A method and device for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid

Abstract

The present invention provides a method and device for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid, and belongs to the field of waste acid treatment and resource utilization. In order to realize the resource utilization of zinc-containing waste hydrochloric acid in the hot-dip galvanizing industry, the method of the present invention adopts a method for pretreating zinc-containing waste hydrochloric acid so that its heavy metals and organic matter reach the set standards, and then obtains high-value-added industrial zinc phosphate and iron phosphate for batteries through chemical oxidation, precipitation, evaporation, filtration and other methods on the basis of effectively treating zinc-containing waste hydrochloric acid, which has good environmental benefits, economic benefits and application prospects. The chemical reagents added by the method of the present invention are low in cost, the resin used for adsorption can be reused, the process operation is simple, the overall cost is low, and it is conducive to promotion and use.

Description

Technical field:

[0001] The invention belongs to the technical field of environmental protection and resource recycling, and specifically relates to a method and a device for preparing industrial zinc phosphate and iron phosphate by utilizing zinc-containing waste hydrochloric acid. Background technology:

[0002] Hot-dip galvanizing is one of the most effective means to delay environmental corrosion of steel materials. Compared with other metal protection methods, hot-dip galvanized products have the advantages of good corrosion resistance, high cost performance, and long service life. In the hot-dip galvanizing process, the process of using hydrochloric acid to clean the rust and oxide film on the surface of steel and backwash the galvanized layer on the surface of unqualified products is widely circulated, thereby generating a large amount of high-zinc and iron-containing waste hydrochloric acid, which mainly contains hydrochloric acid, zinc ions, divalent iron ions, trivalent iron ions, and trace amounts of copper, nickel, chromium and other metal ions. Waste hydrochloric acid is extremely corrosive. If it is discharged directly without treatment, it will not only seriously pollute the environment, but also cause a waste of zinc and iron resources.

[0003] Zinc phosphate can be used as a base material for various types of coatings such as alkyd, phenolic, and epoxy resins. It can also be used to produce non-toxic anti-rust pigments and water-soluble coatings. It can also be used in chlorinated rubber and flame retardants for synthetic polymer materials. It has a wide range of uses and is worth tens of thousands of yuan per ton. It is a high value-added raw material. Iron phosphate is mainly used to manufacture lithium iron phosphate battery materials. At present, lithium iron phosphate batteries are the best high-current output power batteries. They not only have the advantages of ultra-long life and safe use, but also can be quickly charged and discharged at a high current of 2C. In addition, lithium phosphate batteries are environmentally friendly and green, and do not pollute the environment. Among the various methods for preparing lithium iron phosphate, the method using iron orthophosphate (FePO4) as a precursor has the advantages of high specific capacity of the target product, high purity, and good rate low-temperature performance.

[0004] At present, the domestic utilization of waste hydrochloric acid generated by the hot-dip galvanizing industry is mainly focused on obtaining iron hydroxide, zinc chloride, iron chloride and hydrochloric acid. For example, Chinese patent application No. CN201510537807.3 publicly reported a method for recycling waste acid solution from galvanized parts. This method uses ammonia water to adjust the pH value of the solution to make Fe 3+ After being separated and precipitated in the form of Fe(OH)3, it is used for sintering and ironmaking. It contains NH4 + and Zn 2+ The filtrate is compounded to make a plating aid and returned to the hot-dip galvanizing process. The disadvantage of this method is that it does not take into account NH4 +The final recovery and investment cost of ammonia corrosion resistant equipment. Chinese patent application number CN201210043950.3 discloses a comprehensive utilization method of zinc-containing waste hydrochloric acid, which uses a strong alkaline anion exchange resin to recover ZnCl2, which is used as a flux byproduct after elution with a regeneration agent. The solution after resin adsorption treatment is compounded and concentrated with industrial hydrochloric acid and then returned to the hot-dip galvanizing process for use. However, ion exchange resins are expensive and have high production costs. In addition, the subsequent Zn 2+ High-zinc waste acid with a mass concentration of 3% to 20% is difficult to handle and is therefore not conducive to industrial application and promotion.

