A wastewater and waste residue clean treatment system and treatment method

Abstract

The present invention belongs to the technical field of wastewater and waste residue treatment, and specifically relates to a wastewater and waste residue clean treatment system and treatment method, the system includes a smelting module, a waste gas treatment module, a waste water treatment module and a waste salt treatment module arranged in sequence, the waste gas treatment module has a waste gas inlet, a waste water outlet and a desulfurized gypsum slag outlet, the waste water treatment module has a waste water inlet and a waste salt outlet; the waste salt treatment module includes: a first additive supply unit, a carbonization unit, for introducing a first additive and / or a second additive into the waste salt, the second additive being the desulfurized gypsum slag from the waste gas treatment module; a fluorine content detection unit, a control unit, for executing the introduction of a first additive and / or a second additive into the waste salt according to the fluorine content in the waste salt. The present invention can effectively treat the wastewater and waste residue thoroughly, realize efficient treatment of the waste salt produced therefrom to facilitate subsequent cleaning and high-value utilization, and has low de-hardening cost.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater and waste residue treatment, and specifically relates to a wastewater and waste residue clean treatment system and treatment method. Background Art

[0002] The wastewater generated by industries such as electroplating and smelting has complex composition. It not only contains high levels of heavy metals, but also high levels of COD, ammonia nitrogen, etc. The conventional disposal process is to neutralize and precipitate to produce sludge, reuse the treated reclaimed water, and produce waste salt through evaporation and concentration. Sludge, waste salt and other waste residues are hazardous wastes and are then handed over to a third party for disposal. The third party generally uses pyrometallurgical smelting for harmless treatment, producing secondary hazardous waste and waste salt. The waste-producing and disposal companies are often independent, and there are problems such as secondary transportation and incomplete disposal.

[0003] The applicant's early patent CN111394582B discloses a copper-nickel sludge resource recycling process, including: dividing the copper-nickel sludge into copper-containing sludge or nickel-containing sludge according to the copper content and the nickel content. The nickel-containing sludge is treated by a wet process to obtain waste slag, waste salt, copper sulfate and nickel sulfate. The waste slag, waste salt and copper-containing sludge obtained by the wet process are all treated by a pyrometallurgical process, including: pre-treating and smelting the materials to obtain waste slag, copper products and flue gas. The flue gas is treated to obtain products, waste slag, waste salt and waste sludge. The waste slag, waste salt and waste sludge obtained in the pyrometallurgical process system are returned to the pyrometallurgical process system for treatment. This process combines the wet process with the pyrometallurgical process to improve the recovery rate of nickel and copper. However, the treatment effect of the waste salt produced by it needs to be further explored in terms of high-value utilization, and the chlorine content of the waste salt leads to high corrosion requirements and high maintenance costs for the pyrometallurgical process waste gas treatment system.

[0004] In short, the treatment effect of the wastewater and waste residue treatment process needs to be improved, which is not conducive to high-value utilization, and the cost of de-hardening is high, and the maintenance cost of the waste gas treatment system is high. In view of this, the art urgently needs a wastewater and waste residue clean treatment system and process, which can effectively treat the wastewater and waste residue thoroughly, and realize efficient treatment of the waste salt generated by it to facilitate subsequent clean and high-value utilization, and the cost of de-hardening is high. It is preferred that the chlorine in the waste salt is recovered as a refined salt product, so that the chlorine entering the waste gas system is very small, and the maintenance cost is low. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art in that the treatment effect of the wastewater and waste residue treatment process needs to be improved, which is not conducive to high-value utilization and has a high de-hardening cost, and to provide a wastewater and waste residue cleaning treatment system and treatment method. The treatment system and treatment method can effectively treat the wastewater and waste residue thoroughly, and achieve efficient treatment of the waste salt generated therefrom to facilitate subsequent cleaning and high-value utilization, and the de-hardening cost is low.

[0006] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a wastewater and waste residue clean treatment system, comprising a smelting module, a waste gas treatment module, and a wastewater treatment module arranged in sequence, wherein the waste gas treatment module has a waste gas inlet, a waste water outlet, and a desulfurized gypsum slag outlet, and the waste water treatment module has a waste water inlet and a waste salt outlet; and the wastewater and waste residue clean treatment system also includes a waste salt treatment module, and the waste salt treatment module includes:

[0007] a first additive supply unit, wherein the first additive is a metal sulfate and / or a metal oxide;

[0008] A carbonization unit, which has a waste salt inlet, a first additive inlet and a second additive inlet, the waste salt inlet is connected to the waste salt outlet of the wastewater treatment module, the first additive inlet is connected to the first additive supply unit, and the second additive inlet is connected to the desulfurized gypsum slag outlet of the exhaust gas treatment module; used for introducing the first additive and / or the second additive into the waste salt, the second additive being the desulfurized gypsum slag from the exhaust gas treatment module;

[0009] A fluorine content detection unit, which is connected to the wastewater treatment module or the carbonization unit and is used to detect the fluorine content in the waste salt to be treated;

[0010] A control unit is connected to the fluorine content detection unit, the first additive supply unit, and the carbonization unit respectively, and is used to introduce the first additive into the waste salt when the fluorine content in the waste salt is detected to be less than 20 ppm, and to introduce the first additive and the second additive into the waste salt when the fluorine content in the waste salt is detected to be ≥20 ppm.

[0011] In some preferred embodiments, the waste salt treatment module further comprises:

[0012] Water supply unit;

[0013] pH regulator supply unit;

[0014] De-hardening reagent supply unit;

[0015] The de-hardening and heavy metal removal treatment unit has a material inlet, a water inlet, a pH adjusting agent inlet, a de-hardening agent inlet and a purified liquid outlet. The material inlet, water inlet, pH adjusting agent inlet and de-hardening agent inlet are respectively connected to the outlet of the carbonization unit, the water supply unit, the pH adjusting agent supply unit and the de-hardening agent supply unit, and are used to first introduce water into the material obtained from the carbonization unit for water dissolution and filtration to obtain carbonized slag and salt solution, and then introduce the pH adjusting agent and de-hardening agent into the salt solution for de-hardening and heavy metal removal to obtain a purified liquid.

[0016] More preferably, the waste salt treatment module further comprises:

[0017] an evaporation crystallization unit, which is connected to the purified liquid outlet of the hardness and heavy metal removal treatment unit, and is used to evaporate and crystallize the purified liquid to obtain a crystallization mother liquid and a crystallized salt;

[0018] The refining unit is connected to the evaporation crystallization unit and is used for refining the crystallized salt to obtain refined salt.

[0019] More preferably, the carbonization unit further has a third additive inlet, and the third additive inlet is connected to the crystallization mother liquor outlet of the evaporation crystallization unit, and is used for simultaneously introducing the crystallization mother liquor into the waste salt for carbonization treatment.

[0020] More preferably, the waste salt treatment module also has a solid phase slag outlet, a crystallization mother liquor outlet, and a waste gas outlet, the solid phase slag outlet is connected to the smelting module, the crystallization mother liquor outlet is connected to the carbonization unit and / or the smelting module; the waste gas outlet is connected to the waste gas treatment module, and is used to circulate the waste gas generated by the waste salt treatment module to the waste gas treatment module.

[0021] In some preferred embodiments, the wastewater and waste residue cleaning treatment system also includes an external wastewater supply unit and an external waste residue supply unit, the external wastewater supply unit is connected to the wastewater inlet of the wastewater treatment module, the external waste residue supply unit includes an external waste salt supply unit and an external solid waste residue supply unit, the external waste salt supply unit is connected to the waste salt inlet in the carbonization unit, and the external solid waste residue supply unit is connected to the material inlet of the smelting module.

