Multi-source waste heat recovery coupled industrial wastewater treatment system

Abstract

The multi-source waste heat recovery coupled industrial wastewater treatment system of the present invention comprises: a wastewater pretreatment unit, the wastewater pretreatment unit comprises a PH reaction tank, a coagulation sedimentation tank and a first solid-liquid separation device connected in sequence; a multi-source waste heat recovery unit, the multi-source waste heat recovery unit comprises a heat source pipeline, a pipe network steam pipeline and a multi-source waste heat pipeline, the inlet of the heat source pipeline is connected with the outlet of the pipe network steam pipeline and the outlet of the multi-source waste heat pipeline, and the steam introduced into the multi-source waste heat pipeline is at least one of the flash exhaust steam of the pressure kettle, the tail steam of the steam concentrate drying kiln, the exhaust steam of the metallurgical slag or liquid metal water quenching and the flash exhaust steam of high-temperature water; a first heat exchanger; a concentration unit, the concentration unit comprises an evaporator, and the evaporator has a first steam chamber and a concentration chamber. Therefore, the multi-source waste heat recovery coupled industrial wastewater treatment system according to the present invention has the advantages of being convenient for saving energy, water resources and valuable metal resources.

Description

Technical Field

[0001] The invention relates to the technical field of industrial water treatment, and in particular to a multi-source waste heat recovery coupled industrial wastewater treatment system. Background Art

[0002] The industrial wastewater produced by non-ferrous smelting enterprises mainly contains various heavy metals, high salt and high organic matter components, which cannot be treated by biological methods. In order to achieve zero wastewater discharge in the factory area, deep treatment is required. The technologies suitable for deep treatment of industrial wastewater mainly include thermal concentration technology and membrane separation technology, etc., which generally have problems such as long process routes, high energy consumption, high treatment costs, and easy scaling and corrosion of equipment.

[0003] The exhaust steam resources of non-ferrous smelting plants mainly include the following parts: exhaust steam after waste heat power generation in smelting enterprises turns into condensed water after cooling. The latent heat resources carried by the exhaust steam are lost in the cooling process, and the cooling process must continuously consume new water resources, and sewage must be discharged into the environment; in the hydrometallurgical process, the slurry enters the pressure autoclave for leaching under high temperature and high pressure conditions. After leaching, the slurry is flashed in the flash tank through a nozzle to reduce pressure and cool down to form exhaust steam, which is discharged to the outside after passing through the acid mist condenser; the high-temperature slag of non-ferrous smelting top-blown furnace, flash furnace, bottom-blown furnace, fuming furnace, etc. adopts water quenching process. The water quenching instantly partially cools the water and vaporizes it into exhaust steam. The exhaust steam and air are mixed and discharged to the chimney through the induced draft fan. The remaining heat is transferred to the water through slag cooling, forming high-temperature slag flushing water, high-temperature water flash steam and low-temperature flue gas, etc. The latent heat energy of these low-temperature waste heat from different sources has not been further recycled, and is released into the environment by natural evaporation, conduction heat dissipation and thermal radiation, causing a large amount of energy loss and secondary environmental pollution. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention proposes a multi-source waste heat recovery coupled industrial wastewater treatment system.

[0005] The multi-source waste heat recovery coupled industrial wastewater treatment system of the embodiment of the present invention comprises:

[0006] A wastewater pretreatment unit, the wastewater pretreatment unit comprising a pH reaction tank, a coagulation sedimentation tank and a first solid-liquid separation device which are connected in sequence, the inlet of the pH reaction tank being connected to the outlet of the industrial wastewater pipeline to be treated in the smelter, the pH reaction tank being capable of adjusting the pH value of the industrial wastewater therein, the coagulation sedimentation tank being used for precipitating suspended matter in the industrial wastewater therein, the first solid-liquid separation device having a first liquid outlet and a first solid outlet, the pre-evaporation liquid separated by the first solid-liquid separation device being discharged from the first liquid outlet, and the solid separated by the first solid-liquid separation device being discharged from the first solid outlet;

[0007] A multi-source waste heat recovery unit, the multi-source waste heat recovery unit comprising a heat source pipeline, a pipe network steam pipeline and a multi-source waste heat pipeline, the inlet of the heat source pipeline is connected with the outlet of the pipe network steam pipeline and the outlet of the multi-source waste heat pipeline, and the steam introduced into the multi-source waste heat pipeline is at least one of pressure autoclave flash exhaust steam, steam concentrate drying kiln tail steam, metallurgical slag or liquid metal water quenching exhaust steam and high-temperature water flash exhaust steam;

[0008] a first heat exchanger, wherein a cold source inlet of the first heat exchanger is connected to the first liquid outlet of the first solid-liquid separation device, a heat source inlet of the first heat exchanger is connected to the heat source pipeline, and the first heat exchanger is used to heat the separated pre-evaporation liquid;

[0009] A concentration unit, wherein the concentration unit comprises an evaporator, wherein the evaporator has a first steam chamber and a concentration chamber, wherein the first steam chamber has a first steam inlet, and steam can be introduced into the first steam chamber from the first steam inlet, and the concentration chamber has a concentrated liquid inlet, a concentrated liquid outlet and a desalination steam outlet, wherein the concentrated liquid inlet is connected to the cold source outlet of the first heat exchanger so that the heated pre-evaporation liquid can enter the concentration chamber, the first steam chamber can heat the pre-evaporation liquid in the concentration chamber, the steam generated by evaporation of the pre-evaporation liquid in the concentration chamber can be discharged from the desalination steam outlet, and the concentrated water generated after the pre-evaporation liquid in the concentration chamber is concentrated can be discharged from the concentrated liquid outlet.

[0010] In some embodiments, the concentration unit includes the evaporator, the condenser and the first vacuum pumping device, the inlet of the condensing chamber of the condenser is connected to the desalination steam outlet so that the steam generated by the evaporation of the pre-evaporation liquid in the concentration chamber can be passed into the condensing chamber of the condenser for condensation, the cooling water inlet of the condenser is connected to the outlet of the second water supply pipe, the cooling water outlet of the condenser is connected to the inlet of the second return water pipeline, and the air inlet of the first vacuum pumping device is connected to the non-condensable gas outlet of the condenser.

