Lithium-Ion Batteries Safely Recycled Using a New Process

September 2020
The recycling of lithium-ion batteries increasingly involves major challenges. BHS-Sonthofen has developed a new process through various research projects, which is being used for the first time in Scandinavia: A completely gas-tight process reliably prevents fires and the escape of toxic gases.

Fires occur frequently when batteries end up in the incorrect shredding machine. A new process developed by BHS-Sonthofen, which is being used for the first time in Scandinavia, avoids these risks. The batteries are initially fed into the process manually via a hopper. The batteries reach a single-shaft crusher via two electric slides. This process is overlaid with nitrogen from the start to avoid explosions. A screw conveyor transports the shredded material to the batch-type HTC dryer from BHS, which separates the hazardous electrolytes.

The dryer creates a vacuum and heats the input material slowly. The gases escape via a vapor filter, followed by two condensation units: a shell-and-tube heat exchanger and a plate heat exchanger separate the electrolytes. To neutralize harmful acids in the exhaust air, it is passed through a fat-bed reactor filled with milk of lime. A downstream activated carbon filter removes aromatized hydrocarbons from the exhaust air. The gas stream thus cleaned meets all legal specifications.

After drying, the shredded batteries are no longer dangerous. The remaining solid components are removed from the gas-tight area and passed through a dry mechanical sorting process. During this process, the fine black mass is screened. A zigzag sifter sorts the larger components into light and heavy fractions. The heavy fraction primarily contains coarse metallic materials that can be separated into ferrous and non-ferrous fractions by means of eddy current separators and an overbelt magnet. The light fraction passes through a carrier foil to a turbo mill and is finally separated through a screen into the finished metal concentrates.