Resourceful treatment method for smelting ash leached liquid

Abstract

The invention discloses a resourceful treatment method for smelting ash leached liquid. The leached liquid is subjected to multi-stage filtering purification, the purified filtrate is separated through a diffusion dialyzer, and waste acid and recycled acid are produced; carrying out vulcanization reaction on the obtained recycled acid, adding carbide slag into the acid wastewater obtained after the reaction for neutralization and dehydration to obtain an industrial byproduct gypsum, carrying out advanced treatment on the wastewater obtained after separation, and discharging the produced recycled water up to the standard or recycling the recycled water to each production water point; adding nano-iron and ozone into the produced waste acid, and reacting under micro-positive pressure to generate precipitate; the method comprises the following steps: filtering arsenic-precipitated liquid, carrying out sulfuration reaction on the arsenic-precipitated liquid, carrying out solid-liquid separation after the reaction, returning the produced sulfuration slag ingredients to a furnace to recover valuable metals such as zinc and cadmium, adding carbide slag into the filtrate obtained by separation, neutralizing and dehydrating to obtain an industrial byproduct gypsum, carrying out advanced treatment on the obtained sewage, and discharging the produced reuse water up to standard or recycling the reuse water for each production water point. By means of the method, resourceful treatment can be carried out on the smelting ash leached liquid, and the environment-friendly treatment concept of recycling non-ferrous metal and arsenic resources is embodied.

Description

1. Technical Field:

[0001] The present invention belongs to the technical field of metal smelting, and specifically relates to a method for resource-based treatment of waste acid liquid containing high heavy metals and high arsenic produced after leaching of smelting ash, that is, a method for resource-based treatment of liquid after leaching of smelting ash. 2. Background technology:

[0002] The nonferrous smelting process of lead and copper produces soot containing heavy metals and arsenic. The soot is then leached to produce metallic arsenic, producing waste acid liquid containing high levels of heavy metals and arsenic. The sulfide slag produced by the sulfide precipitation method is outsourced for disposal or further production of metallic arsenic. The outsourcing of sulfide slag is currently one of the main ways to remove arsenic from the smelting industry.

[0003] In the prior art, the sulfide precipitation method is used to remove heavy metals and arsenic from waste acid, and after sulfidation, a neutralization reaction is carried out to produce gypsum for sale. The sulfide slag produced by this method contains not only a large amount of arsenic sulfide, but also a part of valuable metals (zinc, cadmium, etc.), and it is impossible to completely separate the arsenic and valuable metals. When disposing of the sulfide slag, it is easy to cause the loss of valuable metals. At the same time, the zinc and cadmium content in the gypsum is relatively high; the neutralization precipitation method, this method removes arsenic and most of the heavy metals in the waste acid into the slag by adding a neutralizer and returns it to the raw material ingredients, causing arsenic to be enriched in the system. Therefore, in order to enable the high-heavy metal and high-arsenic waste acid liquid produced after leaching of smelting ash to be processed to a greater extent, it is necessary to develop a process for resource processing of the liquid after leaching of ash to achieve the purpose of opening the arsenic circuit and recovering valuable metals at the same time.

[0004] Currently, there are patents and literature related to post-leaching liquor treatment processes in the metallurgical industry. For example: 1. Invention patent application CN 201911199060.X discloses a method for treating post-leaching liquor from copper anode mud. This method mixes the post-leaching liquor with waste copper electrolyte and then processes it in a waste copper electrolyte treatment system. This solution utilizes existing waste copper electrolyte treatment systems to treat both waste liquors, significantly reducing equipment and maintenance costs. Mixing the two waste liquors eliminates the risk of increased processing difficulty. Mixing the waste copper electrolyte with the post-leaching liquor acts as a disguised dilution of the post-leaching liquor, effectively reducing the fluctuation in the content of various components in the post-leaching liquor and thus reducing the difficulty of post-leaching liquor treatment. Furthermore, it avoids the direct use of cyclone electrowinning, a process with high power consumption and low processing capacity, eliminating the need to sell the post-leaching liquor, significantly improving copper recovery. 3. Summary of the invention:

[0005] The technical problem to be solved by the present invention is: to enable greater resource recovery of high-heavy metal and high-arsenic waste acid liquor produced after leaching of smelting ash, the present invention provides a method for resource recovery of high-heavy metal and high-arsenic waste acid liquor produced after leaching of smelting ash, namely, a method for resource recovery of smelting ash leached liquor. Through the technical solution of the present invention, arsenic in the waste acid liquor can be significantly removed, generating arsenic sulfide and ferric arsenate for outsourced disposal, thereby reducing arsenic circulation and enrichment in the smelting system. The arsenic open circuit can reach over 80%, reducing arsenic recycling costs. At the same time, the removal rate of heavy metals such as zinc and cadmium in the waste acid liquor can be increased to over 95%, achieving 95% recovery of zinc, cadmium and other heavy metals, embodying the environmental protection management concept of recycling non-ferrous metal and arsenic resources.

