Treatment method and treatment device for chemical nickel waste liquid containing high-concentration nickel

Abstract

The invention relates to a treatment method and a treatment device for nickel melting waste liquid containing high-concentration nickel, and the treatment method comprises the following steps: adjusting the pH value of the nickel melting waste liquid to 9-10, introducing ozone to form free nickel, and converting hypophosphite and phosphite into phosphate to obtain a solution A; forming a nickel hydroxide precipitate from free nickel in the solution A, recovering the nickel hydroxide precipitate, and forming a solution B from a supernatant; adding calcium ions into the solution B to form a precipitate, recovering the precipitate, and forming a solution C from supernate; adding magnesium ions into the solution C to form magnesium ammonium phosphate and recovering the magnesium ammonium phosphate, and forming supernate into a solution D; and adding calcium chloride into the solution D to form calcium phosphate and recovering. The treatment method of the chemical nickel waste liquid provided by the invention is particularly suitable for recovery treatment of the chemical nickel waste liquid with high nickel content, is simple, does not need unavailable treatment equipment, has a good pollutant removal effect, high treatment efficiency and low cost, is suitable for self-treatment of the chemical nickel waste liquid in a circuit board manufacturer, and has good economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of printed circuit board manufacturing, and in particular to a method and a device for treating nickel-containing waste liquid with high nickel concentration. Background Art

[0002] The printed circuit board manufacturing industry requires the use of chemical nickel plating technology. The nickel waste liquid generated by the chemical nickel plating process usually contains high concentrations of chemical nickel (usually above 10,370±6,600 mg / L), high concentrations of chelating agents / high concentrations of organic matter (usually above 14,380 mg C / L), high concentrations of phosphorus and high concentrations of ammonia nitrogen (NH 4 + -N concentration is usually above 4,500±460mg N / L). Therefore, nickel waste liquid needs to be recycled.

[0003] However, at present, the recycling and treatment effect of nickel-ion waste liquid is not ideal. It is difficult to achieve the recycling and removal of various substances in the waste liquid, especially for waste liquid containing high concentration of nickel, which is difficult to treat. Moreover, circuit board manufacturers usually need to outsource the treatment of nickel-ion waste liquid, which is costly. Summary of the invention

[0004] In view of this, in order to overcome at least one of the above-mentioned defects, it is necessary to propose a method and a treatment device for nickel-containing waste liquid with high nickel concentration.

[0005] The present application provides a method for treating nickel-containing waste liquid with high nickel concentration, comprising:

[0006] Step 1, at a pH of 9 to 10, ozone is introduced into the nickel waste liquid to oxidize and destroy the chelated nickel to form free nickel ions, and at the same time, all hypophosphites and phosphites are converted into phosphates to obtain solution A;

[0007] Step 2, the free nickel ions in the solution A form a nickel hydroxide precipitate, and the nickel hydroxide precipitate is recovered, and the supernatant forms a solution B;

[0008] Step 3, adding calcium ions to the solution B to form a calcium phosphate precipitate, wherein the calcium phosphate precipitate is used to adsorb the free nickel ions that are not removed from the solution B, and the supernatant forms a solution C;

[0009] Step 4, adding magnesium ions to the solution C to generate and recover magnesium ammonium phosphate precipitate, and the supernatant forms solution D; and

[0010] Step 5, adding calcium chloride to the solution D to form calcium phosphate and recovering the calcium phosphate.

[0011] In some possible embodiments, in step 1, the concentration of ozone added is 30-50 g / min. 3 / L.

[0012] In some possible embodiments, in step 1, ozone is introduced into the nickel-containing waste liquid for mixed aeration, and the mixed aeration is injected into the ozone oxidation tower through a water injector.

[0013] In some possible embodiments, in step 3, the molar concentration ratio of the calcium ions to the phosphate in solution B is 0.1 to 0.5.

[0014] In some possible embodiments, the calcium ions are derived from calcium chloride or calcium hydroxide.

