Method and device for preparing ammonium sulfate and sodium chloride from ammonium chloride and mirabilite

Abstract

The invention discloses a method and device for preparing ammonium sulfate and sodium chloride from ammonium chloride and mirabilite, and the method comprises the following steps: carrying out double salt reaction on chemical byproducts containing ammonium chloride and mirabilite to generate double salt I and mother liquor I; the mother liquor I enters a mixed salt evaporation process to generate mixed salt I and mother liquor IV; the mixed salt I enters a double salt reaction process, the mother liquor IV enters a sodium chloride evaporation process to generate sodium chloride and mother liquor V, and the mother liquor V and evaporation condensate enter the double salt reaction process; inputting the double salt I into a mixed salt refining process to generate mixed salt II and mother liquor II; the mixed salt II enters a double salt reaction process, and the mother liquor II enters a double salt refining process to generate double salt II and mother liquor III; the double salt II enters a mixed salt refining process, and the mother liquor III enters an ammonium sulfate evaporation process to generate ammonium sulfate and mother liquor VI; and the mother liquor VI enters a double salt refining process. Comprehensive utilization of ammonium chloride is achieved, the problems that industrial ammonium chloride is difficult to sell and poor in economic benefit are solved, meanwhile, high-added-value ammonium sulfate is obtained through regeneration, and the operation cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, relates to alkali production technology, and specifically relates to a method and device for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite. Background Art

[0002] With the development of alkali industry and chemical industry, the output of byproduct ammonium chloride has increased year by year. At present, the main consumption channel of ammonium chloride in my country is to add it into compound fertilizer in the form of nitrogen, which is suitable for crops such as rice, cotton, and vegetables. In the industrial field, ammonium chloride can be used in dry batteries, storage batteries, metallurgy, and electroplating.

[0003] However, the existing application of by-product ammonium chloride still has the disadvantages of low economic value and environmental unfriendliness. Therefore, how to make full use of the excess ammonium chloride and realize the efficient application of ammonium chloride not only has high economic value, but also can make full use of resources to achieve sustainable development of the environment and resources, which is of far-reaching significance.

[0004] In order to solve the above-mentioned defects in the prior art, a method for regenerating ammonium chloride which is a by-product of chemical industry or a by-product of preparing soda ash by the soda process was developed. Summary of the invention

[0005] The invention aims to provide a method for preparing ammonium sulfate and sodium chloride by utilizing ammonium chloride and mirabilite.

[0006] Another object of the present invention is to provide a device for preparing ammonium sulfate and sodium chloride using ammonium chloride and sodium sulfate.

[0007] To achieve the above object, the present invention provides the following technical solutions: A method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite, comprising the following steps: The chemical byproduct containing ammonium chloride is reacted with sodium sulfate in a double salt reaction step to generate double salt I and mother liquor I; The mother liquor I enters the mixed salt evaporation process to generate mixed salt I and mother liquor IV; The mixed salt I enters the double salt reaction process for recycling, the mother liquor IV enters the sodium chloride evaporation process to generate sodium chloride and mother liquor V, and the mother liquor V and the evaporated condensate enter the double salt reaction process for recycling; The double salt I is input into the mixed salt refining process to generate mixed salt II and mother liquor II; The mixed salt II enters the double salt reaction process for recycling, and the mother liquor II enters the double salt refining process to generate double salt II and mother liquor III; The double salt II enters the mixed salt refining process for recycling, and the mother liquor III enters the ammonium sulfate evaporation process to generate ammonium sulfate and mother liquor VI; The mother liquor VI enters the double salt refining process and is recycled.

[0008] Furthermore, the reaction temperature of the double salt reaction step is 0-25°C, and the reaction time is 1-2h.

[0009] The temperature of the mixed salt evaporation process is controlled at the boiling point of the separation point solution, 105-110° C., and the reaction generates mixed salt I and mother liquor IV.

[0010] The reaction temperature of the sodium chloride evaporation process is 108-112° C., and sodium chloride and mother liquor V are separated.

[0011] The reaction temperature of the mixed salt refining process is 106-110°C to obtain mixed salt II and mother liquor II.

[0012] The double salt refining process is to cool down and precipitate, control the cooling temperature to 28-35°C, and centrifuge to obtain double salt II and mother liquor III.

[0013] The ammonium sulfate evaporation process is to evaporate the mother liquor III, control the temperature at 108-112° C., and separate the product ammonium sulfate and the mother liquor VI.