[0005] Compared with the above patents, the present invention can not only realize the resource utilization of zinc-containing waste hydrochloric acid to the maximum extent, but also produce high-value industrial zinc phosphate and iron phosphate, without generating difficult-to-treat solid waste or waste liquid, thus achieving both economic and environmental benefits. Summary of the invention:

[0006] The purpose of the present invention is to provide a method and device for preparing industrial zinc phosphate and iron phosphate by resource utilization of zinc-containing waste hydrochloric acid in view of the deficiencies in the prior art. By reasonably adding chemical agents, the zinc and iron elements in the zinc-containing waste hydrochloric acid are converted into zinc phosphate and iron phosphate, thereby realizing resource utilization of the zinc-containing waste hydrochloric acid and generating economic benefits.

[0007] The present invention adopts the following technical solutions:

[0008] A method for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid comprises the following steps:

[0009] Step 1: Pump the zinc-containing waste hydrochloric acid into a pretreatment impurity removal reaction device to remove organic matter and heavy metals, and filter until the heavy metal content and organic matter content in the filtrate reach the pretreatment standard;

[0010] Step 2: pump the zinc-containing waste hydrochloric acid pretreated in step 1 into a reactor, add hydrochloric acid to adjust the acidity, add sodium nitrite as a catalyst, and introduce oxygen to oxidize the divalent iron ions in the zinc-containing waste hydrochloric acid into trivalent iron ions;

[0011] Step 3, pumping the reaction solution obtained in step 2 into a aging kettle, adding a precipitant, filtering and collecting the filter residue, wherein the filter residue is a mixture of zinc phosphate and iron phosphate, and subjecting the filtrate to multiple-effect evaporation and then flash drying to obtain ammonium chloride;

[0012] Step 4: putting the mixture of zinc phosphate and iron phosphate obtained in step 3 into a pickling kettle, adding water and phosphoric acid, filtering and collecting the filter residue, and obtaining iron phosphate after flash drying of the filter residue, and the obtained filtrate is a zinc dihydrogen phosphate solution;

[0013] Step 5, pumping the filtrate obtained in step 4 into a reaction kettle, adding ammonia water to adjust the pH, filtering and collecting the filter residue, and flash-evaporating and drying the filter residue to obtain zinc phosphate;

[0014] Step 6: Pump the filtrate obtained in step 5 into the aging kettle in step 3 to precipitate the remaining iron ions and zinc ions again, and repeat steps 3 to 5.

[0015] Furthermore, in step 1, during pretreatment, the iron content is adjusted to 11%.

[0016] Furthermore, in step one, the pretreatment impurity removal reaction device includes an organic resin adsorption system, a BDD electrolysis system and a heavy metal resin adsorption system. Both the organic resin and the heavy metal resin can be regenerated. After being saturated with adsorption, the organic resin and the heavy metal resin can be regenerated using 5% alkali solution and 5% dilute hydrochloric acid, respectively.

[0017] Furthermore, in step 2, the acidity is adjusted to be less than 3.5%.

[0018] Furthermore, in step 2, the oxygen pumping pressure is no greater than 0.3 MPa, and the reaction is carried out until the content of divalent iron ions is less than 0.1 mol / L.

[0019] Furthermore, in step three, the precipitating agent is ammonium phosphate and ammonia water.

[0020] Furthermore, in step 4, water and excess phosphoric acid are added to separate zinc phosphate from iron phosphate.

[0021] Furthermore, in step 5, aqueous ammonia is added dropwise to adjust the pH value to 7.0.

[0022] The present invention also provides a device for preparing industrial zinc phosphate and iron phosphate by using zinc-containing waste hydrochloric acid, comprising a pretreatment impurity removal reaction device, a first reactor, a aging reactor, a pickling reactor and a second reactor; the pretreatment impurity removal reaction device, the first reactor and the aging reactor are connected in sequence, and the aging reactor, the pickling reactor and the second reactor are all connected to a filtering device and a flash drying device; the zinc-containing waste hydrochloric acid enters the pretreatment impurity removal reaction device for impurity removal and filtration, the filtrate enters the first reactor for reaction, then the reaction liquid enters the aging reactor for reaction and filtration, the filter residue enters the pickling reactor for reaction, then the reaction liquid enters the filtering device for filtration, the filter residue enters the flash drying device for treatment to obtain iron phosphate, the filtrate enters the second reactor for reaction, and after the reaction is completed, it enters the filtering device for filtration, and the filter residue is treated by the flash drying device to obtain zinc phosphate.

