Method for regenerated raw materials from waste cadmium nickel battery based on solvent extraction
A method for regenerating raw materials of waste Nickel-Cadmium batteries based on solvent extraction is disclosed. The method is used for disassembling, rinsing and shredding industrial waste from Nickel-Cadmium batteries. The solvent extraction technology is easy for large-scale and continuous production, and valuable metals such as cadmium, cobalt and nickel are extracted from the waste Nickel-Cadmium batteries to prepare products such as cadmium nitrate, cobalt nitrate, nickel nitrate which are directly used for producing raw materials for Nickel-Cadmium batteries. No new waste salt and waste residues are generated in the process. High-efficiency separation and purification of all valuable metals during the regeneration of waste Nickel-Cadmium batteries and the full-life cycle regeneration cycle of Nickel-Cadmium batteries are achieved.
1 . A method for regenerating raw materials of waste Nickel-Cadmium batteries based on a solvent extraction comprising the following steps:
1) disassembling, rinsing, and shredding an industrial waste cadmium-nickel battery to obtain a material;
2) leaching the material with a sulfuric acid solution to obtain a leachate;
3) taking the leachate obtained in step 2, adding a first oxidizing agent to the leachate to oxidize Fe 2+ in the leachate to Fe 3+ , adjusting a pH to 0.8-1.8, adding a first extractant, and extracting to obtain a first raffinate and a first organic phase; washing the first organic phase with dilute sulfuric acid, and stripping with an oxalic acid solution to obtain an iron oxalate solution;
4) adjusting a pH of the first raffinate to 2.0-3.0, adding the first extractant to the first raffinate for a first extraction to obtain a second raffinate and a second organic phase; washing the second organic phase with a cadmium sulfate solution, and stripping with a dilute nitric acid solution to obtain a cadmium nitrate solution;
5) adjusting a pH of the second raffinate to 4.5-5.5, and adding a second extractant for a second extraction to obtain a third raffinate and a third organic phase; washing the third organic phase with a cobalt sulfate solution, and stripping with the dilute nitric acid solution to obtain a cobalt nitrate solution;
6) adjusting a pH of the third raffinate to 5.0-6.0, and adding the first extractant to the third raffinate for a third extraction to obtain a sodium sulfate solution and a fourth organic phase; washing the fourth organic phase with a nickel nitrate solution, and stripping with the dilute nitric acid solution to obtain a resulting nickel nitrate solution; wherein the first extractant is formed by mixing P204 and a solvent oil, and the second extractant is formed by mixing DZ272 and the solvent oil; and the first extractant and the second extractant are saponified when used.
2 . The method according to claim 1 , wherein in step 1, a content of K, Li and Ca elements in a waste electrode plate obtained from the step of disassembling, rinsing, and shredding the industrial waste cadmium-nickel battery is less than 0.01 wt %, wherein the waste electrode plate is treated with a two-stage wet shredding, a maximum particle size of a shredded industrial waste cadmium-nickel battery is 10×100 mm, and a moisture content of the shredded industrial waste cadmium-nickel battery is less than 10%.
3 . The method according to claim 1 , wherein in step 2, a mixing ratio of the material to the sulfuric acid solution is 1:5-1:12, a concentration of the sulfuric acid solution is 1.5-3.0 mol/l, a temperature of an acid leaching process is 343-368K, and an acid leaching time is 6-24 h, wherein leaching further comprises stirring during the leaching at a stirring speed of 150-300 rpm.
4 . The method according to claim 1 , wherein in step 2, the step of leaching the material further comprises adding a second oxidizing agent to facilitate a dissolution of the material, wherein the second oxidizing agent is a hydrogen peroxide solution, and a concentration of the hydrogen peroxide solution is 30-40%, and an addition amount of the hydrogen peroxide solution is 6-12% of a volume of the leachate in step 2.
5 . The method according to claim 1 , wherein in step 3, the first oxidizing agent is hydrogen peroxide, and an amount of the first oxidizing agent added is 1.2-2 times a molar amount of ferrous ions in a leaching solution; wherein extracting is performed 3-7 times, the washing is performed 1-3 times, and stripping is performed 3-7 times; and each stripping is performed at 308-323K; extracting and washing operations are performed at 288-298K; and an amount of oxalic acid in the oxalic acid solution is 1.5-2 times a molar amount of the Fe 3+ in the first organic phase.
6 . The method according to claim 1 , wherein in step 4, the first extraction is performed 3-7 times, the washing is performed 3-5 times, and the stripping is performed 3-5 times; wherein an amount of nitric acid in the dilute nitric acid solution is 2-2.5 times a molar amount of Cd 2+ in the second organic phase; and the cadmium nitrate solution obtained by stripping is evaporated and concentrated to obtain the cadmium nitrate solution or a cadmium nitric crystal.
7 . The method according to claim 1 , wherein in step 5), the second extraction is performed 3-7 times, the washing is performed 2-6 times, and the stripping is performed 2-6 times; wherein the second extraction is performed at 308-323K, and the stripping and the washing are performed at 288-298K; wherein an amount of nitric acid in the dilute nitric acid solution is 2-2.5 times a molar amount of Co 2+ in the third organic phase; and wherein the cobalt nitrate solution obtained by stripping is evaporated and concentrated to obtain the cobalt nitrate solution or a cobalt nitric crystal.
8 . The method according to claim 1 , wherein in step 6), the third extraction is performed 6-10 times; the washing is performed 2-6 times; and the stripping is performed 2-6 times; wherein the third extraction is performed at 308-323K, the stripping and the washing are performed at 288-298K; and wherein an amount of nitric acid in the dilute nitric acid solution is 2-2.5 times a molar amount of Ni 2+ in the fourth organic phase, and the resulting nickel nitrate solution obtained by stripping is evaporated and concentrated to obtain the resulting nickel nitrate solution or a nickel nitric crystal.
9 . The method according to claim 1 , wherein the first extractant or the second extractant is saponified with a sodium hydroxide solution having a mass fraction of 25-35%; a concentration of the P204 in the first extractant is 0.5-1.2 mol/L; and a concentration of the DZ272 in the second extractant is 0.05-0.15 mol/L.
10 . The method according to claim 1 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
11 . The method according to claim 2 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
12 . The method according to claim 3 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
13 . The method according to claim 4 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
14 . The method according to claim 5 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
15 . The method according to claim 6 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
16 . The method according to claim 7 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
17 . The method according to claim 8 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.
18 . The method according to claim 9 , wherein the solvent oil is a 230 #solvent oil or a 260 #solvent oil (sulfonated kerosene); the sodium sulfate solution is kept at a temperature of 308-323K, and an industrial grade sodium sulfate is obtained after an evaporation and a concentration of the sodium sulfate solution.