CN116315220A - A recycling process for waste battery pole powder - Google Patents

Abstract

The invention discloses a recovery process of waste battery electrode powder. According to the invention, the dry stripping machine is adopted to strip and remove the electrode powder adhered to the surface of the copper aluminum foil sheet material or the electrode core sheet material before fine grinding and granulating, the stripped and removed copper aluminum particles can be quickly transferred into the first-stage grading bin, the removed electrode powder can be quickly transferred into the second-stage grading bin, the quick separation of copper and aluminum from the electrode powder is realized, the powder removing process can be completed under the condition of reducing copper and aluminum powder as much as possible, the repeated friction between the removed electrode powder and copper and aluminum in the stripping bin is prevented, the further fine grinding of the copper and aluminum material is prevented, and the improvement of the purity of the electrode powder is facilitated. The purity of the polar powder is directly recovered to be more than or equal to 96 percent after stripping and grading, and the purity of the polar powder is improved to be more than 98 percent after sieving by a sieve of 150-250 meshes.

Description

A recycling process for waste battery pole powder

technical field

The invention relates to the recovery of waste batteries, in particular to a recovery process of waste battery pole powder.

Background technique

my country has become the world's largest new energy vehicle market. In 2014, the sales volume of electric vehicles was 70,000, in 2015 it was 300,000, and in 2016 it reached 500,000. As the service life of batteries, key components of electric vehicles, gradually expires, the amount of scrapped power batteries is also increasing. In 2020, the cumulative decommissioning of power batteries in my country will reach about 200,000 tons, and by 2025 this figure will rise to about 780,000 tons.

Scrapped lithium-ion batteries contain lithium hexafluorophosphate, organic carbonates, heavy metals such as cobalt, lithium, and copper, and plastics. These are precious resources with high recycling value. At present, there are mainly two ways to recycle waste power lithium-ion batteries: one is cascade utilization, and the other is dismantling and recycling. Batteries whose capacity has dropped below 50% cannot be used any longer. They can only be disassembled and recycled as resources. , At the same time, for the cascade utilization of scrapped batteries, they also need to be disassembled and recycled as resources.

Lithium-ion batteries are composed of casing, positive electrode sheet (aluminum foil), positive electrode powder (lithium-containing compound), negative electrode sheet (copper foil), negative electrode powder (graphite), electrolyte, diaphragm, etc. The disassembly process is to use mechanical methods, physical Methods, chemical methods, etc. can maximize the separation of its various parts, improve its recycling rate, maximize its economic and social benefits, and reduce environmental pollution.

The existing process is that the copper-aluminum foil sheet material or battery pole sheet material after the waste lithium battery is crushed is directly sent to the grinding equipment such as a grinder or a ball mill to be finely ground and depowdered directly, because the material is made of copper-aluminum metal foil. The fluid adheres to its surface with a large amount of lithium-containing compounds (polar powder). If it is directly finely ground and de-powdered, a large amount of copper-aluminum powder will be mixed with the electrode powder to form a large amount of high-copper and aluminum powder, which will reduce the quality of the electrode powder. Sieve screening will also cause a large amount of extreme powder to lose its recycling value.

Contents of the invention

Aiming at the technical problem that direct fine grinding and depowdering will generate a large amount of copper-aluminum powder mixed with the pole powder to produce a large amount of high-copper-aluminum powder, which reduces the quality of the pole powder, the invention provides a recycling process for waste battery pole powder.

Technical scheme of the present invention is:

A recycling process of waste battery pole powder, before the copper and aluminum foil sheet material or battery pole piece material is finely ground and de-powdered, it is first sent to the stripping equipment, and the surface of the copper and aluminum foil sheet material or the battery pole piece material is glued by the stripping equipment The attached pole powder is peeled off, and the detached pole powder is conveyed out of the stripping chamber by airflow, and transferred to the rear-end grading chamber and dust collection chamber.

