Device for preparing potassium sulfate by regenerating solid hazardous waste salt

Abstract

The utility model provides a device for preparing potassium sulfate by regenerating solid hazardous waste salt, which comprises a solid waste salt refining system, a potassium sulfate preparation system and a glaserite mother liquor refining system, the solid waste salt refining system comprises a waste salt cracking furnace, a waste salt dissolving tank, a plate and frame filter and a mirabilite system which are sequentially connected through pipelines, the waste salt cracking furnace is provided with a waste salt receiving pipe, the plate frame filter is provided with an impurity discharge pipe, the mirabilite system is provided with a mirabilite solid output pipe, the potassium sulfate preparation system comprises a mirabilite liquid preparation kettle, a primary conversion kettle, a centrifugal machine and a secondary conversion kettle which are sequentially connected through pipelines, and the mirabilite liquid preparation kettle is connected with the mirabilite solid output pipe. The first-stage conversion kettle is provided with a first potassium chloride input pipe and a first water input pipe, the centrifugal machine is provided with a glaserite solid output pipe and a glaserite mother liquor output pipe, the second-stage conversion kettle is connected with the glaserite solid output pipe, and the second-stage conversion kettle is provided with a second potassium chloride input pipe, a second water input pipe and a potassium sulfate solid output pipe. The glaserite mother liquor refining system comprises an adsorption-desorption tower, a desorption solution cooling kettle, a crude glaserite evaporation system, a crude glaserite separator and a glaserite refining kettle which are sequentially connected through pipelines, the adsorption-desorption tower is connected with a glaserite mother liquor output pipe, and the glaserite refining kettle is provided with a glaserite solid output pipe; and the glaserite solid output pipe is connected with the secondary conversion kettle. By utilizing the solid waste salt refining system, the potassium sulfate preparation system and the glaserite mother liquor refining system, waste salt is prepared into potassium sulfate which can be sold as agricultural fertilizer, and refined salt is produced as a byproduct, so that the economic benefits of enterprises are improved, the comprehensive utilization of waste salt resources is realized, and the problem of industrial waste salt treatment is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste salt treatment, in particular to a device for preparing potassium sulfate by regenerating solid and hazardous waste salt. Background Art

[0002] Industrial waste salt is waste generated during industrial production, mainly from various production processes in industry, such as pharmaceuticals, dyes, pesticides, fertilizers, etc. According to statistics: fine chemical industry, high-concentration wastewater, printing and dyeing, pharmaceuticals, pesticides, metallurgical industry, phosphorus chemical industry, new energy industry lithium iron phosphate, ternary cathode materials, coal chemical industry, coal chemical solid hazardous waste salt annually produces more than 30 million tons / year. These waste salts contain a large amount of harmful substances, such as heavy metals, toxic organic matter and radioactive substances. Some heavy metal elements such as lead, mercury, cadmium, etc. can cause serious damage to the human nervous system, immune system and reproductive system; some organic pollutants such as benzene and toluene are carcinogenic, teratogenic, mutagenic, etc. Due to their complex composition and high hazard, how to safely and effectively dispose of these waste salts has become an important issue in the field of environmental protection. The disposal methods of waste salt usually include landfill, incineration, chemical method and biological method. The landfill method is to transport the waste salt to a designated landfill site, and isolate it from the environment after layered landfill, covering, compaction and other steps. Incineration is a high-temperature treatment method, which is to mix waste salt with fuel and send it into an incinerator for combustion. Under high temperature, harmful substances in waste salt are oxidized, decomposed, and finally converted into harmless substances. Chemical method is a method of converting harmful substances in waste salt into harmless or low-toxic substances through chemical reactions. Biological method is a method of converting harmful substances in waste salt into harmless or low-toxic substances by using the metabolism of microorganisms. The disposal of waste salt is a complex and important environmental issue. In order to ensure the safe disposal of waste salt, we need to choose the appropriate treatment method according to the actual situation. Of course, waste salt also contains many valuable chemical resources, which can be reused through a series of treatment methods, thereby reducing resource waste and environmental pollution. For example, copper can be extracted by leaching copper, and iron oxide can be obtained after precipitation treatment. The salt in waste salt can be converted into organic acids, biomass and gas by using bacterial flora. For example, Chinese invention patent application CN 117326572 A discloses a method for regenerating baking soda from solid and hazardous waste salt to produce ammonium chloride as a by-product, which uses a series of devices to fully treat solid and hazardous waste salt, realize the comprehensive utilization of waste salt resources, reduce treatment costs, and improve economic benefits. Summary of the invention

