Quality-divided collection and cascade recycling method and system for wastewater of copper smelting plant

Abstract

The invention discloses a quality-divided collection and gradient recycling method and system for wastewater of a copper smelting plant, and belongs to the technical field of industrial wastewater resource recycling. The process units of the whole plant are divided into a plurality of water consumption units according to different water quality, the water consumption units comprise a first-stage water consumption unit, a second-stage water consumption unit, a third-stage water consumption unit and a final-stage water consumption unit, water discharged from the first-stage water consumption unit is supplied to the second-stage water consumption unit, and the part with insufficient supply is supplemented with new production water; common production wastewater produced by the second-stage water consumption unit is supplied to the third-stage water consumption unit; domestic sewage, residual general production wastewater, acidic wastewater and initial rainwater are subjected to quality-divided collection treatment, and the treated water is supplied to a water consumption unit as reuse water. The system and the method can realize sewage disposal diversion, quality-divided treatment, quality-divided recycling and gradient utilization of a whole plant water system, reduce the wastewater treatment scale, and have the advantages of high water circulation utilization rate, low engineering cost and operation cost and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial wastewater resource recycling and utilization, and particularly relates to a method for the separate collection and cascade reuse of copper smelting wastewater. Background Art

[0002] The copper smelting process is characterized by high water consumption and diverse water quality requirements. The main water-consuming units in a copper smelter include replenishment water for the circulating cooling water system, replenishment water for the desalted water station, water for the acid production process, and replenishment water for the slag slow cooling area. The wastewater generated during copper smelting is diverse and complex in composition, resulting in lengthy wastewater treatment processes and high energy consumption.

[0003] Currently, although most domestic copper smelters have implemented differentiated water supply and drainage, production wastewater from each process section is directly discharged to a wastewater treatment station for separate treatment. Qualified reused water produced by the wastewater treatment station is then reused at the appropriate water points. For example, the production wastewater drainage system collects clean sewage from the desalination station and wastewater from the circulating water systems, sending it to the production wastewater treatment station for treatment. The domestic sewage drainage system collects wastewater from domestic facilities throughout the plant and sends it to the domestic sewage treatment station for treatment. The waste acid and acidic wastewater drainage system collects waste acid from the flue gas acidification process and acidic wastewater from each process section, sending them to the waste acid and acidic wastewater treatment station for treatment. Qualified water treated at each wastewater treatment station is then reused according to quality for different water use units. However, this approach fails to consider cascaded utilization and directly discharges wastewater to various wastewater treatment stations for treatment. This results in large wastewater treatment volumes and the large scale of wastewater treatment stations. This requires increased water recovery rates in the membrane concentration stage, increasing the complexity of wastewater treatment and raising investment and operating costs, resulting in insignificant environmental benefits. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method and system for the collection and cascade reuse of wastewater from a copper smelter. By dividing the water used in the process units of the entire plant into several water units according to the different water qualities, the wastewater generated by each water unit is directly utilized in a sequential and cascade manner, thereby comprehensively optimizing the water balance of the entire plant, reducing the scale of wastewater treatment in the copper smelter, improving the recycling rate of wastewater, and reducing investment and operating costs.

[0005] In order to achieve the above object, the present invention provides a method for collecting and recycling wastewater from a copper smelter by separation and cascade, comprising the following steps: Step S1: Divide the plant's process units into several water-using units according to their water quality, including first-level water-using units, second-level water-using units, third-level water-using units, and final-level water-using units; the first-level water-using units include the desalted water station, waste heat boiler, plant-wide living facilities, and sulfur dioxide blower cooling units; the second-level water-using units include various circulating water stations; the third-level water-using units include casting circulating water units; the final-level water-using units include the slag slow cooling yard, blowing slag granulation unit, acid-making section ground washing water unit, flue gas purification process water supply unit, and greening and road sprinkler water units; Step S2: clean wastewater discharged from the desalted water station in the first-stage water unit and direct cooling water discharged from the sulfur dioxide blower cooling unit are supplied to the second-stage water unit, and the insufficient supply is supplemented by new production water; general production wastewater produced by the second-stage water unit is supplied to the third-stage water unit; In step S3, the domestic sewage generated by the living facilities of the entire plant in the first-level water use unit, the remaining general production wastewater supplied by the second-level water use unit, the acidic wastewater generated by flue gas acid production, the acidic wastewater generated by waste acid treatment, and the initial rainwater are collected and treated by quality, and the treated water is then supplied to the final water use unit and other water use units as recycled water.