The electrode powder that falls off during the peeling process will not repeatedly rub against copper and aluminum, so the purity of the electrode powder in the grading bin and dust collection bin is high. Controlling the peeling speed during the peeling process can avoid a large amount of copper and aluminum foil from being finely ground, and more It is beneficial to improve the purity of the powder. About 80% of the electrode powder can be recovered after the copper and aluminum foil sheet or the battery electrode sheet is peeled off, and about 20% of the electrode powder can be further obtained through the traditional fine grinding process.

Further, the devices used in the above-mentioned recovery process include strippers, primary classifiers, secondary classifiers, dust collectors, induced draft fans, copper-aluminum sieves, pole powder sieves, grinding pulverizers and gravity separation equipment. The peeling machine, the primary classifier, the secondary classifier, the dust collector, and the induced draft fan are connected in sequence. The primary classifier is also connected to the copper-aluminum sieve, and the secondary classifier is also connected to the pole powder sieve, copper-aluminum sieve and After the powder is sieved, it is connected with a grinding mill and gravity separation equipment.

Furthermore, the stripping machine is a horizontal axis reflection type stripping equipment, which can effectively complete the stripping and depowdering process of copper and aluminum flakes.

Further, the peeling machine can also be changed to a vertical structure or a pulverizer to achieve the purpose of peeling.

Further, the first-stage classifier and the second-stage classifier can be replaced with one-stage or multi-stage cyclones to realize the rapid separation of the stripped copper and aluminum and the pole powder in the stripping machine chamber.

In the above device, the first-stage classifier is used to quickly transfer and collect the copper-aluminum material after surface de-powdering; the second-stage classifier is used to quickly transfer and collect the electrode powder falling off in the peeling bin; The dust collector is mainly used for intercepting the extreme powder end and improving the recovery rate of the extreme powder; the induced draft fan is the power source for conveying materials to the stripping machine, the primary classifier, and the secondary classifier; the copper The aluminum sieve is used to sieve the copper and aluminum collected in the grading bin, and sieve out the extreme powder contained in the copper and aluminum; Purity; the grinder is used for further finely grinding and depowdering a small part of the non-shedding pole powder in the copper and aluminum foil sheet material after dry stripping, and at the same time, the copper and aluminum foil is granulated to produce uniform particle size Copper and aluminum particles; the gravity separation equipment is used to effectively separate the copper and aluminum particles with uniform particle size after grinding.

The beneficial effects of the present invention are:

In the present invention, before finely grinding and granulating the copper-aluminum foil sheet material or battery electrode sheet material, a dry stripping machine is used to peel off the electrode powder adhered to the surface, which can reduce copper and aluminum fines as much as possible. Complete the powder removal process;

The copper and aluminum particles after peeling and depowdering can be quickly transferred to the first-level grading bin, and the shed electrode powder can be quickly transferred to the second-level grading bin to realize the rapid separation of copper, aluminum and electrode powder, thereby preventing the falling-off electrode powder Repeated friction with the copper and aluminum in the stripping chamber also prevents the further finerization of the copper and aluminum material, which is conducive to improving the purity of the electrode powder;

After stripping and grading, the purity of the electrode powder is directly recovered to ≥96%. In order to further improve the purity of the electrode powder, it can be sieved with 150-250 meshes to increase the purity of the electrode powder to more than 98%. Use ultrasonic screen to increase production capacity;

If copper and aluminum foil sheets or battery pole pieces are directly pulverized and finely ground for depowdering by traditional techniques, the detached pole powder will be repeatedly mixed with copper and aluminum materials in the grinding chamber, and the depowdered copper and aluminum on the surface will also be Continue deep grinding to produce a large amount of copper and aluminum powder mixed into the electrode powder, so that the recovery rate of the sieved electrode powder is only about 95%, and about 3% to 4% of the electrode powder loses its recovery value due to the high content of aluminum and copper; For scrap batteries measured in hundreds of thousands of tons, 3% to 4% not only means huge economic benefits, but also has great significance for the development of the industry.