[0023] Furthermore, the pretreatment and impurity removal reaction device includes a filtering device, an organic resin adsorption system, a BDD electrolysis system and a heavy metal resin adsorption system; the first reactor, the aging reactor, the pickling reactor and the second reactor are all provided with a stirring device.

[0024] Furthermore, the aging kettle is connected to the second reactor, and the filtrate obtained in the second reactor can be pumped into the aging kettle to precipitate the remaining iron ions and zinc ions again, and the above steps three to five are repeated.

[0025] Furthermore, the filtering device is a suction filtration cylinder.

[0026] Beneficial effects of the present invention:

[0027] (1) The present invention not only utilizes the zinc-containing waste hydrochloric acid as a resource, but also produces high-value-added zinc phosphate and iron phosphate, thereby achieving resource utilization and disposal of the waste hydrochloric acid and obtaining economic benefits;

[0028] (2) The present invention utilizes zinc-containing waste hydrochloric acid as a resource without generating other residues or residual liquids that require additional treatment, thereby reducing the processing costs of enterprises and achieving reduction from the source;

[0029] (3) The present invention has a simple structure and is easy to operate. In the process of resource utilization, the resins used can be reused, the added agents are relatively cheap, and there is no complicated and difficult technical operation. Therefore, the overall process is relatively simple and the cost is low, which is suitable for popularization and use. Description of the drawings:

[0030] Figure 1 is a schematic diagram of an apparatus according to an embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the pretreatment process of the present invention;

[0032] Figure 3 It is a schematic diagram of the process flow of preparing iron phosphate and zinc phosphate according to the present invention;

[0033] The markings in the attached drawings are: 1. organic matter adsorption resin system; 2. BDD electrolysis system; 3. heavy metal resin adsorption system; 4. suction filtration cylinder; 5. stirring device; 6. flash drying device; 7. first reactor; 8. aging reactor; 9. pickling reactor; 10. second reactor. Specific implementation method:

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present invention provides a method for preparing industrial zinc phosphate and iron phosphate by using zinc-containing waste hydrochloric acid, comprising the following steps:

[0036] Step 1: Pump the zinc-containing waste hydrochloric acid into a pretreatment impurity removal reaction device to remove organic matter and heavy metals, and filter until the heavy metal content and organic content in the filtrate reach the pretreatment standard; during the pretreatment, adjust the iron content to 11%; the pretreatment impurity removal reaction device includes an organic resin adsorption system, a BDD electrolysis system and a heavy metal resin adsorption system, and both the organic resin and the heavy metal resin can be regenerated. After the organic resin and the heavy metal resin are saturated with adsorption, they can be regenerated using 5% alkali solution and 5% dilute hydrochloric acid respectively;

[0037] Step 2, pumping the zinc-containing waste hydrochloric acid pretreated in step 1 into a reactor, adding hydrochloric acid to adjust the acidity to less than 3.5%, adding sodium nitrite as a catalyst, and passing oxygen, the oxygen pumping pressure is not greater than 0.3MPa, so that the divalent iron ions in the zinc-containing waste hydrochloric acid are oxidized into trivalent iron ions, until the content of the divalent iron ions is less than 0.1mol / L;

[0038] Step 3, pumping the reaction solution obtained in step 2 into a aging kettle, adding ammonium phosphate and ammonia water, filtering and collecting the filter residue, wherein the filter residue is a mixture of zinc phosphate and iron phosphate, and subjecting the filtrate to multi-effect evaporation and then flash drying to obtain ammonium chloride;

[0039] Step 4: putting the mixture of zinc phosphate and iron phosphate obtained in step 3 into a pickling kettle, adding excess water and phosphoric acid to separate the zinc phosphate from the iron phosphate, filtering and collecting the filter residue, and flash-drying the filter residue to obtain iron phosphate, and the obtained filtrate is a zinc dihydrogen phosphate solution;

[0040] Step 5, pumping the filtrate obtained in step 4 into a reaction kettle, adding ammonia water to adjust the pH to 7.0, filtering and collecting the filter residue, and flash-evaporating and drying the filter residue to obtain zinc phosphate;

[0041] Step 6: Pump the filtrate obtained in step 5 into the aging kettle in step 3 to precipitate the remaining iron ions and zinc ions again, and repeat steps 3 to 5.