[0011] In some embodiments, the multi-source waste heat recovery coupled industrial wastewater treatment system includes a concentrated water crystallization unit, and the concentrated water crystallization unit includes a crystallizer;

[0012] The crystallizer comprises a second steam chamber and a crystallization chamber, the second steam chamber comprises a second steam inlet, steam can be introduced into the second steam chamber from the second steam inlet, the crystallization chamber comprises a crystallization inlet, a crystallization outlet and a crystallization steam outlet, the crystallization inlet is connected to the concentrated liquid outlet, the second steam chamber can heat the concentrated water in the crystallization chamber so that the concentrated water in the crystallization chamber evaporates and crystallizes, the steam generated by the evaporation of the concentrated water in the crystallization chamber can be discharged from the crystallization steam outlet, and the crystallized material generated after the concentrated water in the crystallization chamber is crystallized can be discharged from the crystallization outlet.

[0013] In some embodiments, the concentrated water crystallization unit includes the crystallizer, a second vacuum pumping device, a thickener, a second solid-liquid separation device, a steam dryer, and a salt storage tank;

[0014] The second vacuum pumping device is in communication with the non-condensable gas outlet of the crystallizer;

[0015] The inlet of the thickener is connected to the crystallization outlet, the thickener has a third outlet and a fourth outlet, the third outlet is located above the fourth outlet, the third outlet is connected to the crystallization inlet, and the fourth outlet is connected to the inlet of the second solid-liquid separation device;

[0016] The second solid-liquid separation device has a second liquid outlet and a second solid outlet, the liquid separated by the second solid-liquid separation device is discharged from the second liquid outlet and passed into the crystallization inlet, and the solid material separated by the second solid-liquid separation device is discharged from the second solid outlet and passed into the steam dryer for drying;

[0017] The salt storage tank is used to store the solid material dried by the steam dryer.

[0018] In some embodiments, the outlet of the pipeline for the industrial wastewater to be treated in the smelter is connected to the wastewater regulating tank, and the outlet of the wastewater regulating tank is connected to the inlet of the pH reaction tank;

[0019] The pH reaction tank is connected to an acid-base regulating liquid delivery pipeline, and the acid-base regulating liquid delivery pipeline is used to pass the acid-base regulating liquid into the pH reaction tank;

[0020] The pH value of the industrial wastewater discharged from the pH reaction tank is greater than or equal to 7 and less than or equal to 8.5.

[0021] In some embodiments, the coagulation sedimentation tank is connected to a coagulant delivery pipeline, and the coagulant delivery pipeline is used to add coagulation sedimentation reagents into the coagulation sedimentation tank so as to precipitate suspended matter in the industrial wastewater in the coagulation sedimentation tank;

[0022] The coagulation sedimentation tank has a first outlet and a second outlet, the first outlet is located above the second outlet, the first outlet is connected to the cold source inlet of the first heat exchanger, and the second outlet is connected to the inlet of the first solid-liquid separation device;

[0023] The solid separated from the industrial wastewater by the first solid-liquid separation device can be recycled as valuable metal precipitates.

[0024] In some embodiments, the steam introduced into the multi-source waste heat pipeline is one of the exhaust steam from flash evaporation of a pressure autoclave, tail steam from a steam concentrate drying kiln, exhaust steam from water quenching of metallurgical slag or liquid metal, and exhaust steam from high-temperature water flash evaporation;

[0025] The temperature of the steam introduced into the evaporator is greater than or equal to 90° C. and less than or equal to 100° C.

[0026] In some embodiments, the concentration chamber is connected to a scale inhibition pipeline, and the scale inhibition pipeline is used to pass the scale inhibitor into the concentration chamber;

[0027] The first steam inlet is in communication with a heat source outlet of the first heat exchanger;

[0028] The evaporator has a first cooling chamber, the inlet of the first cooling chamber is connected to a first water supply pipe, the outlet of the first cooling chamber is connected to a first water return pipe, and the steam discharged from the first steam chamber of the evaporator is cooled by the cooling water in the first cooling chamber and then passed into the condensation water pipe.

[0029] In some embodiments, the concentrate outlet is connected to the inlet of the precipitation de-weighting tank, the water outlet of the precipitation de-weighting tank is connected to the crystallization inlet, and the precipitation de-weighting tank has a precipitation input pipeline connected thereto, and the precipitation input pipeline is used to introduce a precipitant into the precipitation de-weighting tank;

[0030] The second steam inlet is in communication with the outlet of the heat source pipeline;

[0031] The crystallization steam outlet is communicated with the inlet of the condensation chamber of the condenser;

[0032] The crystallizer has a second cooling chamber, the inlet of the second cooling chamber is connected to the third water supply pipe, the outlet of the second cooling chamber is connected to the third water return pipe, and the steam discharged from the second steam chamber of the crystallizer is cooled by the cooling water in the second cooling chamber and then passed into the condensate water pipe.

[0033] In some embodiments, a switching valve is provided on the inlet of the heat source pipeline, and the inlet of the switching valve is connected to the pipeline network steam pipeline and the multi-source waste heat pipeline. The switching valve can adjust the flow of the pipeline network steam pipeline and the multi-source waste heat pipeline into the heat source pipeline.

[0034] The beneficial effects of the present invention are as follows: the multi-source waste heat recovery coupled industrial wastewater treatment system according to the embodiment of the present invention can utilize one or more waste heat and exhaust steam resources of a non-ferrous metal smelter for the treatment of wastewater in the smelter, and can allocate the pipe network steam in advance according to the production plan of the smelter to predict the exhaust steam output and the wastewater treatment load to achieve a synergistic effect. Thus, the water resources in the wastewater can be recovered and reused in waste heat boilers or chemical water stations, etc., and the valuable salts in the wastewater can also be recovered, thereby saving energy, water resources and valuable metal resources. Therefore, the multi-source waste heat recovery coupled industrial wastewater treatment system according to the embodiment of the present invention has the advantage of being easy to save energy, water resources and valuable metal resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of a multi-source waste heat recovery coupled industrial wastewater treatment system according to an embodiment of the present invention.

[0036] Figure 2 It is a schematic diagram of a multi-source waste heat recovery coupled industrial wastewater treatment system according to a first embodiment of the present invention.

[0037] Figure 3 It is a schematic diagram of a multi-source waste heat recovery coupled industrial wastewater treatment system according to a second embodiment of the present invention.

[0038] Figure 4 It is a schematic diagram of a multi-source waste heat recovery coupled industrial wastewater treatment system according to a third embodiment of the present invention.