[0006] Furthermore, in the step S3, it includes: treating the domestic sewage generated by the domestic facilities of the whole plant in the first-level water-using unit to obtain recycled water; The second-stage water unit is supplied with the remaining general production wastewater and initial rainwater from the plant area for production wastewater pretreatment to obtain pretreated water; The acid wastewater generated by flue gas acidification, the acid wastewater generated by waste acid treatment and the initial rainwater in the sulfuric acid area are treated to obtain primary recycled water; The pretreated water is subjected to wastewater deep treatment to obtain high-salt reuse water and high-quality reuse water; The high-quality recycled water is returned to the desalted water station and / or the sulfur dioxide blower cooling unit of the first-stage water use unit for recycling, and the reclaimed water, the primary recycled water and the high-salt recycled water are returned to the final water use unit for recycling.

[0007] Furthermore, the recycled water is used to supply the greening and road sprinkling water units; the primary recycled water is used to supply the blowing slag granulation unit, the acid production section ground washing water unit, and the flue gas purification process water adding unit; the high-salt recycled water is used to supply the slag slow cooling field, and the insufficient supply is supplemented by primary recycled water and / or general production wastewater.

[0008] Furthermore, the desalted water station uses ultrafiltration-reverse osmosis or ion exchange treatment process to desalinate, and the produced desalted water is supplied to the waste heat boiler.

[0009] Furthermore, the domestic sewage generated by the domestic facilities of the entire plant in the first-level water-using unit is treated to obtain recycled water, including: The domestic sewage is sequentially subjected to a screen-denitrification-A / O biological contact oxidation-precipitation-filtration-disinfection treatment process to obtain recycled water after treatment.

[0010] Furthermore, the second-stage water unit is supplied with the remaining general production wastewater and initial rainwater from the plant area for production wastewater pretreatment to obtain pretreated water, including: The second-stage water use unit is supplied with the remaining general production wastewater and initial rainwater from the plant area, which are sequentially subjected to the hardness removal-coagulation-sedimentation-filtration-disinfection process to obtain pretreated water after treatment.

[0011] Furthermore, acid wastewater generated by flue gas acidification, acid wastewater generated by waste acid treatment and initial rainwater from the sulfuric acid area are treated to obtain primary recycled water, including: The acidic wastewater generated by flue gas acid production, the acidic wastewater generated by waste acid treatment and the initial rainwater in the sulfuric acid area are sequentially subjected to lime iron salt heavy metal removal - aluminum salt fluoride removal - electrochemical treatment process to obtain primary recycled water.

[0012] Another aspect of the present invention provides a copper smelter wastewater separation and collection and cascade reuse system, comprising a plurality of water units divided according to the quality of process water used throughout the plant, including a first-stage water unit, a second-stage water unit, a third-stage water unit, and a final-stage water unit; and a wastewater separation and treatment unit, the wastewater separation and treatment unit being configured to separate and collect domestic sewage generated by domestic facilities throughout the plant in the first-stage water unit, general production wastewater remaining from the second-stage water unit, acidic wastewater generated by flue gas acid production and acidic wastewater generated by waste acid treatment, and initial rainwater, with the treated water being supplied as reused water to the final-stage water unit and other water units. The first-level water unit includes a desalted water station, a waste heat boiler, living facilities throughout the plant, and a sulfur dioxide fan cooling unit, which is connected to a wastewater separation treatment unit to recycle the recycled water treated by the wastewater separation treatment unit; the second-level water unit includes various circulating water stations, which are connected to the desalted water station and the sulfur dioxide fan cooling unit in the first-level water unit to recycle the clean sewage discharged from the desalted water station and the direct cooling water discharged from the sulfur dioxide fan cooling unit; the third-level water unit includes a casting circulating water unit, which is connected to the second-level water unit to recycle the general production wastewater produced by the second-level water unit; The final water use unit includes a slag slow cooling area, a flue gas blowing slag granulation unit, an acid production section ground washing water unit, a flue gas purification process water adding unit, and a greening and road sprinkling water unit. It is connected to a wastewater separation treatment unit and a second-level water use unit to recycle the reused water treated by the wastewater separation treatment unit and the general production wastewater produced by the second-level water use unit.

