Method for removing fe ions and cu ions in nickel-containing wastewater

Abstract

A method for removing Fe ions and Cu ions in nickel-containing wastewater, comprising the following steps: (1) pretreatment process; (2) adsorption process; (3) regeneration process; (4) transformation process. The method uses a styrene-diethylene sulfonic acid cation exchange resin to remove Fe 2+ and Cu 2+ ions, and does not introduce any impurities in the impurity removal process during the treatment process, avoiding the influence of other additives on other processes of water treatment. The method is simple, cost-saving, and improves production efficiency and economic benefits.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal hydrometallurgy technology, specifically a method for removing Fe and Cu ions from nickel-containing wastewater. Background Technology

[0002] In non-ferrous metal smelting processes, nickel-containing wastewater is mainly generated from the hydrometallurgical process of nickel, and this wastewater generally contains Fe and Cu ions. One method for removing Fe and Cu ions from wastewater is sodium sulfide precipitation. However, adding sodium sulfide cannot completely precipitate the Fe and Cu ions in the water. Furthermore, the addition of sodium sulfide causes an increase in sodium (Na) in the water, thus increasing the difficulty of the downstream membrane treatment process. Therefore, using the above methods to remove Fe and Cu impurities from wastewater is prone to contamination due to the need to add chemical agents, failing to meet the requirements for secondary reuse of treated wastewater, or resulting in complex processes and increased production and operating costs. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a simple and low-cost method for removing Fe and Cu ions from nickel-containing wastewater.

[0004] To achieve the above objectives, the present invention provides a method for removing Fe and Cu ions from nickel-containing wastewater, characterized by comprising the following steps:

[0005] (1) Pre-processing:

[0006] In the wastewater treatment process, 5-30% NaOH and sodium carbonate are added to the nickel-containing wastewater at a concentration of 20-50 kg / d. The supernatant is clear and transparent, and its pH value is adjusted to 10.0-12.0. The Ni content in the supernatant is ≤25 mg / L. The supernatant is then filtered through a precision filter press. The filter press effluent enters a pH adjustment device, where 5.0-32.0% industrial hydrochloric acid is added to adjust the pH of the clear liquid to between 6.0 and 9.0, resulting in a neutral aqueous solution.

[0007] (2) Adsorption process:

[0008] The neutral aqueous solution obtained in step (1) was adsorbed using a styrene-diethylene type sulfonic acid cation exchange resin. After resin adsorption, the total amount of Fe2+ and Cu2+ in the water was less than 0.2 mg / L.

[0009] (3) Regeneration process:

[0010] The adsorbed water from step (2) was eluted with hydrochloric acid at a volume concentration of 5%-15% and washed with pure water to obtain the styrene-diethylene sulfonic acid cation exchange resin after washing.

[0011] (4) Transformation process:

[0012] The styrene-diethylene sulfonic acid cation exchange resin obtained in step (3) is eluted with a NaOH solution of 5%-15% by mass and washed with pure water to obtain a regenerated and backwashed styrene-diethylene sulfonic acid cation exchange resin; this regenerated and backwashed styrene-diethylene sulfonic acid cation exchange resin is returned to step (2).

[0013] A further preferred embodiment of the present invention, a method for removing Fe and Cu ions from nickel-containing wastewater, is characterized by:

[0014] 1. The Ni in the nickel-containing wastewater in step (1) 2+ Content less than 2.0 g / L, Fe 2+ Content is 5-10 mg / L, Cu 2+ The content is 5-20 mg / L;

[0015] 2. The precision of the precision filter press in step (1) is 5.0~10.0μm;

[0016] 3. In step (1), add NaOH and sodium carbonate with a mass concentration of 15% at a rate of 35 kg / d, and adjust the pH value to 11.0.

[0017] 4. In step (1), add industrial hydrochloric acid with a mass concentration of 15.0% to adjust the pH of the clarified solution to 7.0;

[0018] 5. In step (3), the elution flow rate of hydrochloric acid is 2.0-3.0 BV / h, and the time is 2-5h;

[0019] 6. In step (3), the elution flow rate of hydrochloric acid is 2.5 BV / h, and the elution time is 3.5h;

[0020] 7. In steps (3) and (4), the washing flow rate of pure water is 2-5 BV / h, and the washing time is 2-3.5h.

[0021] 8. In steps (3) and (4), the washing flow rate of pure water is 3 BV / h, and the washing time is 3h.

[0022] 9. In step (4), the flow rate of the NaOH solution for transformation is 2 BV / h, and the time is 0.5-2.5h.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. This invention uses a styrene-diethylene type sulfonic acid-based cation exchange resin to remove Fe. 2+ and Cu 2+Furthermore, it does not introduce any impurities during the purification process, thus avoiding the impact of other additives on other water treatment procedures.

