Rotary Kiln

A rotary kiln is a thermal processing system used in both battery recycling and battery material manufacturing. It consists of a long, slightly inclined, rotating cylindrical tube in which materials are heated as they move steadily through the system.

In lithium-ion battery recycling, rotary kilns are a key part of the Material Separation and Material Recovery stages. They are used for pyrolysis — heating black mass or other battery components in an inert atmosphere to remove binders, organics, and harmful fluorine compounds without combustion. This “thermal cleaning” step produces a stable, purified product ready for hydrometallurgical metal recovery.

In battery manufacturing, kilns can be configured for precursor synthesis and active material calcination, offering precise temperature control and atmosphere management for critical material properties.

Rotary kilns are valued for their ability to provide continuous, high-throughput processing with adjustable residence times. They maintain full control over heating profiles, atmosphere composition, and sealing, making them essential where chemical changes must occur without contamination or oxidation.

Modern kilns are often paired with integrated cooling systems and modular offgas treatment to ensure both product quality and environmental compliance.

Common Types of Rotary Kilns in Battery Applications:

• Indirectly heated kilns (no flame contact; ideal for inert or controlled-atmosphere processing such as black mass pyrolysis)
• Direct-fired kilns (rare in battery recycling; used in some high-temperature material synthesis)
• Gas-tight sealed kilns (critical when processing hazardous or reactive materials)
• Mobile or modular kilns (for on-site or smaller capacity recycling operations)