[0022] In some preferred embodiments, the smelting module comprises:

[0023] A smelting unit having a material inlet, a waste gas outlet and a solid phase outlet, wherein the waste gas outlet is connected to the waste gas inlet of the waste gas treatment module, and optionally, the material inlet is connected to the desulfurized gypsum slag outlet in the waste gas treatment module and / or the smoke outlet of the waste gas treatment module;

[0024] Pre-mixed slag unit;

[0025] A matching control unit is connected to the smelting unit and the pre-matching slag unit, and is used to adjust the slag type of the smelting treatment of wastewater and waste slag according to the pre-matching slag.

[0026] In some preferred embodiments, the waste gas treatment module includes a dust and mist removal unit, a flue gas washing unit, an optional flue gas defluorination unit, a desulfurization unit, and a denitrification unit with a denitrification agent inlet. The calcium and magnesium slag outlet of the flue gas defluorination unit is connected to the material inlet of the smelting module, and the wastewater outlet of the waste gas treatment module is connected to the wastewater inlet of the wastewater treatment module; the wastewater treatment module includes a heavy metal removal unit, a hardness removal unit, an ammonia distillation treatment unit, and an evaporation concentration unit. The wastewater treatment module also has a condensate outlet, an ammonia water outlet and a mother liquor outlet. The condensate outlet is connected to the water inlet of the flue gas washing unit and / or the water inlet of the desulfurization unit, the ammonia water outlet is connected to the denitrification agent inlet of the denitrification unit, and the mother liquor outlet is connected to the smelting module.

[0027] In a second aspect, the present invention provides a method for treating wastewater and waste residue in a clean manner, wherein the waste raw material to be treated is treated in the wastewater and waste residue treatment system described in the first aspect, wherein the waste raw material to be treated includes foreign solid waste residue and foreign waste salts or foreign waste water, and the treatment method includes the following steps:

[0028] S1. Smelting external solid waste slag in a smelting module to obtain solid products and waste gas;

[0029] S2, treating the waste gas obtained in S1 in a waste gas treatment module to obtain waste water and desulfurized gypsum slag;

[0030] S3, treating the wastewater obtained in S2 or the wastewater obtained in S2 and the external wastewater in a wastewater treatment module to obtain waste salt;

[0031] S4, carbonizing the waste salt obtained in S3 or the waste salt obtained in S3 and the external waste salt in a waste salt treatment module;

[0032] Wherein, in the carbonization treatment described in S4, a first additive is introduced into the waste salt when the fluorine content in the waste salt is less than 20 ppm, and a first additive and a second additive are introduced into the waste salt when the fluorine content in the waste salt is ≥20 ppm; the first additive is a metal sulfate and / or a metal oxide, and the mass amount of the first additive is less than 10 wt% of the mass of the waste salt, preferably 0.5 wt%-10 wt%; the second additive is the desulfurized gypsum slag obtained in S2, and the amount of the desulfurized gypsum slag in terms of calcium element is more than 2 times, preferably 2-5 times, the theoretical molar amount required to generate calcium fluoride in terms of the fluorine content of the waste salt.

[0033] In some preferred embodiments, the carbonization treatment conditions include: a carbonization temperature of 400-600°C, a carbonization time of 0.5-3h, and more preferably, the COD in the salt solution obtained by carbonization treatment, water dissolution and filtration is controlled to be ≤50ppm, and F ≤10ppm.

[0034] Preferably, the metal sulfate or metal oxide is selected from at least one of sulfates or oxides of copper, nickel, iron and zinc.

[0035] In some preferred embodiments, the treatment method further includes: S5, dissolving the material obtained by the carbonization treatment in water, filtering to obtain carbonized slag and a salt solution with a concentration of more than 20wt%, and then introducing a pH regulator and a dehardening agent to perform dehardening and heavy metal removal treatment to obtain a purified liquid, and then evaporating, crystallizing and refining the purified liquid to obtain a crystalline mother liquor and refined salt.

[0036] Preferably, at least part of the crystallization mother liquor is circulated and introduced into the carbonization treatment. More preferably, the circulation amount of the crystallization mother liquor is less than 6 wt% of the mass of the waste salt.

[0037] Preferably, the water-dissolving conditions include: dissolving in water at a mass fraction of the carbonized material accounting for 20-25wt% of the total amount of the aqueous solution.

[0038] Preferably, the conditions for the de-hardening and heavy metal removal treatment include: using sodium hydroxide and / or lime to adjust the pH of the reaction system to 9-11, the amount of sodium carbonate used is 1-2 times the theoretical amount of the reaction system in moles, the reaction time is 0.5-3h, and the contents of Cd, Fe, Cu, Ni, Zn, Cr, Mn and Pb in the purified liquid are controlled to be no higher than 2ppm, the fluorine content is ≤10ppm, the solution chromaticity value is ≤100 degrees, and the total hardness of calcium and magnesium is ≤50ppm.

[0039] In some preferred embodiments, the foreign waste salt satisfies: the sum of the mass contents of sodium sulfate and sodium chloride is above 90wt%, the potassium content is ≤1wt%, the ammonium ion content is ≤1wt%, and the moisture content is <10wt%.

[0040] In some preferred embodiments, the external wastewater is mainly composed of sodium salt, the sum of the content of sodium sulfate and sodium chloride is greater than 30 g / L, and the content of potassium is ≤0.1 g / L.

[0041] In some preferred embodiments, the foreign solid waste comprises heavy metal hazardous solid waste containing copper and nickel, wherein the dry basis content of copper element is ≥3wt%, and the dry basis content of chromium element is <3wt%.

[0042] In some preferred embodiments, in S1, the smelting process includes: regulating according to the pre-mixed slag, introducing the carbonized slag, calcium-magnesium slag and crystallization mother liquor produced in the waste salt treatment module as regulators during the regulation process, and not introducing fluorite.

[0043] More preferably, the pre-mixed slag is Fe x O y-SiO2-CaO-MgO-Al2O3 multi-component slag system, where x and y are natural numbers that satisfy the chemical valence balance of Fe and O, respectively. x O y -The sum of the contents of the oxides in SiO2-CaO-MgO-Al2O3 is ≥90wt%, the F content in the pre-mixed slag is <5wt%, the P content is <5wt%, and the melting point of the pre-mixed slag is 1150-1300℃.

[0044] In some preferred embodiments, the waste gas treatment in S2 includes dust removal and mist removal, flue gas washing, optional flue gas defluorination, desulfurization, and denitrification; the wastewater treatment in S3 includes heavy metal removal, hardness removal, ammonia evaporation treatment, and evaporation concentration, wherein the ammonia evaporation treatment is carried out when the hardness of the wastewater is less than 100 ppm and the ammonia nitrogen concentration is ≥30 mg / L, and ammonia water is simultaneously produced during the ammonia evaporation treatment.

[0045] Preferably, the treatment method also includes: recycling the condensed water produced by evaporation and concentration in the wastewater treatment for use as the flue gas washing water and / or the desulfurization water in the waste gas treatment, recycling the ammonia water produced in the wastewater treatment as a denitrification agent in the denitrification process of the waste gas treatment, recycling the mother liquor produced in the wastewater treatment to the smelting treatment; recycling the smoke and part of the desulfurization gypsum slag produced in the waste gas treatment to the smelting treatment; recycling the waste gas produced in the waste salt treatment module to the waste gas treatment, recycling the solid phase slag produced in the waste salt treatment module to the smelting treatment, and recycling the crystallization mother liquor produced in the waste salt treatment module to the carbonization treatment.

