SGS has significant expertise incorporating gravity separation in gold flowsheets.
It is an attractive unit operation as it has high efficiency, low capital and operating costs, is easy to secure and uses few if any chemicals that might cause environmental concerns. Gravity separation always features in any flowsheet where there is sufficient difference between the specific gravity of the valuable and gangue minerals.
There are many testing procedures and types of equipment available for gravity separation. As an impartial third party, SGS provides the assessment required to develop a flowsheet that is optimized for your ore. Since we do not sell gravity separation equipment, we are truly impartial when it comes to determining the optimal flowsheet for your ore.
SGS experts can evaluate the following options:
- Knelson Concentrator
- Mozley Multi-Gravity Separator
- Falcon Concentrator
- Gekko Systems Protocol gravity separation test
- Wilfley tables
Including gravity separation protocols in gold flowsheets provide several benefits including:
- Optimizing recovery as there is less gold in the circulating load
- Reducing the possibility of gold losses to tailings
- Increasing overall recovery as particles of metallic gold are captured and treated
- Removing significant amounts of gold (often up to 30%) early in the processing circuit, with limited handling and no reagents
- Decreasing carbon requirements during CIP
Process mineralogy is valuable to the success of gravity separation and SGS has the industry-leading high definition mineralogy capability required. High definition mineralogy tools such as QEMSCAN® rapidly and inexpensively analyzes hundreds of thousands of points on a polished section, providing critical deportment information. Data generated by the QEMSCAN® guides the selection of grind size, thus liberation, optimizing the amount of gold that can be recovered by gravity separation.
The Knelson Separator consists of a conical drum with a series of V-shaped riffles. It is the preferred choice for free milling gold.
Mozley Multi-gravity Separator
The Mozley separator is operates at a lower g force than the Knelson or Falcon. It is used for the recovery of ultra-fine particles that have similar specific gravities.
The Falcon Concentrator is a conical, vertically spinning, smooth walled drum, with slurry moving upward from the central feedpoint. The main separation mechanism is percolated trickling, enhanced by the centrifugal force. It has traditionally been used for mid-density separations, especially sulfide minerals.
Gekko Systems Protocol Gravity Separation Test
This test involves processing a sample over a Wilfley shaking table several times in succession at progressively finer grind sizes. The combined concentrates from the progressive grinding stages are tabled again and additional concentrate splits are generated. These are recombined. The tailing (if any) from this stage is recombined with the initial tailings.
The mass concentrate is again ground and tabled. All resulting products are dried, weighed, sampled and assayed for gold and silver. After data review, a tailing is identified and proportionally recombined with tailings generated earlier.
SGS’s technical experts provide you with impartial assessment of gravity separation techniques to design the circuit that is best for you ore. SGS has the combined mineralogy and gravity separation expertise and equipment required to develop an optimal flowsheet and test it at the pilot plant scale.