[0039] Reference numerals:

[0040] 1. Pipeline for industrial wastewater to be treated in a smelter, 11. PH reaction tank, 111. Acid-base regulating liquid delivery pipeline, 12. Coagulation sedimentation tank, 121. First outlet, 122. Second outlet, 123. Coagulant delivery pipeline, 13. First solid-liquid separation device, 131. First liquid outlet, 132. First solid outlet, 14. Wastewater regulating tank;

[0041] 2. Heat source pipeline, 21. Pipeline network steam pipeline, 22. Multi-source waste heat pipeline;

[0042] 3. First heat exchanger, 31. Cold source inlet, 32. Cold source outlet, 33. Heat source inlet, 34. Heat source outlet;

[0043] 4. evaporator, 41. first steam inlet, 42. concentrate inlet, 43. concentrate outlet, 44. desalination steam outlet, 45. scale prevention pipeline, 46. first water supply pipeline, 47. first water return pipeline;

[0044] 5. condenser, 51. second water supply pipeline, 52. second water return pipeline, 53. first vacuum pumping device;

[0045] 6. crystallizer, 61. second steam inlet, 62. crystallization inlet, 63. crystallization outlet, 64. crystallization steam outlet, 65. third water supply pipeline, 66. third water return pipeline, 67. condensate water pipeline, 68. sedimentation and deweighting tank, 681. sedimentation input pipeline;

[0046] 71. Second vacuum pumping device, 72. Thickener, 721. Third outlet, 722. Fourth outlet, 73. Second solid-liquid separation device, 74. Steam dryer, 75. Salt storage tank. DETAILED DESCRIPTION

[0047] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0048] The following describes a multi-source waste heat recovery coupled industrial wastewater treatment system according to an embodiment of the present invention with reference to the accompanying drawings. Figures 1 to 4 As shown, the multi-source waste heat recovery coupled industrial wastewater treatment system according to an embodiment of the present invention includes a wastewater pretreatment unit, a multi-source waste heat recovery unit, a first heat exchanger 3 and a concentration unit.

[0049] The wastewater pretreatment unit includes a PH reaction tank 11, a coagulation sedimentation tank 12 and a first solid-liquid separation device 13 which are connected in sequence, so that industrial wastewater can enter the PH reaction tank 11, the coagulation sedimentation tank 12 and the first solid-liquid separation device 13 in sequence.

[0050] The inlet of the pH reaction tank 11 is connected to the outlet of the pipeline 1 of the industrial wastewater to be treated in the smelter, and the pH reaction tank 11 can adjust the pH value of the industrial wastewater therein. Specifically, the pH reaction tank 11 is connected to the acid-base regulating liquid delivery pipeline 111, and the acid-base regulating liquid delivery pipeline 111 is used to pass the acid-base regulating liquid (acid-base regulating agent) into the pH reaction tank 11. The pH value of the industrial wastewater discharged from the pH reaction tank 11 is greater than or equal to 7 and less than or equal to 8.5. By adjusting the pH value of the wastewater, the effect of removing calcium, magnesium and valuable heavy metal ions in the water is achieved, and the concentration of the valuable heavy metal ions is recovered to reach the original ore grade.

[0051] like Figure 3 As shown, in some embodiments, the outlet of the smelter's industrial wastewater pipeline 1 is connected to the wastewater regulating tank 14, and the outlet of the wastewater regulating tank 14 is connected to the inlet of the pH reaction tank 11. The wastewater regulating tank 14 can balance the fluctuation of the wastewater quality and quantity in the plant area, and subsequently perform wastewater pretreatment.

[0052] In some embodiments, the industrial wastewater from nonferrous metal smelters treated by the present invention may be wastewater generated from different production links of the smelter, for example, wastewater may be waste acid wastewater treatment liquid, circulating wastewater, chemical treatment station wastewater, and high-salinity wastewater discharged by wet method.

[0053] The coagulation sedimentation tank 12 is used to precipitate suspended matter in the industrial wastewater therein. Specifically, the coagulation sedimentation tank 12 is connected to the coagulant delivery pipeline 123. After the industrial wastewater after the pH value is adjusted by the pH reaction tank 11 is passed into the coagulation sedimentation tank 12, the coagulant delivery pipeline 123 is used to add a coagulation sedimentation agent (coagulant agent) into the coagulation sedimentation tank 12 so as to precipitate the suspended matter in the industrial wastewater in the coagulation sedimentation tank 12.

[0054] like Figures 1 to 4 As shown, the first solid-liquid separation device 13 is used for solid-liquid separation, and the first solid-liquid separation device 13 has a first liquid outlet 131 and a first solid outlet 132. The industrial wastewater in the coagulation sedimentation tank 12 is introduced into the first solid-liquid separation device 13, the pre-evaporation liquid separated by the first solid-liquid separation device 13 is discharged from the first liquid outlet 131, and the solid separated by the first solid-liquid separation device 13 is discharged from the first solid outlet 132. For example, the first solid-liquid separation device 13 includes a filter, and the filter is used to perform solid-liquid separation on the effluent of the coagulation sedimentation tank 12. The filter can be a filter press or a centrifugal filter.

[0055] In some embodiments, the solid separated from the industrial wastewater by the first solid-liquid separation device 13 can be recycled as a valuable metal precipitate. For example, the filter residue obtained after filtration by the first solid-liquid separation device 13 can be recycled as a valuable metal precipitate and enter the upstream smelting stage.

[0056] like Figures 1 to 4 As shown, in some embodiments, the coagulation sedimentation tank 12 has a first outlet 121 and a second outlet 122, and the first outlet 121 is located above the second outlet 122. The first outlet 121 is connected to the cold source inlet 31 of the first heat exchanger 3, and the second outlet 122 is connected to the inlet of the first solid-liquid separation device 13. Specifically, the first outlet 121 is the upper water outlet of the coagulation sedimentation tank 12, and the second outlet 122 is the lower outlet of the coagulation sedimentation tank 12. As a result, the clear liquid (liquid before evaporation) of the upper layer of the industrial wastewater in the coagulation sedimentation tank 12 can be passed into the cold source inlet 31 of the first heat exchanger 3, so as to be preheated in the first heat exchanger 3. The relatively turbid part of the lower layer of the industrial wastewater in the coagulation sedimentation tank 12 can be passed into the first solid-liquid separation device 13 for solid-liquid separation.

[0057] like Figures 1 to 4 As shown, the multi-source waste heat recovery unit includes a heat source pipeline 2 , a pipeline network steam pipeline 21 and a multi-source waste heat pipeline 22 .