[0046] Beneficial effects:

[0047] The present invention uses the desulfurized gypsum slag generated by the waste gas treatment module directly as the fluorine-fixing agent of the waste salt treatment module, and is used to introduce a carbonization unit for high fluorine content to carry out co-fluorine-fixing carbonization with the first additive and efficiently promote COD decomposition, and introduces only the first additive to the carbonization unit for promoting COD decomposition when the fluorine content is low, and its corresponding structural connection mode, so that in the clean treatment of waste water and waste residue, COD efficient decomposition of waste salt or efficient fluorine-fixing carbonization of waste salt can be achieved at low cost to promote high-value utilization in the subsequent preparation of refined salt, and at the same time, it is beneficial to reduce the cost of de-hardening, save cost and energy, so as to achieve harmless treatment and reuse of waste water and waste residue. Specifically, metal sulfate or metal oxide can promote the decomposition of COD, so that efficient carbonization treatment can be carried out under low carbonization temperature, energy can be saved, and the carbonization effect is good; when the fluorine content is high, the desulfurized gypsum slag generated in the system is used to carry out co-carbonization with metal sulfate or metal oxide, which is beneficial to improve the fluorine-fixing effect, remove fluorine cleanly, promote COD decomposition, reduce equipment corrosion, and reduce the subsequent de-hardening cost.

[0048] In a preferred embodiment of the present invention, the waste salt is further processed after carbonization to obtain a refined salt product, and the chlorine in the waste salt is recovered as a refined salt product, so that the solid phase slag of part of the product of the waste salt treatment module enters the waste gas treatment module after circulation through the smelting module with very little chlorine, low maintenance cost, and more conducive to zero emission and high-value utilization; the refined salt product of the present invention meets the total recovery rate of GB / T6009-2014 Class I first-class and Class II first-class sodium sulfate of more than 90%, and the whiteness is more than 82. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 The present invention is a process flow chart of a specific implementation method of the wastewater and waste residue cleaning treatment method of the present invention. DETAILED DESCRIPTION

[0051] In the description of the present invention, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0052] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "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 or an electrical connection; it can be directly connected or connected, or indirectly connected or connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article. Among them, the terms "optional" and "optional" all mean that they can be included or not (or can be included or not).

[0054] In the present invention, unless otherwise specified, hardness is calculated based on the molar amount of the corresponding element converted to CaCO3.

[0055] In a first aspect, the present invention provides a wastewater and waste residue clean treatment system, comprising a smelting module, a waste gas treatment module, and a wastewater treatment module arranged in sequence, wherein the waste gas treatment module has a waste gas inlet, a waste water outlet, and a desulfurized gypsum residue outlet, and the waste water treatment module has a waste water inlet and a waste salt outlet. The wastewater and waste residue clean treatment system of the present invention also includes a waste salt treatment module.

[0056] The waste salt treatment module comprises:

[0057] a first additive supply unit, wherein the first additive is a metal sulfate and / or a metal oxide;

[0058] A carbonization unit, which has a waste salt inlet, a first additive inlet and a second additive inlet, the waste salt inlet is connected to the waste salt outlet of the wastewater treatment module, the first additive inlet is connected to the first additive supply unit, and the second additive inlet is connected to the desulfurized gypsum slag outlet of the exhaust gas treatment module; used for introducing the first additive and / or the second additive into the waste salt, the second additive being the desulfurized gypsum slag from the exhaust gas treatment module;

[0059] A fluorine content detection unit, which is connected to the wastewater treatment module or the carbonization unit and is used to detect the fluorine content in the waste salt to be treated;

[0060] A control unit is connected to the fluorine content detection unit, the first additive supply unit, and the carbonization unit, respectively, and is used to introduce the first additive into the waste salt when the fluorine content in the waste salt is detected to be less than 20 ppm, and to introduce the first additive and the second additive into the waste salt when the fluorine content in the waste salt is detected to be ≥20 ppm. When the fluorine content in the waste salt is less than 20 ppm, the first additive is introduced into the waste salt to promote the decomposition of COD; when the fluorine content in the waste salt is ≥20 ppm, the first additive and the second additive are introduced into the waste salt to promote the decomposition of COD and efficient defluorination.

[0061] The waste salt inlet is connected to the waste salt outlet of the wastewater treatment module, which can be directly connected or indirectly connected, such as the waste salt can be transported to the waste salt treatment system through a pipeline or a mechanical device. It can be understood that the communication described in the present invention means that material transportation can be achieved, which can be a closed channel, a semi-closed channel or an open channel, etc.

[0062] It should be pointed out that in the carbonization unit of the present invention, only the first additive or the second additive can be introduced, or the first additive and the second additive can be introduced; preferably, the first additive can be introduced, or the first additive and the second additive can be introduced, and the control unit controls the introduction of the corresponding additive based on the detection result of the fluorine content detection unit.

[0063] In the present invention, the fluorine content detection unit can be arranged in the wastewater treatment module, can be arranged in the carbonization unit, or can be arranged outside the wastewater treatment module and the carbonization unit as an independent device, as long as it can detect the fluorine content in the waste salt to be treated.

[0064] It can be understood that the smelting module is used to smelt the waste raw materials to be processed to obtain the solid phase of the product (alloy phase, matte phase and slag) to generate waste gas, and the waste gas treatment module is used to treat the waste gas generated by the smelting module; accordingly, the waste gas outlet of the smelting module is connected to the inlet of the waste gas treatment module.

[0065] In some preferred embodiments, the waste salt treatment module further comprises:

[0066] Water supply unit;

[0067] pH regulator supply unit;

[0068] De-hardening reagent supply unit;

[0069] The de-hardening and heavy metal removal treatment unit has a material inlet, a water inlet, a pH adjusting agent inlet, a de-hardening agent inlet, and a purified liquid outlet. The material inlet, water inlet, pH adjusting agent inlet, and de-hardening agent inlet are respectively connected to the outlet of the carbonization unit, the water supply unit, the pH adjusting agent supply unit, and the de-hardening agent supply unit, and are used to first introduce water into the material obtained from the carbonization unit for water dissolution, filter to obtain carbonized slag and salt solution, and then introduce pH adjusting agent and de-hardening agent into the salt solution for de-hardening and heavy metal removal to obtain purified liquid. Under this preferred embodiment, the present invention can further dissolve the material obtained from the carbonization unit in water, remove hardness and heavy metals, and is more conducive to directly obtaining purified salt.

[0070] Among them, the pH adjuster in the pH adjuster supply unit may include sodium hydroxide and / or lime. In addition to adjusting the pH, lime can further remove fluorine. Those skilled in the art can select the components and dosage of the pH adjuster based on the effect and cost. When lime is added, the calcium concentration in the liquid will increase, and the dosage of the subsequent de-hardening agent (such as sodium carbonate) will be increased, so sodium hydroxide is preferred.

[0071] The dehardening agent in the dehardening agent supply unit is preferably sodium carbonate.

[0072] More preferably, the waste salt treatment module further comprises:

[0073] an evaporation crystallization unit, which is connected to the purified liquid outlet of the hardness and heavy metal removal treatment unit, and is used to evaporate and crystallize the purified liquid to obtain a crystallization mother liquid and a crystallized salt;

[0074] The refining unit is connected to the evaporation crystallization unit and is used to refine the crystallized salt to obtain refined salt. Under this preferred embodiment, the present invention can directly prepare refined salt by subjecting waste salt to the above-mentioned specific treatment. The refined salt meets the product requirements and is more conducive to the high-value utilization of wastewater and waste residue clean treatment.

[0075] It is understandable that the evaporation crystallization unit and the refining unit can be two independent units or partially shared devices, such as a shared reaction kettle but controlled by two control mechanisms to perform evaporation crystallization or refining, as long as the above functions can be achieved.