[0015] In some possible embodiments, in step 4, after adding magnesium ions to the solution C, the molar ratio of orthophosphate:ammonia nitrogen:magnesium ions in the resulting solution is 1:1:(1-3).

[0016] In some possible embodiments, in step 5, the molar ratio of calcium chloride to phosphate is (1-3):1.

[0017] An embodiment of the present application also provides a treatment device adopted in the treatment method of nickel-containing waste liquid with high nickel concentration as described above, wherein the treatment device includes a pH adjustment tank, a water ejector, an ozone oxidation tower, a first sedimentation tank, a second sedimentation tank and a third sedimentation tank connected in sequence, wherein the water ejector is connected to the bottom of the ozone oxidation tower, and ozone enters from the bottom of the ozone oxidation tower, and the top of the ozone oxidation tower is connected to the first sedimentation tank, the second sedimentation tank and the third sedimentation tank in sequence, the ozone oxidation tower is used to complete the steps 1 and 2, the first sedimentation tank is used to complete the step 3, the second sedimentation tank is used to complete the step 4, and the third sedimentation tank is used to complete the step 5.

[0018] In some possible embodiments, the treatment device further includes a nickel recovery device connected to the bottom of the ozone oxidation tower, and the nickel recovery device is used to recover the nickel hydroxide precipitate.

[0019] In some possible embodiments, the processing device further includes an ozone recovery processing device connected to the top of the ozone oxidation tower, and the ozone recovery processing device is used to recover and process residual ozone.

[0020] Compared with the prior art, the embodiment of the present application uses ozone to destroy the chelating agent that chelates nickel in the nickel waste liquid, and oxidizes hypophosphite and phosphite, then firstly recovers the nickel hydroxide by precipitation, and then adds magnesium salt and ammonia nitrogen / phosphorus to generate struvite precipitate (Mg(NH 3 )PO4 ), to achieve resource recycling and cyclic utilization; the method for treating the waste liquid is particularly suitable for the recycling of nickel-containing waste liquid with high nickel content. The method is simple, does not require special treatment equipment, has good pollutant removal effect, high treatment efficiency, and low cost. It is suitable for circuit board manufacturers to treat nickel-containing waste liquid by themselves, and has good economic benefits. The method for treating nickel-containing waste liquid according to the embodiment of the present application can fully remove high-content nickel, and the nickel removal rate reaches more than about 97.4%. The purity of the obtained nickel hydroxide reaches more than about 95%, the total phosphorus removal rate is more than about 97%, and the ammonia nitrogen removal rate is more than about 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flow chart of a method for treating nickel-ion waste liquid provided in one embodiment of the present application.

[0022] Figure 2 A schematic diagram of the structure of a nickel-ion waste liquid treatment device provided in one embodiment of the present application.

[0023] Figure 3 This application is a curve diagram showing the effect of the amount of ozone added on the removal rate of nickel in the nickel-containing waste liquid with the same nickel content under different pH conditions.

[0024] Figure 4 This application is a curve chart showing the effect of different ozone addition amounts on nickel removal rate for nickel-containing waste liquid with different nickel contents.

[0025] Figure 5 This is a curve chart showing the effect of different treatment times on nickel removal rate in this application.

[0026] Figure 6 In this application, after further removing residual nickel by using calcium phosphate precipitate, a curve diagram of the change of nickel content in the precipitate and reaction time was obtained through experimental measurement.

[0027] Figure 7 This is a graph showing the change in total phosphorus concentration with reaction time when magnesium ions and phosphate react at different molar ratios in step 4 of the present application.

[0028] Figure 8 This is a graph showing the change in ammonia nitrogen concentration with reaction time when magnesium ions and phosphate react at different molar ratios in step 4 of the present application.

[0029] Fig. 9 In step 5 of the present application, calcium chloride and calcium hydroxide are added respectively to further remove residual phosphorus, and a curve showing the change of total phosphorus removal rate with increasing Ca / P ratio is shown.