[0042] The present invention also provides a device for preparing industrial zinc phosphate and iron phosphate by using zinc-containing waste hydrochloric acid, comprising a pretreatment impurity removal reaction device, a first reactor, a aging reactor, a pickling reactor and a second reactor; the pretreatment impurity removal reaction device, the first reactor and the aging reactor are connected in sequence, and the aging reactor, the pickling reactor and the second reactor are all connected to a filtering device and a flash drying device; the pretreatment impurity removal reaction device comprises a filtering device, an organic resin adsorption system, a BDD electrolysis system and a heavy metal resin adsorption system; the first reactor, the aging reactor, the pickling reactor and the second reactor are all provided with a stirring device; the aging reactor and the second reactor are connected, and the filtrate obtained in the second reactor can be pumped into the aging reactor to precipitate the remaining iron ions and zinc ions again, and the above steps three to five are repeated.

[0043] Example 1

[0044] Combination Figure 2 and Figure 3 , this embodiment is described in detail.

[0045] The present embodiment involves a method for resource-based utilization of zinc-containing waste hydrochloric acid to prepare industrial zinc phosphate and iron phosphate, comprising the following steps:

[0046] Step 1: Pump the zinc-containing waste hydrochloric acid that meets the factory entry standards into the reactor, and add iron powder and zinc powder at the same time. This step can replace the impurity heavy metals in the zinc-containing waste hydrochloric acid and adjust the iron content and acidity. After filtering through the plate and frame filter press, the heavy metal content and organic matter content in the filtrate are tested. In the pretreatment, the iron content is adjusted to 11% and the acidity is less than 3.5%.

[0047] After testing, if the heavy metal and organic matter content in the filtrate reaches the pretreatment standard, it will be directly pumped into the waste acid storage tank for the preparation of iron phosphate and zinc phosphate.

[0048] If the heavy metal content in the filtrate reaches the pretreatment standard, but the organic content exceeds the pretreatment standard, it will enter the organic resin adsorption system, and then be treated by the BDD electrolysis system until the organic content reaches the pretreatment standard, and then pumped into the waste acid storage tank. The organic resin adsorption system is an adsorption tank (2.2 meters in diameter and 2 meters in height), which contains resin, and the waste acid stays for about 20 minutes. After the resin is saturated with adsorption, it is regenerated with a 5% dilute alkaline solution, which is performed once every 10 days. The positive electrode of the BDD electrolysis system is made of diamond material, and the negative electrode is made of titanium metal material. The waste liquid to be treated is pumped into the electrolysis system, and the organic matter therein is decomposed into carbon dioxide and water through the principle of electrochemistry. The waste acid stays in the electrolysis system for about 3 minutes.

[0049] If the heavy metal content in the filtrate exceeds the pretreatment standard and the organic matter content reaches the pretreatment standard, it will enter the heavy metal resin adsorption system to remove the heavy metals until the heavy metal content reaches the pretreatment standard and then pumped into the waste acid storage tank. The heavy metal adsorption tank is filled with resin, and the adsorption system consists of three adsorption tanks with a diameter of 2.2 meters and a height of 2 meters. The residence time of the waste acid in the resin is about 1 hour. After the resin is saturated with adsorption, it is regenerated with 5% dilute hydrochloric acid solution, which is performed once every 20 days.

[0050] If the heavy metal content and organic matter content in the filtrate are detected to exceed the pretreatment standard, it will first enter the organic resin adsorption system and BDD electrolysis system to be treated until the organic matter content reaches the pretreatment standard, and then enter the heavy metal resin adsorption system to remove heavy metals until the heavy metal content reaches the pretreatment standard, and then be pumped into the waste acid storage tank for the next step of preparing iron phosphate and zinc phosphate.

[0051] Several batches of zinc-containing waste hydrochloric acid entering the factory and the zinc-containing waste hydrochloric acid after pretreatment were tested and the average values ​​were calculated. The results all met the post-pretreatment standards. The specific test data and factory entry and pretreatment standards are shown in Table 1.

[0052] Table 1 Sample test results and standard limits

[0053]

[0054] Step 2: Pump the qualified pretreated zinc-containing waste hydrochloric acid into the reactor, add hydrochloric acid and sodium nitrite, start the circulation pump, and introduce oxygen. The oxygen pumping pressure is not more than 0.3MPa, and the divalent iron ions in the zinc-containing waste hydrochloric acid are oxidized into trivalent iron ions until the content of divalent iron ions is less than 0.1mol / L.

