The waste minerals that are physically enclosed within the individual grains or nodules of an ore, particularly in phosphatic deposits. Because this material is locked inside the target mineral structure, it cannot be separated by simple crushing and washing. Metallurgists must account for endogangue when designing chemical or thermal extraction processes, as it lowers the overall grade of the concentrate.
Heard on the job
We can wash away the clay, but the silica endogangue will require a more aggressive chemical separation to meet the purity specs.
Do not mix it up with
- Exogangue: Endogangue is trapped inside the ore grains, whereas exogangue is the loose waste material sitting between the grains.