Evaporative crystallization system for producing large manganese sulfate particles

Abstract

The utility model discloses an evaporative crystallization system for producing large manganese sulfate particles, which comprises a liquid conveying unit and a crystallization unit, the liquid conveying unit comprises a stock solution tank, a mother solution tank and a preheater, the stock solution tank is connected with the mother solution tank through a stock solution pump, and the mother solution tank is connected with the preheater through a mother solution pump. The crystallization unit comprises a forced circulation heat exchanger, an Osli crystallizer, a thickener, a centrifugal machine and a settling tank, the forced circulation heat exchanger is connected with the preheater through a forced circulation pump, a flash chamber of the Osli crystallizer is connected with the forced circulation pump, the thickener is connected with the bottom of a crystallization chamber of the Osli crystallizer through a discharging pump, and the centrifugal machine is connected with the thickener; the manganese sulfate solution is subjected to controllable secondary nucleation in the crystallizer by controlling the saturation of the system, the content of fine grains in the crystallizer and the design of the crystallizer, so that good manganese sulfate crystal morphology and size distribution are obtained.

Description

Technical Field

[0001] The utility model relates to the technical field of manganese sulfate production, in particular to an evaporation crystallization system for producing large particles of manganese sulfate. Background Technique

[0002] Manganese sulfate is soluble in water and insoluble in ethanol, and exists in the form of various hydrates; Manganese sulfate is a trace element required by crops for synthesizing fatty acids, and can be used as a fertilizer to be applied to the soil to increase production. Adding manganese sulfate to animal feed has a fattening effect. Manganese sulfate is also a raw material and analytical reagent for preparing other manganese salts, and is also used in the industrial production of electrolytic manganese, dyes, papermaking, ceramics, etc.

[0003] Traditional multi-effect evaporators for manganese sulfate adopt a multi-effect evaporation crystallization process to separate manganese sulfate solution and recover it through a salt collector, but there are problems such as smaller crystal particle size and poor quality. Based on this, the utility model proposes an evaporation crystallization system for producing large particles of manganese sulfate that can solve the above problems. Content of the Utility Model

[0004] The purpose of the utility model is to provide an evaporation crystallization system for producing large particles of manganese sulfate to solve the problems raised in the above background technique.

[0005] To achieve the above purpose, the utility model provides the following technical solution: An evaporation crystallization system for producing large particles of manganese sulfate, including an infusion unit and a crystallization unit;

[0006] The infusion unit includes a stock solution tank, a mother liquor tank and a preheater. The stock solution tank and the mother liquor tank are connected by a stock solution pump, and the mother liquor tank and the preheater are connected by a mother liquor pump, which is used to transport the unsaturated manganese sulfate solution into the mother liquor tank and then transport it to the preheater for preheating;

[0007] The crystallization unit includes a forced circulation heat exchanger, an Oslo crystallizer, a thickener, a centrifuge and a settling tank. The forced circulation heat exchanger is connected to the preheater through a forced circulation pump, and the flash chamber of the Oslo crystallizer is connected to the forced circulation pump, which is used to transport the preheated manganese sulfate solution into the forced circulation heat exchanger to increase the temperature and pressure and then enter the flash chamber of the Oslo crystallizer for flashing;

[0008] The thickener is connected to the bottom of the crystallization chamber of the Oslo crystallizer through a discharge pump, and the centrifuge is connected to the thickener, which is used to transport the crystalline material in the crystallization chamber of the Oslo crystallizer into the thickener for thickening and then transport it into the centrifuge for solid-liquid separation;

[0009] The settling tank is connected to the top of the crystallization chamber of the Oslo crystallizer through an impurity discharge pump, which is used for overflowing and discharging impurities.

[0010] As a preferred technical solution, the middle part of the crystallization chamber of the Oslo crystallizer is connected to the forced circulation pump, which is used to circulate and suck the clear liquid into the circulation heat exchanger.

[0011] As a preferred technical solution, the centrifuge is connected to the mother liquor tank and is used to return the separated clear liquid to the mother liquor tank.

[0012] As a preferred technical solution, the settling tank is connected to the mother liquor tank and is used to discharge the settled fine crystals back to the mother liquor tank.

[0013] As a preferred technical solution, a secondary separator is connected to the top of the crystallization chamber of the Oslo crystallizer, which is used to remove the foam from the steam discharged from the crystallization chamber of the Oslo crystallizer through the secondary separator.

[0014] As a preferred technical solution, the secondary separator is connected to a compressor, and the compressor is connected to the forced circulation heat exchanger, which is used to transport the defoamed steam to the forced circulation heat exchanger after increasing the temperature and pressure through the compressor.