[0003] The technical problem solved by the utility model is the problem of recycling and processing of waste salt.

[0004] The utility model provides a device for preparing potassium sulfate by regenerating solid hazardous waste salt, comprising a solid waste salt refining system, a potassium sulfate preparation system and a potassium glauberite mother liquor refining system. The solid waste salt refining system comprises a waste salt cracking furnace, a waste salt dissolving tank, a plate-frame filter and a glauberite system which are sequentially connected by pipelines. The waste salt cracking furnace is provided with a waste salt receiving pipe, the plate-frame filter is provided with an impurity discharge pipe, and the glauberite system is provided with a glauberite solid output pipe.

[0005] The potassium sulfate preparation system comprises a sodium sulfate liquid preparation kettle, a primary conversion kettle, a centrifuge, and a secondary conversion kettle which are connected in sequence through pipelines. The sodium sulfate liquid preparation kettle is connected to a sodium sulfate solid output pipe. The primary conversion kettle is provided with a first potassium chloride input pipe and a first water input pipe. The centrifuge is provided with a potassium sulfate solid output pipe and a potassium sulfate mother liquor output pipe. The secondary conversion kettle is connected to the potassium sulfate solid output pipe. The secondary conversion kettle is provided with a second potassium chloride input pipe, a second water input pipe, and a potassium sulfate solid output pipe.

[0006] The glauberite mother liquor refining system comprises an adsorption and analysis tower, an analysis liquid cooling kettle, a crude glauberite evaporation system, a crude glauberite separator, and a glauberite refining kettle which are sequentially connected through pipelines. The adsorption and analysis tower is connected to a glauberite mother liquor output pipe, and the glauberite refining kettle is provided with a glauberite solid output pipe, which is connected to a secondary conversion kettle.

[0007] Furthermore, the mirabilite system is also provided with a refrigerated mother liquor reflux pipe for recycling the refrigerated mother liquor, and the reflux pipe is connected to the waste salt dissolution tank.

[0008] Furthermore, the solution generated during the adsorption process of the adsorption and desorption tower is connected to a multi-effect evaporation unit through an output pipe, the multi-effect evaporation unit is provided with a sodium chloride solid output pipe, the multi-effect evaporation unit is also provided with a mother salt reflux pipe and a first evaporation condensate reflux pipe, the mother salt reflux pipe is connected to the mirabilite liquid preparation kettle, and the first evaporation condensate reflux pipe is respectively connected to the primary conversion kettle, the secondary conversion kettle, and the potassium mirabilite refining kettle.

[0009] Furthermore, the analysis liquid cooling kettle is provided with a sodium sulfate output pipe for recycling and reusing the sodium sulfate, the sodium sulfate output pipe is connected to the analysis liquid preparation tank, the analysis liquid preparation tank is provided with a third water input pipe and a sodium sulfate solution output pipe, and the sodium sulfate solution output pipe is connected to the adsorption analysis tower.

[0010] Furthermore, the crude sodium sulfate evaporation system is also provided with a second evaporation condensate output pipe, and the second evaporation condensate output pipe is connected to the analytical solution preparation tank.

[0011] Furthermore, the secondary conversion kettle is also provided with a potassium mother liquor reflux pipe, and the potassium mother liquor reflux pipe is connected to the mirabilite solution preparation kettle.

