阅读说明：本技术 磷酸铁锂废旧电池中磷和铁的回收方法 (Method for recovering phosphorus and iron in waste lithium iron phosphate battery ) 是由 马登 陈学刚 裴忠冶 王云 李东波 于 2021-06-07 设计创作，主要内容包括：本发明公开了一种磷酸铁锂废旧电池中磷和铁的回收方法。该方法包括：将磷酸铁渣、碳质还原剂和熔剂置于混料机中进行混料,其中,混料时加入粘结剂,所述磷酸铁渣是通过对磷酸铁锂废旧电池进行处理得到的；将得到的混料加入电炉中进行还原熔炼,熔炼温度为1300～1500℃,得到磷铁、含有P-2O-5蒸汽的烟气、以及炉渣。本发明采用火法冶炼的方法可从废旧磷酸铁锂电池中有效提取得到磷和铁资源,且产出的炉渣不属于危废渣,且本发明可进行大规模处理,不仅可以带来经济效益,而且可解决废旧磷酸铁锂电池堆放等带来的环境问题。(The invention discloses a method for recovering phosphorus and iron in waste lithium iron phosphate batteries. The method comprises the following steps: placing iron phosphate slag, a carbonaceous reducing agent and a flux in a mixer for mixing, wherein a binder is added during mixing, and the iron phosphate slag is obtained by treating waste lithium iron phosphate batteries; adding the obtained mixed material into an electric furnace for reduction smelting at the smelting temperature of 1300-1500 ℃ to obtain ferrophosphorus and P 2 O 5 Flue gas of steam, and slag. The method adopts a pyrometallurgical method to effectively extract phosphorus and iron resources from waste lithium iron phosphate batteries, the produced slag does not belong to dangerous waste residues, and the method can carry out large-scale treatment, so that the method can bring aboutEconomic benefit, and can solve the environmental problems caused by stacking of waste lithium iron phosphate batteries and the like.)

1. A method for recovering phosphorus and iron in waste lithium iron phosphate batteries is characterized by comprising the following steps:

placing iron phosphate slag, a carbonaceous reducing agent and a flux in a mixer for mixing, wherein a binder is added during mixing, and the iron phosphate slag is obtained by treating waste lithium iron phosphate batteries;

adding the obtained mixed material into an electric furnace for reduction smelting at the temperature of 1300-1500 ℃ to obtain ferrophosphorus and P₂O₅Flue gas of steam, and slag.

2. The recovery process of claim 1, wherein the carbonaceous reducing agent comprises: one or more of coke, anthracite, petroleum coke, crushed coal, active carbon and the like.

3. A recovery method according to claim 1, characterized in that the fluxing agent comprises: one or more of quartz, lime, bauxite, magnesia and fluorite.

4. The recycling method according to claim 1, wherein the melting time per pass is 1 to 6 hours.

5. The recycling method according to claim 1, wherein the binder is added in an amount of 1 to 10% by weight based on the total weight of the iron phosphate slag, the carbonaceous reducing agent and the flux.

6. The recycling method according to claim 1, wherein the binder is water.

7. The recovery method according to claim 1, wherein the slag form of the electric furnace reduction smelting process is CaO-FeO-SiO₂-Al₂O₃-MgO-CaF₂And (5) forming slag.

8. A recycling method according to claim 1, characterized in that the method further comprises:

with said compound containing P₂O₅Preparing phosphoric acid from the steam smoke;

and carrying out water crushing on the furnace slag to obtain water crushed slag.

9. A recycling method according to claim 1, characterized in that, before compounding, the method further comprises: according to the dosage ratio of the iron phosphate slag, the carbonaceous reducing agent and the flux being 1: (0.1-0.4): (0.05-0.2) blending.

Technical Field

The invention relates to the technical field of waste battery recovery, in particular to a method for recovering phosphorus and iron in lithium iron phosphate waste batteries.

Background

With the wide application of new energy automobiles, the generation amount of waste lithium iron phosphate batteries is increased year by year, and lithium, phosphorus and iron resources in the waste lithium iron phosphate batteries need to be recycled. At present, the recovery of phosphorus resources and iron resources in waste lithium iron phosphate batteries is mainly wet extraction.

For example: the Chinese application CN201110147698.6 discloses a method for recovering lithium and iron from an electric automobile lithium iron phosphate power battery, the Chinese application CN201810460794.8 discloses a comprehensive recovery method of lithium iron phosphate waste, and the Chinese application CN201510773893.8 discloses a recovery and utilization method of a lithium iron phosphate power battery.

