CN-118026124-B - Method for recycling phosphorus from nickel-containing mother solution of ferric phosphate

CN118026124BCN 118026124 BCN118026124 BCN 118026124BCN-118026124-B

Abstract

The invention provides a method for recycling phosphorus from nickel-containing mother liquor of ferric phosphate, which comprises the following steps of S1, mixing nickel-containing mother liquor of ferric phosphate with an iron source solution, adding ferric phosphate seed crystals to obtain first slurry, S2, mixing the first slurry with an oxidant, heating to obtain second slurry, S3, carrying out solid-liquid separation on the second slurry to obtain recycled phosphorus liquid and ferric phosphate dihydrate, mixing the ferric phosphate dihydrate with concentrated sulfuric acid and a reducing agent, and carrying out solid-liquid separation to obtain pickle liquor containing phosphate.

Inventors

ZHOU ZHENGHUA
QIU NENG
PENG MINGSHENG
ZENG XIAO
TANG SHENGHE
WANG HAO
LI CHANGDONG

Assignees

宜昌邦普宜化新材料有限公司
广东邦普循环科技有限公司
湖南邦普循环科技有限公司

Dates

Publication Date: 20260508
Application Date: 20240207

Claims (9)

1. A method for recovering phosphorus from a nickel-containing mother liquor of ferric phosphate, comprising the steps of: S1, mixing a nickel-containing mother solution of ferric phosphate with an iron source solution, and adding ferric phosphate seed crystals to obtain first slurry; s2, mixing the first slurry with an oxidant, and heating to obtain a second slurry; S3, carrying out solid-liquid separation on the second slurry to obtain a phosphorus-recovered solution and ferric phosphate dihydrate, mixing the ferric phosphate dihydrate with concentrated sulfuric acid and a reducing agent, and carrying out solid-liquid separation to obtain a phosphoric acid leaching solution, wherein the phosphoric acid leaching solution is used for a phosphorus preparation process of the ferronickel leaching solution; The nickel-containing mother liquor of the iron phosphate is prepared by adopting sulfuric acid leaching solution of nickel-iron alloy, removing impurities, adding phosphoric acid as a phosphorus source, adding an oxidant, and controlling pH to produce battery-grade iron phosphate, wherein the nickel-containing mother liquor contains sulfuric acid and phosphate ions; the reducing agent is nickel iron powder.
2. The method of claim 1, further comprising the step of: and S4, using the phosphorus recovery liquid for leaching and impurity removal of cobalt nickel hydroxide.
3. The method of claim 1, wherein the concentration of phosphorus element in the iron phosphate nickel-containing mother liquor is 3-5.5 g/L.
4. The method according to claim 1, wherein step S1 satisfies one or more of the following conditions: a. The concentration of Fe 2+ in the iron source solution is 40-50 g/L; b. The iron source solution is a chromium-removing liquid after nickel-iron alloy leaching; c. after the ferric phosphate nickel-containing mother solution is mixed with an iron source solution, the molar ratio of iron to phosphorus elements is 1-3:1; d. the granularity D50 of the ferric phosphate seed crystal is 5-12 mu m; e. the mass of the iron phosphate seed crystal is 0.5% -10% of the total mass of the iron phosphate nickel-containing mother liquor and the iron source solution.
5. The method of claim 1, wherein in the step S2, the oxidant is at least one of oxygen, hydrogen peroxide, chlorate or perchlorate, and/or the molar ratio of the oxidant to Fe 2+ in the first slurry is 1-1.5:1.
6. The method according to claim 1, wherein in the step S2, the mixing temperature is room temperature, the mixing time is 30-90 min, and/or the heating temperature is 60-90 ℃, and the heating time is 2-10 h.
7. The method according to claim 1, wherein in the step S3, the mass concentration of the concentrated sulfuric acid is 98%, and/or the dosage of the concentrated sulfuric acid is 100-150 g/L, and/or the molar ratio of the reducing agent to the ferric phosphate dihydrate is 1.2-2:1.
8. The method according to claim 1, wherein in step S3, the temperature of the mixing is 60 to 90 ℃, and the time of the mixing is 2 to 4 hours.
9. The method according to claim 1, wherein in the step S3, the content of phosphorus element in the phosphorus-recovered liquid is 0.1-0.5 g/L.