[0076] More preferably, the carbonization unit further has a third additive inlet, which is connected to the crystallization mother liquor outlet of the evaporation crystallization unit, and is used to simultaneously introduce the crystallization mother liquor into the waste salt for carbonization treatment. Under this preferred embodiment, the crystallization mother liquor of the evaporation crystallization unit in the system is also introduced, so that the crystallization mother liquor can be further synergistically utilized to achieve resource emission reduction and high-value utilization.

[0077] More preferably, the waste salt treatment module further has a solid phase slag outlet, a crystallization mother liquor outlet, and a waste gas outlet, wherein the solid phase slag outlet is connected to the smelting module, and the crystallization mother liquor outlet is connected to the carbonization unit and / or the smelting module; the waste gas outlet is connected to the waste gas treatment module, and is used to circulate the waste gas generated by the waste salt treatment module to the waste gas treatment module. Under this preferred embodiment, the clean treatment system of the present invention can achieve harmless treatment and reuse of the "three wastes" generated in the system, which is more conducive to zero emissions and high-value utilization.

[0078] In some preferred embodiments, the wastewater and waste residue cleaning treatment system also includes an external wastewater supply unit and an external waste residue supply unit, the external wastewater supply unit is connected to the wastewater inlet of the wastewater treatment module, the external waste residue supply unit includes an external waste salt supply unit and an external solid waste residue supply unit, the external waste salt supply unit is connected to the waste salt inlet in the carbonization unit, and the external solid waste residue supply unit is connected to the material inlet of the smelting module.

[0079] The foreign solid waste residue in the foreign solid waste residue supply unit of the present invention refers to other solid waste residues except waste salt, including heavy metal sludge, carbonized slag (which may contain fluorine-containing slag), calcium magnesium slag, smelting slag and other foreign waste residues. Foreign in the present invention means that it comes from outside the wastewater and waste residue cleaning treatment system of the present invention, and is not generated in the system of the present invention.

[0080] In some preferred embodiments, the smelting module comprises:

[0081] A smelting unit having a material inlet, a waste gas outlet and a solid phase outlet, wherein the waste gas outlet is connected to the waste gas inlet of the waste gas treatment module, and optionally (that is, those skilled in the art can choose whether this step exists or not according to needs), the material inlet is connected to the desulfurized gypsum slag outlet in the waste gas treatment module and / or the smoke outlet of the waste gas treatment module (which can be the smoke outlet of each treatment unit in the waste gas treatment module);

[0082] Pre-mixed slag unit. The desulfurized gypsum slag in the waste gas treatment module is circulated to the smelting unit to play a role in slag making and sulfidation.

[0083] It can be understood that the pre-mixed slag unit is used to provide pre-mixed slag so as to facilitate regulation and control during the smelting process.

[0084] The solid phase outlet is used to discharge the solid phase material obtained by the smelting unit, such as alloy, matte, slag, etc. The solid phase outlet can be one or more, and when multiple, it can be used to discharge different materials.

[0085] In some preferred embodiments, the smelting module further comprises: a composition control unit connected to the smelting unit and the pre-compounding slag unit, and used to control the slag type of the smelting treatment of wastewater and waste slag according to the pre-compounding slag. In this preferred embodiment, the composition control unit can realize automatic composition based on the pre-compounding slag.

[0086] In some preferred embodiments, the waste gas treatment module includes a dust and mist removal unit, a flue gas washing unit, an optional flue gas defluorination unit, a desulfurization unit, and a denitrification unit with a denitrification agent inlet. The calcium and magnesium slag outlet of the flue gas defluorination unit is connected to the material inlet of the smelting module, and the wastewater outlet of the waste gas treatment module is connected to the wastewater inlet of the wastewater treatment module.

[0087] The optional flue gas defluorination unit of the present invention means that the flue gas defluorination unit may be performed or not, and those skilled in the art may select it according to actual needs.

[0088] Preferably, the wastewater treatment module includes a heavy metal removal unit, a hardness removal unit, an ammonia evaporation treatment unit, and an evaporation concentration unit.

[0089] More preferably, the wastewater treatment module further has a condensed water outlet, an ammonia water outlet and a mother liquor outlet, the condensed water outlet is connected to the water inlet of the flue gas scrubbing unit and / or the water inlet of the desulfurization unit, the ammonia water outlet is connected to the denitrification agent inlet of the denitrification unit, and the mother liquor outlet is connected to the smelting module. Under this preferred solution, part of the materials in the system are recycled, which is more conducive to improving the high-value utilization of the clean treatment system and saving costs.

[0090] In a second aspect, the present invention provides a method for treating wastewater and waste residue in a clean manner, wherein the waste raw material to be treated is treated in the wastewater and waste residue treatment system described in the first aspect, wherein the waste raw material to be treated includes foreign solid waste residue and foreign waste salts or foreign waste water, and the treatment method is as follows: Figure 1 As shown, the following steps are included:

[0091] S1. Smelting external solid waste slag in a smelting module to obtain solid products and waste gas;

[0092] S2, treating the waste gas obtained in S1 in a waste gas treatment module to obtain waste water and desulfurized gypsum slag;

[0093] S3, treating the wastewater obtained in S2 or the wastewater obtained in S2 and the external wastewater in a wastewater treatment module to obtain waste salt;

[0094] S4, carbonizing the waste salt obtained in S3 or the waste salt obtained in S3 and the external waste salt in a waste salt treatment module,

[0095] Wherein, in the carbonization treatment described in S4, a first additive is introduced into the waste salt when the fluorine content in the waste salt is less than 20 ppm, and a first additive and a second additive are introduced into the waste salt when the fluorine content in the waste salt is ≥20 ppm; the first additive is a metal sulfate and / or a metal oxide, and the mass amount of the first additive is less than 10 wt% of the mass of the waste salt, preferably 0.5 wt%-10 wt%; the second additive is the desulfurized gypsum slag obtained in S2, and the amount of the desulfurized gypsum slag in terms of calcium element is more than 2 times, preferably 2-5 times, the theoretical molar amount required to generate calcium fluoride in terms of the fluorine content of the waste salt.

[0096] Preferably, the metal sulfate or metal oxide is selected from at least one of sulfates or oxides of metals such as copper, nickel, iron and zinc. It is understandable that the first additive can be at least one of the metal sulfates and / or at least one of the metal oxides.

[0097] The mass dosage of the first additive is less than 10wt% of the waste salt mass, for example, it can be 0.5, 0.8, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10wt% and the like.

[0098] The amount of the desulfurized gypsum slag calculated as calcium element is more than twice the theoretical molar amount of waste salt calculated as fluorine content required to generate calcium fluoride, for example, it can be 2, 2.5, 3, 3.5, 4.5, 5, 6, 7wt%, etc.

[0099] More preferably, the first additive is a metal sulfate, and the metal type of the metal sulfate can be a single type or a mixture of other types. In this preferred embodiment, compared with metal oxides, metal sulfate can be adjusted into a salt solution and mixed with waste salt, and the water content of the waste salt after mixing is controlled to be less than 10%, so that the first additive can be fully contacted with the waste salt, the mixing is more uniform, and it is more conducive to promoting the decomposition of organic matter in the waste salt at high temperature, the reaction is more effective and thorough, and the residual COD is lower.

[0100] In some specific preferred embodiments, the first additive is copper sulfate. Compared with other metal sulfates, this preferred solution is more conducive to promoting the decomposition of organic matter in waste salt at high temperature, the reaction is more effective and thorough, and the residual COD is lower.

[0101] In some preferred embodiments, in S1, the smelting process includes: regulating according to the pre-mixed slag. More preferably, the carbonized slag, calcium magnesium slag and crystallization mother liquor produced in the waste salt treatment module are introduced as regulators during the regulation process, and fluorite is not introduced. Those skilled in the art may also introduce other additives, such as smelting additives, such as quartz stone, according to the needs of slag making.