[0006] In order to solve the above problems, the technical solution adopted by the present invention is:

[0007] The present invention provides a method for resource recovery treatment of smelting ash leaching liquid, the method comprising the following steps:

[0008] 1) subjecting the smelting ash leaching liquid to multi-stage filtration purification to obtain a purified filtrate;

[0009] 2) The purified filtrate obtained in step 1) enters the acid inlet of the diffusion dialyzer, and primary water is introduced at the same time, with the volume ratio of the primary water to the filtrate being 1:1.3-1.6; the filtrate and the primary water are separated by a homogeneous anion exchange membrane; after separation, waste acid is produced at the acid outlet, and recovered acid is produced at the primary water outlet;

[0010] 3) A sulfiding agent is added to the recovered acid produced in step 2) to carry out a sulfidation reaction, and the pressure of the sulfidation reactor is controlled to be less than 30 kPa, so that the heavy metals and arsenic in the recovered acid are converted into metal sulfides and arsenic sulfide precipitates (which can be subsequently outsourced for disposal or further processed to produce metallic arsenic); carbide slag is added to the acidic wastewater obtained after the sulfidation reaction to adjust its pH to 7-8 to produce gypsum, which is then dehydrated using a solid-liquid separation device to obtain industrial by-product gypsum (mainly composed of calcium sulfate dihydrate). The wastewater obtained after separation is subjected to advanced treatment, and the produced recycled water meets discharge standards or is reused at various production water points;

[0011] 4) Nano-iron is added to the waste acid produced in step 2), ozone is introduced, and the reaction is carried out for 60 to 120 minutes under a slightly positive pressure environment to generate iron arsenate (scorodite) precipitate; then, a sulfiding agent is added to the liquid after the arsenic precipitation to sulfide the zinc and cadmium in the liquid after the arsenic precipitation to generate zinc sulfide and cadmium sulfide precipitates, and then solid-liquid separation is performed. The produced sulfide slag is recycled to recover the zinc and cadmium valuable metals, and calcium carbide slag is added to the separated filtrate to adjust its pH value to 7 to 8 to produce gypsum, which is dehydrated using a solid-liquid separation device to obtain industrial by-product gypsum (mainly composed of calcium sulfate dihydrate). The resulting wastewater is deeply treated, and the produced recycled water meets the discharge standards or is reused at various production water points.

[0012] According to the above-mentioned resource recovery method for the post-leaching liquid of smelting ash, the post-leaching liquid of smelting ash in step 1) is a high-heavy metal and high-arsenic waste acid liquid produced after leaching of smelting ash; the main components and their contents in the waste acid liquid are: 150-250g / L of sulfuric acid, 25,000-35,000mg / L of arsenic, 20,000-30,000mg / L of cadmium, and 15,000-25,000mg / L of zinc.

[0013] According to the above-mentioned resource recovery method of the liquid after leaching of smelting ash, the specific process of multi-stage filtration and purification in step 1) is: the liquid after leaching of smelting ash is transported to the bag filter and the security filter in sequence by a pump for filtration and purification, the filtration accuracy of the bag filter is 5μm, and the filtration accuracy of the security filter is 1μm (through filtration and purification, suspended matter, fine particles and crystals therein are retained).

[0014] According to the above-mentioned resource recovery method of the liquid after leaching of smelting ash, the turbidity of the purified filtrate in step 1) is ≤0.5NTU.

[0015] According to the above-mentioned resource recovery treatment method for the liquid after leaching of smelting smoke ash, the diffusion dialyzers described in step 2) are composed of multiple units, each of which is composed of multiple homogeneous anion exchange membranes, screens and end plates; the filtrate and primary water are respectively on both sides of the homogeneous anion exchange membrane, and through the action of osmotic pressure, 25-30% of the arsenic, 65-70% of the sulfuric acid, 1-5% of the zinc and 1-5% of the cadmium in the filtrate migrate into the primary water to form recovered acid, and 70-75% of the arsenic and 30-35% of the sulfuric acid, 95-99% of the zinc and 95-99% of the cadmium are retained in the filtrate to form waste acid.

