FR3121150A1 - Recovery of shredded electric vehicle batteries - Google Patents

Abstract

Pyro-metallurgical process for recycling shredded waste from the production of new and defective or used batteries from electric vehicles or portable Li-ion type batteries. Figure for abstract: FIGURE 5

Description

Pyro-metallurgical process for recycling shredded waste from the production of new and defective or used batteries from electric vehicles or portable Li-ion type batteries.

The batteries of electric or portable vehicles of the Li-ion type include valuable elements that it is important to properly recycle, Copper Cu, Aluminum Al (2 metals present in metallic form), Nickel Ni, Cobalt Co , Manganese Mn and of course Lithium – the latter in the form of combined oxides.

In all known sectors, the recycling of these batteries - whether they are scrap or waste from the production of new batteries, used batteries or defective new batteries - goes through a grinding stage (shredder-type grinder), which separates Copper and Aluminum (metals) in good proportions, and produces a "Black Mass" bringing together the other metals as well as a significant proportion of carbon, in elemental (fixed C) or combined form, in plastics and oils assimilated to hydrocarbons.

It is specified that during the production of new batteries, waste is produced such as waste from the cutting of anode and cathode coils, scrap anodes and cathodes, assemblies of defective anodes and cathodes called bundles , defective assemblies of anodes and cathodes put in a bag without solvent called dry cell and defective bags with solvents. By way of example, a synoptic of the production of waste in the manufacture of new batteries is attached.

Several solutions are currently proposed and tested to valorize this Black Mass, most often by hydro-metallurgical means – and in several stages.

This document proposes a pyro-metallurgical recovery solution that goes through 3 stages:
- Black Mass agglomeration (pelletizing, briquetting, or extrusion) – with addition of iron ore and a suitable binder
- A carburizing fusion in a rotating converter (or another type of converter equipped with a stirring device), allowing the separation of the Lithium in a slag at 40-50% Li2O, easily recoverable in the current production channels for this metal
- Oxidizing refining in the same converter, or in a second specialized converter, leading to an alloy of the FeNiCo type containing at least 50% (Ni+Co), which can be used in the production of high-strength steels (in particular steels used in aeronautics), and a slag rich in manganese, iron and lime, which constitutes an excellent raw material for furnaces for the production of Ferro-Manganese.

Contents
1. Problem to be solved .............................. .................................................. .......3
1.1 Composition of electric vehicle batteries ...................................................... .........3
1.2 Recycling sector – Objective of the proposed process ............................................... .......6
1.3 State of the art .............................................. .................................................. ......7
1.4 Principle of the proposed process ............................................... ..........................................9
2. Example ............................................... .................................................. .....................11
2.1. Composition of the “Black Mass + Fe Ore” mix......................................... ..........11
2.2. Material balances ................................................ .................................................. .......11
2.2.1. Amalgamation ................................................ .................................................. .................11
2.2.2. Refining ................................................ .................................................. ..............12
2.3. Valuable opportunities .................................................. ..............................................12
2.4. Case of a Low Phosphorus Black Mass .............................................. ...........................13
3. Summary........................................... .................................................. ........................15

1. Problem to solve

1.1 Constitution of electric vehicle batteries

Electric vehicle batteries are of 2 types:
- NiMH (Nickel Metal Hydride) type batteries
- Li-ion type batteries

It is this last type which tends to impose itself nowadays. The possibility and efficiency of recycling Li-ion batteries is a major challenge in the development of electric vehicles or portable applications (telephony, computers, electric bicycles, etc.).

The recycling of Li-ion batteries is giving rise to significant developments among the manufacturers of these batteries, and multiple alliances have recently been formed for this purpose.

We propose in what follows a solution combining grinding and a pyrometallurgical process for the complete recycling of these Li-ion batteries.

The principle and the exact constitution of these Li-ion batteries are widely described elsewhere, we will simply recall the size of these batteries, which weigh from a few grams (button type) to several hundred kg, as suggested on the above, and give the overall composition in Table 1.