[0012] The utility model has the following beneficial effects: The utility model utilizes a solid waste salt refining system, a potassium sulfate preparation system, and a potassium sulfate mother liquor refining system to make waste salt into potassium sulfate, which can be sold as agricultural fertilizer and produce refined salt as a by-product, thereby improving the economic benefits of the enterprise, realizing the comprehensive utilization of waste salt resources, and solving the problem of waste salt treatment in the industry. The utility model is a device for regenerating solid hazardous waste salt to prepare potassium sulfate, which is equipped with a frozen mother liquor reflux pipe, a salt mother salt reflux pipe, an evaporation condensate reflux pipe, and an analytical liquid preparation tank, so as to realize the recycling and reuse of various raw materials, maximize the optimal utilization of waste salt, and have a smooth regeneration process. The auxiliary agent used is low-cost, which reduces the operating cost of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 , Schematic diagram of the device for regenerating solid and hazardous waste salt to prepare potassium sulfate according to the utility model. DETAILED DESCRIPTION

[0014] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0015] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0016] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0017] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0018] like Figure 1As shown, a device for regenerating solid and hazardous waste salt to prepare potassium sulfate includes a solid waste salt refining system 1, a potassium sulfate preparation system 2 and a glauber's salt mother liquor refining system 3.

[0019] The solid waste salt refining system 1 includes a waste salt cracking furnace, a waste salt dissolving tank, a plate and frame filter, and a Glauber's salt system which are connected in sequence through pipelines. The waste salt cracking furnace is provided with a waste salt receiving pipe, the plate and frame filter is provided with an impurity discharge pipe, the Glauber's salt system is provided with a Glauber's salt solid output pipe, and the Glauber's salt system is also provided with a refrigerated mother liquor reflux pipe for recycling and reusing the frozen mother liquor, and the frozen mother liquor reflux pipe is connected to the waste salt dissolving tank.

[0020] The potassium sulfate preparation system 2 includes a mirabilite liquid preparation kettle, a primary conversion kettle, a centrifuge, and a secondary conversion kettle, which are connected in sequence through pipelines. The mirabilite liquid preparation kettle is connected to the mirabilite solid output pipe, the primary conversion kettle is provided with a first potassium chloride input pipe and a first water input pipe, the centrifuge is provided with a potassium glauberite solid output pipe and a potassium glauberite mother liquor output pipe, the secondary conversion kettle is connected to the potassium glauberite solid output pipe, the secondary conversion kettle is provided with a second potassium chloride input pipe, a second water input pipe and a potassium sulfate solid output pipe, the secondary conversion kettle is also provided with a potassium mother liquor reflux pipe, and the potassium mother liquor reflux pipe is connected to the mirabilite liquid preparation kettle.

[0021] The potassium glauberite mother liquor refining system 3 comprises an adsorption and analysis tower, an analysis liquid cooling kettle, a crude potassium glauberite evaporation system, a crude potassium glauberite separator, and a potassium glauberite refining kettle, which are sequentially connected by pipelines. The adsorption and analysis tower is connected to the potassium glauberite mother liquor output pipe, and the potassium glauberite refining kettle is provided with a potassium glauberite solid output pipe, which is connected to the secondary conversion kettle. The crude potassium glauberite separator is also provided with a crude potassium glauberite mother liquor reflux pipe, which is connected to the sodium glauberite liquid preparation kettle for recycling again.

[0022] The analytical solution cooling kettle is provided with a sodium sulfate output pipe for recycling and reusing sodium sulfate, and the sodium sulfate output pipe is connected to the analytical solution preparation tank, and the analytical solution preparation tank is provided with a water input pipe and a sodium sulfate solution output pipe, and the sodium sulfate solution output pipe is connected to the analytical tower. The crude sodium sulfate evaporation system is also provided with a second evaporation condensate output pipe, and the second evaporation condensate output pipe is connected to the analytical solution preparation tank.