[0058] The inlet of the heat source pipeline 2 is connected with the outlet of the network steam pipeline 21 and the outlet of the multi-source waste heat pipeline 22, that is, the network steam pipeline 21 and the multi-source waste heat pipeline 22 are arranged in parallel and connected with the inlet of the heat source pipeline 2. Specifically, a switching valve is provided on the inlet of the heat source pipeline 2, and the inlet of the switching valve is connected with the network steam pipeline 21 and the multi-source waste heat pipeline 22. The switching valve can adjust the flow rate of the network steam pipeline 21 and the multi-source waste heat pipeline 22 into the heat source pipeline 2. Therefore, the switching valve can be used to adjust the flow rate ratio of the network steam pipeline 21 and the multi-source waste heat pipeline 22 into the heat source pipeline 2. Therefore, the official steam can supplement the steam volume, so that the heat source pipeline 2 has sufficient steam discharge.

[0059] The steam introduced into the multi-source waste heat pipeline 22 is at least one of the exhaust steam from flash evaporation of a pressure kettle, tail steam from a steam concentrate drying kiln, exhaust steam from water quenching of metallurgical slag or liquid metal, and exhaust steam from flash evaporation of high-temperature water.

[0060] Specifically, the flash exhaust steam of multiple pressure kettles is the exhaust steam (90℃-96℃) after passing through an isothermal washing tower. The isothermal washing tower is a device that can directly exchange heat between hot water and steam that has been cleaned of mineral dust, acid, alkali and other impurities entrained in the pressure kettle. The tail steam of the steam concentrate drying kiln is the tail steam discharged from the direct heat exchange device between hot water and steam that has been cleaned of dust, sulfide and other impurities entrained in the concentrate drying kiln. The exhaust steam of metallurgical slag or liquid metal water quenching is the large amount of exhaust steam generated during the water quenching process of metallurgical slag or liquid metal. The high-temperature water flash exhaust steam is the steam generated during the high-temperature water flash evaporation process, that is, the secondary steam generated by the flash evaporation of high-temperature hot water rapidly sprayed into the negative pressure tank body. High-temperature water is water with a temperature greater than or equal to 80℃. For example, high-temperature water has a temperature greater than or equal to 80℃ and less than or equal to 100℃.

[0061] The multi-source waste heat recovery unit can use at least one of the pipeline steam and the flash exhaust steam of the pressure kettle, the tail steam of the steam concentrate drying kiln, the exhaust steam of the metallurgical slag or liquid metal water quenching and the high-temperature water flash exhaust steam as heating steam to improve the utilization rate of energy and save energy. The pipeline steam can be used as a compensating heat source so that the multi-source waste heat recovery unit can provide sufficient steam.

[0062] In some embodiments, the steam introduced into the multi-source waste heat pipeline 22 is one of the flash exhaust steam of the autoclave, the tail steam of the steam concentrate drying kiln, the exhaust steam of the metallurgical slag or liquid metal water quenching, and the flash exhaust steam. That is, one of the flash exhaust steam of the autoclave, the tail steam of the steam concentrate drying kiln, the exhaust steam of the metallurgical slag or liquid metal water quenching, and the flash exhaust steam is introduced into the multi-source waste heat pipeline 22 so as to serve as the steam source output by the multi-source waste heat recovery unit.

[0063] like Figures 1 to 4As shown, the cold source inlet 31 (wastewater inlet) of the first heat exchanger 3 is connected to the first liquid outlet 131 of the first solid-liquid separation device 13, the first outlet 121 is connected to the cold source inlet 31 of the first heat exchanger 3, and the heat source inlet 33 (steam inlet) of the first heat exchanger 3 is connected to the heat source pipeline 2. The first heat exchanger 3 is used to heat the separated pre-evaporation liquid. Specifically, the first heat exchanger 3 is a steam heat exchanger, and the steam (steam 1) in the heat source pipeline 2 is passed into the first heat exchanger 3 to serve as a heat source, so as to heat the pre-evaporation liquid (industrial wastewater) entering the first heat exchanger 3 through the cold source inlet 31. For example, the first heat exchanger 3 can be a wall-type heat exchanger such as a tube type or a plate type, and a suitable structure and heat exchange area can be selected according to the inlet water temperature, steam temperature conditions, etc., and a corrosion-resistant and anti-scaling coating can be added, or a corrosion-resistant and anti-scaling material can be used.

[0064] like Figures 1 to 4 As shown, the concentration unit includes an evaporator 4 , a condenser 5 and a first vacuuming device 53 .

[0065] The evaporator 4 has a first steam chamber and a concentration chamber, and the first steam chamber has a first steam inlet 41, and steam can be passed into the first steam chamber from the first steam inlet 41. Specifically, the first steam inlet 41 is connected to the heat source outlet 34 (steam outlet) of the first heat exchanger 3, so that the steam (steam 2) after heat exchange in the first heat exchanger 3 can be passed into the first steam chamber as a heat source. For example, the evaporator 4 is a low-temperature multi-effect evaporator, and the wastewater first enters the first-effect evaporator to exchange heat with the multi-source waste heat exhaust steam, and after increasing the concentration, it enters the next-effect evaporator step by step, and the temperature and pressure in each effect evaporator are reduced step by step.

[0066] In some embodiments, the temperature of the steam introduced into the evaporator 4 is greater than or equal to 90° C. and less than or equal to 100° C. For example, the temperature of the steam introduced into the evaporator 4 is 95° C.

[0067] The concentration chamber has a concentrate inlet 42, a concentrate outlet 43 and a desalination steam outlet 44. The concentrate inlet 42 is connected to the cold source outlet 32 ​​(wastewater outlet) of the first heat exchanger 3 so that the heated pre-evaporation liquid can enter the concentration chamber. The first steam chamber (the steam inside) can heat the pre-evaporation liquid in the concentration chamber, thereby concentrating the pre-evaporation liquid in the concentration chamber of the evaporator 4. The steam generated by the evaporation of the pre-evaporation liquid in the concentration chamber can be discharged from the desalination steam outlet 44, and the concentrated water generated by the concentration of the pre-evaporation liquid in the concentration chamber can be discharged from the concentrate outlet 43. That is, the pre-evaporation liquid formed by industrial wastewater can be concentrated by using the steam introduced into the evaporator 4 to obtain concentrated water.