: Overview of an electric vehicle battery

[Table 1] Composition - type of a Li-ion battery

The active core of the battery (cathode / anode / electrolyte) is mainly composed of oxides and/or phosphates such as LiNiO2, LiCoO2, LiMnO2, LiFePO4, graphite and fluoride LiPF6 for the electrolyte, dissolved in an organic solvent .

More specifically, the production of new batteries is accompanied by the production of several levels of waste or scrap, such as waste from the cutting of anode and cathode coils, scrap anode and cathode, assemblies of defective anodes and cathodes referred to as bundles, defective anode and cathode assemblies packaged without solvent referred to as dry cell and defective pouches with solvents.

By way of example, Table 2 below presents a synoptic of the production of this waste in the manufacture of new batteries, at different stages.

[Table 2] Overview of waste production in the manufacture of Li-ion batteries The valuable elements that it is crucial to properly recycle because of the environmental and energy cost, are Copper Cu, Aluminum Al (2 metals present in metallic form), Nickel Ni, Cobalt Co, Manganese Mn and of course Lithium – although the latter is less expensive in economic and ecological terms.

We note the potentially significant presence of Phosphorus P, a steel pollutant, and of Fluorine F, a source of corrosion of the refractories and steels making up the treatment installation.

1.2 Recovery sector – Objective of the proposed process

Recycling of large Li-ion batteries mostly involves complete shredding ( )

Li-ion batteries in the grip of a crusher

This grinding and subsequent separation tools effectively separate the metals present in metallic form – Al, Cu and Fe (steel). The remainder is crushed and/or recovered in the form of a muddy mass, made up of fines of less than 2 mm, and an organic liquid, mass called “Black Mass”

The objective of full recycling is to recover in usable forms
all elements of value, in usable forms. This objective can be achieved by different types of processes – hydro-metallurgical or pyro-metallurgical. The whole of the sector is schematized in the below.

Whole chain of Li-ion battery recycling

1.3 State of the art

At the present time, it seems that most of the companies or groups which have embarked on the recycling of Li-ion batteries are experimenting or moving towards a scheme such as presented at , with crushing and recovery of the Black Mass by hydro-metallurgical processes

This sector is presented as an example on the diagram of the below,
published by Volkswagen.

An example of a Black Mass analysis is given in Table 3 below.

Black Mass analysis (% mass, dry)

It should be noted that:
- This analysis is representative of a "mix" of batteries from various sources, and therefore containing various active compounds, and in particular a large proportion of batteries with an active compound containing Phosphorus P (e.g. LiFePO4)
- If one starts from used batteries of the same type free of Phosphorus or with a low P content, in particular if batches of defective new batteries without P are recycled on an installation, the P content will be very low or nothing.
- There are still significant residual contents of Copper Cu and Aluminum Al, present in metallic form, and therefore incompletely eliminated in the grinding and subsequent separation step
- The high phosphorus content must be eliminated as best as possible from the metal to be recovered.

Recycling sector for Li-ion batteries with hydrometallurgical treatment of Black Mass (according to Volkswagen)

We will not make here a comparison of the sectors proposed, but we can simply say that in this case the hydro-metallurgical processes present a priori heavy handicaps compared to a pyro-metallurgical process.
- They require a large number of steps (at least as many as the metals to be separated);
- they are very large consumers of chemical reagents that are dangerous for humans and the environment and expensive;
- they will lead to more ultimate waste (polluted acid solutions) to be neutralized and placed in storage.

This is provided that a pyro-metallurgical solution can achieve the goal of extracting all valuable metals into a usable form.