[0013] Furthermore, the wastewater separation treatment unit includes a domestic sewage treatment station, a production wastewater pretreatment system, a production wastewater deep treatment system and an acidic wastewater treatment station; The domestic sewage treatment station is used to treat the domestic sewage of the domestic facilities of the whole plant to obtain recycled water; The production wastewater pretreatment system is used to pretreat the remaining general production wastewater supplied by the second-stage water unit and the initial rainwater in the factory area to obtain pretreated water; The wastewater deep treatment system is used to perform deep wastewater treatment on the pretreated water to obtain high-salt reuse water and high-quality reuse water; The acid wastewater treatment station is used to treat acid wastewater generated by flue gas acidification, acid wastewater generated by waste acid treatment, and initial rainwater in the sulfuric acid area to obtain primary recycled water.

[0014] Furthermore, the slag slow cooling yard is connected to the wastewater deep treatment system to recycle high-salt reuse water. The slag slow cooling yard is also connected to the acidic wastewater treatment station and the second-level water use unit to receive primary reuse water and general production wastewater to supplement the insufficient supply of high-salt reuse water.

[0015] Furthermore, the blowing slag granulation unit, the acid-making section ground flushing water unit and the flue gas purification process water adding unit are connected to an acid wastewater treatment station to recycle primary reuse water.

[0016] Furthermore, the greening and road sprinkler water unit is connected with the domestic sewage treatment station and the production wastewater pretreatment system to recycle recycled water and pretreated water.

[0017] Furthermore, the desalted water station and the sulfur dioxide blower cooling unit in the first-stage water use unit are connected to the wastewater deep treatment system to recycle and utilize high-quality recycled water.

[0018] Furthermore, the waste heat boiler in the first-stage water-using unit is connected to the desalted water station to receive desalted water discharged from the desalted water station; wherein the desalted water station includes an ultrafiltration-reverse osmosis or ion exchange device for producing desalted water.

[0019] Furthermore, the secondary water use unit includes a furnace body circulating water station, an equipment circulating water station, an oxygen station circulating water station, a waste heat power generation circulating water station and an acid production circulating water station. The acid production circulating water station is connected to the sulfur dioxide blower cooling unit, and the furnace body circulating water station, the equipment circulating water station, the oxygen station circulating water station and the waste heat power generation circulating water station are all connected to the casting circulating water unit, and are also connected to the slag slow cooling field.

[0020] Furthermore, the production wastewater pretreatment system includes a hardness removal unit, a coagulation unit, a sedimentation unit, a filtration unit and a disinfection unit connected in sequence.

[0021] Furthermore, the domestic sewage treatment station includes a grid unit, a denitrification unit, an A / O biological contact oxidation unit, a sedimentation unit, a filtration unit and a disinfection unit which are connected in sequence.

[0022] Furthermore, the production wastewater deep treatment system includes an ultrafiltration unit and a two-stage reverse osmosis unit connected in sequence.

[0023] Furthermore, the acidic wastewater treatment station includes a lime iron salt heavy metal removal unit, an aluminum salt fluoride removal unit and an electrochemical treatment unit connected in sequence.

[0024] Compared with the prior art, the present invention has the following beneficial effects: the present invention divides the process units of the whole plant into several water-using units according to the different water qualities of the water they use. On the premise of meeting the water quality of the water they use, each water-using unit gives priority to using water of lower water quality level, and the insufficient part is supplemented by water of higher water quality level; the process units of the whole plant are subjected to different wastewater collection according to the different discharge water quality. The discharged wastewater of the water-using units is preferentially directly reused in the water-using units, and the remaining part is discharged to the corresponding wastewater treatment station for quality separation treatment, and the treated water is separated and reused in each water-using unit. The present invention can realize the separation of clean and dirty water, quality separation treatment, quality separation reuse and cascade utilization of the water system of the whole plant by grading the water-using units of the copper smelter and collecting, treating and reusing the wastewater by quality separation, thereby reducing the scale of wastewater treatment, simplifying the wastewater collection network, and comprehensively optimizing the water supply and drainage balance of the whole plant. It has the advantages of high water recycling rate, low engineering cost and operating cost, energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The schematic diagram of the structure of the copper smelter wastewater separation and collection and cascade recycling system of the present invention is shown; Figure 2 A schematic diagram of a water balance process for wastewater treatment using a method for separate collection and cascade reuse of wastewater from a copper smelter, as employed in an embodiment of the present invention, is shown; Figure 3 The diagram shows a water balance flow chart of wastewater treatment by the method for collecting and recycling wastewater from a copper smelter adopted in the comparative example of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0027] Example 1 A copper smelter wastewater separation and collection and cascade reuse system, referring to Figure 1 The system includes a first-level water use unit, a second-level water use unit, a third-level water use unit, a final water use unit, and a wastewater quality treatment unit.

