulfate and ammonium chloride double decomposition device has a sodium chloride outlet, and the freeze crystallization device has an ammonium sulfate outlet. The product water end of the nanofiltration device is connected to the inlet ends of a first sodium chloride brine mixing tank and a second sodium chloride brine mixing tank via pipelines. The outlet end of the first sodium chloride brine mixing tank is connected to the inlet end of the sodium chloride and ammonium bicarbonate double decomposition device. The sodium chloride and ammonium bicarbonate double decomposition device is equipped with a sodium bicarbonate outlet and an ammonium chloride outlet. The ammonium chloride outlet is connected to the inlet of the sodium sulfate and ammonium chloride double decomposition device via a pipeline. The outlet of the second sodium chloride brine mixing tank is connected to the inlet of the ion membrane electrolyzer via a pipeline. The ion membrane electrolyzer is also equipped with a chlorine outlet, a hydrogen outlet, and a sodium hydroxide outlet. The sodium chloride outlet of the sodium sulfate and ammonium chloride double decomposition device is connected to the inlet of the first sodium chloride brine mixing tank and the second sodium chloride brine mixing tank via pipelines, respectively.

[0007] The waste salt dissolving and purification device, nanofiltration device, sodium sulfate brine mixing tank, sodium chloride brine mixing tank, metathesis device, freeze crystallization device, and ion membrane electrolyzer of this utility model are all existing mature commercial products. The focus of this utility model is to connect the above devices and couple multiple technologies to produce sodium hydroxide, chlorine, hydrogen, sodium bicarbonate, ammonium chloride, and ammonium sulfate, thereby carrying out resource-based treatment and utilization of industrial sodium-based waste salt.

[0008] The present invention has the following advantages: The present invention realizes the treatment and resource utilization of industrial sodium-based waste salt, and produces sodium hydroxide, chlorine, hydrogen, sodium bicarbonate, ammonium chloride and ammonium sulfate. The resource conversion rate is high and no secondary pollution such as industrial waste salt and hazardous mother liquor is generated, which takes into account both ecological and environmental protection and economic benefits. Attached Figure Description

[0009] Figure 1 is a schematic diagram of the structure of this utility model.

[0010] As shown in the figure: 1. Waste salt dissolving and purification device; 2. Nanofiltration device; 3. Sodium sulfate brine mixing tank; 4. Sodium sulfate and ammonium chloride double decomposition device; 5. Freeze crystallization device; 6. Sodium chloride brine mixing tank; 7. Sodium chloride and ammonium bicarbonate double decomposition device; 8. Sodium chloride brine mixing tank; 9. Ion-exchange membrane electrolyzer. Detailed Implementation

[0011] The embodiments of the present utility model will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present utility model and are not intended to limit its scope of protection. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which this utility model pertains.

[0012] As shown in Figure 1: Waste salt dissolving and purification device 1, nanofiltration device 2, sodium sulfate brine mixing tank 3, sodium sulfate and ammonium chloride double decomposition device 4, and freeze crystallization device 5 are sequentially connected by pipelines. Freeze crystallization device 5 has an ammonium sulfate outlet, and sodium sulfate and ammonium chloride double decomposition device 4 has a sodium chloride outlet. The product water end of nanofiltration device 2 is connected by pipelines to the inlet ends of the first sodium chloride brine mixing tank 6 and the second sodium chloride brine mixing tank 8, respectively. The outlet end of the first sodium chloride brine mixing tank 6 is connected to the inlet end of the sodium chloride and ammonium bicarbonate double decomposition device 7. The sodium chloride and ammonium bicarbonate double decomposition device 7 is equipped with a sodium bicarbonate discharge end and an ammonium chloride discharge end. The ammonium chloride discharge end is connected to the feed end of the sodium sulfate and ammonium chloride double decomposition device 4 through a pipeline. The discharge end of the second sodium chloride brine mixing tank 8 is connected to the feed end of the ion membrane electrolyzer 9 through a pipeline. The ion membrane electrolyzer 9 is also equipped with a chlorine outlet end, a hydrogen outlet end, and a sodium hydroxide outlet end. The sodium chloride outlet end of the sodium sulfate and ammonium chloride double decomposition device 4 is connected to the feed ends of the first sodium chloride brine mixing tank 6 and the second sodium chloride brine mixing tank 8 through pipelines, respectively.

[0013] In use, industrial sodium-based waste salt is dissolved in water in the waste salt dissolving and purification device 1 to remove hardness, impurities, and COD, and then enters the nanofiltration device 2 for salt separation, thus dividing the process into three production stages.

[0014] Section 1: Nanofiltration concentrate is sodium sulfate brine. Sodium sulfate is added and a saturated salt solution is prepared in sodium sulfate brine mixing tank 3 as a production raw material. Ammonium chloride is added and the solution is concentrated in sodium sulfate and ammonium chloride double decomposition device 4 at high temperature (e.g., 80-100℃). NaCl is preferentially precipitated. After filtering out NaCl, the solution is slowly cooled to low temperature (e.g., 0℃) in freezing crystallization device 5, and ammonium sulfate is precipitated. The produced sodium chloride is used as the production raw material for Section 2 and Section 3.

[0015] Section 2: Nanofiltration permeate uses sodium chloride concentrated brine as production raw material. Sodium chloride is added and saturated brine is prepared in the first sodium chloride brine mixing tank 6. Ammonium bicarbonate is added and sodium chloride and ammonium bicarbonate double decomposition unit 7 are used to produce sodium bicarbonate and ammonium chloride. Among them, ammonium chloride is used as the production raw material of Section 1.

[0016] Section 3: Nanofiltration permeate uses sodium chloride concentrated brine as raw material. Sodium chloride is added and saturated brine is prepared in the second sodium chloride brine mixing tank 8. Sodium hydroxide, chlorine and hydrogen are produced through ion-exchange membrane electrolysis cell 9.

[0017] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A device for the resource utilization of industrial sodium-based waste salt, characterized in that... The system includes a waste salt dissolving and purification device, a nanofiltration device, a sodium sulfate brine mixing tank, a sodium sulfate and ammonium chloride double decomposition device, and a freeze crystallization device connected in sequence. The sodium sulfate and ammonium chloride double decomposition device has a sodium chloride outlet, and the freeze crystallization device has an ammonium sulfate outlet. The product water end of the nanofiltration device is connected to the inlet ends of the first sodium chloride brine mixing tank and the second sodium chloride brine mixing tank via pipelines. The outlet end of the first sodium chloride brine mixing tank is connected to the inlet end of the sodium chloride and ammonium bicarbonate double decomposition device. The sodium chloride and ammonium bicarbonate double decomposition device has a sodium bicarbonate outlet and an ammonium chloride outlet. The outlet end of the second sodium chloride brine mixing tank is connected to the inlet end of the ion-exchange membrane electrolyzer via pipelines. The ion-exchange membrane electrolyzer also has a chlorine outlet, a hydrogen outlet, and a sodium hydroxide outlet.

2. The industrial sodium-based waste salt resource utilization device according to claim 1, characterized in that... The ammonium chloride discharge end of the sodium chloride and ammonium bicarbonate metathesis unit is connected to the feed end of the sodium sulfate and ammonium chloride metathesis unit via a pipeline.

3. The industrial sodium-based waste salt resource utilization device according to claim 1, characterized in that... The sodium chloride outlet of the sodium sulfate and ammonium chloride metathesis unit is connected to the feed ends of the first sodium chloride brine mixing tank and the second sodium chloride brine mixing tank via pipelines.

Images