[0102] More preferably, the pre-mixed slag is Fe x Oy -SiO2-CaO-MgO-Al2O3 multi-component slag system, where x and y are natural numbers that satisfy the chemical valence balance of Fe and O, respectively. x O y -The sum of the contents of each oxide in SiO2-CaO-MgO-Al2O3 is ≥90wt%.

[0103] More preferably, the F content in the pre-mixed slag is less than 5wt%, and the P content is less than 5wt%.

[0104] It should be understood that Fe x O y -SiO2-CaO-MgO-Al2O3 multi-component slag system refers to a multi-component slag system containing FeO and / or Fe2O3, SiO2, CaO, MgO, and Al2O3 oxides.

[0105] More preferably, the melting point of the pre-mixed slag is 1150-1300°C.

[0106] In the above-mentioned preferred control scheme of the present invention, the carbonized slag, calcium-magnesium slag and crystallization mother liquor generated by the system are used as regulators, so that the system waste can be fully utilized for slag type control, and while ensuring the smooth progress of the smelting process, the waste generated in the system can be harmlessly treated and reused, which is more conducive to achieving zero emissions and high-value utilization; and there is no need to introduce fluorite additionally, and the added carbonized slag can play the role of fluorite in reducing the melting point of the slag, which is more conducive to reducing costs. Among them, calcium-magnesium slag is used as the main material for calcium regulation, and the crystallization mother liquor is mainly sodium chloride with a small amount of sodium sulfate. The introduction of sodium is conducive to reducing the melting point of the slag. The COD in the crystallization mother liquor can be completely decomposed and harmlessly treated under the high temperature of the smelting process, and the sulfur and heavy metals such as copper and nickel contained are converted into matte for recovery.

[0107] In the smelting process of the present invention, after the above-mentioned adjustment and matching, products and slag are produced, the products include alloy phase and matte phase, and the slag can be used as auxiliary building materials. The slag contains F<5wt%.

[0108] More preferably, the foreign solid waste residue includes heavy metal hazardous solid waste containing copper and nickel, wherein the dry basis content of copper element is ≥3wt%, and the dry basis content of chromium element is <3wt%; for example, it can be foreign copper and nickel heavy metal sludge generated by the surface treatment industry, etc., which can be used in the present invention.

[0109] More preferably, the external wastewater is mainly sodium salt, the sum of the content of sodium sulfate and sodium chloride is greater than 30g / L, and the potassium content is ≤0.1g / L. The present invention can achieve the recovery and treatment of high-content sodium salt. The external wastewater can be, for example, wastewater generated by industries such as electroplating and smelting, which can all be used in the present invention.

[0110] Preferably, the foreign waste salt meets the following requirements: the sum of the mass content of sodium sulfate and sodium chloride is above 90wt%, the potassium content is ≤1wt%, the ammonium ion content is ≤1wt%, and the moisture content is <10wt%. The foreign waste salt can be, for example, waste salt generated by the foreign wastewater treatment industry, and can be used in the present invention.

[0111] In some more preferred embodiments, in S1, the waste raw materials to be processed also include wastewater generated in the system (such as electrostatic precipitator wastewater generated in the wastewater treatment in the system, wastewater generated in flue gas washing, etc.), liquid phases such as mother liquor or crystallization mother liquor, and solid phase residues such as waste salt and sludge generated in the system.

[0112] The waste gas generated by the smelting module S1 enters the waste gas treatment module S2.

[0113] In some preferred embodiments, the waste gas treatment in S2 includes dust removal and mist removal, flue gas washing, optional flue gas defluorination, desulfurization, denitrification, etc. The dust removal and mist removal is preferably electrostatic demisting. The denitrification is preferably SCR denitrification.

[0114] The gas treated by the waste gas treatment module in S2 meets the emission standards, and the obtained desulfurized gypsum slag is used as the fluorine-fixing agent in the carbonization treatment in S4. The waste water (including electric demisting waste water and flue gas washing waste water) generated in the waste gas treatment module in S2 enters the waste water treatment module in S3.

[0115] Preferably, the wastewater treatment in S3 includes heavy metal removal, hardness removal, ammonia evaporation treatment, evaporation concentration, etc., wherein the ammonia evaporation treatment is carried out when the hardness of the wastewater is less than 100 ppm and the ammonia nitrogen concentration is ≥30 mg / L, and ammonia water is simultaneously produced during the ammonia evaporation treatment.

[0116] In some preferred embodiments, the treatment method further includes: recycling the condensed water produced by evaporation and concentration in the wastewater treatment for use as the flue gas washing water and / or the desulfurization water in the waste gas treatment, recycling the ammonia water produced in the wastewater treatment as a denitrification agent in the denitrification process of the waste gas treatment, and recycling the mother liquor produced in the wastewater treatment to the smelting treatment.

[0117] In some preferred embodiments, the treatment method further comprises: recycling the smoke dust (as waste residue) and the optional part of desulfurized gypsum slag generated in the waste gas treatment to the smelting treatment. Since the smoke dust contains valuable metals in addition to being a regulator, it can be recycled. The optional part of desulfurized gypsum slag means that part of the desulfurized gypsum slag may or may not be introduced. It is understood that the part of desulfurized gypsum slag refers to the remaining part except for the desulfurized gypsum slag introduced into the waste salt.

[0118] In some preferred embodiments, the treatment method further includes: recycling the waste gas generated in the waste salt treatment module to the waste gas treatment, recycling the solid slag generated in the waste salt treatment module to the smelting treatment, and recycling the crystallization mother liquor generated in the waste salt treatment module to the carbonization treatment.

[0119] In the preferred embodiment of the above-mentioned recycling application of the present invention, the clean treatment method of the present invention can achieve harmless treatment and reuse of the "three wastes" generated in the system, which is more conducive to zero emission and high-value utilization.

[0120] The solid phase slag produced in the waste salt treatment module, such as carbonized slag (which may include fluorine-containing slag), calcium-magnesium slag, etc. The carbonized slag refers to the slag filtered out during the water dissolution process after carbonization treatment, which is mainly composed of carbon and water-insoluble matter after high-temperature carbonization of organic matter. The calcium-magnesium slag refers to the de-hardening slag, neutralization slag, etc. produced by the de-hardening and heavy metal removal treatment in the waste salt treatment module. The crystallization mother liquor refers to the highly concentrated crystallization mother liquor produced by the evaporation crystallization process in the waste salt treatment module, containing high concentrations of COD and sulfate.

[0121] In some preferred embodiments, the carbonization treatment conditions in S4 include: a carbonization temperature of 400-600°C and a carbonization time of 0.5-3h. The carbonization treatment step of the present invention, especially for the case of a higher fluorine content, uses the desulfurized gypsum slag produced in the system to participate in the co-solidification fluorine carbonization, which can achieve efficient carbonization at a lower and appropriate carbonization temperature, save energy and reduce the subsequent de-hardening cost; at the same time, it efficiently promotes COD decomposition. Under the same conditions, if the carbonization temperature is lower than 400°C, the effect of COD decomposition is relatively poor, and if the carbonization temperature is higher than 600°C, then there is a possibility of waste salt agglomeration.

[0122] The carbonization temperature is 400-600°C, for example, specifically 400, 450, 500, 550, 600°C.

[0123] The carbonization time is 0.5-3 h, for example, specifically 0.5, 1, 1.5, 2, 2.5, 3 h.

[0124] In some preferred embodiments, the treatment method further comprises: S5, dissolving the material obtained by the carbonization treatment in water, filtering to obtain carbonized slag and a salt solution with a concentration of more than 20 wt%. It is understandable that the upper limit of the concentration of the salt solution is a saturated solution.