[0028] The wastewater separation and treatment units include a domestic sewage treatment station, a production wastewater pretreatment system, a production wastewater advanced treatment system, and an acidic wastewater treatment station. The domestic sewage treatment station treats domestic sewage from all the plant's domestic facilities to produce recycled water. The production wastewater pretreatment system pre-treats the remaining general production wastewater from the second-level water use unit and initial rainwater from the plant area to produce pre-treated water. The advanced wastewater treatment system performs advanced treatment on the pre-treated water to produce high-salt reuse water and high-quality reuse water. The acidic wastewater treatment station treats acidic wastewater generated by flue gas acidification, acidic wastewater from the waste acid treatment station, and initial rainwater from the sulfuric acid area to produce primary reuse water.

[0029] The domestic sewage treatment station includes a screen unit, denitrification unit, A / O biological contact oxidation unit, sedimentation unit, filtration unit, and disinfection unit, all connected in sequence. The industrial wastewater pretreatment system includes a hardness removal unit, coagulation unit, sedimentation unit, filtration unit, and disinfection unit, all connected in sequence. The industrial wastewater advanced treatment system includes an ultrafiltration unit and a two-stage reverse osmosis unit, all connected in sequence. The acidic wastewater treatment station includes a lime and iron salt heavy metal removal unit, an aluminum salt defluoridation unit, and an electrochemical treatment unit, all connected in sequence.

[0030] Among them, the first-level water-using units include the desalting water station, waste heat boiler, plant-wide living facilities and sulfur dioxide fan cooling unit. The desalting water station and sulfur dioxide fan cooling unit are connected to the wastewater deep treatment system to recycle and utilize high-quality recycled water. The waste heat boiler is connected to the desalting water station to receive the desalted water discharged from the desalting water station. The desalting water station includes an ultrafiltration-reverse osmosis or ion exchange device for producing desalted water. The plant-wide living facilities are connected to the domestic sewage treatment station.

[0031] Among them, the second-level water-using units include various circulating water stations, including furnace body circulating water station, equipment circulating water station, oxygen station circulating water station, waste heat power generation circulating water station and acid production circulating water station. The furnace body circulating water station, equipment circulating water station, oxygen station circulating water station and waste heat power generation circulating water station are all connected to the desalted water station to recycle the clean sewage discharged from the desalted water station; the acid production circulating water station is connected to the sulfur dioxide fan cooling unit to recycle the direct cooling water discharged from the sulfur dioxide fan cooling unit.

[0032] Among them, the third-level water unit is a casting circulating water unit, which is connected to the second-level water unit to recycle the general production wastewater produced by the second-level water unit.

[0033] Among them, the final water use units include the slag slow cooling yard, the flue gas blowing slag granulation unit, the acid section ground washing water unit, the flue gas purification process water adding unit, and the greening and road sprinkling water unit. The slag slow cooling yard is connected to the wastewater deep treatment system to recycle high-salt reused water. The slag slow cooling yard is also connected to the acid wastewater treatment station and the secondary water use unit to receive primary reused water and general production wastewater to supplement the insufficient supply of high-salt reused water; the blowing slag granulation unit, the acid section ground washing water unit and the flue gas purification process water adding unit are connected to the acid wastewater treatment station to recycle primary reused water; the greening and road sprinkling water unit is connected to the domestic sewage treatment station and the production wastewater pretreatment system to recycle reclaimed water and pretreated water.

[0034] Example 2 A copper smelter adopts the method of wastewater separation and collection and cascade reuse of copper smelter wastewater of the present invention to treat wastewater. Figure 2 , the implementation process is as follows: The process units of the copper smelter are divided into first-level water use units, second-level water use units, third-level water use units and final water use units according to the different water quality of their water use; the first-level water use units are the desalted water station, waste heat boiler, living facilities of the whole plant and sulfur dioxide fan cooling unit; the second-level water use units are various circulating water stations, including furnace body circulating water station, equipment circulating water station, oxygen station circulating water station, waste heat power generation circulating water station and acid production circulating water station; the third-level water use unit is the casting circulating water unit; the final water use units are the slag slow cooling field, blowing slag granulation unit, acid production section ground washing water unit, flue gas purification process water adding unit, greening and road sprinkling water unit.