[0014] Furthermore, the device for completing the above method includes a sodium chloride device and an ammonium sulfate device respectively connected to the double salt reaction device through pipelines; The double salt reaction system comprises an ammonium chloride storage tank and a sodium sulfate storage tank which are respectively connected to the reaction tank through pipelines, and a temperature controller is arranged on the reaction tank; The sodium chloride device comprises a mixed salt evaporation device and an ammonium chloride evaporation device connected by pipelines; The ammonium sulfate device comprises a mixed salt refining device, a double salt refining device and an ammonium sulfate evaporating device which are sequentially connected through pipelines.

[0015] The invention utilizes by-product ammonium chloride and mirabilite to prepare ammonium sulfate and sodium chloride, and comprises a double salt reaction process, a sodium chloride process and an ammonium sulfate process. The by-product ammonium chloride and mirabilite are used to generate double salt I in the double salt reaction process, wherein the reaction temperature is controlled at 0-25°C, the reaction time is 1-2h, the generated double salt I enters the ammonium sulfate system, and the generated MⅠ enters the sodium chloride system; the sodium chloride system mainly comprises a mixed salt evaporation process, a sodium chloride evaporation process and an auxiliary system, the mixed salt evaporation process mainly evaporates MⅠ in the mixed salt evaporation process, controls the temperature at the boiling point of the solution at 105-110°C, separates the mixed salt I and the mother liquor MIV, the mixed salt I returns to the double salt reaction process, and the mother liquor MIV enters the sodium chloride evaporation process; the sodium chloride evaporation process evaporates the mother liquor MIV in the sodium chloride evaporation process, controls the temperature at the boiling point of the solution at 108-112°C, separates the chloride Sodium and mother liquor MV, wherein mother liquor MV returns to the double salt reaction process; the ammonium sulfate system is mainly composed of a mixed salt refining process, a double salt refining process, an ammonium sulfate evaporation process and an auxiliary system. The mixed salt refining process is to evaporate double salt I, control the separation point of the mixed salt process (106-110°C), and obtain mixed salt II and mother liquor MV; mixed salt II returns to the double salt reaction process, and mother liquor MV enters the double salt refining process; the double salt refining process is that the mother liquor MV and the ammonium sulfate process are centrifuged and the mother liquor MV is cooled and precipitated in the double salt refining process, and the cooling temperature is controlled to be 28-35°C, and the double salt II and mother liquor MV are centrifuged and separated; double salt II returns to the mixed salt refining process, and the mother liquor MV is sent to the ammonium sulfate evaporation process; the ammonium sulfate evaporation process is that the mother liquor MV is evaporated in the ammonium sulfate evaporation process, and the separation temperature of the ammonium sulfate evaporation process is controlled to be 108-112°C, and the separated products are ammonium sulfate and mother liquor MV are returned to the double salt refining process.

[0016] The invention provides a method for regenerating ammonium chloride produced as a byproduct of chemical industry or byproduct of preparing soda ash by a combined alkali process. The method prepares ammonium sulfate and sodium chloride by using the byproduct ammonium chloride and sodium sulfate, thereby realizing comprehensive utilization of ammonium chloride and solving the problems of difficult sales and poor economic benefits of ammonium chloride in the industry. Meanwhile, high-value-added agricultural ammonium sulfate can be obtained by regeneration and sold as agricultural fertilizer, thereby improving the economic benefits of the enterprise and reducing the operating costs of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention.

[0018] In the figure: 1-double salt reaction device, 2-sodium chloride device, 3-ammonium sulfate device, 4-reaction tank, 5-mixed salt evaporation device, 6-ammonium chloride evaporation device, 7-mixed salt refining device, 8-double salt refining device, 9-ammonium sulfate evaporation device. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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 creative work are within the scope of protection of the present invention.

[0020] A method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite, comprising the following steps: reacting a chemical byproduct containing ammonium chloride with mirabilite in a double salt reaction process, wherein the reaction temperature of the double salt reaction process is 0-25°C and the reaction time is 1-2h, to generate double salt I and mother liquor I; the mother liquor I enters a mixed salt evaporation process, wherein the temperature of the mixed salt evaporation process is controlled at a separation point solution boiling point of 105-110°C, to generate mixed salt I and mother liquor IV; the mixed salt I enters a double salt reaction process for recycling, and the mother liquor IV enters a sodium chloride evaporation process, wherein the reaction temperature of the sodium chloride evaporation process is 108-112°C, and the separation Sodium chloride and mother liquor V are obtained; the mother liquor V and the evaporated condensate enter the double salt reaction process for recycling; the double salt I is input into the mixed salt refining process, the reaction temperature of the mixed salt refining process is 106-110°C, and mixed salt II and mother liquor II are generated; the mixed salt II enters the double salt reaction process for recycling, the mother liquor II enters the double salt refining process for cooling and precipitation, the cooling temperature is controlled at 28-35°C, and the double salt II and mother liquor III are obtained by centrifugation; the double salt II enters the mixed salt refining process for recycling, the mother liquor III enters the ammonium sulfate evaporation process for evaporation, and the temperature is controlled at 108-112°C, Ammonium sulfate and mother liquor VI are generated; the mother liquor VI enters the double salt refining process and is recycled.