[0016] According to the above-mentioned resource recovery method of the liquid after leaching of smelting ash, the sulfiding agent in step 3) is sodium hydrosulfide liquid or sodium sulfide liquid; the mass ratio of the sulfiding agent to the recovered acid is 1 to 1.2:10.

[0017] According to the resource recovery method of the liquid after leaching of smelting ash, the gypsum obtained in step 3) has an As content of less than 0.05%, a Zn content of less than 0.05%, a Cd content of less than 0.05%, and a moisture content of less than 20%.

[0018] According to the above-mentioned resource recovery method for the liquid after leaching of smelting ash, the amount of nano-iron added in step 4) is 4.5-10g of nano-iron per L of waste acid, so that the iron / arsenic molar ratio is 4-6.5:1; the ozone introduction rate is 0.1-1L / min; the particle size of the nano-iron is 10nm; and the micro-positive pressure is P<0.05MPa.

[0019] According to the above-mentioned resource recovery method of the liquid after leaching of smelting ash, the sulfiding agent in step 4) is sodium hydrosulfide liquid or sodium sulfide liquid; the mass ratio of the sulfiding agent to the waste acid is 1:3-4.

[0020] According to the resource recovery method of the liquid after leaching of smelting ash, the gypsum obtained in step 4) has an As content of less than 0.1%, a Zn content of less than 0.1%, a Cd content of less than 0.1%, and a moisture content of less than 20%.

[0021] In the technical solution of the present invention, the principle of acid separation by the diffusion dialyzer is as follows: since the homogeneous anion exchange membrane has selective permeability to anions, the anions on the waste acid side migrate smoothly into the water side, and due to the requirement of electrical neutrality, the cations also migrate into the water side simultaneously; + The hydration radius of ions is relatively small and the charge number is small, while the hydration radius of cations in metal salts is large and the charge number is large, so H + It will preferentially migrate through the membrane, and the metal cations are blocked, thereby achieving the separation of the acid in the waste acid;

[0022] In the technical solution of the present invention, the micro-positive pressure nano-iron and ozone arsenic removal technology is adopted: nano-iron has high reactivity and high specific surface area (33.5m 2 / g), in a strong oxidizing environment, iron ions are oxidized to ferric hydroxide, arsenite is oxidized to arsenic acid, and ferric hydroxide and arsenic acid react to form a stable ferric arsenate precipitate. The reaction environment of slightly positive pressure and a certain temperature is conducive to the formation of precipitation, while reducing the amount of nano-iron used. The relevant reaction equation is as follows:

[0023] 2Fe+O3+3H2O=2Fe(OH)3;

[0024] H3AsO3+O3=H3AsO4;

[0025] Fe(OH)3+H3AsO4=FeAsO4·2H2O+H2O.

[0026] The positive beneficial effects of the present invention are:

[0027] 1. Compared with the current mainstream sulfidation process and neutralization process, the present invention provides a process route for the coordinated disposal of arsenic by combining technologies such as homogeneous anion exchange membrane, sulfidation reaction, and neutralization reaction.

[0028] 2. The key to the technical solution of the present invention lies in the use of "micro-positive pressure nano-iron and ozone arsenic removal technology", that is, under a micro-positive pressure environment, nano-iron + ozone is reacted with high-arsenic waste acid to produce scorodite. This process route and technical solution are mainly aimed at waste acid liquid containing high heavy metals and arsenic that is difficult to treat in the smelting system.

[0029] 3. The process route of the present invention can significantly remove arsenic from the waste acid solution, generating arsenic sulfide and ferric arsenate for outsourcing disposal, thereby reducing the circulation and enrichment of arsenic in the smelting system. The arsenic open circuit rate can reach more than 80%, reducing the arsenic circulation cost; at the same time, the removal rate of heavy metals such as zinc and cadmium in the waste acid solution can be increased to more than 95%, achieving 95% recovery and utilization of heavy metals such as zinc and cadmium, reflecting the environmental protection management concept of recycling non-ferrous metals and arsenic resources. 4. Description of the accompanying drawings:

[0030] Figure 1 A schematic flow chart of the method for resource recovery treatment of smelting ash leaching liquid according to the present invention. V. Specific implementation methods:

[0031] The present invention is further described below with reference to the following examples, but the scope of protection of the technical solution of the present invention is not limited thereto.