[0035] The water supply systems of the entire plant are: new production water, domestic water, desalted water, and high-quality reuse water, primary reuse water, reclaimed water and high-salt reuse water after wastewater separation treatment; the drainage systems of the entire plant are: clean sewage from the desalted water station, direct cooling water discharged from the sulfur dioxide fan cooling unit, general production wastewater generated by various circulating water stations, domestic sewage generated by the living facilities of the entire plant, acidic wastewater generated by flue gas acid production, acidic wastewater generated by waste acid treatment and initial rainwater.

[0036] The desalted water station and sulfur dioxide blower cooling unit use new production water or high-quality recycled water as their water source. Domestic facilities throughout the plant use domestic water as their water source, and the waste heat boiler uses desalted water as its water source. Various circulating water stations are supplied with clean sewage and direct cooling water, with any shortfalls supplemented by new production water. Casting circulating water uses general production wastewater from the second-stage water-using unit as its water source. High-salt recycled water is used for the slag slow cooling area, with any shortfalls supplemented by primary recycled water. Primary recycled water is used for ground washing in the blowing slag granulation unit and acidification section, for the preparation of waste acid and acidic wastewater treatment reagents, and for adding water to the flue gas purification process. Recycled reclaimed water is used for landscaping and road irrigation.

[0037] In this embodiment, the 1300m3 of desalted water in the first-stage water unit is used 3 / d water volume for desalination, and 335m 3 / d Clean sewage is supplied to the furnace body circulating water station, equipment circulating water station, oxygen station circulating water station, waste heat power generation circulating water station for recycling, and then 8500m 3 / d produces new water for replenishment, generating 1250m 3 / d of general production wastewater; 965m 3 Demineralized water is supplied to waste heat boilers (including smelting waste heat boilers and acid conversion waste heat boilers) daily. Since the impurities in the concentrated water discharged from the demineralized water station are solely concentrated salts from municipal water and are free of other pollutants, it can be used as clean sewage. Its water quality meets the requirements of GB19923-2024, "Municipal Wastewater Recycling - Industrial Water Quality," and can be directly supplied to the circulating water station for use.

[0038] 1920m 3 / d of new production water is supplied to the sulfur dioxide fan cooling unit, and after the cooling is completed, the 1920m 3 / d of direct cooling water is supplied to the acid production circulating water station for recycling, and then 2320m 3 / d of new water production to supplement, generating 570m 3 / d of general production wastewater.

[0039] The 500m3 generated by the second-level water unit 3 / dGeneral production wastewater is supplied to the casting circulating water unit for recycling. Since the casting circulating water unit (referring to the circulating water for disc casting in the copper smelting process) is a turbid circulation system, the production has lower requirements for water quality. The sewage from the indirect cooling open circulating cooling water system (circulating water station) can be used as the supplementary water for the casting cycle, which can greatly reduce the amount of general production wastewater entering the wastewater treatment station and reduce the scale of the wastewater treatment station. 3 / dGeneral production wastewater is supplied to the slag slow cooling field for recycling, and the remaining 970m 3 / d General production wastewater and initial rainwater in the factory area are pretreated. The production wastewater pretreatment adopts the process of hardness removal-coagulation-sedimentation-filtration-disinfection to obtain pretreated water. 3 / d of pre-treated water was subjected to deep wastewater treatment, which was treated by ultrafiltration-two-stage reverse osmosis process to obtain 200m 3 / d of high-salinity recycled water and 700m 3 / d of high-quality recycled water. 3 / d of high-salt recycled water is supplied to the slag slow cooling field for recycling, 3 / d of high-quality recycled water is supplied to the desalination plant for utilization. Pretreated water undergoes advanced wastewater treatment, and the resulting reverse osmosis product can replace new production water as high-quality recycled water and be reused in the desalination plant as raw water. The primary pollutant in the reverse osmosis concentrate is salt, meeting the requirements of GB 25467-2010, "Copper, Nickel, and Cobalt Industrial Pollutant Emission Standards." This high-salt recycled water can be used in the slag slow cooling area.