The application all adopts that the wet process draws elements such as iron, lithium, along with lithium iron phosphate battery quantity increases day by day, and the wet process smelting technology will be unable to satisfy the processing of scrapped battery to the lithium iron phosphate waste battery is handled to hydrometallurgy, can produce a large amount of danger waste residues, influences environmental safety.

Disclosure of Invention

Based on the above, the invention aims to provide a method for recovering phosphorus and iron in waste lithium iron phosphate batteries, the invention adopts a pyrometallurgical method to extract phosphorus and iron resources from waste lithium iron phosphate batteries, the produced slag does not belong to dangerous waste residues, and the invention can carry out large-scale treatment.

The above purpose of the invention is realized by the following technical scheme:

according to one aspect of the invention, the method for recovering phosphorus and iron in the waste lithium iron phosphate battery provided by the invention comprises the following steps:

placing iron phosphate slag, a carbonaceous reducing agent and a flux in a mixer for mixing, wherein a binder is added during mixing, and the iron phosphate slag is obtained by treating waste lithium iron phosphate batteries;

adding the mixed material into an electric furnace for reduction smelting at the temperature of 1300-1500 ℃ to obtain ferrophosphorus and P₂O₅Flue gas of steam, and slag.

Optionally, the carbonaceous reducing agent comprises: one or more of coke, anthracite, petroleum coke, crushed coal, active carbon and the like.

Optionally, the fusing agent comprises: one or more of quartz, lime, bauxite, magnesia and fluorite.

Optionally, the smelting time of each furnace is 1-6 h.

Optionally, the addition amount of the binder is 1-10% of the total weight of the iron phosphate slag, the carbonaceous reducing agent and the flux.

Optionally, the binder is water.

Optionally, the slag type of the electric furnace reduction smelting process is CaO-FeO-SiO₂-Al₂O₃-MgO-CaF₂And (5) forming slag.

Optionally, the method further comprises: with said compound containing P₂O₅Preparing phosphoric acid from the steam smoke; and carrying out water crushing on the furnace slag to obtain water crushed slag which can be sold.

Optionally, before mixing, the method further comprises: according to the dosage ratio of the iron phosphate slag, the carbonaceous reducing agent and the flux being 1: (0.1-0.4): (0.05-0.2) blending.

Compared with the prior art, the method for recovering phosphorus and iron from the waste lithium iron phosphate batteries adopts a high-temperature pyrometallurgical method to extract phosphorus and iron from the waste lithium iron phosphate batteries, and can be used for treating large-scale waste lithium iron phosphate batteries, such as waste lithium iron phosphate batteries with the scale of more than 10 million tons; the phosphorus and iron elements are recovered, and the produced slag does not belong to hazardous waste residues, so that the method has environmental protection benefit and economic benefit; the invention has the advantages of simple process flow, low production cost and high recovery rate of phosphorus and iron elements.

Drawings

Fig. 1 is a schematic process flow diagram of the method for recovering phosphorus and iron from waste lithium iron phosphate batteries.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a method for recovering phosphorus and iron in waste lithium iron phosphate batteries, which adopts a pyrometallurgical method and can comprise the following steps: processing the waste lithium iron phosphate battery to obtain iron phosphate slag; placing the iron phosphate slag, the carbonaceous reducing agent and the flux into a mixer for mixing, and adding a binder during mixing; adding the mixed material into an electric furnace for reduction smelting at the smelting temperature of 1300-1500 ℃ to obtain ferrophosphorus and P₂O₅Flue gas of steam, and slag (which is not a hazardous waste residue). The iron phosphate slag is obtained by processing waste lithium iron phosphate batteries by adopting a conventional method in the field, for example, by conventional crushing treatment and sorting treatment.

Fig. 1 schematically shows a process flow of a method for recovering phosphorus and iron from waste lithium iron phosphate batteries. As shown in fig. 1, the method for recovering phosphorus and iron from waste lithium iron phosphate batteries provided by the present invention may specifically include:

and step S1, blending iron phosphate slag obtained by conventionally processing the waste lithium iron phosphate battery, a carbonaceous reducing agent and a flux. Wherein, during batching, the dosage ratio of the iron phosphate slag, the carbonaceous reducing agent and the flux is 1: (0.1-0.4): (0.05-0.2) the materials are mixed, which is beneficial to improving the recovery rate of the ferro-phosphorus. Further, the ratio may be 1: (0.1-0.4): (0.05-0.1) and can obtain greater economic benefit.

The carbonaceous reducing agent may include: one or more of coke, anthracite, petroleum coke, crushed coal (i.e., granulated coal), activated carbon, and the like. For example, crushed coal can be used as the carbonaceous reducing agent, which has environmental benefits and reduces production cost.