[0068] In some embodiments, the concentration chamber is connected to the anti-scaling pipe 45, and the anti-scaling pipe 45 is used to introduce an anti-scaling agent into the concentration chamber, thereby reducing scaling in the concentration chamber. For example, the evaporator 4 can select a falling film evaporator, and the evaporator nozzle is an atomizing nozzle. During the evaporation process, an anti-scaling agent can also be added to prevent the scaling of calcium and magnesium ions in the wastewater. The composition of the anti-scaling agent is the same as one or more of the anions and cations of calcium, magnesium, sulfate, carbonate, and hydroxide ions in the wastewater. It is added into the wastewater, and during the low-temperature multiple-effect evaporation process, the calcium, magnesium, sulfate, and carbonate ions in the wastewater are continuously grown on the anti-scaling agent, and avoid growing on the surface of the metal heat exchange pipe inside the evaporator 4, thereby preventing scaling during operation.

[0069] In some embodiments, the evaporator 4 has a first cooling chamber, the inlet of the first cooling chamber is connected to the first water supply pipe 46, the outlet of the first cooling chamber is connected to the first water return pipe 47, and the steam discharged from the first steam chamber of the evaporator 4 is cooled by the cooling water in the first cooling chamber and then passed into the condensed water pipe 67. Specifically, the first water supply pipe 46 passes cooling water (water supply 1) into the first cooling chamber to cool the steam discharged from the first steam chamber of the evaporator 4, and the cooling water (water return 1) after heat exchange can be passed into the first water return pipe 47 for discharge.

[0070] The inlet of the condensing chamber of the condenser 5 is connected to the desalination steam outlet 44, so that the steam generated by the evaporation of the pre-evaporation liquid in the concentration chamber can be passed into the condensing chamber of the condenser 5 for condensation, and the desalted water formed by the condensation of the steam generated by the evaporation of the pre-evaporation liquid is discharged from the outlet of the condensing chamber of the condenser 5.

[0071] The cooling water inlet of the condenser 5 is connected to the outlet of the second water supply pipe 51, and the cooling water outlet of the condenser 5 is connected to the inlet of the second return water pipeline 52. The water in the second water supply pipe 51 (supply water 2) enters the condenser 5 so that the steam in the condensation chamber can be condensed by water. After heat exchange, the water (return water 2) can be discharged into the second return water pipeline 52.

[0072] The air inlet of the first vacuum pumping device 53 is connected to the non-condensable gas outlet of the condenser 5. Specifically, the first vacuum pumping device 53 (vacuum pump 1) evacuates the evaporator 4 and the condenser 5 and maintains a certain negative pressure state, accelerates the low-temperature evaporation rate of industrial wastewater, and assists in removing the non-condensable gas in the condenser 5 and discharging it into the air from the air outlet.

[0073] In some embodiments, a multi-source waste heat recovery coupled industrial wastewater treatment system includes a concentrated water crystallization unit, which includes a crystallizer 6, a second vacuum pump 71, a thickener 72, a second solid-liquid separation device 73, a steam dryer 74 and a salt storage tank 75.

[0074] In some embodiments, the first vacuum pumping device 53 and the second vacuum pumping device 71 are the same vacuum pump.

[0075] The crystallizer 6 is a device for separating and purifying solid substances from a solution. The crystallizer 6 has a second steam chamber and a crystallization chamber, and the second steam chamber has a second steam inlet 61, and steam can be passed into the second steam chamber from the second steam inlet 61. The second steam inlet 61 is connected to the outlet of the heat source pipeline 2, so that the steam (steam 3) of the heat source pipeline 2 can be passed into the second steam chamber of the crystallizer 6, thereby providing a heat source for the crystallizer 6. The heat source of the crystallizer 6 is allocated from a multi-source waste heat recovery unit, and the ratio of waste heat exhaust steam (at least one of the pressure autoclave flash exhaust steam, steam concentrate drying kiln tail steam, metallurgical slag or liquid metal water quenching exhaust steam and high-temperature water flash exhaust steam) resources to the pipeline network steam can be allocated according to the characteristics of the desired crystallized material.

[0076] The crystallization chamber has a crystallization inlet 62, a crystallization outlet 63 and a crystallization steam outlet 64. The crystallization inlet 62 is connected to the concentrated liquid outlet 43, so that the concentrated water obtained by the evaporator 4 can be passed into the crystallization chamber of the crystallizer 6. The second steam chamber can heat the concentrated water in the crystallization chamber to evaporate and crystallize the concentrated water in the crystallization chamber. The steam generated by the evaporation of the concentrated water in the crystallization chamber can be discharged from the crystallization steam outlet 64, and the crystallized material generated after the concentrated water in the crystallization chamber is crystallized can be discharged from the crystallization outlet 63.

[0077] In some embodiments, the crystallization steam outlet 64 is connected to the inlet of the condensation chamber of the condenser 5, so that the steam generated by the evaporation of concentrated water in the crystallization chamber can be passed into the condenser 5 to condense into desalted water and discharged from the outlet of the condensation chamber of the condenser 5.

[0078] The crystallizer 6 has a second cooling chamber, the inlet of the second cooling chamber is connected to the third water supply pipe 65, the outlet of the second cooling chamber is connected to the third water return pipe 66, and the steam discharged from the second steam chamber of the crystallizer 6 is cooled by the cooling water in the second cooling chamber and then passed into the condensation water pipe 67. Specifically, the water (water supply 3) in the third water supply pipe 651 enters the crystallizer 6 so that the steam discharged from the second steam chamber of the crystallizer 6 is condensed by water, and the water (water return 3) after heat exchange can be passed into the third water return pipe 66 for discharge. For example, the crystallizer 6 is a forced circulation crystallizer.

[0079] The second vacuum pumping device 71 is connected to the non-condensable gas outlet of the crystallizer 6. The second vacuum pumping device 71 (vacuum pump 2) provides negative pressure to the crystallizer 6 to accelerate the crystallization of concentrated water.

[0080] The thickener 72 is a device for separating solids from liquids so as to further purify the crystallized material. The inlet of the thickener 72 is connected to the crystallization outlet 63. The thickener 72 has a third outlet 721 and a fourth outlet 722. The third outlet 721 is located above the fourth outlet 722. The third outlet 721 is connected to the crystallization inlet 62, and the fourth outlet 722 is connected to the inlet of the second solid-liquid separation device 73. Specifically, the third outlet 721 is the upper outlet of the thickener 72, and the fourth outlet 722 is the lower outlet of the thickener 72. The clear liquid in the upper layer of the thickener 72 can enter the crystallizer 6 through the third outlet 721 to evaporate and crystallize again. The solid material (salt) in the lower layer of the thickener 72 can be passed into the second solid-liquid separation device 73 for solid-liquid separation.