Description

Method for recycling phosphorus from nickel-containing mother solution of ferric phosphate Technical Field The invention belongs to the field of recycling of new energy material resources, and particularly relates to a method for recycling phosphorus from ferric phosphate nickel-containing mother liquor. Background The lithium ion battery has the advantages of high voltage, high energy density and long cycle life, and becomes a popular market in the new energy industry, so that the market is fully developed for developing battery materials. Lithium iron phosphate (LFP) and ternary materials (NCM/NCA) are the mainstream markets for current market analysis of positive electrode materials. The market demand for iron phosphate and nickel sulfate has been continuously increasing. The nickel-iron alloy obtained by the laterite-nickel ore pyrometallurgy has nickel content above 15% and iron content above 60%, and a large number of enterprises begin to prepare ferric phosphate dihydrate and nickel sulfate solution by taking the nickel-iron alloy as raw materials in the market at present, so that the utilization rate of the nickel-iron alloy is fully improved. At present, in one of the production methods of battery-grade ferric phosphate, the main process is that after impurity removal of ferronickel alloy leaching solution, phosphoric acid is added as a phosphorus source, an oxidant is added, and parameters such as pH are controlled to produce the battery-grade ferric phosphate product. The method has the following problems that in most of the prior art, the cost of the auxiliary materials such as alkali, flocculating agent and the like adopted by the back end for dephosphorization is high, the recycling comprehensive utilization of phosphorus resources is not realized, the prior art basically only considers dephosphorization and does not consider the recovery of phosphorus, and the used auxiliary materials can introduce impurities to influence the crystal structure and the morphological characteristics of the battery-level ferric phosphate product at the back end. Therefore, there is a need to propose a synthesis method with high resource utilization. Disclosure of Invention The present disclosure is directed to solving at least one of the technical problems in the prior art as described above. Therefore, the invention provides a method for recovering phosphorus from the nickel-containing mother liquor of ferric phosphate, wherein the recovery rate of phosphorus in the method is more than 90 percent, and the method has the advantages of low raw material cost, simple and convenient process flow, high resource utilization rate, low impurity removal cost, good economic benefit and the like. According to a first aspect of the present disclosure, there is provided a method for recovering phosphorus from an iron phosphate nickel-containing mother liquor, comprising the steps of: S1, mixing a nickel-containing mother solution of ferric phosphate with an iron source solution, and adding ferric phosphate seed crystals to obtain first slurry; s2, mixing the first slurry with an oxidant, and heating to obtain a second slurry; s3, carrying out solid-liquid separation on the second slurry to obtain a recovered phosphorus rear liquid and ferric phosphate dihydrate, mixing the ferric phosphate dihydrate with concentrated sulfuric acid and a reducing agent, and carrying out solid-liquid separation to obtain a phosphoric acid leaching solution. The nickel-containing mother liquor of the iron phosphate is nickel-containing mother liquor after the battery-grade iron phosphate is produced by adopting the sulfuric acid leaching solution of the nickel-iron alloy through impurity removal, adding phosphoric acid as a phosphorus source, adding an oxidant, controlling pH and other parameters, so that the nickel-containing mother liquor contains sulfuric acid with a certain concentration and phosphate ions. The method comprises the steps of adding an iron source into a nickel-containing mother solution of ferric phosphate to form a crude ferric phosphate dihydrate precipitate, and re-dissolving the amorphous ferric phosphate dihydrate precipitate and delivering the amorphous ferric phosphate dihydrate precipitate to a downstream phosphorus preparation process, wherein the phosphorus preparation process is carried out according to a certain proportion of ferric phosphate to phosphorus, and the synthesis process synthesizes a battery grade ferric phosphate product which has certain morphological characteristics and meets the requirement of impurity element content under specific process conditions. The method disclosed by the invention is used for treating the nickel-containing mother liquor of the ferric phosphate, and the obtained pickle liquor containing phosphate radicals is used for the phosphorus matching process of the front-end nickel-iron pickle liquor, so that the utilization rate of phosphorus resources is improved. In some embodim