[0055] Step 3: pump the reaction liquid obtained in step 2 into a aging kettle, add ammonium phosphate and ammonia water, and after reaction precipitation, filter the reaction liquid through a suction filtration cylinder, and evaporate the filtrate through multiple effects and then flash dry to obtain ammonium chloride; the filter residue is a mixture of zinc phosphate and iron phosphate.

[0056] In this step, the chemical reactions that occur are as follows:

[0057] FeCl3+(NH4)3PO4→FePO 4↓ +3NH4Cl

[0058] 3ZnCl2+2(NH4)3PO4→Zn3(PO4) 2↓ +6NH4Cl

[0059] Step 4: Put the mixture of zinc phosphate and iron phosphate obtained in step 3 into the pickling kettle, add water and excess phosphoric acid, then zinc phosphate and phosphoric acid react to form zinc hydrogen phosphate, which dissolves in water. After filtering through a plate filter cylinder, the solid is flash-dried to obtain iron phosphate, and the filtrate is a zinc dihydrogen phosphate solution.

[0060] In this step, the chemical reactions that occur are as follows:

[0061] Zn3(PO4)2+4H3PO4→3Zn(H2PO4)2

[0062] Step 5: pump the zinc dihydrogen phosphate solution obtained in step 4 into a reaction kettle, add ammonia water to adjust the pH value to 7.0, filter through a plate filter cylinder, flash dry the solid to obtain zinc phosphate, and the filtrate is ammonium phosphate and diammonium hydrogen phosphate.

[0063] The reactions that occur in this step are as follows:

[0064] 3Zn(H2PO4)2+9NH4OH→Zn3(PO4)2+(NH4)3PO4+3(NH4)2HPO4+9H2O

[0065] Step 6: Pump the filtrate obtained in step 5 into the aging kettle in step 3 to precipitate the remaining iron ions and zinc ions again, and repeat steps 3 to 5.

[0066] The zinc phosphate and iron phosphate prepared by the process are tested. After flash drying, the product purity of zinc phosphate is about 99.0%, which meets the relevant index requirements in "Industrial Zinc Phosphate" (HG / T 4824-2015); the product purity of iron phosphate can reach 99.5%, which meets the quality requirements of HG / T 4701-2014 for iron phosphate for batteries. Therefore, the present invention has application value.

[0067] Example 2

[0068] Combination Figure 1 The present embodiment involves a device for resource utilization of zinc-containing waste hydrochloric acid to prepare industrial zinc phosphate and iron phosphate, comprising a pretreatment impurity removal reaction device, a first reactor 7, an aging reactor 8, a pickling reactor 9 and a second reactor 10; the pretreatment impurity removal reaction device, the first reactor 7, and the aging reactor 8 are connected in sequence, and the aging reactor 8, the pickling reactor 9 and the second reactor 10 are all connected to a suction cylinder 4 and a flash drying device 6; the pretreatment impurity removal reaction device comprises a suction cylinder, an organic resin adsorption system 1, a BDD electrolysis system 2 and a heavy metal resin adsorption system 3.

[0069] In this embodiment, a stirring device 5 is provided inside the first reaction kettle 7, the aging kettle 8, the pickling kettle 9 and the second reaction kettle 10 to stir the reaction liquid in the device to complete the reaction.

[0070] In this embodiment, the aging kettle 8 is connected to the second reactor 10, and a liquid pump and a valve are provided between the aging kettle 8 and the second reactor 10. The filtrate obtained in the second reactor 10 can be pumped into the aging kettle 8 to precipitate the remaining iron ions and zinc ions again, and steps 3 to 5 of the above embodiment 1 are repeated. In this embodiment, a valve and a liquid pump are provided between the pretreatment impurity removal reaction device, the first reactor 7, and the aging kettle 8.

[0071] In this embodiment, the aging kettle 8, the pickling kettle 9 and the second reaction kettle 10 are connected to the same set of suction cylinders 4 and flash drying devices 6 (refer to Figure 1 ); In other embodiments of the present invention, the aging kettle 8, the pickling kettle 9 and the second reaction kettle 10 can also be connected to different suction cylinders and flash drying devices for separate treatment.