[0025] 2. The method of the present invention is simple, saves costs, and improves production efficiency and economic benefits. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1, a method for removing Fe and Cu ions from nickel-containing wastewater, comprising the following steps: (1) Pretreatment process: In the wastewater treatment process, NaOH and sodium carbonate with a mass concentration of 5-30% are added to the nickel-containing wastewater at a dosage of 20-50 kg / d. The supernatant is clear and transparent, and its pH value is adjusted to 10.0-12.0. The supernatant contains Ni ≤25 mg / L. The supernatant is filtered through a precision filter press, and the filter press outlet enters a pH adjustment device. Industrial hydrochloric acid with a mass concentration of 5.0-32.0% is added to adjust the pH of the clear liquid to between 6.0-9.0, thereby obtaining a neutral aqueous solution; (2) Adsorption process: The neutral aqueous solution obtained in step (1) is adsorbed using styrene-diethylene sulfonic acid. The cation exchange resin is used for adsorption, and the total amount of Fe2+ and Cu2+ in the water after adsorption is less than 0.2 mg / L; (3) Regeneration process: The product water after adsorption in step (2) is eluted with hydrochloric acid with a volume concentration of 5%-15% and washed with pure water to obtain the styrene-diethylene sulfonic acid cation exchange resin after water washing; (4) Transformation process: The styrene-diethylene sulfonic acid cation exchange resin obtained in step (3) is eluted with NaOH solution with a mass concentration of 5%-15% and washed with pure water to obtain the styrene-diethylene sulfonic acid cation exchange resin after regeneration and backwashing; The styrene-diethylene sulfonic acid cation exchange resin after regeneration and backwashing is returned to step (2).

[0028] Example 2, in the method for removing Fe and Cu ions from nickel-containing wastewater according to Example 1, in step (1) the Ni in the nickel-containing wastewater... 2+ Content less than 2.0 g / L, Fe 2+ Content is 5-10 mg / L, Cu 2+ The content is 5-20 mg / L.

[0029] Example 3: In the method for removing Fe and Cu ions from nickel-containing wastewater according to Example 1 or 2, the precision filter press in step (1) has a precision of 5.0~10.0 μm. The preferred precision is 7.0 μm.

[0030] Example 4: In a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-3, in step (1), NaOH and sodium carbonate with a mass concentration of 15% are added at a rate of 35 kg / d, and the pH value is adjusted to 11.0.

[0031] Example 5: In a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-4, industrial hydrochloric acid with a mass concentration of 15.0% is added in step (1) to adjust the pH of the clarified liquid to 7.0.

[0032] Example 6, in a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-5, the elution flow rate of hydrochloric acid in step (3) is 2.0-3.0 BV / h, and the time is 2-5h.

[0033] Example 7, in a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-6, the elution flow rate of hydrochloric acid in step (3) is 2.5 BV / h and the time is 3.5h.

[0034] Example 8, in the method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-7, the washing flow rate of pure water in steps (3) and (4) is 2-5 BV / h, and the washing time is 2-3.5h. Preferably, the washing flow rate is 3.5 BV / h, and the washing time is 3h.

[0035] Example 9, in the method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-8, the washing flow rate of pure water in steps (3) and (4) is 3 BV / h, and the washing time is 3h.

[0036] Example 10, in a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-9, in step (4), the flow rate of the NaOH solution in the conversion solution is 2 BV / h, and the time is 0.5-2.5h. The selected time is 1.5h.

[0037] Example 11, in a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-10, the Ni-containing wastewater is... 2+ 1.25 g / L, Fe 2+ 5.73 mg / L, Cu 2+The nickel concentration was 14.58 mg / L. 15% NaOH and 20 kg of sodium carbonate were added to adjust the pH of the wastewater to 11.5, allowing the nickel to settle completely. After complete sedimentation, the supernatant contained 20.0 mg / L of nickel. The supernatant was then passed through a 5.0 μm filter press, and 5.0% industrial hydrochloric acid was added to the effluent to adjust the pH to 6.57. The resulting solution then entered the resin column to adsorb Fe. 2+ Cu 2+ Flow rate 2.5 BV / h, wastewater treatment capacity 150 m³ 3 The Fe in the final resin-produced water 2+ +Cu 2+ =0.12mg / L.

[0038] After adsorption saturation, the resin was backwashed with 10.0% hydrochloric acid at a flow rate of 2.0 BV / h. After regeneration, the resin was washed with pure water for 2.5 h. Then, the resin was transformed with 5% NaOH at a flow rate of 0.5 BV / h for 2 h, followed by washing with pure water for 2 h at a flow rate of 2 BV / h.

[0039] Example 12, in a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-11, the Ni-containing wastewater is... 2+ 1.82 g / L, Fe 2+ 7.50 mg / L, Cu 2+ The concentration of nickel in the wastewater was 18.25 mg / L. 10% NaOH and 30 kg of sodium carbonate were added to adjust the pH to 10.8, allowing the nickel to settle completely. After complete sedimentation, the supernatant contained 15.7 mg / L of nickel. The supernatant was then filtered through a 10.0 μm filter press. 10% industrial hydrochloric acid was added to the effluent to adjust the pH to 7.58. The resulting solution then entered the resin column to adsorb Fe. 2+ Cu 2+ Flow rate 3.0 BV / h, wastewater treatment capacity 180 m³ 3 The Fe in the final resin-produced water 2+ +Cu 2+ =0.08mg / L.