The fusing agent may include: one or more of quartz (sand), lime, bauxite, magnesia and fluorite. For example, quartz sand, lime, bauxite and oxidized coal mine can be selected, the proportion can be 2 (1-2) to 2 (1-2), the recovery rate of the phosphorus and the iron can be further improved, and the output is environment-friendly.

Step S2, the ingredients are placed in a mixer, such as a cylindrical mixer, and mixed, and water may be added as a binder during mixing, but the mixing is not limited to this, and may also be waste cane sugar water, for example. The dosage of the binder is generally 1% -10% of the addition of the materials, wherein the materials refer to the total weight of the iron phosphate slag, the carbonaceous reducing agent and the flux.

Step S3, adding the mixed materials into an electric furnace for reduction smelting, wherein the reduction smelting temperature can be 1300-1500 ℃, the smelting time of each furnace can be 1-6 h, and ferrophosphorus, slag and flue gas are obtained after electric furnace smelting, and the flue gas contains P₂O₅A fume of steam. Wherein the obtained ferrophosphorus can be directly sold; crushing the obtained furnace slag with water to obtain water crushed slag, and taking out; and recovering waste heat of the obtained flue gas, wherein the flue gas is applied to a phosphoric acid preparation process to produce and obtain phosphoric acid. The slag form of the electric furnace reduction smelting process is CaO-FeO-SiO₂-Al₂O₃-MgO-CaF₂And (5) forming slag. The slag form selected by the invention has the beneficial effects of low melting point of the slag and low smelting temperature. According to the invention, phosphorus and iron in the waste lithium iron phosphate battery can be effectively recovered by carrying out pyrometallurgical smelting in an electric furnace at 1300-1500 ℃, and the output is pollution-free.

The technical solution of the present application will be described in detail with reference to specific examples. It is to be understood that the following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

In examples 1 and 2, the components of the lithium iron phosphate waste battery are shown in table 1.

TABLE 1 lithium iron phosphate waste battery components (wt%)

Example 1

Firstly weighing 1t of iron phosphate slag, 300kg of granulated coal, 20kg of quartz sand, 10kg of lime, 20kg of magnesia and 20kg of bauxite, adding all the raw materials into a cylindrical mixer for mixing, adding water serving as a binder during mixing, adding 50kg of the binder, and then adding the mixed materials into an electric furnace for reduction smelting at the smelting temperature of about 1500 ℃, wherein the smelting time of each furnace is 1 hour.

The test result proves that the ferrophosphorus comprises the following components: 74.34 percent of Fe and 24.86 percent of P; the yield of the ferro-phosphorus is 387.12kg, and the smoke generation amount is 530.46Nm³In flue gas, P₂O₅The content of (a) was 5.35% by volume.

Example 2

Firstly weighing 1t of iron phosphate slag, 280kg of granulated coal, 20kg of quartz sand, 20kg of lime, 20kg of magnesia and 20kg of bauxite, adding all the raw materials into a cylindrical mixer for mixing, adding water serving as a binder during mixing, adding 50kg of the binder, and then adding the mixed materials into an electric furnace for reduction smelting, wherein the smelting temperature is about 1450 ℃, and the smelting time of each furnace is 1 h.

The test result proves that the ferrophosphorus comprises the following components: 74.34 percent of Fe and 24.86 percent of P; the yield of the ferro-phosphorus is 373.12kg, and the smoke generation amount is 516.58Nm³In flue gas, P₂O₅The content of (b) was 5.29% by volume.

It should be noted that, in the above two embodiments, the carbonaceous reducing agent is the granulated coal, which is not intended to limit the scope of the present invention, and other carbonaceous reducing agents or combinations thereof can achieve the technical effects of the present invention.

In summary, the invention optimizes the proportion of the iron phosphate slag, the carbonaceous reducing agent and the flux, adopts a pyrometallurgical method to place the iron phosphate slag, the carbonaceous reducing agent and the flux in a cylindrical mixer for mixing, then adds the mixture into an electric furnace for reduction smelting, and under the action of high temperature of 1300-1500 ℃, the iron phosphate slag, the reducing agent and the flux react to produce ferrophosphorus and P-containing phosphorus₂O₅Flue gas of steam and high-temperature slag, wherein the recovery rate of phosphorus and iron elements is high, the produced ferrophosphorus can be directly sold for sale, P₂O₅The steam is used for producing phosphoric acid, the furnace slag does not belong to hazardous waste residue and can be sold after being treated, high recovery rate extraction of phosphorus and iron is realized, and environmental protection benefit and economic benefit are also realized; in addition, the pyrometallurgical recovery method can be used for processing large-scale waste batteries, for example, the lithium iron phosphate waste batteries with the scale of more than 10 million tons can be processed.

The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in this art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.