Gravity Concentration
Written By: Team Sepro | Date: 03.08.19
Gravity concentration, one of the oldest mineral beneficiation processes, has evolved over the decades and continues to play an important role in modern mineral processing operations. Sepro Labs has a wide variety of gravity concentration testing options available such as centrifugal units, spirals, shaking tables and analytical tables, though in particular advanced centrifugal gravity concentration technology remains a specialty.

While the traditional low-mass yield technology continues to be successful for high density precious minerals such as gold, clients are increasingly looking to continuous and ultrafine centrifugal concentration as a means of optimizing processing plants and increasing production.
Benefits

- Lowest operation and installation costs compared to other beneficiation technologies.
- Low environmental impact – no reagent requirements.
- Can easily generate saleable concentrates and provide a quick cash flow with gold and precious metal applications.
- Provides versatility for treating a wide particle size range: jigs, spirals target coarse particle sizes while centrifugal concentrators can recover much finer particle sizes.
- Advancements in centrifugal technology allow for recovery of particles previously lost to tailings, such as ultrafine (<50 micron) particles.
- During the exploration phase gravity concentration can help define a more accurate grade when there is a nugget effect with a given ore.
Expertise
The Sepro Labs team is lead by Ish Grewal, one of the world’s leading gravity concentration experts, and continues to remain on the cutting edge of gravity concentration technology. In particular, centrifugal gravity concentration technologies continue to advance and Sepro Labs is currently in the process of establishing laboratory testing procedures that more accurately determine potential full-scale recoveries for ultrafine and continuous gravity concentration units. In addition to the consistent and repeatable industry-standard gravity concentration test programs, Sepro Labs offers a unique service: mathematical modelling of gravity circuits. Based on real-world results and research, Sepro Labs can accurately predict the recoveries within a standard gravity and comminution circuit using the data from gravity recoverable gold test programs.
Test Details
Test Name | Minimum Sample Size | Details |
Basic GRG | 10 kg | 3 pass test + basic analysis |
Detailed GRG | 20 kg | 3 pass test + particle size analysis, report, modeling Includes assay by size fraction of cons, tails |
Bulk Gravity Assay | 10 x 5 kg | 2 pass test – see Bulk Gravity Assay brochure |
Metallurgical Scoping Program | 50 kg | See Metallurgical Scoping Program brochure |
MAT Table | 5 kg | Customized to project – see Lab Equipment |
Dense Media Separation | 100 kg | See Dense Media Separation |
Applications
Standard Gravity Applications: |
Gold, silver and platinum group metals |
Gold from cyclone feed, underflow or overflow within a grinding circuit |
Gold in alluvial gold operations |
Gold from aggregate plants |
Continuous Gravity Applications: |
Tin |
Tantalum |
Tungsten |
Chromium |
Cobalt |
Ultrafine Gravity Applications: |
Ultrafine tin slimes |
Ultrafine tantalum slimes |
Ultrafine tungsten slimes |
Scavenging from deslime cyclone overflow |
High recovery upgrade of fine flotation concentrates |