1.4 Principle of the proposed process

The proposed process comprises 3 steps:
- An agglomeration of the Black Mass (pelletizing, briquetting, or extrusion) – with an appropriate binder
- A fuel-reducing fusion in a rotating converter (known as TBRC, Top Blown Rotary Converter) or possibly in a fixed converter whose bath is agitated by another means, in particular by injecting gas into the bottom of the reactor
- An oxidative refining in the same converter, or in a 2nd specialized converter
The process is schematized in .

Diagram of the proposed pyro-metallurgical process

The principle of the process, and the objectives of each step, can be summarized as follows:
1) The agglomeration of the Black Mass with a binder and possibly an addition of an iron source (see later) aims to obtain a product sufficiently resistant to be stored in bulk then in the hopper, and to be loaded continuously into the converter by a conveyor
2) The carburizing-reducing fusion must make it possible, by using the carbon contained in the Black Mass, to "reduce" the oxides of the reducible metals (Ni, Cu, Co, Fe, Mn), and to recover them with a good yield in a carburized metal alloy, called FeNiCoMnC; in this step, the aim is to separate the lithium in a slag rich in Li (~50% Li) and also to desulfurize and partially dephosphorize the metal obtained. The energy input necessary for these very endothermic reduction reactions is provided mainly by the combustion of the CO gas resulting from the oxide reduction reactions, and by the combustion of the excess carbon (in the form of fixed C and HC hydrocarbons) by an injection of oxygen; depending on the composition of the Black Mass, an additional energy supply may be necessary, by a gas-oxygen burner.
3) An oxidizing refining by injection of oxygen then makes it possible to extract from the FeNiCoMnC alloy, the Manganese, the Carbon, and a large part of the Phosphorus, in order to obtain, on the one hand, a FeNiCo alloy usable in the manufacture of certain high-alloy steels, and on the other hand, a slag rich in Manganese and lime, which can be used in the manufacture of FerroManganese.
In this step, the presence of iron in a large proportion makes it possible to “protect” the metals of greater value (Ni and Co) The alloy is cast either in a ladle or in ingots on an ingot machine – as presented in – and the slag is poured into a ladle, from where it can possibly be granulated or poured into a heap to allow its natural cooling or accelerated by sprinkling water.

2. Example

2.1. Composition of the mix “Black Mass + Mineral Fe

To the Black Mass of composition given in Table 2, standard iron ore containing 94% iron oxide Fe2O3 is added, in the proportion 1 t BM + 0.5 t Fe ore. A mixture results. ) of the composition shown in Table 4 below.

[Table 4] Composition of the Black Mass + Fe Ore mix

2.2. Material balances

2.2.1. Merger

The melting stage is carried out in the converter, according to the material balance presented in Table 5 below.

[Table 5] Melting material balance

The fusion therefore gives, for 1 t of Black Mass,
451 kg of FeNiCoMnC alloy, with the composition indicated in Table 4; an acceptable S content (0.1%) is observed, but the P content (0.56%) is much too high for use as an alloy raw material. in the carburized alloy.
150 kg of slag rich in Li (42% Li2O); in this case the yield is taken as a flat rate of 1, knowing that with the recycling of the dust all the Li will finally be recovered in the slag
13 kg of dust recovered in the gas treatment line by filtration, which will be recycled in the input mixture to be agglomerated.

2.2.2. Refining

The refining step consists in extracting the Manganese, an easily oxidizable metal, by injecting oxygen, at the same time as the Carbon, a large part of the Phosphorus, and a part of the Iron will be eliminated. A summary of this refining step is presented in Table 6.

Energetically, all of these oxidation reactions are largely exothermic, and will more than cover reactor losses.
[Table 6] Material balance of refining

The refining therefore gives, for 1 t of Black Mass,
312 kg of FeNiCo alloy with the composition indicated in Table 5; there are acceptable contents of S (0.069%) and P (0.081%)
We note in the right column the yields of the metals recovered in the FeNiCo alloy – distinguishing the yield during refining, and the overall yield of the element, starting from the Black Mass.
257 kg of slag rich in Mn, Fe and lime
14 kg of dust whose composition is close to that of slag, to which they can be incorporated before pouring.