[0030] Main component symbols

[0031] Processing device 100

[0032] pH adjustment tank 1

[0033] Water ejector 2

[0034] Ozone oxidation tower 3

[0035] Nickel recovery unit 4

[0036] First sedimentation tank 5

[0037] Second sedimentation tank 6

[0038] The third sedimentation tank 7

[0039] Ozone recovery treatment device 8

[0040] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0043] It should be noted that, in the present application, if used, the terms "first", "second", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more. Positional terms such as "upper", "lower", "left", and "right" are defined relative to the orientation of the components schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts. They are used for description and clarification relative to, and they may change accordingly according to changes in the orientation of the components placed in the accompanying drawings. The term "direction" includes unidirectional or bidirectional along the straight line where the direction is located, and cannot be simply understood as unidirectional along the straight line where the direction is located.

[0044] In this application, if used, unless otherwise expressly specified and limited, the term "connection" should be understood in a broad sense, for example, "connection" can be fixed connection, detachable connection, or integrated; can be directly connected or indirectly connected through an intermediate medium. The term "and / or" used herein includes any and all combinations of one or more of the relevant listed items.

[0045] It will be understood that when a layer, region or component is referred to as being “on” another layer, region or component, it can be directly or indirectly on the other layer, region or component. That is, for example, intervening layers, regions or components may be present.

[0046] At present, during the production process of circuit boards, such as printed circuit boards (PCB) or flexible printed circuits (FPC), chemical nickel plating is required. Chemical nickel plating waste liquid (also called nickel plating waste liquid) contains high concentration of chemical nickel, usually the concentration of chemical nickel exceeds 10,370±6,600mg / L. It is difficult to treat nickel plating waste liquid with high nickel concentration, and it is difficult to completely recover nickel. At the same time, because the nickel plating solution is thermally unstable and easy to precipitate, in order to reduce the impact on product effects and improve the yield during the chemical nickel plating process, a chelating agent needs to be added to the plating solution to increase the solubility of nickel. Such chelating agents include ethylene diamine tetracetic acid (EDTA), nitrilotriacetic acid (NTA), citrate and tartrate (the weight composition ratio is approximately EDTA: NTA: citrate: tartrate = 1: 50: 50: 50), etc. The nickel ions and the chelating agent form a chelated state, which greatly increases the difficulty of waste liquid treatment. In addition, the concentration of chelating agents or organic matter in the waste liquid is relatively high, usually exceeding 14,380 mg C / L, which further increases the difficulty of treatment. In addition, chemical nickel plating is a natural oxidation-reduction process of the solution to achieve the deposition of metal on the surface of the coating. Hypophosphite and phosphite are usually used as reducing agents. Therefore, high concentrations and high solubility of hypophosphite and phosphite exist in the waste liquid, resulting in a high total phosphorus concentration in the waste liquid, which is difficult to treat. In addition, the high ammonia nitrogen content (NH 4 + -N=4,500±460mg N / L): In order to stabilize the pH during the chemical nickel plating operation, ammonia nitrogen is added as a pH buffer.

[0047] To solve the above problems, please refer to Figure 1 The present invention provides a method for treating nickel-containing waste liquid with high nickel concentration, which specifically comprises the following steps:

[0048] Step 1, under the condition of pH 9-10, ozone is introduced into the nickel waste liquid to oxidize and destroy the chelated nickel to form free nickel ions, and at the same time, all hypophosphites and phosphites are converted into phosphates to obtain solution A.

[0049] In step 1, the pH value is adjusted to between 9 and 10 using an alkaline agent, which can increase the production of hydroxyl radicals (OH.). The hydroxyl radicals will oxidize the chelating agent to destroy the chelating structure between the chelating agent and nickel, thereby releasing free nickel ions. The free nickel ions will further produce nickel hydroxide precipitation under alkaline conditions to facilitate discharge.