[0081] The second solid-liquid separation device 73 has a second liquid outlet and a second solid outlet. The liquid separated by the second solid-liquid separation device 73 is discharged from the second liquid outlet and passed into the crystallization inlet 62 (to be evaporated and crystallized again). The solid material separated by the second solid-liquid separation device 73 is discharged from the second solid outlet and passed into the steam dryer 74 for drying. The salt storage tank 75 is used to store the solid material dried by the steam dryer 74. For example, the second solid-liquid separation device 73 is a pusher centrifuge or a belt filter.

[0082] like Figure 4 As shown, in some embodiments, the concentrated liquid outlet 43 is connected to the inlet of the sedimentation and de-weighting tank 68, the water outlet of the sedimentation and de-weighting tank 68 is connected to the crystallization inlet 62, and the sedimentation and de-weighting tank 68 has a sedimentation input pipeline 681 connected thereto, and the sedimentation input pipeline 681 is used to pass a precipitant into the sedimentation and de-weighting tank 68. The sedimentation and de-weighting tank 68 is a device for separating solids from liquids. The precipitant combines with the valuable metals in the concentrated water to form solid particles. The solid particles suspended in the liquid are settled to the bottom by the principle of gravity sedimentation, thereby achieving solid-liquid separation, and the separated concentrated water is passed into the crystallizer 6. For example, the precipitant is a sodium sulfide precipitant.

[0083] like Figure 2 As shown, in the multi-source waste heat recovery coupled industrial wastewater treatment system according to the first embodiment of the present invention, metallurgical slag water from a non-ferrous metal smelting plant is used to quench exhaust steam to treat sodium sulfate wastewater and prepare sodium sulphate.

[0084] Nonferrous smelting wastewater is wastewater from upstream processes. The hardness of the wastewater is 200 mg / L to 500 mg / L (measured in CaCO3), the sodium sulfate content is 80 g / L to 120 g / L, and the pH is 5.0 to 6.5.

[0085] The sodium sulfate wastewater first enters the wastewater regulating tank 14 to balance the fluctuation of the wastewater quality and quantity in the plant area, and is transported to the wastewater PH reaction tank 11 by a water pump. The PH regulating agent is NaOH added to the PH reaction tank 11, and the PH reaction end point is set to 8.0, and then it is transported to the coagulation sedimentation tank 12 by a water pump. The wastewater is coagulated and precipitated in the coagulation sedimentation tank 12 to remove suspended particles and colloids. The wastewater after coagulation and precipitation is connected to the first solid-liquid separation device 13 through the bottom outlet (second outlet 122) of the coagulation sedimentation tank 12, and the wastewater is filtered.

[0086] The multi-source waste heat recovery unit uses the metallurgical slag water quenching exhaust steam (metallurgical slag water quenching exhaust steam in metallurgical slag or liquid metal water quenching exhaust steam) in the non-ferrous metal smelting plant as the steam source. The temperature of the metallurgical slag water quenching exhaust steam recovered in the multi-source waste heat recovery unit is 70℃ to 85℃. When the exhaust steam resource is insufficient, the pipeline steam is supplemented, and the steam needs to be cooled to below 100℃ before entering the evaporator 4.

[0087] The number of effects of the low-temperature evaporator 4 is determined by the exhaust steam temperature and properties of the multi-source waste heat recovery unit, the amount of water in the liquid before evaporation, and the required concentration multiple. Therefore, the number of effects of the low-temperature evaporator 4 for treating sodium sulfate wastewater is set to 4, and the wastewater is concentrated by the fourth-effect evaporator 4 and then transported to the crystallizer 6. The sodium sulfate concentrated water is evaporated and crystallized in the crystallizer 6, and when it is concentrated in the crystallizer 6 until crystal precipitation is observed or the concentrated water density reaches 1.2 to 1.4, it can be discharged to the thickener 72 to further promote crystal formation. The clear liquid on the top of the thickener 72 can be returned to the crystallizer 6.

[0088] like Figure 3 As shown, in the multi-source waste heat recovery coupled industrial wastewater treatment system according to the second embodiment of the present invention, the high-temperature hot water flash evaporation exhaust steam from the copper smelter is used to concentrate and treat calcium sulfate wastewater and reverse osmosis concentrated water.

[0089] The industrial wastewater is a mixture of acidic heavy metal wastewater and reverse osmosis concentrated water after pretreatment in the chemical area of ​​the smelter. The pretreatment method of acidic heavy metal wastewater is that the wastewater is subjected to sulfidation, gypsum and deep heavy and arsenic removal, and the arsenic and heavy metal concentrations meet the standards. The main component of the wastewater is calcium sulfate; the reverse osmosis concentrated water comes from the reverse osmosis device in the water treatment workshop of the smelter. After the two wastewaters are mixed, the hardness of the wastewater is 2000mg / L (in terms of Ca), the pH is 7.5, and the water volume is 1200m 3 / d (cubic meters / day).

[0090] The calcium sulfate wastewater and reverse osmosis concentrate generated by pretreatment of the acidic heavy wastewater in the copper smelter are first discharged into the wastewater regulating tank 14, and then the two wastewater components are homogenized and adjusted and then transported to the wastewater PH reaction tank 11 through a water pump for PH adjustment. The PH adjusting agent is sulfuric acid added to the PH reaction tank 11. After the PH adjustment end point is set to about 7.0, it is pumped to the first heat exchanger 3 through the coagulation sedimentation tank 12 and the first solid-liquid separation device 13, and after heat exchange, it enters the low-temperature thermal evaporator 4 as pre-evaporation liquid.

[0091] The multi-source waste heat recovery unit uses the high-temperature water flash exhaust steam in the copper smelter as the steam source. The temperature of the high-temperature hot water flash exhaust gas in the copper smelter is about 70°C. The exhaust gas temperature can be used to evaporate and concentrate the mixed wastewater of calcium sulfate and reverse osmosis concentrated water in the low-temperature evaporator 4. When the exhaust steam resource is insufficient, the pipeline steam is supplemented. The steam needs to be cooled to below 100°C before entering the low-temperature evaporator 4.

[0092] The number of 4 evaporator effects is determined by the exhaust steam temperature and properties of the multi-source waste heat recovery unit, the amount of water in the pre-concentration liquid, and the required concentration multiple. Therefore, the number of 4 low-temperature evaporators for treating sodium sulfate wastewater is set to 3 effects, and the wastewater is concentrated by the third-effect evaporator 4 and then transported to the slag flushing tank (sedimentation tank). Calcium sulfate precipitates in the slag flushing tank (sedimentation tank) and is separated from the concentrated water. The concentrated water overflows and is discharged to the slag flushing tank in the smelter for reuse, and the calcium sulfate is transported out for disposal.