[0023] The solution generated during the adsorption process of the adsorption and analysis tower is connected to a multi-effect evaporation unit through an output pipe. The multi-effect evaporation unit is provided with a sodium chloride solid output pipe. The multi-effect evaporation unit is also provided with a mother salt reflux pipe and a first evaporation condensate reflux pipe. The mother salt reflux pipe is connected to the mirabilite liquid preparation kettle. The first evaporation condensate reflux pipe is respectively connected to the primary conversion kettle, the secondary conversion kettle and the potassium mirabilite refining kettle.

[0024] The method for preparing potassium sulfate by regeneration through the above device comprises the following steps:

[0025] In the first step, the waste salt enters the waste salt cracking furnace through the waste salt receiving pipe. At 550°, the COD in the waste salt is treated by high-temperature anaerobic cracking. In this embodiment, the waste salt cracking furnace uses fuel gas as a heat source to crack the macromolecular organic matter in the waste salt into small molecular organic gas. The gas containing small molecular organic matter passes through a bag filter to remove large dust particles, and then enters the interlayer of the cracking furnace as fuel to supplement the cracking heat source for solid hazardous waste salt. The cracked waste salt enters the waste salt dissolution tank for dissolution. The dissolved waste salt enters the plate and frame filter for filtration. After removing impurities, a sodium sulfate mixed salt solution is obtained. The sodium sulfate mixed salt solution enters the mirabilite system and is cooled by refrigerated water to precipitate the mirabilite solid in the solution. At the same time, the frozen mother liquor is separated and refluxed into the waste salt dissolution tank for recycling again.

[0026] In the second step, the Glauber's salt solid enters the Glauber's salt liquid preparation kettle, dissolves to form the Glauber's salt solution, the Glauber's salt solution enters the primary conversion kettle, potassium chloride solid and water are added, the Glauber's salt solution reacts with the potassium chloride solid and water in the kettle, the slurry generated by the reaction enters the centrifuge, and is separated to obtain potassium glauber's salt solid and potassium glauber's salt mother liquor, the potassium glauber's salt solid enters the secondary conversion kettle, potassium chloride and water are added, and the reaction obtains potassium sulfate solid, the separated potassium mother liquor is refluxed into the Glauber's salt liquid preparation kettle, and is recycled again;

[0027] In the third step, the potassium glauberite mother liquor enters the adsorption and analysis tower, and the adsorption process is advanced, and the adsorbent is added. In this embodiment, the adsorbent adopts a modified cationic adsorbent, and selectively adsorbs potassium ions in the potassium glauberite mother liquor at 30-25°C. When the adsorbent reaches a saturated state, it enters the analysis process, and generates an analysis mother liquor at 40°C±3. The analysis mother liquor is a mixed solution of potassium sulfate and sodium sulfate. The analysis mother liquor enters the analysis liquid freezing kettle, and refrigerating water is added to cool it to 20-12°C, so that the sodium glauberite in the solution is precipitated, and a separation mother liquor is obtained at the same time. The separation mother liquor enters the crude sodium glauberite evaporation system, evaporates and crystallizes to obtain a crude sodium glauberite solid, and at the same time, a crude potassium glauberite mother liquor is separated. The crude potassium glauberite mother liquor is refluxed into the sodium glauberite liquid preparation kettle for recycling. The crude sodium glauberite solid enters the potassium glauberite refining kettle, and sodium sulfate in the washed crude potassium glauberite solid is added at 40°C to obtain refined potassium glauberite. The refined potassium glauberite enters the secondary conversion kettle to continue to prepare potassium sulfate. The sodium sulfate precipitated from the analytical solution freezing kettle is recycled and enters the analytical solution preparation tank to prepare a sodium sulfate solution. The sodium sulfate solution is refluxed into the analytical tower to parse out the potassium ions adsorbed by the adsorbent, thereby regenerating the adsorbent. The solution generated during the adsorption process of the adsorption analytical tower is mainly composed of sodium chloride. The solution generated during the adsorption process enters the multi-effect evaporation unit for evaporation and crystallization to obtain sodium chloride solid. The separated salt mother liquor is refluxed into the sodium sulfate liquid preparation kettle for recycling again. The evaporation condensate obtained by evaporation is refluxed into the primary conversion kettle, the secondary conversion kettle and the potassium glauberite refining kettle for recycling.

