Skip to Menu Skip to Search Contact Us Finland Websites & Languages Skip to Content

SGS has significant expertise developing traditional gravity separation flowsheets using gravity recovery tests such as the gravity recoverable gold test (GRG test). 


These improve gold recovery.

Gravity separation can quickly generate a precious metal concentrate that can be sold direct to refineries, resulting in better payment terms, faster payback and immediate cash-flow. The small footprint of these gravity plants means less capital outlay and better security for small-volume, high-value concentrates.

SGS experts use the gravity recovery gold (GRG) technique to assess:

  • The amount of gravity recoverable gold in a sample
  • The feasibility of a direct refining product vs a to-smelter concentrate
  • Efficiency of base metal vs gangue 
  • Gold recovery of tailings

The gravity recoverable gold (GRG) test (as designed by Laplante, A.R., F. Woodcock and L. Huang, 2001) generates data that enables the scale-up and design of a gravity treatment circuit. In practice, composites are prepared that are then passed through the Falcon concentrator. The concentrate is retained while the tailings sample is recovered and reused. The concentration from each pass and the final tailings are assayed for gold and silver, which gives gravity/release data.

The concentrates are cleaned using a Mozley Laboratory Separator (MLS), and the MLS concentrate is assayed for gold. The tailings from the MLS are recombined with the tailings from the Falcon for final assessment. The gravity tails feedstock is assayed in duplicate for gold and silver. 

SGS can provide bench-scale flowsheet development, pilot scale testing and plant audit and optimization services, depending on the needs of a project or facility. With our array of equipment and experience, we can readily provide bankable cost effective processing flowsheets and advice on operational best practices during plant start up based on our extensive production experience.