[0125] More preferably, the carbonization treatment in S4 controls the COD≤50ppm and F≤10ppm in the salt solution obtained after carbonization treatment, water dissolution and filtration. The carbonization treatment process of the present invention can maximize the carbonization fluorine fixation effect at a relatively low cost.

[0126] Preferably, the water-dissolving conditions include: dissolving in water at a mass fraction of the carbonized material accounting for 20-25wt% of the total amount of the aqueous solution.

[0127] More preferably, the treatment method further comprises: S5, performing a hardness removal and heavy metal removal treatment after the water dissolution to obtain a purified liquid, and then evaporating, crystallizing and refining the purified liquid to obtain a crystallization mother liquor and refined salt.

[0128] Preferably, at least part of the crystallization mother liquor is circulated and introduced into the carbonization treatment. More preferably, the circulation amount of the crystallization mother liquor is less than 6wt% of the mass of the waste salt. In the preferred embodiment of the present invention, as the evaporation crystallization proceeds, impurities such as COD and fluorine content in the crystallization mother liquor will accumulate more and more, and eventually form a crystallization mother liquor with high COD and fluorine content approaching saturation, which is partially circulated to the carbonization treatment, and can be synergistically treated with the waste salt raw material, while ensuring that the water content of the carbonized raw material is below 10%, so as to achieve low emissions while being more conducive to the refined salt quality meeting high requirements.

[0129] In the present invention, it should be understood that the refined salt includes sodium sulfate, sodium chloride and other mixed salts. The single products of the obtained refined salt after separation all meet the corresponding product standards. Other mixed salts can be used as printing and dyeing auxiliaries.

[0130] Preferably, a pH adjuster and a de-hardening agent are introduced into the de-hardening and heavy metal removal treatment.

[0131] More preferably, the conditions for the de-hardening and de-heavy metal removal treatment include: using sodium hydroxide and / or lime to adjust the pH of the reaction system to 9-11, the amount of sodium carbonate used is 1-2 times the theoretical amount of the reaction system in moles, and the reaction time is 0.5-3h.

[0132] Further preferably, the de-hardening and de-heavy metal removal treatment controls the contents of Cd, Fe, Cu, Ni, Zn, Cr, Mn and Pb in the purified liquid to be no higher than 2 ppm, the fluorine content is ≤10 ppm, the solution chromaticity value is ≤100 degrees, and the total hardness of calcium and magnesium is ≤50 ppm.

[0133] The present invention is further described in detail below with reference to specific embodiments.

[0134] Example 1

[0135] A method for treating wastewater and waste residue in a clean manner, wherein the waste raw materials to be treated are treated in a wastewater and waste residue treatment system, wherein the waste raw materials to be treated are foreign wastewater, foreign solid waste residue, and foreign waste salt; wherein the foreign wastewater is mainly sodium salt, the sum of the contents of sodium sulfate and sodium chloride is 45 g / L, and the potassium content is 0.05 g / L; the foreign solid waste residue comprises heavy metal hazardous solid waste containing copper and nickel, wherein the dry basis content of copper is 6.5 wt%, and the dry basis content of chromium is 2.2 wt%; the foreign waste salt satisfies: the sum of the mass contents of sodium sulfate and sodium chloride is above 90 wt%, the potassium content is ≤1 wt%, the ammonium ion content is ≤1 wt%, and the water content is <10 wt%; the treatment method comprises the following steps:

[0136] S1. Smelting external solid waste slag in a smelting module to obtain solid products and waste gas;

[0137] The smelting process comprises: regulating according to the pre-matched slag, introducing the carbonized slag, calcium magnesium slag and crystallization mother liquor produced in the waste salt treatment module as regulators during the regulation process, not introducing fluorite, controlling the F content in the pre-matched slag to be 2.0wt% and the P content to be 0.8wt%; wherein the pre-matched slag is Fe x O y -SiO2-CaO-MgO-Al2O3 multi-component slag system, where x and y are natural numbers that satisfy the chemical valence balance of Fe and O, respectively. x O y - The sum of the contents of the oxides in SiO2-CaO-MgO-Al2O3 is 92wt%, and the melting point of the pre-mixed slag is 1200°C;

[0138] S2, treating the waste gas obtained in S1 in a waste gas treatment module to obtain waste water and desulfurized gypsum slag; the waste gas treatment includes dust removal and demisting, flue gas washing, flue gas defluorination, desulfurization, and denitrification;

[0139] S3, treating the wastewater obtained in S2 and the external wastewater in a wastewater treatment module to obtain waste salt; the wastewater treatment includes heavy metal removal, hardness removal, ammonia evaporation treatment, and evaporation concentration, wherein the ammonia evaporation treatment is performed when the hardness of the wastewater is less than 100 ppm and the ammonia nitrogen concentration is ≥30 mg / L, and ammonia water is simultaneously produced during the ammonia evaporation treatment;

[0140] S4, the waste salt obtained in S3 and the external waste salt are carbonized in the waste salt treatment module; the carbonization temperature is 575°C, and the carbonization time is 2h; after the carbonization treatment, the obtained material is dissolved in water (the material mass fraction accounts for 22wt% of the total aqueous solution), and the carbonized slag and the salt solution with a concentration of about 21.0wt% are filtered to obtain the carbonized slag and the salt solution with a concentration of about 21.0wt%, and the COD content and the water-soluble fluorine content (which is the water-soluble fluorine element content) in the salt solution are tested respectively according to the test standards "HJ 828-2017 Determination of Chemical Oxygen Demand of Water Quality by Dichromate Method" and "GB / T 7484 Determination of Fluoride in Water Quality by Ion Selective Electrode Method", and the COD removal rate and the water-soluble fluorine removal rate of the salt solution are calculated. The test results are shown in Table 1, wherein the removal rate is calculated as follows:

[0141]

[0142] Where:

[0143] C 炭化后 The COD or fluoride ion concentration of the salt solution obtained after filtration is measured from a solution prepared with a mass fraction of m% (not less than 20wt%) of 100g of carbonized material, mg / L;

[0144] C 炭化前 The COD or fluoride ion concentration measured is mg / L, which is a salt solution prepared with 100g of dry waste salt according to the same mass fraction of the material, m%.

[0145] m 炭化渣 The weight of the carbonized slag obtained by filtering, washing and drying 100g of the carbonized material in a solution prepared according to the material mass fraction m%, g;

[0146] S5. Sodium hydroxide and sodium carbonate are introduced into the salt solution obtained by the carbonization treatment to carry out hardness removal and heavy metal removal treatment in a hardness removal and heavy metal removal treatment unit to obtain a purified liquid, and then the purified liquid is evaporated, crystallized and refined to obtain a crystallization mother liquor and refined salt; part of the crystallization mother liquor is circulated and introduced into the carbonization treatment, and the amount of the crystallization mother liquor is 3wt% of the waste salt raw material in the carbonization treatment; the quality of the refined salt is tested according to the standard GB / T 6009 industrial sodium sulfate, and the results are shown in Table 2.

[0147] Furthermore, the condensed water generated by evaporation and concentration in the wastewater treatment is recycled for use as the flue gas washing water and the desulfurization water in the waste gas treatment, the ammonia water generated in the wastewater treatment is recycled as a denitrification agent in the denitrification process of the waste gas treatment, the mother liquor generated in the wastewater treatment is recycled to the smelting treatment; the smoke dust generated in the waste gas treatment and the remaining part of the desulfurization gypsum slag are recycled to the smelting treatment; the waste gas generated in the waste salt treatment module is recycled to the waste gas treatment, the solid phase slag generated in the waste salt treatment module is recycled to the smelting treatment, and the crystallization mother liquor generated in the waste salt treatment module is recycled to the carbonization treatment.

