Battery recycling: shredding, separation and black mass processing

Mechanical sample preparation and process development for lithium-ion batteries

In battery recycling, mechanical processing is a crucial step in producing a usable intermediate fraction – the so-called black mass – from used lithium-ion batteries. Typical process steps include safe discharge, disassembly, comminution, sieving, magnetic separation, and the separation of aluminum, copper, plastic, and active material fractions. For laboratories, pilot plants, and process development, reproducible particle sizes, defined material flows, and clean sample division are essential. LITech supports this process chain with machines for pre-comminuted grinding, fine grinding, and representative sample preparation.

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Practical benefits of battery recycling and processing

The controlled shredding of used batteries creates the conditions for reliable analyses, safe process development, and the economical recovery of critical raw materials. It is used to provide black mass for hydrometallurgical processes, to characterize material flows, to design pilot plants, and to scale up recycling processes from the laboratory to pilot plant or production scale.

Material data for battery recycling

The focus is primarily on used lithium-ion batteries from production, electronics, energy storage, or electromobility. The material has a heterogeneous structure and, depending on the cell chemistry, contains active materials, metal foils, plastics, electrolyte residues, and casing components. Cell chemistry, residual energy, particle composition, metal content, and the desired end product are particularly relevant for designing the reprocessing process.

Property	Value
Use case	Mechanical reprocessing of used lithium-ion batteries
Alternative terms	LIB recycling, Li-ion recycling, black mass processing
Typical ingredients	Cells, modules, production rejects, electronic batteries, EV batteries
Relevant recyclable materials	Lithium, nickel, cobalt, manganese, copper, aluminum, graphite
Essential accompanying substances	Plastics, separator films, housing materials, electrolyte residues
Material character	Heterogeneous, multi-component, containing metals and polymers
Process-critical property	Residual energy and safety risk before shredding
Separation-relevant characteristics	Grain size, density, magnetizability, material composition
The goal of mechanical processing	Dissolution of the compounds and production of defined fractions or black mass.
Important notes	Composition and behavior depend strongly on cell chemistry and structure.

How does battery recycling work in mechanical processing?

Before the actual metal recovery, batteries are first safely discharged and – depending on the process design – pre-sorted or disassembled. This is followed by controlled comminution. The aim is to break down the material composites and enable defined fractionation. In subsequent steps, coarser casing and foil components are separated from the finer active material fraction. This fine fraction is commonly referred to in the market as black mass and then serves as feedstock for hydrometallurgical or pyrometallurgical recovery processes.

Process step	Objective	Typical machine or method	Typical result
Safe unloading and preparation	Reduce risk before reprocessing	Unloading, pre-sorting, dismantling	Safe starting state for the process
Pre-shredding	Bringing large components down to processable size	Jaw crusher or suitable pre-crushing	Defined coarse fraction
Primary comminution	Unlocking material composites	Hammer mill	Release of active material as well as metal and plastic fractions
Sieving and classification	Separate fractions according to grain size	Sieving machine or analytical sieving	Coarse and fine fractions
Magnetic separation	Separating ferromagnetic components	Magnetic separator	iron-containing fraction separated
Fractionation of the fine fraction	Enrich black mass	Sieving and further separation steps	Fine fraction containing active material
Fine grinding for analysis	Bringing the laboratory sample to analytical resolution	Vibrating disc mill	Reproducible fine sample
Sample division and homogenization	Obtain a representative subsample	Rotary sample divider	Comparable and reproducible laboratory sample

Typical process parameters in battery reprocessing

The exact settings depend heavily on cell format, chemistry, safety concept, and target product. For laboratory and pilot plant trials, the feed size, target particle size, throughput, separation steps, and desired sample representativeness are particularly important. The following table shows typical guideline values for mechanical preparation and sample preparation.

Parameter	Typical range or guideline value
Feed size before primary comminution	Up to approximately 30 mm for prepared fractions
Target particle size of the mechanical fine fraction	Approximately 0,5 to 2 mm
Throughput mechanical comminution	Laboratory- to pilot-plant dependent, from experimental scale to several hundred kg/h
Safety requirements	Only after safe unloading and a suitable safety concept
Important separation criteria	Grain size, density, magnetizability, material type
Analytical fine sample	Depending on the method, grinding down to the analytical fineness is possible.
Sample division	Representative and reproducible required
Process goal	Black mass production, fractionation, material characterization, process development

Variants and alternatives in battery recycling

Dry mechanical vs. downstream metallurgy

Mechanical processing primarily serves to break down material composites and generate fractions for further recovery steps. The actual metal recovery then usually takes place hydrometallurgically or pyrometallurgically. The mechanical stage directly influences the purity, homogeneity, and economic efficiency of the subsequent processes.

Laboratory vs. pilot plant

In the laboratory, the focus is on reproducible sample preparation, material characterization, and process development. In pilot plants or on an industrial scale, throughput, reliable material handling, and stable fractionation are paramount.

Direct black mass production vs. selective fractionation

Depending on the objective, the process can be designed for the most efficient possible production of black mass or for further fractionation of metal foils, iron content, casings and active material.

Which machines are suitable for battery recycling?

For the coarse and pre-crushing of hard or brittle battery components, robust processing machines such as jaw crushers or hammer mills are suitable. A disc mill is useful for the rapid fine grinding of defined, dry sample fractions down to analytical fineness. If tough, fibrous, or film-containing components are the primary focus, a cutting mill can be a suitable alternative. For reproducible laboratory results, representative sample division – for example, with a rotary sample divider – is also recommended.

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Technical questions about battery recycling and black mass

Use LITech AI for questions about mechanical processing, black mass, separation stages, target particle sizes, suitable machines and typical laboratory procedures in lithium-ion battery recycling.

Frequently asked questions about battery recycling

Black mass is a fine fraction containing metals and active materials from the recycling of lithium-ion batteries. Depending on the cell chemistry, it contains, among other things, lithium, nickel, cobalt, manganese, and graphite.

The comminution process breaks down material composites, increases the surface area and enables the separation of active material, metal foils, plastics and housing components.

Typical processes include safe unloading, disassembly or pre-sorting, comminution, sieving, magnetic separation, fractionation and sample division.

A jaw crusher is suitable for hard and brittle components. A hammer mill is frequently used for high-performance, near-process crushing.

For the production of a fine fraction or black mass, particle sizes in the lower millimeter range are often targeted. The exact target size depends on the battery chemistry, separation concept, and subsequent processing.

Only representative subsamples provide reliable analytical values. This is particularly important because battery materials are heterogeneous and contain various fractions.

A cutting mill is useful when tough, fibrous or film-containing components such as plastics or separators are the main focus.

The resulting black mass or defined fine fraction is then usually further processed hydrometallurgically or pyrometallurgically to recover valuable metals.