 |
The huge increase in the use of lithium-ion batteries has led to a growing need for Li-ion battery recycling. For this, the hydromet process is widely used. pH and ORP control are essential to maximizing the recovery of valuable components and for process efficiency.
However, the presence of hydrofluoric acid in the process makes in-line pH and ORP (redox) measurement very challenging, as the acid is corrosive to glass.
The hydromet process involves acid leaching at very low pH that takes place in oxidizing conditions, necessitating ORP control in addition to pH control.
This application note looks at the hydromet process for Li-ion battery recycling, why tight pH and ORP control are so critical, and METTLER TOLEDO's solutions for reliable in-line measurement.
The InPro™ 3252i and InPro 4262i sensors both simultaneously measure pH and ORP and are designed to withstand hydromet process conditions. Both sensors feature hydrofluoric acid-resistant glass membranes, leading to a long operating lifetime in Li-ion battery recycling.
For hydromet processes with a high concentration of suspended solids, the InPro 4262i has a solid polymer electrolyte and open junction reference system that resists clogging. For processes with a low to medium solids load, the InPro 3252i, with pre-pressurized reference electrolyte and ceramic diaphragm, is more suitable.
METTLER TOLEDO’s Intelligent Sensor Management (ISM™) technology in both sensors provides additional measurement reliability. ISM sensors continuously monitor their condition and predictively communicate when maintenance will be required.
Scheduling sensor calibration and/or replacement becomes easy and avoids using sensors that are no longer performing reliably. ISM sensors feature an on-board microprocessor that stores calibration data. Proprietary software supports calibration in any convenient location using a laptop computer. Running an ISM maintenance program can reduce the workload by up to 90 %.
.png/_jcr_content/renditions/cq5dam.web.1280.1280.png "ISM pH Sensors")
.png/_jcr_content/renditions/cq5dam.web.1280.1280.png "Transmitters")