[0015] As a preferred technical solution, the forced circulation pump is connected to a distilled water tank, and the distilled water tank is connected to the preheater through a distilled water pump.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] The fine crystals that have not settled in the thickener, the fine crystals that leak through the centrifuge screen, and the fine crystals collected by the settling tank are gathered in the mother liquor tank. When the system feeds, the unsaturated raw material first enters the raw material tank, dissolves the fine crystals in the mother liquor tank, and then enters the evaporation crystallization system after preheating, so as to realize controllable secondary nucleation of the manganese sulfate solution in the crystallizer by controlling the system saturation, the fine crystal content in the crystallizer, and the crystallizer design, thereby obtaining good crystal morphology and size distribution of manganese sulfate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the system of the present utility model;

[0019] In the figure: 1, raw liquid tank; 2, raw liquid pump; 3, mother liquor tank; 4, mother liquor pump; 5, preheater; 6, forced circulation pump; 7, forced circulation heat exchanger; 8, Oslo crystallizer; 9, discharge pump; 10, thickener; 11, centrifuge; 12, impurity discharge pump; 13, settling tank; 14, secondary separator; 15, compressor; 16, distilled water tank; 17, distilled water pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts belong to the scope of protection of the present utility model.

[0021] Please refer to Figure 1

[0022] An evaporation crystallization system for producing large particles of manganese sulfate:

[0023] The liquid infusion unit includes a stock solution tank 1, a mother liquor tank 3, and a preheater 5. The stock solution tank 1 and the mother liquor tank 3 are connected by a stock solution pump 2, and the mother liquor tank 3 and the preheater 5 are connected by a mother liquor pump 4, which is used to transport the unsaturated manganese sulfate solution into the mother liquor tank 3 and then transport it to the preheater 5 for preheating.

[0024] In the mother liquor tank 3, the temperature of the mother liquor is reduced to increase the solubility of the unsaturated manganese sulfate solution. At the same time, the unsaturated manganese sulfate solution can dissolve the fine crystals in the mother liquor tank 3, thereby achieving the purpose of eliminating fine crystals.

[0025] The crystallization unit includes a forced circulation heat exchanger 7, an Oslo crystallizer 8, a thickener 10, a centrifuge 11, and a settling tank 13. The forced circulation heat exchanger 7 is connected to the preheater 5 through a forced circulation pump 6, and the flash chamber of the Oslo crystallizer 8 is connected to the forced circulation pump 6, which is used to transport the preheated manganese sulfate solution into the forced circulation heat exchanger 7 to increase the temperature and pressure and then enter the flash chamber of the Oslo crystallizer 8 for flashing.

[0026] The middle part of the crystallization chamber of the Oslo crystallizer 8 is connected to the forced circulation pump 6, which is used to circulate and suction the clear liquid into the circulation heat exchanger.

[0027] The solution enters the Oslo crystallizer 8 and is circulated by the forced circulation pump 6. It exchanges heat with the secondary steam in the tube side and shell side of the forced circulation heat exchanger 7 to increase the temperature and pressure, and then flashes in the flash chamber of the Oslo crystallizer 8. The flashed material crystallizes and floats in the crystallization chamber, and so on, so that the material evaporates and crystallizes.

[0028] The thickener 10 is connected to the bottom of the crystallization chamber of the Oslo crystallizer 8 through a discharge pump 9, and the centrifuge 11 is connected to the thickener 10, which is used to transport the crystalline material in the crystallization chamber of the Oslo crystallizer 8 into the thickener 10 for thickening and then transport it into the centrifuge 11 for solid-liquid separation.

[0029] The centrifuge 11 is connected to the mother liquor tank 3, which is used to return the separated clear liquid to the mother liquor tank 3.

[0030] When the solid content of the material in the crystallization chamber reaches 10-20%, the material begins to be discharged into the thickener 10 . After being thickened to a solid content of 30-40% in the thickener 10 , the material enters the centrifuge 11 for separation, and the clear liquid overflows into the mother liquid tank 3 .

[0031] The settling tank 13 is connected to the top of the crystallization chamber of the Oslo crystallizer 8 through the impurity discharge pump 12 for overflow discharge of impurities;

[0032] The sedimentation tank 13 is connected to the mother liquid tank 3 and is used to discharge the fine crystals after sedimentation back to the mother liquid tank 3;

[0033] The fine crystals and impurities floating on the top of the crystallization chamber of the Oslo crystallizer 8 are sent to the sedimentation tank 13 through the impurity discharge pump 12. After sedimentation, the fine crystals are discharged from the bottom to the mother liquid tank 3, and return to the system after dissolution and crystallization. The impurities overflow from the top of the sedimentation tank 13 and are discharged.