[0148] Among them, in the carbonization treatment described in S4, the fluorine content in the waste salt is ≥20ppm, and a first additive and a second additive are introduced into the waste salt; the first additive and its dosage (as a percentage of the waste salt) are shown in Table 1; the second additive is the desulfurized gypsum slag obtained in S2, and the dosage of the desulfurized gypsum slag in terms of calcium element is a multiple of the theoretical molar dosage required to generate calcium fluoride based on the fluorine content of the waste salt as shown in Table 1.

[0149] The conditions for the de-hardening and de-heavy metal removal treatment in S5 include: using sodium hydroxide to adjust the pH of the reaction system to 10.5, the amount of sodium carbonate used is 1.1 times the theoretical amount of the reaction system in moles, the reaction time is 1 hour, and the contents of Cd, Fe, Cu, Ni, Zn, Cr, Mn and Pb in the purified liquid are controlled to be no higher than 2ppm, the fluorine content is ≤10ppm, the solution chromaticity value is ≤100 degrees, the total hardness of calcium and magnesium is ≤50ppm, and the total fluorine content is ≤10ppm.

[0150] Embodiment 2-8

[0151] The method of Example 1 is referred to, except that the type and amount of the first additive and the amount of desulfurized gypsum slag are different, as shown in Table 1. The test results are shown in Tables 1 and 2.

[0152] Example 9

[0153] The method of Example 1 was used, except that the carbonization temperature was different, specifically 500° C. The test results are shown in Tables 1 and 2.

[0154] Example 10

[0155] The method of Example 1 was used, except that the carbonization time was different, specifically 1 hour. The test results are shown in Tables 1 and 2.

[0156] Comparative Example 1

[0157] The method of Example 1 was used, except that the first additive and desulfurized gypsum slag were not introduced. The test results are shown in Tables 1 and 2.

[0158] Comparative Example 2

[0159] The method of Example 1 was used, except that no desulfurized gypsum slag was introduced and only the first additive was introduced. The test results are shown in Tables 1 and 2.

[0160] Comparative Example 3

[0161] The method of Example 1 was followed, except that the first additive was not introduced and only desulfurized gypsum slag was used. The test results are shown in Tables 1 and 2.

[0162] Comparative Examples 4-6

[0163] The method of Example 1 is referred to, except that the type and amount of the first additive and the amount of desulfurized gypsum slag are different, as shown in Table 1. The test results are shown in Tables 1 and 2.

[0164] Table 1

[0165]

[0166]

[0167] Table 2

[0168]

[0169]

[0170] It can be seen from the above embodiments and comparative examples and Tables 1-2 that the scheme of the present invention can achieve the clean treatment of wastewater and waste residues, and can effectively carbonize and fix fluorine and remove fluorine for waste salt with high fluorine content, without the need for additional defluorination and decolorization processes, and effectively promote COD decomposition, can effectively reduce the cost of hardness removal and impurity removal, and can achieve zero emission and high-value utilization. The scheme of the comparative example that is not within the scope of the present invention has poor comprehensive effects of COD removal and fluorine fixation, cannot obtain high-quality finished products, and cannot achieve the significant effects of the present invention.

[0171] It can be seen from Examples 1-10 that the preferred carbonization additive scheme or preferred carbonization conditions of the present invention can further efficiently remove COD and solid fluorine, which is more conducive to obtaining high-quality products. Further, it can be seen from Examples 1, 7 and 8 that the preferred scheme of the present invention is adopted, and under the same carbonization temperature and time conditions, the amount of additive is appropriately increased, which can make the COD and fluorine residues lower. It can be seen from Examples 9 and 10 that the preferred scheme of the present invention is adopted, the temperature is appropriately high, which can make the COD and fluorine residues lower; the carbonization time is appropriately long, and the COD and fluorine residues will become lower.

[0172] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A wastewater and waste residue cleaning treatment system, comprising a smelting module, a waste gas treatment module, and a wastewater treatment module arranged in sequence, characterized in that: The waste gas treatment module has a waste gas inlet, a waste water outlet and a desulfurized gypsum slag outlet, and the waste water treatment module has a waste water inlet and a waste salt outlet; and the waste water and waste slag cleaning treatment system also includes a waste salt treatment module, and the waste salt treatment module includes: a first additive supply unit, wherein the first additive is a metal sulfate and / or a metal oxide; A carbonization unit, which has a waste salt inlet, a first additive inlet and a second additive inlet, the waste salt inlet is connected to the waste salt outlet of the wastewater treatment module, the first additive inlet is connected to the first additive supply unit, and the second additive inlet is connected to the desulfurized gypsum slag outlet of the exhaust gas treatment module; used for introducing the first additive and / or the second additive into the waste salt; A fluorine content detection unit, which is connected to the wastewater treatment module or the carbonization unit and is used to detect the fluorine content in the waste salt to be treated; A control unit is connected to the fluorine content detection unit, the first additive supply unit, and the carbonization unit, respectively, and is used to introduce the first additive into the waste salt when the fluorine content in the waste salt is detected to be less than 20 ppm, and to introduce the first additive and the second additive into the waste salt when the fluorine content in the waste salt is detected to be ≥20 ppm; the mass dosage of the first additive is less than 10 wt% of the mass of the waste salt, the second additive is desulfurized gypsum slag from the exhaust gas treatment module, and the dosage of the desulfurized gypsum slag in terms of calcium element is more than twice the theoretical molar dosage required to generate calcium fluoride in terms of the fluorine content of the waste salt.

2. The wastewater and waste residue cleaning treatment system according to claim 1 is characterized in that: The waste salt treatment module also includes: Water supply unit; pH regulator supply unit; De-hardening reagent supply unit; The de-hardening and heavy metal removal treatment unit has a material inlet, a water inlet, a pH adjusting agent inlet, a de-hardening agent inlet and a purified liquid outlet. The material inlet, water inlet, pH adjusting agent inlet and de-hardening agent inlet are respectively connected to the outlet of the carbonization unit, the water supply unit, the pH adjusting agent supply unit and the de-hardening agent supply unit, and are used to first introduce water into the material obtained from the carbonization unit for water dissolution and filtration to obtain carbonized slag and salt solution, and then introduce the pH adjusting agent and de-hardening agent into the salt solution for de-hardening and heavy metal removal to obtain a purified liquid.

3. The wastewater and waste residue cleaning treatment system according to claim 2 is characterized in that: The waste salt treatment module also includes: an evaporation crystallization unit, which is connected to the purified liquid outlet of the hardness and heavy metal removal treatment unit, and is used to evaporate and crystallize the purified liquid to obtain a crystallization mother liquid and a crystallized salt; The refining unit is connected to the evaporation crystallization unit and is used for refining the crystallized salt to obtain refined salt.

4. The wastewater and waste residue cleaning treatment system according to claim 3 is characterized in that: The carbonization unit also has a third additive inlet, which is connected to the crystallization mother liquor outlet of the evaporation crystallization unit and is used to simultaneously introduce the crystallization mother liquor into the waste salt for carbonization treatment.

5. The wastewater and waste residue cleaning treatment system according to any one of claims 2 to 4, characterized in that: The waste salt treatment module also has a solid phase slag outlet, a crystallization mother liquor outlet, and a waste gas outlet. The solid phase slag outlet is connected to the smelting module, and the crystallization mother liquor outlet is connected to the carbonization unit and / or the smelting module; the waste gas outlet is connected to the waste gas treatment module, and is used to circulate the waste gas generated by the waste salt treatment module to the waste gas treatment module.