If the copper and aluminum foil sheet or battery electrode sheet is directly crushed and finely ground according to the traditional process, the purity of the electrode powder will be low. It is necessary to use a sieve with a mesh size of 400 mesh or more to improve the purity of the electrode powder. The production efficiency is low and it is easy to block. Mesh, not conducive to continuous mass production;

If the copper-aluminum foil sheet or battery electrode sheet is first stripped and de-powdered by a stripping machine for the powder adhered to the surface, about 80% of the scrap after pyrolysis and carbonization in the early stage can be de-powdered. The purity of the electrode powder directly recovered in the second electrode bin under the aid of the machine can reach more than 96%. If it is sieved through 150 mesh or 250 mesh, the purity of the electrode powder can be increased by 1% to 2%, and it is suitable for continuous mass production;

After the stripping and depowdering process, 80% of the pole powder can be recovered. The remaining 20% of the pole powder in the copper and aluminum foil sheet is obtained by traditional methods. Only one-fifth of the total pole powder is involved in the crushing and fine grinding process. It can greatly reduce the generation of high-copper aluminum powder, and improve the recovery rate of the extremely powder on the basis of improving the quality of the recycled extremely powder.

Description of drawings

Fig. 1 is the block flow diagram of recovery process of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with specific examples, but the present invention is not limited thereto.

Example 1

1 ton of ternary battery scrap that has undergone high-temperature pyrolysis and linear sieving contains about 46.15% of positive electrode powder, about 12.82% of negative electrode powder, and about 20.5% of copper and aluminum. The recovery rate of the positive and negative electrode powder is about 95%, about 560.215kg can be recovered, and about 438.425kg of positive electrode powder can be recovered, and the purity is about 95%. The recovery value is about 52062.97 yuan.

If 80% of the powder is stripped first, and then crushed and finely ground to remove the powder, the recovery rate of the powder can reach more than 97%, and the purity can reach about 98%. Then the same positive powder can be recycled about 447.655kg, and the recovery value of the positive powder is about 54837.74 Yuan.

First use the stripping and depowdering process and then go through the crushing and fine grinding process. In the case of 1 ton of ternary battery scraps of the same weight, an additional net profit of 2,774.77 yuan can be obtained. If 5,000 tons of ternary batteries are processed annually, it can gain more in one year. The net profit is about 10.8216 million yuan.

Claims (6)

1. The recovery process of the waste battery pole powder is characterized in that the waste battery pole powder is firstly sent to stripping equipment before the copper aluminum foil sheet material or the battery cell pole piece material is finely ground and destoner, the pole powder adhered to the surface of the copper aluminum foil sheet material or the battery cell pole piece material is stripped by the stripping equipment, and the desquamated pole powder is conveyed to leave a stripping bin through air flow and is transferred to a grading bin at the rear end and a dust collection bin.

2. The process for recycling spent battery pole powder according to claim 1, wherein the non-exfoliated pole powder is further obtained by a conventional fine grinding process.

3. The device adopted by the recovery process according to claim 1 or 2, which is characterized by comprising a stripping machine, a primary classifier, a secondary classifier, a dust collector, a draught fan, a copper-aluminum screen, a pole powder screen, a grinding pulverizer and gravity separation equipment, wherein the stripping machine, the primary classifier, the secondary classifier, the dust collector and the draught fan are sequentially connected, the primary classifier is also connected with the copper-aluminum screen, the secondary classifier is also connected with the pole powder screen, and the copper-aluminum screen and the pole powder screen are connected with the grinding pulverizer and the gravity separation equipment.

4. A device according to claim 3, wherein the stripper is a horizontal axis reflective stripping apparatus.

5. A device according to claim 3, wherein the stripping machine is of a vertical construction or a shredder for stripping purposes.

6. A device according to claim 3, wherein the primary classifier and the secondary classifier are capable of being one or more stages of cyclones.

Images