[0028] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and alterations made to the technical solutions of the present invention by those skilled in the art should all fall within the protection scope of the claims of the present invention.

[0029] Other parts of the present invention not described in detail belong to the prior art and will not be described in detail here.

[0030] Although the present invention has been described in conjunction with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can implement various changes, substitutions and modifications to the subject matter listed here without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims.

Claims

1. A device for regenerating solid and hazardous waste salt to prepare potassium sulfate, characterized in that: It includes a solid waste salt refining system, a potassium sulfate preparation system and a glauber's salt mother liquor refining system. The solid waste salt refining system includes a waste salt cracking furnace, a waste salt dissolving tank, a plate and frame filter, and a glauber's salt system which are sequentially connected through pipelines. The waste salt cracking furnace is provided with a waste salt receiving pipe, the plate and frame filter is provided with an impurity discharge pipe, and the glauber's salt system is provided with a glauber's salt solid output pipe. The potassium sulfate preparation system includes a glauber's salt liquid preparation kettle, a primary conversion kettle, a centrifuge, and a secondary conversion kettle which are sequentially connected through pipelines. The glauber's salt liquid preparation kettle is connected to the glauber's salt solid output pipe, the primary conversion kettle is provided with a first potassium chloride input pipe and a first water input pipe, the centrifuge is provided with a glauber's salt solid output pipe and a glauber's salt mother liquor output pipe, the secondary conversion kettle is connected to the glauber's salt solid output pipe, and the secondary conversion kettle is provided with a second potassium chloride input pipe, a second water input pipe, and a potassium sulfate solid output pipe. The glauberite mother liquor refining system comprises an adsorption and analysis tower, an analysis liquid cooling kettle, a crude glauberite evaporation system, a crude glauberite separator, and a glauberite refining kettle which are sequentially connected through pipelines. The adsorption and analysis tower is connected to a glauberite mother liquor output pipe, and the glauberite refining kettle is provided with a glauberite solid output pipe, which is connected to a secondary conversion kettle.

2. The device for regenerating solid and hazardous waste salt to prepare potassium sulfate according to claim 1, characterized in that: The mirabilite system is also provided with a refrigerated mother liquor reflux pipe for recycling the refrigerated mother liquor, and the reflux pipe is connected to the waste salt dissolving tank.

3. The device for regenerating solid and hazardous waste salt to prepare potassium sulfate according to claim 1, characterized in that: The solution generated during the adsorption process of the adsorption and analysis tower is connected to a multi-effect evaporation unit through an output pipe, the multi-effect evaporation unit is provided with a sodium chloride solid output pipe, the multi-effect evaporation unit is also provided with a mother salt reflux pipe and a first evaporation condensate reflux pipe, the mother salt reflux pipe is connected to the mirabilite liquid preparation kettle, and the first evaporation condensate reflux pipe is respectively connected to the primary conversion kettle, the secondary conversion kettle, and the potassium mirabilite refining kettle.

4. The device for regenerating solid and hazardous waste salt to prepare potassium sulfate according to claim 1, characterized in that: The analytical solution cooling kettle is provided with a sodium sulfate output pipe for recycling sodium sulfate, the sodium sulfate output pipe is connected to an analytical solution preparation tank, the analytical solution preparation tank is provided with a third water input pipe and a sodium sulfate solution output pipe, and the sodium sulfate solution output pipe is connected to the adsorption analytical tower.

5. The device for regenerating solid and hazardous waste salt to prepare potassium sulfate according to claim 4, characterized in that: The crude potassium sulfate evaporation system is also provided with a second evaporation condensate output pipe, and the second evaporation condensate output pipe is connected to the analytical solution preparation tank.

6. The device for regenerating solid and hazardous waste salt to prepare potassium sulfate according to claim 1, characterized in that: The secondary conversion kettle is also provided with a potassium mother liquor reflux pipe, which is connected to the mirabilite solution preparation kettle.

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