[0040] 150m 3 / d of domestic water supply is supplied to the living facilities of the whole plant, generating 130m 3 / d domestic sewage, 130m 3 / d domestic sewage is sent to the domestic sewage treatment station for sewage treatment, and 130m 3 / d recycled water, domestic sewage station adopts screen-denitrification-A / O biological contact oxidation-precipitation-filtration-disinfection treatment process, the treated water meets the requirements of GBT18920-2020 "Urban Wastewater Recycling and Urban Miscellaneous Water Quality" standard, 130m 3 / d recycled water is used for greening and road irrigation. At the same time, 70m3 of wastewater that has not been deeply treated is used. 3 / d of pretreated water is also used as recycled water for greening and road irrigation.

[0041] The waste acid discharged from the flue gas acidification section is treated with sulfide arsenic removal and lime neutralization in the waste acid treatment station to produce acidic wastewater, which is then combined with the acidic wastewater produced in the flue gas acidification section and the initial rainwater in the sulfuric acid area and sent to the acid wastewater treatment station for acid waste treatment. The acid wastewater treatment station uses lime iron salt to remove heavy metals - aluminum salt to remove fluoride - electrochemical treatment process to remove heavy metals and other impurities in the wastewater, and neutralizes the wastewater to obtain 1650m 3 / d primary recycled water, the treated primary recycled water meets the requirements of GB 25467-2010 "Copper, Nickel and Cobalt Industrial Pollutant Emission Standard". 3 / d primary recycled water is supplied to the slag slow cooling area (650m 3 / d), blowing slag granulation unit (100m 3 / d), acid production section ground flushing water unit (10m 3 / d) and flue gas purification process water adding unit (890m 3 / d).

[0042] Comparative Example 1 A copper smelter uses the method of collecting and recycling wastewater from copper smelter for wastewater treatment. The process is based on Figure 3 , and its implementation process is as follows: 13340m 3 / d produced new water is supplied to the desalination station (600m 3 / d), sulfur dioxide fan cooling unit (1920m 3 / d)、Casting circulating water unit (500m 3 / d) and various circulating water stations (10320m 3 / d), of which the furnace circulating water station, equipment circulating water station, oxygen station circulating water station, and waste heat power generation circulating water station supply a total of 8000m 3 / d, acid production circulating water station supplies 2320m 3 / d, and the 1920m3 of sulfur dioxide discharged by the fan cooling unit 3 / d Direct cooling water is supplied to the acid production circulating water station.

[0043] The 1820m3 produced by various circulating water stations 3 / d General production wastewater, 335m3 of desalted water station output 3 / d clean sewage and initial rainwater from the factory are used for pre-treatment of production wastewater to obtain 2155m 3 / d pre-treated water. 2085m 3 / d of pre-treated water was subjected to deep wastewater treatment to obtain 550m 3 / d high-salinity recycled water and 1535m 3 / d of high-quality recycled water.3 / d of high-salt recycled water is supplied to the slag slow cooling field for recycling, 3 / d of high-quality recycled water is supplied to the desalted water station (700m 3 / d) and various circulating water stations (835 m 3 / d) for reuse. 3 / d desalted water is supplied to waste heat boilers (including smelting waste heat boilers and acid conversion waste heat boilers).

[0044] 150m 3 / d of domestic water supply is supplied to the living facilities of the whole plant, generating 130m 3 / d domestic sewage, 130m 3 / d domestic sewage is sent to the domestic sewage treatment station for sewage treatment, and 130m 3 / d recycled water, and 70m3 of wastewater that has not been deeply treated 3 / d of pretreated water is also used as recycled water for greening and road irrigation.

[0045] The waste acid discharged from the flue gas acidification section is treated by sulfidation to remove arsenic and lime neutralization in the waste acid treatment station to produce acidic wastewater, which is then combined with the acidic wastewater produced in the flue gas acidification section and the initial rainwater in the sulfuric acid area and sent to the acidic wastewater treatment station for acid waste treatment to obtain 1650m 3 / d primary recycled water. The 1650m 3 / d primary recycled water is supplied to the slag slow cooling area (650m 3 / d), blowing slag granulation unit (100m 3 / d), acid production section ground flushing water unit (10m 3 / d) and flue gas purification process water adding unit (890m 3 / d).

[0046] The present invention classifies the water quality of the water used in the process units of the whole plant and divides it into several water use units. The wastewater generated by the water use units at each level is directly utilized in a sequential and cascade manner. The wastewater generated by the first-level water use unit is supplied to the second-level water use unit, and the wastewater generated by the second-level water use unit is supplied to the third-level water use unit. The wastewater discharged from the whole plant is then collected and treated according to quality and reused in the water use units. This greatly reduces the scale of the wastewater treatment station, simplifies the wastewater collection network, and comprehensively optimizes the water supply and drainage balance of the whole plant. It has the advantages of high water recycling rate, low engineering cost and operating cost, energy saving and environmental protection.