[0040] After adsorption saturation, the resin was backwashed with 15.0% hydrochloric acid at a flow rate of 2.5 BV / h. After regeneration, the resin was washed with pure water for 2.0 h. Then, the resin was converted with 10% NaOH at a flow rate of 2.0 BV / h for 3.5 h, followed by washing with pure water for 3.0 h at a flow rate of 2 BV / h.

[0041] Example 13, in a method for removing Fe and Cu ions from nickel-containing wastewater according to any one of Examples 1-12, the Ni-containing wastewater is... 2+ 2.0 g / L, Fe 2+9.7 mg / L, Cu 2+ The concentration of nickel in the wastewater was 20.0 mg / L. 30% NaOH and 45 kg of sodium carbonate were added to adjust the pH to 11.65, allowing the nickel to settle completely. After complete sedimentation, the supernatant contained 22.5 mg / L of nickel. The supernatant was then filtered through a 5.0 μm filter press. 31.5% industrial hydrochloric acid was added to the effluent to adjust the pH to 8.25. The resulting solution then entered the resin column to adsorb Fe. 2+ Cu 2+ Flow rate 3.0 BV / h, wastewater treatment capacity 180 m³ 3 The Fe in the final resin-produced water 2+ +Cu 2+ =0.12mg / L.

[0042] After adsorption saturation, the resin is backwashed with 30% hydrochloric acid at a flow rate of 3.0 BV / h. After regeneration, the resin is washed with pure water for 2.0 h. Then, the resin is converted with 15% NaOH at a flow rate of 2.0 BV / h for 4.0 h, followed by washing with pure water for 2.5 h at a flow rate of 2 BV / h.

[0043] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for removing Fe and Cu ions from nickel-containing wastewater, characterized in that, Includes the following steps: (1) Pre-processing: In the wastewater treatment process, NaOH and sodium carbonate with a mass concentration of 5-30% are added to the nickel-containing wastewater at a dosage of 20-50 kg / d. The supernatant is clear and transparent, and its pH value is adjusted to 10.0-12.

0. The Ni content in the supernatant is ≤25 mg / L. The supernatant is then filtered through a precision filter press. The filter press effluent enters a pH adjustment device, where industrial hydrochloric acid with a mass concentration of 5.0-32.0% is added to adjust the pH of the clear liquid to between 6.0 and 9.0, resulting in a neutral aqueous solution. (2) Adsorption process: The neutral aqueous solution obtained in step (1) was adsorbed using a styrene-diethylene type sulfonic acid cation exchange resin. After resin adsorption, the total amount of Fe2+ and Cu2+ in the water was less than 0.2 mg / L. (3) Regeneration process: The adsorbed water from step (2) was eluted with hydrochloric acid at a volume concentration of 5%-15% and washed with pure water to obtain the styrene-diethylene sulfonic acid cation exchange resin after washing. (4) Transformation process: The styrene-diethylene sulfonic acid cation exchange resin obtained in step (3) is eluted with a NaOH solution of 5%-15% by mass and washed with pure water to obtain a regenerated and backwashed styrene-diethylene sulfonic acid cation exchange resin; this regenerated and backwashed styrene-diethylene sulfonic acid cation exchange resin is returned to step (2).

2. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 1, characterized in that: In step (1), the nickel-containing wastewater contains Ni 2+ Content less than 2.0 g / L, Fe 2+ Content is 5-10 mg / L, Cu 2+ The content is 5-20 mg / L.

3. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 1, characterized in that: The precision of the precision filter press in step (1) is 5.0~10.0μm.

4. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 1, characterized in that: In step (1), NaOH and sodium carbonate with a mass concentration of 15% are added at a rate of 35 kg / d, and the pH value is adjusted to 11.

0.

5. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 1, characterized in that: In step (1), industrial hydrochloric acid with a mass concentration of 15.0% is added to adjust the pH of the clarified solution to 7.

0.

6. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 1, characterized in that: In step (3), the elution flow rate of hydrochloric acid is 2.0-3.0 BV / h, and the time is 2-5h.

7. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 6, characterized in that: In step (3), the elution flow rate of hydrochloric acid is 2.5 BV / h, and the elution time is 3.5 h.

8. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 1, characterized in that: In both steps (3) and (4), the washing flow rate of pure water is 2-5 BV / h, and the washing time is 2-3.5h.

9. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 8, characterized in that: In both steps (3) and (4), the washing flow rate of pure water is 3 BV / h, and the washing time is 3h.

10. The method for removing Fe and Cu ions from nickel-containing wastewater according to claim 1, characterized in that: In step (4), the flow rate of the NaOH solution for transformation is 2 BV / h, and the time is 0.5-2.5h.