[0050] In step 1, the concentration of ozone added is 30-50 g O 3 / L. After studying the effect of different ozone doses on nickel removal rate, it is known that the nickel removal rate will first increase and then decrease with the increase of ozone dose. When the amount of ozone added is 30-50g O 3 / L range, the best nickel removal rate can be maintained.

[0051] In step 1, ozone is introduced into the nickel waste liquid for mixed aeration, and mixed aeration is injected into the ozone oxidation tower through a water injector, which can improve the effect of destroying chelation.

[0052] Step 2: The free nickel ions in the solution A form a nickel hydroxide precipitate, and the nickel hydroxide precipitate is recovered, and the supernatant forms a solution B.

[0053] Under the condition of high pH and chelate breaking, large particles of nickel hydroxide are formed in the reaction tank and precipitated and collected, and the purity of nickel hydroxide is above 95%.

[0054] Step 3, adding calcium ions to the solution B to form a calcium phosphate precipitate, wherein the calcium phosphate precipitate is used to adsorb the free nickel ions that are not removed from the solution B, and the supernatant forms solution C.

[0055] After step 2, there is still a small amount of nickel in the supernatant that has not been removed, and calcium phosphate has the effect of adsorbing nickel. Therefore, calcium ions such as CaCl are added to solution B. 2 , Ca(OH) 2 etc., to remove the remaining nickel precipitate.

[0056] Wherein, the molar concentration ratio of the calcium ions to the phosphate in the solution B is 0.1 to 0.5.

[0057] Step 4, adding magnesium ions to the solution C to generate and recover magnesium ammonium phosphate precipitate, and the supernatant forms solution D.

[0058] In step 4, after adding magnesium ions to the solution C, the molar ratio of orthophosphate:ammonia nitrogen:Mg ions in the resulting solution is 1:1:(1-3).

[0059] Step 5, adding calcium chloride to the solution D to form calcium phosphate and recovering the calcium phosphate.

[0060] In step 5, the molar ratio of calcium chloride to phosphate is (1-3):1, further can be (1-2):1, specifically can be 1.2:1.

[0061] like Figure 2 As shown, the treatment device 100 adopted by the aforementioned treatment method provided in the embodiment of the present application includes a pH adjustment tank 1, a water ejector 2, an ozone oxidation tower 3, a first sedimentation tank 5, a second sedimentation tank 6 and a third sedimentation tank 7 which are connected in sequence, wherein the bottom of the ozone oxidation tower 3 is connected to a nickel recovery device 4, and the top of the ozone oxidation tower 3 is connected to the first sedimentation tank 5, the second sedimentation tank 6 and the third sedimentation tank 7 in sequence, and in addition, the top of the ozone oxidation tower 3 is also connected to an ozone recovery treatment device 8.

[0062] In step 1, the nickel-oxide waste liquid is first discharged into the pH adjusting tank 1, and the pH of the nickel-oxide waste liquid is adjusted to 9-10 in the pH adjusting tank 1, and then the nickel-oxide waste liquid with adjusted pH is injected into the ozone oxidation tower 3 from the bottom of the ozone oxidation tower 3 through the water injector 2, and ozone is introduced into the bottom of the ozone oxidation tower 3 to fully mix and react with the ozone waste liquid.

[0063] The bottom of the ozone oxidation tower 3 is connected to a nickel recovery device 4. In step 2, under high pH and chelate breaking conditions, free nickel will be converted into nickel hydroxide precipitate, and the nickel recovery device 4 can be used to recover nickel hydroxide. Solution B formed by the supernatant is located in the ozone oxidation tower 3, and sequentially enters the first precipitation tank 5, the second precipitation tank 6 and the third precipitation tank 7 connected to the top. Among them, the solution B enters the first precipitation tank 5 from the top of the ozone oxidation tower 3 to perform the step 3 to add calcium ions to remove the unreacted free nickel impurities in the front section, and the obtained solution C enters the second precipitation tank 6 from the first precipitation tank 5 to perform the step 4 to synthesize magnesium ammonium phosphate for recovery, and the obtained solution D enters the third precipitation tank 7 from the second precipitation tank 6 to perform the step 5 to add calcium ions to form calcium phosphate for recovery.