[0047] According to the comparison of wastewater treatment capacity between the comparative example and the embodiment, the production wastewater pretreatment in this embodiment only needs to treat 970m3 of wastewater. 3 / d, while the pretreatment of production wastewater in the comparative proportion requires 2155m 3 Thus, by adopting the method for separate collection and cascade reuse of copper smelter wastewater for wastewater treatment according to the present invention, the treatment scale of the production wastewater treatment station is reduced by more than 50% of the wastewater treatment volume, which greatly reduces the investment and operating costs of wastewater treatment and has good economic benefits.

[0048] The above embodiments are merely illustrative of embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. The present invention may also be implemented in other specific ways or in other specific forms without departing from the gist or essential features of the present invention. Therefore, the embodiments described should be considered illustrative and not restrictive in all respects. The scope of the present invention should be described by the appended claims, and any variations equivalent to the intent and scope of the claims should also be included within the scope of the present invention.

Claims

1. A method for collecting and recycling wastewater from a copper smelter by separation and cascade, characterized in that: The following steps are involved: Step S1: Divide the plant's process units into several water-using units according to their water quality, including first-level water-using units, second-level water-using units, third-level water-using units, and final-level water-using units; the first-level water-using units include desalted water stations, waste heat boilers, plant-wide domestic facilities, and sulfur dioxide fan cooling units; the second-level water-using units include various circulating water stations; The third-level water unit includes a casting circulating water unit; the final-level water unit includes a slag slow cooling area, a blowing slag granulation unit, a surface washing water unit for the acid production section, a flue gas purification process water unit, and a greening and road sprinkling water unit; Step S2: clean wastewater discharged from the desalted water station in the first-stage water unit and direct cooling water discharged from the sulfur dioxide blower cooling unit are supplied to the second-stage water unit, and the insufficient supply is supplemented by new production water; general production wastewater produced by the second-stage water unit is supplied to the third-stage water unit; In step S3, the domestic sewage generated by the living facilities of the entire plant in the first-level water use unit, the remaining general production wastewater supplied by the second-level water use unit, the acidic wastewater generated by flue gas acid production, the acidic wastewater generated by waste acid treatment, and the initial rainwater are collected and treated by quality, and the treated water is then supplied to the final water use unit and other water use units as recycled water.

2. The method for collecting and recycling wastewater from a copper smelter by separation and classification according to claim 1 is characterized in that: In the step S3, it includes: Treat the domestic sewage generated by the plant's domestic facilities in the first-level water-using unit to obtain recycled water; The second-stage water unit is supplied with the remaining general production wastewater and initial rainwater from the plant area for production wastewater pretreatment to obtain pretreated water; The acid wastewater generated by flue gas acidification, the acid wastewater generated by waste acid treatment and the initial rainwater in the sulfuric acid area are treated to obtain primary recycled water; The pretreated water is subjected to wastewater deep treatment to obtain high-salt reuse water and high-quality reuse water; The high-quality recycled water is returned to the desalted water station and / or the sulfur dioxide blower cooling unit of the first-stage water use unit for recycling, and the reclaimed water, the primary recycled water and the high-salt recycled water are returned to the final water use unit for recycling.

3. The method for collecting and recycling wastewater from a copper smelter by separation and classification according to claim 2 is characterized in that: The recycled water is used to supply the greening and road sprinkling water units; the primary recycled water is used to supply the blowing slag granulation unit, the acid production section ground washing water unit, and the flue gas purification process water adding unit; the high-salt recycled water is used to supply the slag slow cooling field, and the insufficient supply is supplemented by primary recycled water and / or general production wastewater.

4. The method for collecting and recycling wastewater from a copper smelter by separation and classification according to claim 1 is characterized in that: The desalted water station uses ultrafiltration-reverse osmosis or ion exchange treatment technology to desalinate, and the produced desalted water is supplied to the waste heat boiler.

5. The method for collecting and recycling wastewater from a copper smelter by separation and classification according to claim 2, characterized in that: The domestic sewage generated by the plant's domestic facilities in the first-level water-using unit is treated to obtain recycled water, including: The domestic sewage is sequentially subjected to a screen-denitrification-A / O biological contact oxidation-precipitation-filtration-disinfection treatment process to obtain recycled water after treatment.