[0032] Example 1:

[0033] See attached Figure 1 The resource recovery treatment method of the smelting ash leaching liquid of the present invention has the following detailed steps (this embodiment uses the leaching liquid of the ash from a copper smelter as the treatment object, and the main components and their contents in the leaching liquid are: sulfuric acid 181g / L, arsenic 27710mg / L, cadmium 22727.2mg / L, zinc 19751.2mg / L):

[0034] 1) The ash leached liquid is pumped to a bag filter and a security filter for filtration and purification. The flow rate is 1.5m3 / h. The filtration accuracy of the bag filter is 5μm, and the filtration accuracy of the security filter is 1μm (through filtration and purification, suspended matter, fine particles and crystals are intercepted). The turbidity of the purified filtrate is ≤0.5NTU;

[0035] 2) The purified filtrate obtained in step 1) enters the acid inlet of the diffusion dialyzer via a magnetic pump, and primary water is introduced simultaneously, with the volume ratio of the primary water to the filtrate being 1:1.4; the filtrate and the primary water are separated by a homogeneous anion exchange membrane; after separation, waste acid is produced at the acid outlet, and recovered acid is produced at the primary water outlet; 29.26% of the arsenic, 68.2% of the sulfuric acid, 4.9% of the zinc, and 4.9% of the cadmium in the filtrate migrate into the primary water to form recovered acid; 70.7% of the arsenic, 31.8% of the sulfuric acid, 95.1% of the zinc, and 95.1% of the cadmium in the filtrate are retained in the filtrate to form waste acid;

[0036] After separation by the diffusion dialyzer, the test data of the main components in the recovered acid and waste acid are shown in Table 1.

[0037] Table 1 Detection data of the main components in the recovered acid and spent acid obtained in this embodiment

[0038] name As (mg / L) Cu (mg / L) Cd (mg / L) Zn (mg / L) <![CDATA[H2SO4(g / l)]]> Waste acid 14000 1068.36 15202.36 12338.31 51 Acid recovery 8325 72 1189 915.8 133

[0039] Retention rate = waste acid flow rate * heavy metal content / (waste acid flow rate * waste acid heavy metal content + recovered acid flow rate * recovered acid heavy metal content) * 100%;

[0040] 3) 8% sodium hydrogen sulfide liquid is added to the recovered acid produced in step 2) to carry out a sulfidation reaction. The pressure of the sulfidation reactor is controlled at 15 kPa, and the mass ratio of the sodium hydrogen sulfide liquid to the recovered acid is 1.1:10. The reaction generates metal sulfides and arsenic sulfide precipitates (heavy metals and arsenic in the recovered acid) (which can be subsequently outsourced for disposal or further processed to produce metallic arsenic). Calcium carbide slag is added to the acidic wastewater obtained after solid-liquid separation to adjust its pH to 7-8 to produce gypsum. The gypsum is then dehydrated using a solid-liquid separation device to produce industrial by-product gypsum (the main component is calcium sulfate dihydrate; the As, Zn, and Cd contents in the gypsum are 0.012%, 0.02%, and 0.029%, respectively, and the moisture content is 18%). The wastewater obtained after separation is subjected to advanced treatment, and the produced recycled water meets discharge standards or is reused at various production water points.

[0041] 4) adding 4.6 g / L of nano-iron to the waste acid produced in step 2) and introducing 0.5 L / min of ozone, heating to 85° C., maintaining the pressure in the reactor at 0.03 MPa, stirring and reacting for 75 minutes to generate iron arsenate (scorodite) precipitate; then adding 8% sodium hydrogen sulfide liquid to the arsenic precipitation solution to react, with the mass ratio of the sodium hydrogen sulfide liquid to the waste acid being 1:3.6, and undergoing a sulfidation reaction to sulfide the zinc and cadmium in the arsenic precipitation solution to generate zinc sulfide and cadmium sulfide precipitates, and then performing solid-liquid separation, and the generated sulfide slag ingredients are recycled to recover zinc. , cadmium and other valuable metals, carbide slag is added to the separated filtrate to adjust its pH value to 7-8 to make gypsum, which is dehydrated using solid-liquid separation equipment to make industrial by-product gypsum (the main component is calcium sulfate dihydrate; the As, Zn and Cd contents in the gypsum are 0.077%, 0.05% and 0.062% respectively, and the moisture content is 18.5%). The obtained wastewater is deeply treated, part of which meets the discharge standards, and part is transported to the slow cooling yard for slag bag cooling. After deep treatment, the As content is 0.04 mg / L, and the contents of other heavy metals are below the detection limit, which meets the workshop drainage standards.