6. The wastewater and waste residue cleaning treatment system according to claim 1 is characterized in that: The wastewater and waste residue cleaning treatment system further includes an external wastewater supply unit and an external waste residue supply unit, wherein the external wastewater supply unit is connected to the wastewater inlet of the wastewater treatment module, and the external waste residue supply unit includes an external waste salt supply unit and an external solid waste residue supply unit, wherein the external waste salt supply unit is connected to the waste salt inlet of the carbonization unit, and the external solid waste residue supply unit is connected to the material inlet of the smelting module; Wherein, the smelting module comprises: A smelting unit having a material inlet, a waste gas outlet and a solid phase outlet, wherein the waste gas outlet is connected to the waste gas inlet of the waste gas treatment module, and the material inlet is connected to the desulfurized gypsum slag outlet in the waste gas treatment module and / or the smoke outlet of the waste gas treatment module; Pre-mixed slag unit; A compatibility control unit, which is connected to the smelting unit and the slag pre-mixing unit, and is used to control the slag type of the smelting treatment of wastewater and waste slag according to the pre-mixed slag; and / or The exhaust gas treatment module comprises a dust and mist removal unit, a flue gas washing unit, an optional flue gas defluorination unit, a desulfurization unit, and a denitrification unit having a denitrification agent inlet. The calcium and magnesium slag outlet of the flue gas defluorination unit is connected to the material inlet of the smelting module, and the wastewater outlet of the exhaust gas treatment module is connected to the wastewater inlet of the wastewater treatment module; the wastewater treatment module comprises a heavy metal removal unit, a hardness removal unit, an ammonia distillation treatment unit, and an evaporation concentration unit. The wastewater treatment module also has a condensate outlet, an ammonia water outlet, and a mother liquor outlet. The condensate outlet is connected to the water inlet of the flue gas washing unit and / or the water inlet of the desulfurization unit, the ammonia water outlet is connected to the denitrification agent inlet of the denitrification unit, and the mother liquor outlet is connected to the smelting module.

7. A method for cleaning wastewater and waste residue, characterized in that: The waste material to be treated is treated in the wastewater and waste residue cleaning treatment system according to any one of claims 1 to 6, wherein the waste material to be treated includes foreign solid waste residue and foreign waste salt with or without foreign salt, foreign waste water with or without foreign salt, and the treatment method includes the following steps: S1. Smelting external solid waste slag in a smelting module to obtain solid products and waste gas; S2, treating the waste gas obtained in S1 in a waste gas treatment module to obtain waste water and desulfurized gypsum slag; S3, treating the wastewater obtained in S2 or the wastewater obtained in S2 and the external wastewater in a wastewater treatment module to obtain waste salt; S4, carbonizing the waste salt obtained in S3 or the waste salt obtained in S3 and the external waste salt in a waste salt treatment module; Wherein, in the carbonization treatment described in S4, a first additive is introduced into the waste salt when the fluorine content in the waste salt is less than 20 ppm, and a first additive and a second additive are introduced into the waste salt when the fluorine content in the waste salt is ≥20 ppm; the first additive is a metal sulfate and / or a metal oxide, and the mass amount of the first additive is less than 10 wt% of the mass of the waste salt; the second additive is the desulfurized gypsum slag obtained in S2, and the amount of the desulfurized gypsum slag in terms of calcium element is more than twice the theoretical molar amount required to generate calcium fluoride in terms of the fluorine content of the waste salt.

8. The processing method according to claim 7, characterized in that: The mass dosage of the first additive is 0.5wt%-10wt% of the mass of the waste salt, and / or the dosage of the desulfurized gypsum slag in terms of calcium element is 2-5 times the theoretical molar dosage required to generate calcium fluoride in terms of fluorine content of the waste salt.

9. The processing method according to claim 7, characterized in that: The carbonization treatment conditions include: a carbonization temperature of 400-600° C. and a carbonization time of 0.5-3 h.

10. The processing method according to claim 7, characterized in that: The metal sulfate or metal oxide is selected from at least one of sulfates or oxides of copper, nickel, iron and zinc.

11. The processing method according to claim 7, characterized in that: The treatment method also includes: S5, dissolving the material obtained from the carbonization treatment in water, filtering to obtain carbonized slag and a salt solution with a concentration of more than 20wt%, then introducing a pH regulator and a de-hardening agent to perform de-hardening and heavy metal removal treatment to obtain a purified liquid, and then evaporating, crystallizing and refining the purified liquid to obtain a crystallization mother liquor and refined salt; at least part of the crystallization mother liquor is recycled and introduced into the carbonization treatment, and the circulation amount of the crystallization mother liquor is less than 6wt% of the mass of the waste salt.

12. The processing method according to claim 11, characterized in that: The COD in the salt solution obtained after carbonization treatment, water dissolution and filtration is controlled to be ≤50ppm and F≤10ppm.

13. The processing method according to claim 11, characterized in that: The conditions for the de-hardening and heavy metal removal treatment include: using sodium hydroxide and / or lime to adjust the pH of the reaction system to 9-11, the amount of sodium carbonate used is 1-2 times the theoretical amount of the reaction system in moles, the reaction time is 0.5-3h, and the contents of Cd, Fe, Cu, Ni, Zn, Cr, Mn and Pb in the purified liquid are controlled to be no higher than 2ppm, the fluorine content is ≤10ppm, the solution chromaticity value is ≤100 degrees, and the total hardness of calcium and magnesium is ≤50ppm.

14. The processing method according to claim 7, characterized in that: The external wastewater is mainly composed of sodium salt, with the sum of sodium sulfate and sodium chloride contents greater than 30g / L, and potassium content ≤0.1g / L; the external solid waste residue includes heavy metal hazardous solid waste containing copper and nickel, wherein the dry basis content of copper element is greater than 3wt%, and the dry basis content of chromium element is less than 3wt%; the external waste salt meets the following requirements: the sum of the mass contents of sodium sulfate and sodium chloride is above 90wt%, the potassium content is ≤1wt%, the ammonium ion content is ≤1wt%, and the moisture content is less than 10wt%.

15. The processing method according to claim 7, characterized in that: In S1, the smelting process includes: regulating according to the pre-matched slag, introducing the carbonized slag, calcium magnesium slag and crystallization mother liquor produced in the waste salt treatment module as regulators during the regulation process, and not introducing fluorite; wherein the pre-matched slag is Fe x O y -SiO2-CaO-MgO-Al2O3 multi-component slag system, where x and y are natural numbers that satisfy the chemical valence balance of Fe and O, respectively. x O y -The sum of the contents of each oxide in SiO2-CaO-MgO-Al2O3 is ≥90wt%, the F content in the pre-mixed slag is <5wt%, the P content is <5wt%, and the melting point of the pre-mixed slag is 1150-1300℃.

16. The processing method according to claim 7, characterized in that: The waste gas treatment described in S2 includes dust removal and demisting, flue gas washing, optional flue gas defluorination, desulfurization, and denitrification; the wastewater treatment described in S3 includes heavy metal removal, hardness removal, ammonia evaporation treatment, and evaporation concentration, wherein the ammonia evaporation treatment is carried out when the hardness of the wastewater is less than 100 ppm and the ammonia nitrogen concentration is ≥30 mg / L, and ammonia water is simultaneously produced during the ammonia evaporation treatment.

17. The processing method according to claim 16, characterized in that: The treatment method also includes: recycling the condensed water produced by evaporation and concentration in the wastewater treatment for use as water for flue gas washing and / or desulfurization in the waste gas treatment, recycling the ammonia water produced in the wastewater treatment as a denitrification agent in the denitrification process of the waste gas treatment, recycling the mother liquor produced in the wastewater treatment to the smelting treatment; recycling the smoke and part of the desulfurized gypsum slag produced in the waste gas treatment to the smelting treatment; recycling the waste gas produced in the waste salt treatment module to the waste gas treatment, recycling the solid phase slag produced in the waste salt treatment module to the smelting treatment, and recycling the crystallization mother liquor produced in the waste salt treatment module to the carbonization treatment.

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