2.3. Rewarding opportunities

The 3 products obtained have guaranteed outlets, and the uses can be specified:
- The FeNiCo alloy at 49%Fe, 35%Ni, 14%Co can be advantageously used in the production of high-alloy steels of the Maraging type, used in aviation, and which typically contain 17~19%Ni, 8 ~12% Co. It can therefore replace Ni and Co inputs in the form of ferroalloys.
- The slag rich in Li2O (40 to 50% depending on the content of the Black Mass) constitutes a very rich Li ore that can easily be incorporated into the extraction and production of Li by hydrometallurgy.
- FeO-MnO-CaO slag containing ~27%MnO (~21%Mn) will be a raw material of choice for carbothermic reduction furnaces producing ferromanganese. In these furnaces, 40% Mn, but large quantities of CaO lime are added thereto, because a high basicity of the slag obtained favors the Manganese yield. The FeO-MnOCaO slag resulting from the upgrading of the Black Mass will therefore replace both a Manganese ore, an addition of CaO lime, and an addition of Iron.

2.4. Case of a Low Phosphorus Black Mass

A Phosphorus-free or low-Phosphorus Black Mass has a similar typical composition, an example of which is given in Table 7 below.

The phosphorus content here is 10 times lower than in standard black-mass.

[Table 7] Typical composition of a low phosphorus black-mass

A usable die is of course the die described for high phosphorus black-mass, comprising 2 stages (melting and refining) and ultimately giving a low phosphorus FeNiCo alloy usable in the production of high-alloy steels with high Ni contents. and Co.

The results of this sector are collated in Table 8 below.

[Table 8] Melting and refining balances for Low Phosphorus Black Mass

However, it appears that the main poison element for the recycling of high-value metals (Ni and Co), namely Phosphorus, is in this case well eliminated from the smelting stage, where it is lowered to less than 0 .1%P in the FeNiCoMnC ferroalloy.

Admittedly, the FeNiCo alloys of the "Maraging" type present in their standard analysis low Mn and C contents (often less than 0.2% each). However, possibilities of direct use of the FeNiCoMnC ferroalloy may exist, either by introducing them in a preliminary phase of the development (where Mn and C will be eliminated), or for versions derived from these types of ferroalloy, tolerating higher contents. of Mn and C.

3. Summary

Li-ion type batteries include as valuable elements that it is crucial to properly recycle, Copper Cu, Aluminum Al (2 metals present in metallic form), Nickel Ni, Cobalt Co, Manganese Mn and of course Lithium – the latter in the form of combined oxides.

In all the known sectors, the recycling of these batteries - whether waste from the production of used batteries or defective new batteries - goes through a grinding stage (shredder-type grinder), which separates in good proportions Copper and Aluminum (metals), and produces a "Black Mass" bringing together the other metals, as well as a large proportion of carbon, in elemental (fixed C) or combined form, in plastics and oils assimilated to hydrocarbons .

Several solutions are currently proposed and tested to valorize this Black Mass, most often by hydro-metallurgical means – and in several stages.

This document proposes a pyro-metallurgical recovery solution that goes through 3 stages:
- Black Mass agglomeration (pelletizing, briquetting, or extrusion) – with addition of iron ore and a suitable binder
- A carburizing-reducing fusion in a rotating converter (or another type of converter equipped with a stirring device), allowing the separation of the Lithium in a slag at 40-50% Li2O, very recoverable in the current elaboration sectors of this metal
- Oxidizing refining in the same converter, or in a second specialized converter, leading to an alloy of the FeNiCo type containing approximately 50% (Ni+Co), which can be used in the production of high-strength steels (in particular steels used in aeronautics), and a slag rich in manganese, iron and lime, which constitutes an excellent raw material for furnaces for the production of Ferro-Manganese.

Claims (1)

There are no claims