[0064] In addition, an ozone recovery treatment device 8 is provided on the top of the ozone oxidation tower 3 for treating the ozone discharged from the ozone oxidation tower 3 .

[0065] The present application is further described below through specific embodiments.

[0066] Use Figure 2The nickel-plating waste liquid treatment device 100 shown in the figure recovers the nickel-plating waste liquid, wherein: Figure 2 The device shown can achieve 4 tons / day of nickel-containing waste liquid recovery and treatment, wherein the total nickel concentration in the on-site treated nickel-containing waste liquid is 18,000±4000 mg / L.

[0067] In the first step, the pH value of the nickel waste liquid in the pH adjustment tank 1 is adjusted to between 9 and 10, and the waste liquid is injected with ozone into the oxidation tower 3 using the water injector 2. The ozone will oxidize and destroy the chelated nickel to form free nickel ions, and at the same time, all the hypophosphites and phosphites are converted into phosphates to obtain solution A.

[0068] In the second step, since the waste liquid in the ozone oxidation tower 3 is in a highly alkaline environment, the free nickel ions will form nickel hydroxide precipitates, and will be discharged into the nickel recovery device 4 through the bottom mud discharge design of the ozone oxidation tower 3, and the supernatant will form solution B. At the same time, the excess ozone is processed by the ozone recovery treatment device to avoid environmental pollution.

[0069] In the third step, solution B is passed from the top of the ozone oxidation tower 3 into the first precipitation tank 5, calcium ions are added to solution B, and precipitation reaction is carried out for about 1 hour, calcium phosphate adsorbed with residual nickel ions is recovered, and the supernatant forms solution C.

[0070] Among them, Ca:P=0.1-0.5, the residual free nickel ions in solution B can be adsorbed by calcium phosphate, and the calcium ions can be derived from calcium chloride or calcium hydroxide, etc. After the impurity removal step, the subsequent magnesium addition step can effectively improve the purity of magnesium ammonium phosphate.

[0071] The fourth step is to add magnesium ions to solution C, wherein the resulting solution contains orthophosphate: ammonia nitrogen: Mg 2+ =1:1:1.5, the precipitation reaction is carried out for 1 hour, the magnesium ammonium phosphate precipitate is formed and recovered, and the supernatant forms solution D.

[0072] The fifth step is to add calcium chloride to solution D, wherein Ca:P=1-1.2, and react for 1 hour to form calcium phosphate precipitate for recovery.

[0073] The removal of different impurities in nickel-containing waste liquid is analyzed below, and the results are as follows.

[0074] like Figure 3 As shown in FIG. 1 , for nickel-containing waste liquid with the same nickel content, under different pH conditions (pH 8, 9 and 10 respectively), the effect of ozone addition on the nickel removal rate in the nickel-containing waste liquid is shown. Figure 3 The experimental operating conditions are that the wastewater is diluted ten times (10x wastewater), that is, the amount of ozone introduced is also diluted 10 times relative to the reagent wastewater. Figure 3It can be seen that the nickel removal rate will first increase and then decrease with the increase of ozone addition. Therefore, when the ozone addition is approximately 30-50g O 3 / L, and an alkaline environment with a pH of 9 to 10 is more conducive to the generated hydroxyl radicals oxidizing the chelating agent to destroy the chelating structure between the chelating agent and nickel, releasing free nickel ions.