[0093] After the above operation, the high-temperature water flash exhaust gas in the copper smelter can be used to concentrate the acidic heavy wastewater and reverse osmosis concentrated water to obtain produced water that can be reused in the production link and reused in the slag flushing process. After the original wastewater is concentrated, the water volume is reduced to 25% of the original water volume (300m 3 / d), and ultimately achieve zero wastewater discharge.

[0094] like Figure 4 As shown, in the multi-source waste heat recovery coupled industrial wastewater treatment system according to the third embodiment of the present invention, the nickel smelter pressure kettle flash exhaust steam is used to treat sodium sulfate wastewater and prepare sodium sulfate.

[0095] The smelting wastewater of the nickel smelter is the wastewater produced by the upstream process. The main components of the wastewater are sodium sulfate with a content of 120 g / L to 140 g / L, a pH of 7.0 to 8.5, and Ni of 0.05 g / L.

[0096] The sodium sulfate wastewater first enters the wastewater regulating tank 14 to balance the fluctuation of wastewater quality and quantity in the plant area, and is transported to the wastewater PH reaction tank 11 through a water pump. The PH regulating agent is NaOH added to the PH reaction tank 11, and the PH reaction end point is set to 8.5, and then connected to the first solid-liquid separation device 13 through the bottom water outlet (second outlet 122) to filter the wastewater.

[0097] The multi-source waste heat recovery unit uses the flash exhaust steam of the autoclave in the non-ferrous metal smelting plant (the flash exhaust steam of the autoclave is a type of flash exhaust steam of the pressure autoclave) as the steam source. The temperature of the flash exhaust steam of the autoclave in the multi-source waste heat recovery unit is 95°C. The exhaust steam temperature can be used to evaporate and concentrate the sodium sulfate wastewater in the low-temperature evaporator 4.

[0098] The number of effects of the low-temperature evaporator 4 is determined by the exhaust steam temperature and properties of the multi-source wastewater recovery unit, the amount of water before concentration, and the required concentration multiple. Therefore, the number of effects of the low-temperature evaporator 4 for treating sodium sulfate wastewater is set to 3. During the evaporation process of evaporator 4, scale inhibitors can also be added to prevent the scaling of calcium and magnesium ions in the wastewater. The composition of the scale inhibitor is the same as one or more of the anions and cations of calcium, magnesium, sulfate, carbonate, and hydroxide ions in the wastewater, and is added into the wastewater.

[0099] After the wastewater is concentrated by the third-effect evaporator 4, it is transported to the sedimentation and de-weighting tank 68. The wastewater is concentrated in the low-temperature evaporator 4, so that the concentration of nickel metal ions in the wastewater is increased. The concentrated water after low-temperature evaporation and concentration is de-weighted and nickel is recovered by sulfidation. Specifically, the wastewater is fed to the sedimentation and de-weighting tank 68 at a wastewater inlet rate of 100 g / m 3 Up to 500g / m 3 Sodium sulfide precipitant is added in proportion to make the nickel in the concentrated water react with sodium sulfide to form nickel sulfide precipitate. The recovered nickel sulfide can be returned to the nickel electrolysis workshop for reuse.

[0100] The bottom outlet of the sedimentation and deweighting tank 68 is connected to the filter of the solid-liquid separation device to filter the concentrated water. The filtrate is pumped to the evaporation crystallizer 6, in which the sodium sulfate concentrated water is evaporated and crystallized.

[0101] The crystallizer 6 can be a forced circulation crystallizer 6. When the crystals are concentrated in the crystallizer 6 until crystals are observed to precipitate or the concentrated water density reaches 1.2 to 1.4, the material can be discharged to the thickener 72 to further promote crystallization. The clear liquid on the thickener 72 can be returned to the crystallizer 6.

[0102] The multi-source waste heat recovery coupled industrial wastewater treatment system according to the embodiment of the present invention can utilize one or more waste heat and exhaust steam resources of a non-ferrous metal smelter for the treatment of wastewater in the smelter, and can allocate the pipe network steam in advance according to the production plan of the smelter to predict the exhaust steam output and wastewater treatment load to achieve a synergistic effect. Thus, the water resources in the wastewater can be recovered and reused in waste heat boilers or chemical water stations, etc., and the valuable salts in the wastewater can also be recovered, thereby saving energy, water resources and valuable metal resources.

[0103] Therefore, the multi-source waste heat recovery coupled industrial wastewater treatment system according to the embodiment of the present invention has the advantage of being easy to save energy, water resources and valuable metal resources.

[0104] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0105] 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 at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0106] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0107] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0108] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0109] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A multi-source waste heat recovery coupled industrial wastewater treatment system, characterized in that: include: A wastewater pretreatment unit, the wastewater pretreatment unit comprising a pH reaction tank, a coagulation sedimentation tank and a first solid-liquid separation device which are connected in sequence, the inlet of the pH reaction tank being connected to the outlet of the industrial wastewater pipeline to be treated in the smelter, the pH reaction tank being capable of adjusting the pH value of the industrial wastewater therein, the coagulation sedimentation tank being used for precipitating suspended matter in the industrial wastewater therein, the first solid-liquid separation device having a first liquid outlet and a first solid outlet, the pre-evaporation liquid separated by the first solid-liquid separation device being discharged from the first liquid outlet, and the solid separated by the first solid-liquid separation device being discharged from the first solid outlet; A multi-source waste heat recovery unit, the multi-source waste heat recovery unit comprising a heat source pipeline, a pipe network steam pipeline and a multi-source waste heat pipeline, the inlet of the heat source pipeline is connected with the outlet of the pipe network steam pipeline and the outlet of the multi-source waste heat pipeline, and the steam introduced into the multi-source waste heat pipeline is at least one of pressure autoclave flash exhaust steam, steam concentrate drying kiln tail steam, metallurgical slag or liquid metal water quenching exhaust steam and high-temperature water flash exhaust steam; a first heat exchanger, wherein a cold source inlet of the first heat exchanger is connected to the first liquid outlet of the first solid-liquid separation device, a heat source inlet of the first heat exchanger is connected to the heat source pipeline, and the first heat exchanger is used to heat the separated pre-evaporation liquid; A concentration unit, the concentration unit comprising an evaporator, the evaporator having a first steam chamber and a concentration chamber, the first steam chamber having a first steam inlet, steam can be passed into the first steam chamber from the first steam inlet, the concentration chamber having a concentrate inlet, a concentrate outlet and a desalination steam outlet, the concentrate inlet is connected to the cold source outlet of the first heat exchanger so that the heated pre-evaporation liquid enters the concentration chamber, the first steam chamber can heat the pre-evaporation liquid in the concentration chamber, the steam generated by evaporation of the pre-evaporation liquid in the concentration chamber can be discharged from the desalination steam outlet, and the concentrated water generated after the pre-evaporation liquid in the concentration chamber is concentrated can be discharged from the concentrate outlet; The first steam inlet is in communication with a heat source outlet of the first heat exchanger; The multi-source waste heat recovery coupled industrial wastewater treatment system comprises a concentrated water crystallization unit, and the concentrated water crystallization unit comprises a crystallizer; The crystallizer has a second steam chamber and a crystallization chamber. The second steam chamber has a second steam inlet. Steam can flow into the second steam chamber from the second steam inlet. The second steam chamber can heat the concentrated water in the crystallization chamber to evaporate and crystallize the concentrated water in the crystallization chamber.

2. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 1 is characterized in that: The concentration unit includes the evaporator, the condenser and the first vacuum pumping device. The inlet of the condensing chamber of the condenser is connected with the desalination steam outlet so that the steam generated by the evaporation of the pre-evaporation liquid in the concentration chamber can be introduced into the condensing chamber of the condenser for condensation. The cooling water inlet of the condenser is connected with the outlet of the second water supply pipeline, the cooling water outlet of the condenser is connected with the inlet of the second return water pipeline, and the air inlet of the first vacuum pumping device is connected with the non-condensable gas outlet of the condenser.

3. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 2 is characterized in that: The crystallization chamber has a crystallization inlet, a crystallization outlet and a crystallization steam outlet. The crystallization inlet is connected to the concentrated liquid outlet. The steam generated by evaporation of concentrated water in the crystallization chamber can be discharged from the crystallization steam outlet. The crystallization material generated after crystallization of concentrated water in the crystallization chamber can be discharged from the crystallization outlet.

4. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 3 is characterized in that: The concentrated water crystallization unit comprises the crystallizer, a second vacuum pumping device, a thickener, a second solid-liquid separation device, a steam dryer and a salt storage tank; The second vacuum pumping device is in communication with the non-condensable gas outlet of the crystallizer; The inlet of the thickener is connected to the crystallization outlet, the thickener has a third outlet and a fourth outlet, the third outlet is located above the fourth outlet, the third outlet is connected to the crystallization inlet, and the fourth outlet is connected to the inlet of the second solid-liquid separation device; The second solid-liquid separation device has a second liquid outlet and a second solid outlet, the liquid separated by the second solid-liquid separation device is discharged from the second liquid outlet and passed into the crystallization inlet, and the solid material separated by the second solid-liquid separation device is discharged from the second solid outlet and passed into the steam dryer for drying; The salt storage tank is used to store the solid material dried by the steam dryer.

5. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 1 is characterized in that: The outlet of the pipeline for the industrial wastewater to be treated in the smelter is connected to the wastewater regulating tank, and the outlet of the wastewater regulating tank is connected to the inlet of the pH reaction tank; The pH reaction tank is connected to an acid-base regulating liquid delivery pipeline, and the acid-base regulating liquid delivery pipeline is used to pass the acid-base regulating liquid into the pH reaction tank; The pH value of the industrial wastewater discharged from the pH reaction tank is greater than or equal to 7 and less than or equal to 8.

5.

6. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 1 is characterized in that: The coagulation sedimentation tank is connected to a coagulant delivery pipeline, and the coagulant delivery pipeline is used to add coagulation sedimentation reagents into the coagulation sedimentation tank so as to precipitate suspended matter in the industrial wastewater in the coagulation sedimentation tank; The coagulation sedimentation tank has a first outlet and a second outlet, the first outlet is located above the second outlet, the first outlet is connected to the cold source inlet of the first heat exchanger, and the second outlet is connected to the inlet of the first solid-liquid separation device; The solid separated from the industrial wastewater by the first solid-liquid separation device can be recycled as valuable metal precipitates.

7. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 1 is characterized in that: The steam introduced into the multi-source waste heat pipeline is one of the exhaust steam from flash evaporation of a pressure autoclave, tail steam from a steam concentrate drying kiln, exhaust steam from water quenching of metallurgical slag or liquid metal, and exhaust steam from flash evaporation of high-temperature water; The temperature of the steam introduced into the evaporator is greater than or equal to 90° C. and less than or equal to 100° C.

8. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 3 is characterized in that: The concentration chamber is communicated with a scale inhibition pipeline, and the scale inhibition pipeline is used to introduce a scale inhibitor into the concentration chamber; The evaporator has a first cooling chamber, the inlet of the first cooling chamber is connected to a first water supply pipe, the outlet of the first cooling chamber is connected to a first water return pipe, and the steam discharged from the first steam chamber of the evaporator is cooled by the cooling water in the first cooling chamber and then passed into the condensation water pipe.

9. The multi-source waste heat recovery coupled industrial wastewater treatment system according to claim 8 is characterized in that: The concentrated liquid outlet is connected to the inlet of the sedimentation and de-weighting tank, the water outlet of the sedimentation and de-weighting tank is connected to the crystallization inlet, and the sedimentation and de-weighting tank has a sedimentation input pipeline connected thereto, and the sedimentation input pipeline is used to introduce a precipitant into the sedimentation and de-weighting tank; The second steam inlet is in communication with the outlet of the heat source pipeline; The crystallization steam outlet is communicated with the inlet of the condensation chamber of the condenser; The crystallizer has a second cooling chamber, the inlet of the second cooling chamber is connected to the third water supply pipe, the outlet of the second cooling chamber is connected to the third water return pipe, and the steam discharged from the second steam chamber of the crystallizer is cooled by the cooling water in the second cooling chamber and then passed into the condensate water pipe.

10. The multi-source waste heat recovery coupled industrial wastewater treatment system according to any one of claims 1 to 9, characterized in that: A switching valve is provided on the inlet of the heat source pipeline, and the inlet of the switching valve is connected to the pipeline network steam pipeline and the multi-source waste heat pipeline. The switching valve can adjust the flow of the pipeline network steam pipeline and the multi-source waste heat pipeline into the heat source pipeline.

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