[0034] A secondary separator 14 is connected to the top of the crystallization chamber of the Oslo crystallizer 8, and is used to remove foam from the steam discharged from the crystallization chamber of the Oslo crystallizer 8 through the secondary separator 14;

[0035] The secondary separator 14 is connected to a compressor 15, which is connected to the forced circulation heat exchanger 7, and is used to heat and pressurize the steam after defoaming through the compressor 15 and then transport it to the forced circulation heat exchanger 7;

[0036] The forced circulation pump 6 is connected to a distilled water tank 16, and the distilled water tank 16 is connected to the preheater 5 via a distilled water pump 17;

[0037] The secondary steam coming out of the Oslo crystallizer 8 passes through the secondary separator 14 for defoaming and then enters the compressor 15 for temperature and pressure increase. After being compressed, the secondary steam enters the forced circulation heat exchanger 7 for heat exchange with the forced circulation material. In the process of heating the material, this part of the steam condenses into water and flows to the distilled water tank 16 and is sent to the preheater 5 by the distilled water pump 17 to preheat the feed before being discharged from the system.

[0038] The Oslo crystallizer 8 is a supersaturation generating area and a crystal growth area respectively arranged at two places of the crystallizer. The crystals are fluidized and suspended in the circulating liquid, providing a good environment for crystal growth. Through the above process, the fine crystals that have not settled in the thickener 10, the fine crystals that leak from the screen of the centrifuge 11, and the fine crystals collected by the sedimentation tank 13 are collected in the mother liquid tank 3. When the system is fed, the unsaturated raw material first enters the raw material tank, dissolves the fine crystals in the mother liquid tank 3, and then enters the evaporation crystallization system after preheating. By controlling the system saturation, the fine crystal content in the crystallizer and the crystallizer design, the manganese sulfate solution undergoes controllable secondary nucleation in the crystallizer, thereby obtaining a good manganese sulfate crystal morphology and size distribution.

[0039] Although embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. An evaporation crystallization system for producing large particles of manganese sulfate, characterized in that, It includes an infusion unit and a crystallization unit. The infusion unit includes a stock solution tank (1), a mother liquor tank (3) and a preheater (5). The stock solution tank (1) and the mother liquor tank (3) are connected by a stock solution pump (2), and the mother liquor tank (3) and the preheater (5) are connected by a mother liquor pump (4), which is used to transport the unsaturated manganese sulfate solution into the mother liquor tank (3) and then transport it to the preheater (5) for preheating. The crystallization unit includes a forced circulation heat exchanger (7), an Oslo crystallizer (8), a thickener (10), a centrifuge (11) and a settling tank (13). The forced circulation heat exchanger (7) is connected to the preheater (5) by a forced circulation pump (6). The flash chamber of the Oslo crystallizer (8) is connected to the forced circulation pump (6), which is used to transport the preheated manganese sulfate solution into the forced circulation heat exchanger (7) to increase the temperature and pressure and then enter the flash chamber of the Oslo crystallizer (8) for flashing. The thickener (10) is connected to the bottom of the crystallization chamber of the Oslo crystallizer (8) by a discharge pump (9). The centrifuge (11) is connected to the thickener (10), which is used to transport the crystalline material in the crystallization chamber of the Oslo crystallizer (8) into the thickener (10) for thickening and then transport it into the centrifuge (11) for solid-liquid separation. The settling tank (13) is connected to the top of the crystallization chamber of the Oslo crystallizer (8) by an impurity discharge pump (12), which is used for overflowing and discharging impurities.

2. The evaporation crystallization system for producing large particles of manganese sulfate according to claim 1, wherein, The middle part of the crystallization chamber of the Oslo crystallizer (8) is connected to the forced circulation pump (6), which is used to cyclically suck the clear liquid into the circulation heat exchanger.

3. The evaporation crystallization system for producing large particles of manganese sulfate according to claim 1, wherein, The centrifuge (11) is connected to the mother liquor tank (3), which is used to return the separated clear liquid into the mother liquor tank (3).

4. An evaporation crystallization system for producing large particles of manganese sulfate according to claim 1, characterized in that, The settling tank (13) is connected to the mother liquor tank (3), which is used to discharge the settled fine crystals back into the mother liquor tank (3).

5. An evaporation crystallization system for producing large particles of manganese sulfate according to claim 1, characterized in that, A secondary separator (14) is connected to the top of the crystallization chamber of the Oslo crystallizer (8), which is used to remove the foam from the steam discharged from the crystallization chamber of the Oslo crystallizer (8) through the secondary separator (14).

6. The evaporation crystallization system for producing large particles of manganese sulfate according to claim 5, characterized in that The secondary separator (14) is connected to a compressor (15). The compressor (15) is connected to the forced circulation heat exchanger (7), which is used to transport the defoamed steam into the forced circulation heat exchanger (7) after increasing the temperature and pressure through the compressor (15).

7. An evaporation crystallization system for producing large particles of manganese sulfate according to claim 6, characterized in that The forced circulation pump (6) is connected to a distilled water tank (16). The distilled water tank (16) is connected to the preheater (5) by a distilled water pump (17).

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