[0075] like Figure 4 As shown in the figure, it is a curve diagram of the effect of different amounts of ozone addition on the nickel removal rate of nickel-containing waste liquids with different actual nickel contents. The pH value is 9, the nickel content of one nickel-containing waste liquid is 17600 mg / L, and the nickel content of the other nickel-containing waste liquid is 4000 mg / L. Figure 4 It can be seen that the nickel-containing waste liquid with different nickel contents has basically the same change trend under different ozone addition amounts, and the nickel removal rates in the waste liquids with two nickel contents are basically the same. It can be seen that the waste liquid treatment method provided in the embodiment of the present application has a better treatment effect on nickel-containing waste liquid with high nickel content. The treatment method provided in the embodiment of the present application can be used to treat nickel-containing waste liquid with a total nickel concentration of 18,000±4000 mg / L.

[0076] like Figure 5 As shown in the figure, it is a curve chart of the effect of different treatment times on the nickel removal rate. After the introduction of ozone, the nickel removal rate reaches more than 80% in a short time (less than 0.5 hour). As time goes by, the rate of nickel removal tends to be flat. After 4 days of treatment, the nickel content in the nickel-chemical waste liquid can finally be achieved to be lower than 14.9 mg / L, and the nickel removal rate reaches more than about 97.4%.

[0077] like Figure 6 As shown, after further removing residual nickel with calcium phosphate precipitate, the nickel content in the precipitate is about 0.21w / w%. Calcium phosphate can effectively adsorb and remove the residual free nickel ions that are not removed in solution B, thereby fully removing nickel from the waste liquid.

[0078] like Figure 7 As shown, in step 4, when magnesium ions and phosphate react in different molar ratios, the total phosphorus concentration changes with the reaction time. When the molar ratio of the added magnesium ions and the phosphate in the solution is 1.5:1 or 2.5:1, the total phosphorus concentration decreases more, the reduction of orthophosphate in the waste liquid is more than 800 mg / L, and the phosphorus removal rate in step 4 is about more than 50%.

[0079] like Figure 8As shown, in step 4, when magnesium ions and phosphates react in different molar ratios, the concentration of ammonia nitrogen changes with the reaction time. When the molar ratio of the added magnesium ions and the phosphates in the solution is 1.5:1 or 2.5:1, the reduction of ammonia nitrogen in the waste liquid is about 370 mg / L, and the ammonia nitrogen removal rate is about 90%.

[0080] Combination Figure 7 and Figure 8 It can be seen that in step 4, the ratio of the molar concentration of orthophosphate to that of ammonia nitrogen is about 1:1. After adding magnesium ions, Mg 2+ +NH 3 +PO 4 3- →Mg(NH 3 )PO 4 , magnesium ammonium phosphate is formed, which can be recycled and reused.

[0081] like Fig. 9 As shown in FIG. 5 , calcium chloride and calcium hydroxide are added to further remove residual phosphorus, and the total phosphorus removal rate changes with the increase of Ca / P ratio. Fig. 9 It can be seen that when calcium chloride is added, the total phosphorus removal rate increases with the increase of Ca / P ratio, and can reach a total phosphorus removal rate of 97%; while when calcium hydroxide is added, the total phosphorus removal rate does not change with the increase of Ca / P ratio, and the removal effect is not as good as that of calcium chloride. The reason is that the waste liquid has been adjusted to alkaline, which limits the solubility of calcium hydroxide, resulting in poor total phosphorus removal rate. In addition, when calcium chloride is added, the phosphorus removal effect is better when the Ca / P ratio reaches 1.2.

[0082] The examples of the present application provide the removal rates of different pollutants in nickel-containing waste liquid and the characteristics of the output precipitates, as shown in Table 1.

[0083] Table 1

[0084]

[0085] By adopting the method for treating nickel chloride waste liquid of the embodiment of the present application, high-content nickel can be fully removed, and the nickel removal rate reaches more than about 97.4%. The purity of the obtained nickel hydroxide reaches more than about 95%, the total phosphorus removal rate is more than about 97%, and the ammonia nitrogen removal rate is more than about 90%.