[0072] The zinc-containing waste hydrochloric acid enters the pretreatment impurity removal reaction device for impurity removal and filtration, the filtrate enters the first reactor 7 for reaction, then the reaction liquid enters the aging reactor 8 for reaction and filtration, the filter residue enters the pickling reactor 9 for reaction, then the reaction liquid enters the suction cylinder 4 for filtration, the filter residue enters the flash drying device 6 for treatment to obtain iron phosphate, the filtrate enters the second reactor 10 for reaction, after the reaction is completed, it enters the suction cylinder 4 for filtration, and the filter residue is treated by the flash drying device 6 to obtain zinc phosphate.

[0073] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A method for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid, characterized in that: The following steps are involved: Step 1: Pump the zinc-containing waste hydrochloric acid into a pretreatment impurity removal reaction device to remove organic matter and heavy metals, and filter until the heavy metal content and organic matter content in the filtrate reach the pretreatment standard; Step 2: pump the zinc-containing waste hydrochloric acid pretreated in step 1 into a reactor, add hydrochloric acid and sodium nitrite, and introduce oxygen to oxidize the divalent iron ions in the zinc-containing waste hydrochloric acid into trivalent iron ions; Step 3: pumping the reaction solution obtained in step 2 into a aging kettle, adding a precipitant, filtering and collecting the filter residue, wherein the filter residue is a mixture of zinc phosphate and iron phosphate; Step 4: putting the mixture of zinc phosphate and iron phosphate obtained in step 3 into a pickling kettle, adding water and phosphoric acid, filtering and collecting the filter residue, and obtaining iron phosphate after flash drying of the filter residue, and the obtained filtrate is a zinc dihydrogen phosphate solution; Step 5, pumping the filtrate obtained in step 4 into a reaction kettle, adding ammonia water to adjust the pH, filtering and collecting the filter residue, and flash-evaporating and drying the filter residue to obtain zinc phosphate; Step 6: Pump the filtrate obtained in step 5 into the aging kettle in step 3 to precipitate the remaining iron ions and zinc ions again, and repeat steps 3 to 5.

2. The method for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid according to claim 1, characterized in that: Step 1: During pretreatment, the iron content is adjusted to 11%.

3. The method for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid according to claim 1, characterized in that: In step 2, the acidity is adjusted to less than 3.5%; the oxygen pump pressure is not greater than 0.3 MPa, and the reaction is carried out until the content of divalent iron ions is less than 0.1 mol / L.

4. The method for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid according to claim 1, characterized in that: In step three, the precipitating agents are ammonium phosphate and ammonia water.

5. The method for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid according to claim 1, characterized in that: In step 4, water and excess phosphoric acid are added to separate the zinc phosphate from the iron phosphate.

6. The method for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid according to claim 1, characterized in that: In step 5, aqueous ammonia is added dropwise to adjust the pH value to 7.

0.

7. A device for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid, characterized in that: The invention comprises a pretreatment impurity removal reaction device, a first reaction kettle (7), a maturation kettle (8), a pickling kettle (9) and a second reaction kettle (10); the pretreatment impurity removal reaction device, the first reaction kettle (7) and the maturation kettle (8) are connected in sequence, and the maturation kettle (8), the pickling kettle (9) and the second reaction kettle (10) are all connected to a filtering device and a flash drying device; the zinc-containing waste hydrochloric acid enters the pretreatment impurity removal reaction device for impurity removal and filtration, the filtrate enters the first reaction kettle (7) for reaction, and then the reaction liquid enters the maturation kettle (8) for reaction and filtration, and the filter residue enters the pickling kettle (9) for drying. ), the reaction liquid then enters a filtering device for filtration, the filter residue enters a flash drying device for treatment to obtain iron phosphate, the filtrate enters a second reactor (10) for reaction, and after the reaction is completed, enters a filtering device for filtration, the filter residue is treated by a flash drying device to obtain zinc phosphate; the pretreatment and impurity removal reaction device comprises a filtering device, an organic resin adsorption system (1), a BDD electrolysis system (2) and a heavy metal resin adsorption system (3); the first reactor (7), the aging reactor (8), the pickling reactor (9) and the second reactor (10) are all provided with a stirring device (5).

8. The device for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid according to claim 7, characterized in that: The aging kettle (8) is connected to the second reaction kettle (10), and the filtrate obtained in the second reaction kettle (10) can be pumped into the aging kettle (8) to precipitate the remaining iron ions and zinc ions again.

9. The device for preparing industrial zinc phosphate and iron phosphate using zinc-containing waste hydrochloric acid according to claim 7 or 8, characterized in that: The filtering device is a suction filter cylinder.

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