6. The method for collecting and recycling wastewater from a copper smelter by quality control and cascade reuse according to claim 2, characterized in that: The second-stage water unit is supplied with the remaining general production wastewater and initial rainwater from the plant area for production wastewater pretreatment to obtain pretreated water, including: The second-stage water use unit is supplied with the remaining general production wastewater and initial rainwater from the plant area, which are sequentially subjected to the hardness removal-coagulation-sedimentation-filtration-disinfection process to obtain pretreated water after treatment.

7. The method for collecting and recycling wastewater from a copper smelter by separation and classification according to claim 2, characterized in that: Acid wastewater generated by flue gas acidification, acid wastewater generated by waste acid treatment and initial rainwater from the sulfuric acid area are treated to obtain primary recycled water, including: The acidic wastewater generated by flue gas acid production, the acidic wastewater generated by waste acid treatment and the initial rainwater in the sulfuric acid area are sequentially subjected to lime iron salt heavy metal removal - aluminum salt fluoride removal - electrochemical treatment process to obtain primary recycled water.

8. A copper smelter wastewater separation and collection and cascade reuse system, characterized in that: The system includes several water units divided according to the quality of the plant's process water, including a first-level water unit, a second-level water unit, a third-level water unit, and a final water unit; and a wastewater separation treatment unit, which is used to collect and treat domestic sewage generated by the plant's domestic facilities in the first-level water unit, general production wastewater remaining from the second-level water unit, acidic wastewater generated by flue gas acid production and acidic wastewater generated by waste acid treatment, and initial rainwater. The treated water is supplied as recycled water to the final water unit and other water units. The first-level water unit includes a desalted water station, a waste heat boiler, living facilities throughout the plant, and a sulfur dioxide fan cooling unit, which is connected to a wastewater separation treatment unit to recycle the recycled water treated by the wastewater separation treatment unit; the second-level water unit includes various circulating water stations, which are connected to the desalted water station and the sulfur dioxide fan cooling unit in the first-level water unit to recycle the clean sewage discharged from the desalted water station and the direct cooling water discharged from the sulfur dioxide fan cooling unit; the third-level water unit includes a casting circulating water unit, which is connected to the second-level water unit to recycle the general production wastewater produced by the second-level water unit; The final water use unit includes a slag slow cooling area, a flue gas blowing slag granulation unit, an acid production section ground washing water unit, a flue gas purification process water adding unit, and a greening and road sprinkling water unit. It is connected to a wastewater separation treatment unit and a second-level water use unit to recycle the reused water treated by the wastewater separation treatment unit and the general production wastewater produced by the second-level water use unit.

9. The copper smelter wastewater separation and collection and cascade reuse system according to claim 8 is characterized in that: The wastewater separation treatment unit includes a domestic sewage treatment station, a production wastewater pretreatment system, a production wastewater deep treatment system and an acidic wastewater treatment station; The domestic sewage treatment station is used to treat the domestic sewage of the domestic facilities of the whole plant to obtain recycled water; The production wastewater pretreatment system is used to pretreat the remaining general production wastewater supplied by the second-stage water unit and the initial rainwater in the factory area to obtain pretreated water; The wastewater deep treatment system is used to perform deep wastewater treatment on the pretreated water to obtain high-salt reuse water and high-quality reuse water; The acid wastewater treatment station is used to treat acid wastewater generated by flue gas acidification, acid wastewater generated by waste acid treatment, and initial rainwater in the sulfuric acid area to obtain primary recycled water.

10. The copper smelter wastewater separation and collection and cascade reuse system according to claim 9 is characterized in that: The slag slow cooling yard is connected to the wastewater deep treatment system to recycle high-salt reuse water. The slag slow cooling yard is also connected to the acid wastewater treatment station and the second-level water unit to receive primary reuse water and general production wastewater to supplement the insufficient supply of high-salt reuse water. And / or, the blowing slag granulation unit, the acid-making section ground flushing water unit and the flue gas purification process water adding unit are connected to an acid wastewater treatment station to recycle primary reuse water; And / or, the greening and road sprinkler water unit is connected with the domestic sewage treatment station and the production wastewater pretreatment system to recycle recycled water and pretreated water; And / or, the desalted water station and the sulfur dioxide blower cooling unit in the first-stage water use unit are connected to the wastewater deep treatment system to recycle and utilize high-quality recycled water.

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