[0086] The embodiment of the present application uses ozone to destroy the chelating agent that chelates nickel in the nickel waste liquid, and oxidizes hypophosphite and phosphite, then first recovers the nickel hydroxide by precipitation, and then adds magnesium salt and ammonia nitrogen / phosphorus to generate struvite precipitate (Mg(NH 3 )PO 4), achieving resource recycling and cyclic utilization. The waste liquid treatment method is particularly suitable for the recycling of nickel-containing waste liquid with high nickel content. The method is simple, does not require special treatment equipment, has good pollutant removal effect, high treatment efficiency, and low cost. It is suitable for circuit board manufacturers to treat nickel-containing waste liquid by themselves, and has good economic benefits.

Claims

1. A method for treating nickel-containing waste liquid with high nickel concentration, characterized in that: include: Step 1, at a pH of 9 to 10, ozone is introduced into the nickel waste liquid to oxidize and destroy the chelated nickel to form free nickel ions, and at the same time, all hypophosphites and phosphites are converted into phosphates to obtain solution A; Step 2, the free nickel ions in the solution A form a nickel hydroxide precipitate, and the nickel hydroxide precipitate is recovered, and the supernatant forms a solution B; Step 3, adding calcium ions to the solution B to form a calcium phosphate precipitate, wherein the calcium phosphate precipitate is used to adsorb the free nickel ions that are not removed from the solution B, and the supernatant forms a solution C; Step 4, adding magnesium ions to the solution C to generate and recover magnesium ammonium phosphate precipitate, and the supernatant forms solution D; as well as Step 5, adding calcium chloride to the solution D to form calcium phosphate and recovering the calcium phosphate.

2. The method for treating nickel-containing waste liquid with high nickel concentration according to claim 1, characterized in that: In step 1, the concentration of ozone added is 30-50 g O3 / L.

3. The method for treating nickel-containing waste liquid with high nickel concentration according to claim 1, characterized in that: In the step 1, ozone is introduced into the nickel waste liquid for mixed aeration, and the mixed aeration is injected into the ozone oxidation tower through a water ejector.

4. The method for treating nickel-containing waste liquid with high nickel concentration according to claim 1, characterized in that: In step 3, the molar concentration ratio of the calcium ions to the phosphate in solution B is 0.1 to 0.

5.

5. The method for treating nickel-containing waste liquid with high nickel concentration according to claim 4, characterized in that: The calcium ions are derived from calcium chloride or calcium hydroxide.

6. The method for treating nickel-containing waste liquid with high nickel concentration according to claim 1, characterized in that: In step 4, after adding magnesium ions to solution C, the resulting solution contains orthophosphate: ammonia nitrogen: Mg 2+ The molar ratio is 1:1:(1~3).

7. The method for treating nickel-containing waste liquid with high nickel concentration according to claim 1, characterized in that: In step 5, the molar ratio of calcium chloride to phosphate is (1-3):

1.

8. A treatment device used in the method for treating nickel-containing waste liquid with high nickel concentration as claimed in any one of claims 1 to 7, characterized in that: It includes a pH adjustment tank, a water ejector, an ozone oxidation tower, a first sedimentation tank, a second sedimentation tank and a third sedimentation tank which are connected in sequence, wherein the water ejector is connected to the bottom of the ozone oxidation tower, and ozone enters from the bottom of the ozone oxidation tower, and the top of the ozone oxidation tower is connected to the first sedimentation tank, the second sedimentation tank and the third sedimentation tank in sequence, the ozone oxidation tower is used to complete the steps 1 and 2, the first sedimentation tank is used to complete the step 3, the second sedimentation tank is used to complete the step 4, and the third sedimentation tank is used to complete the step 5.

9. The processing device according to claim 8, characterized in that It also includes a nickel recovery device connected to the bottom of the ozone oxidation tower, and the nickel recovery device is used to recover the nickel hydroxide precipitate.

10. The processing device according to claim 8, characterized in that It also includes an ozone recovery and treatment device connected to the top of the ozone oxidation tower, and the ozone recovery and treatment device is used to recover and treat residual ozone.

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