[0042] Example 2:

[0043] The resource treatment method of the smelting ash leaching liquid of the present invention is basically the same as that of Example 1, except that:

[0044] In step 4), 1 L of the waste acid obtained in step 2) was poured into a reaction vessel with a sealed lid, ozone was introduced at 0.3 L / min, and the mixture was heated to 85°C. Then, 4.6 g of nano-iron was added and stirred at a pressure of 0.03 MPa for 80 minutes to generate ferric arsenate (scoralite) precipitate; after filtration, an arsenic precipitation solution and ferric arsenate precipitate were obtained; the components and their contents in the obtained arsenic precipitation solution were: As 5.3 mg / L, Zn 11980 mg / L, Cd 14859 mg / L, Cu 990 mg / L; convert the Zn, Cd, and Cu contents into As, and calculate the total arsenic content to be 16608 mg / L; take 500 ml of the filtered arsenic precipitation liquid, add 30 g of 32% sodium hydrosulfide, and stir to react for 15 minutes. After standing, a large amount of black precipitate will appear at the bottom of the cup; take the supernatant and filter it, and the Zn, Cu, and Cd contents will be 2.2 mg / L, 0.5 mg / L, and 1.6 mg / L, respectively.

[0045] Example 3:

[0046] The resource treatment method of the smelting ash leaching liquid of the present invention is basically the same as that of Example 1, except that:

[0047] In step 4), 1 L of the spent acid obtained in step 2) is poured into a reaction vessel with a sealed lid, ozone is introduced at 0.3 L / min, and the mixture is heated to 90° C., followed by addition of 4.6 g of nano-iron. The mixture is stirred and reacted at 0.03 MPa for 80 minutes to generate a ferric arsenate (scoralite) precipitate. After filtration, an arsenic precipitation solution and a ferric arsenate precipitate are obtained. The components and contents of the arsenic precipitation solution are as follows: As 3.8 mg / L, Zn 11363 mg / L, Cd 14159 mg / L, and Cu 956 mg / L. The contents of Zn, Cd, and Cu are converted to As, and the total arsenic content is calculated to be 15790 mg / L. After the temperature is increased, there is a slight loss of heavy metals (<5%).

[0048] Example 4:

[0049] The resource treatment method of the smelting ash leaching liquid of the present invention is basically the same as that of Example 1, except that:

[0050] Take 500ml of the filtrate after solid-liquid separation in step 3) of Example 1, add carbide slag slurry (Baume value 26), adjust the pH to 7, and stir the reaction for 15min; after standing, a large amount of off-white precipitate is formed at the bottom of the cup, and after drying, the CaSO4·2H2O content is 85.67%, and the Cu, As, Cd, and Zn contents are 0.0031%, 0.0039%, 0.002%, and 0.011%, respectively; the Cu, As, Cd, and Zn contents of the supernatant are 0.1, 0.3, 0.06, and 0.8mg / L, respectively.