[0021] The device used to complete the above method is as follows Figure 1 As shown, it includes a sodium chloride device 2 and an ammonium sulfate device 3 respectively connected to the double salt reaction device 1 through pipelines; the double salt reaction system 1 includes an ammonium chloride storage tank and a mirabilite storage tank respectively connected to the reaction tank 4 through pipelines, and a temperature controller is arranged on the reaction tank 4; the sodium chloride device 2 includes a mixed salt evaporation device 5 and an ammonium chloride evaporation device 6 connected through pipelines; the ammonium sulfate device 3 includes a mixed salt refining device 7, a double salt refining device 8 and an ammonium sulfate evaporation device 9 connected in sequence through pipelines; wherein the mixed salt evaporation device 5, the ammonium chloride evaporation device 6, and the mixed salt refining device 7 are respectively connected to the reaction tank 4 through pipelines to form a cycle; the double salt refining device 8 forms a reverse cycle with the mixed salt refining device 7 through pipelines, and the ammonium sulfate evaporation device 9 forms a reverse cycle with the double salt refining device 8 through pipelines.

[0022] The above description of the present invention is illustrative rather than restrictive. Those skilled in the art will appreciate that many modifications, changes or equivalents may be made within the spirit and scope defined in the claims, but they will all fall within the scope of protection of the patent of the present invention.

Claims

1. A method for preparing ammonium sulfate and sodium chloride using ammonium chloride and mirabilite, characterized in that: The steps are: The chemical byproduct containing ammonium chloride is reacted with sodium sulfate in a double salt reaction step to generate double salt I and mother liquor I; The mother liquor I enters the mixed salt evaporation process to generate mixed salt I and mother liquor IV; The mixed salt I enters the double salt reaction process for recycling, the mother liquor IV enters the sodium chloride evaporation process to generate sodium chloride and mother liquor V, and the mother liquor V and the evaporated condensate enter the double salt reaction process for recycling; The double salt I is input into the mixed salt refining process to generate mixed salt II and mother liquor II; The mixed salt II enters the double salt reaction process for recycling, and the mother liquor II enters the double salt refining process to generate double salt II and mother liquor III; The double salt II enters the mixed salt refining process for recycling, and the mother liquor III enters the ammonium sulfate evaporation process to generate ammonium sulfate and mother liquor VI; The mother liquor VI enters the double salt refining process and is recycled.

2. The method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite according to claim 1, characterized in that: The reaction temperature of the double salt reaction step is 0-25°C, and the reaction time is 1-2h.

3. The method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite according to claim 1, characterized in that: The temperature of the mixed salt evaporation process is controlled at the boiling point of the separation point solution, 105-110° C., and the reaction generates mixed salt I and mother liquor IV.

4. The method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite according to claim 1, characterized in that: The reaction temperature of the sodium chloride evaporation process is 108-112° C., and sodium chloride and mother liquor V are separated.

5. The method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite according to claim 1, characterized in that: The reaction temperature of the mixed salt refining process is 106-110°C to obtain mixed salt II and mother liquor II.

6. The method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite according to claim 1, characterized in that: The double salt refining process is to cool down and precipitate, control the cooling temperature to 28-35°C, and centrifuge to obtain double salt II and mother liquor III.

7. The method for preparing ammonium sulfate and sodium chloride by using ammonium chloride and mirabilite according to claim 1, characterized in that: The ammonium sulfate evaporation process is to evaporate the mother liquor III, control the temperature at 108-112° C., and separate the product ammonium sulfate and the mother liquor VI.

8. A device for carrying out the method according to any one of claims 1 to 7, characterized in that: It includes a sodium chloride device and an ammonium sulfate device respectively connected to the double salt reaction device through pipelines; The double salt reaction system comprises an ammonium chloride storage tank and a sodium sulfate storage tank which are respectively connected to the reaction tank through pipelines, and a temperature controller is arranged on the reaction tank; The sodium chloride device comprises a mixed salt evaporation device and an ammonium chloride evaporation device connected by pipelines; The ammonium sulfate device comprises a mixed salt refining device, a double salt refining device and an ammonium sulfate evaporating device which are sequentially connected through pipelines.

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