What the site does
Sriperumbudur and the wider Chennai corridor host one of India's heaviest concentrations of vehicle assembly, electronics manufacturing and export logistics. The refinery opened in the Mahindra World City SEZ in 2018, making it the network's longest-running Indian refining site, and at 32,000 TPA it remains the largest. Its location puts it within reach of both southern manufacturing clusters and Chennai's port.
As a hydrometallurgical refinery it receives black mass rather than packs. Feed arrives from the network's Indian campuses and grading sites and from registered third-party shredders, and leaves as battery-grade nickel sulphate, cobalt sulphate and lithium carbonate. Because it has been running the longest, the site holds the network's deepest assay history for the LFP and NMC chemistries common in Indian vehicles.
What arrives at the gate
Feedstock at Sriperumbudur, Tamil Nadu reflects its catchment and plant type. Every consignment is weighed, photographed and logged against the originating manifest before it enters the process area.
- Black mass from Indian integrated campuses
- Third-party black mass from registered shredders
- Cathode production scrap from cell and material makers
- Off-specification electrode material from southern Indian manufacturing
The process, step by step
The 3 operating lines — black mass leaching, solvent extraction, battery-grade salt crystallisation — run the sequence below.
| Stage | What happens |
|---|---|
| Feed assay & sampling | Incoming black mass is homogenised and assayed by ICP-OES for Li, Ni, Co, Mn, Cu, Al and fluoride before it is released to leach. |
| Sulphuric acid leaching | Two-stage leach at 60–85 °C with peroxide reductant dissolves cathode metals at 96–99% extraction efficiency. |
| Impurity removal | Iron, aluminium and copper are precipitated and filtered; graphite is recovered as a separate low-ash cake. |
| Solvent extraction trains | Sequential Co, Ni and Mn circuits with counter-current mixer-settlers deliver individual metal raffinates. |
| Crystallisation & drying | Nickel and cobalt sulphate hexahydrate plus lithium carbonate are crystallised to 99.5%+ battery grade and bagged under nitrogen. |
| Batch certification | Every batch ships with a certificate of analysis, mass balance and chain-of-custody record for EPR and IRA reporting. |
What sets the site apart
Longest operating record. Running since 2018, the refinery has the most complete assay history for Indian feed chemistries anywhere in the network.
Port-adjacent logistics. Proximity to Chennai port simplifies moving refined salts and permitted intermediates in and out of the country.
Batch-level certification. Every output batch ships with an analysis certificate and mass balance that producers can use in their EPR reporting.
Where material goes next
Material that Sriperumbudur, Tamil Nadu does not finish on site moves to the nearest specialist facility in the network, keeping transport distances and dwell times down.
| Facility | Role | Distance |
|---|---|---|
| Bengaluru — Hosur Diagnostics Centre | Cell Grading & Diagnostics | 230 km |
| Nagpur — Butibori Second-Life Works | Second-Life BESS Works | 893 km |
Field note