The Kell Process: Comparative advantages over Smelting

1. Kell Process PGM production pipeline of <2 weeks vs 10-14 weeks for smelting

  • Reduction in inventory lock-up cost results in 1-3% additional effective recovery for the Kell Process

2. Smelting melts the whole concentrate to recover the PGM, Au and base metals


Kell only dissolves the base metal sulFides and precious metals, leaving most of the gangue minerals in their original form

  • Kell Process operating costs – 50-60% of smelting & refining
  • Total energy consumption – 50% of smelting
  • Electrical energy consumption – less than >80% of smelting
  • Energy consumption costs – 25% of smelting (based on RSA tariffs)
  • CO2 emissions – 70% reduction
  • Installed electrical power requirement – less than 90% of smelting (e.g. 38 MW for smelting and 4 MW for Kell for 25 t/h UG2 concentrate)
  • The Kell Process works with lower grade concentrates and is less sensitive to gangue minerals such as talc and chromite
  • Lower volumes of solid waste production
  • Metal production in country = sovereign beneficiation and value addition
  • Zero toxic waste

3. Kell achieves comparable metal recoveries to smelting (~96% value recovery) and recovers Cobalt from PGM concentrates

  • Very importantly, Kell recovers Cobalt which is mostly lost in the PGM smelting/converting process. The value of Cobalt currently lost by the PGM industry in Southern Africa amounts to more than $200 million per year and the value of Cobalt contained in Southern African PGM resources is $37 billion - most of which will be lost to smelter slag under current technology.
  • Kell can increase the recovery at the concentrator by removing the concentrate grade and quality constraints imposed by shipping and smelting.

4. Kell has no constraints on smelter grade or impurities such as Cr2O3, MgO

  • Allows for higher concentrator mass pulls to lower grade, higher impurity concentrates
  • Can result in 5-15% additional recovery of metals at the concentrator compared with smelting