[0051] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the present invention in any other form. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields with similar requirements for arsenic open circuit and heavy metal recovery control. However, any simple modification, equivalent change and modification of the above embodiments based on the technical essence of the present invention that does not deviate from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A method for recycling smelting ash leaching liquid, characterized in that: The processing method comprises the following steps: 1) subjecting the smelting ash leaching liquid to multi-stage filtration purification to obtain a purified filtrate; 2) The purified filtrate obtained in step 1) enters the acid inlet of the diffusion dialyzer, and primary water is introduced at the same time, with the volume ratio of the primary water to the filtrate being 1:1.3-1.6; the filtrate and the primary water are separated by a homogeneous anion exchange membrane; after separation, waste acid is produced at the acid outlet, and recovered acid is produced at the primary water outlet; 3) adding a sulfiding agent to the recovered acid produced in step 2) to carry out a sulfidation reaction, controlling the pressure of the sulfidation reactor to be less than 30 kPa, so that heavy metals and arsenic in the recovered acid are converted into metal sulfides and arsenic sulfide precipitation; adding carbide slag to the acidic wastewater obtained after the sulfidation reaction to adjust its pH value to 7-8 to produce gypsum, which is then dehydrated using a solid-liquid separation device to obtain industrial by-product gypsum. The wastewater obtained after separation is subjected to advanced treatment, and the produced recycled water meets the discharge standards or is reused at various production water points; 4) Nano-iron is added to the waste acid produced in step 2), ozone is introduced, and the reaction is carried out for 60 to 120 minutes under a slightly positive pressure environment to generate an iron arsenate precipitate; then, a sulfiding agent is added to the liquid after the arsenic precipitation to sulfide the zinc and cadmium in the liquid after the arsenic precipitation to generate zinc sulfide and cadmium sulfide precipitates, and then solid-liquid separation is performed. The produced sulfide slag is recycled to recover the zinc and cadmium valuable metals, and calcium carbide slag is added to the separated filtrate to adjust its pH value to 7 to 8 to produce gypsum, which is dehydrated using a solid-liquid separation device to obtain industrial by-product gypsum. The resulting wastewater is deeply treated, and the produced recycled water meets the discharge standards or is reused at various production water points.

2. The resource recovery treatment method of the smelting ash leaching liquid according to claim 1, characterized in that: The smelting ash leaching liquid in step 1) is a high-heavy metal and high-arsenic waste acid liquid generated after leaching of the smelting ash; the main components and their contents in the waste acid liquid are: 150-250g / L of sulfuric acid, 25,000-35,000mg / L of arsenic, 20,000-30,000mg / L of cadmium, and 15,000-25,000mg / L of zinc.

3. The resource recovery treatment method of the smelting ash leaching liquid according to claim 1, characterized in that: The specific process of multi-stage filtration and purification in step 1) is as follows: the liquid after leaching of smelting smoke ash is pumped to the bag filter and the security filter in sequence for filtration and purification. The filtration accuracy of the bag filter is 5μm, and the filtration accuracy of the security filter is 1μm.

4. The method for recycling the liquid after leaching of smelting ash according to claim 1, characterized in that: The turbidity of the purified filtrate in step 1) is ≤0.5NTU.

5. The method for recycling the liquid after leaching of smelting ash according to claim 1, characterized in that: The diffusion dialyzers in step 2) are composed of multiple units, each of which is composed of multiple homogeneous anion exchange membranes, spacers and end plates; the filtrate and primary water are respectively on both sides of the homogeneous anion exchange membrane, and through the action of osmotic pressure, 25-30% of arsenic, 65-70% of sulfuric acid, 1-5% of zinc and 1-5% of cadmium in the filtrate migrate into the primary water to form recovered acid, and 70-75% of arsenic, 30-35% of sulfuric acid, 95-99% of zinc and 95-99% of cadmium are retained in the filtrate to form waste acid.

6. The resource recovery treatment method of smelting ash leaching liquid according to claim 1, characterized in that: The sulfiding agent in step 3) is sodium hydrosulfide liquid or sodium sulfide liquid; the mass ratio of the sulfiding agent to the recovered acid is 1 to 1.2:

10.

7. The resource recovery treatment method of smelting ash leaching liquid according to claim 1, characterized in that: In step 3), the As content, Zn content, and Cd content of the gypsum obtained are less than 0.05%, less than 0.05%, and less than 20% of moisture.

8. The resource recovery treatment method of smelting ash leaching liquid according to claim 1, characterized in that: The amount of nano-iron added in step 4) is 4.5-10 g of nano-iron per L of waste acid, so that the iron / arsenic molar ratio is 4-6.5:1; the ozone introduction rate is 0.1-1 L / min; the particle size of the nano-iron is 10 nm; and the micro-positive pressure is P<0.05 MPa.

9. The resource recovery treatment method of smelting ash leaching liquid according to claim 1, characterized in that: The sulfiding agent in step 4) is sodium hydrosulfide liquid or sodium sulfide liquid; the mass ratio of the sulfiding agent to the waste acid is 1:3-4.

10. The resource recovery treatment method of smelting ash leaching liquid according to claim 1, characterized in that: In step 4), the As content, Zn content, Cd content, and moisture content of the gypsum obtained are less than 0.1%, less than 0.1%, and less than 20%.

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