Reasons why the Rocklabs Gravity Gold Concentrator was built
The size of the largest gold particles plays an overwhelming role and it is critically important to have a rough idea about the size of such particles and how and where they tend to occur. The Theory of Sampling clearly demonstrates that if sample mass is not sufficient for material containing coarse gold particles (i.e., gold larger than 80 μm), devastating economic consequences are on the horizon through massive misclassification and reconciliation problems.
The practice of always cutting high grade during exploration should be eliminated by generating data less susceptible to the creation of outliers, as is the case with conventional 30-g fire assays used for materials containing gold particles larger than 80 μm. Isolated gold assay outliers should be treated with respect as they are often an indication that an incorrect grade control strategy is used.
A similar problem exists at the plant; outliers showing up in Final Tails of a CIL/CIP circuit are extremely valuable data, and their elimination is an irresponsible act in most cases. In such a circuit, all the fine gold that is easy to sample has been leached; the only remaining gold is the one that is likely to be extremely difficult to sample because of insufficient subsample assaying mass issues.
The mission of the Rocklabs Gravity Gold Concentrator is to eliminate all these problems.
- Collects all the coarse gold (>80 μm) from samples ranging between 1 to 10-Kg.
Two assays only: one fire assay for the entire gold concentrate, and one regular 30-g fire assay for the tail from the concentrator.
- Minimizes the amount of high grade and increases ore grade reserves above gold cutoff grade; this increase can be economically very substantial on some gold projects.
- Allows geologists to deliver far more reliable data to the geostatistician, which in turn leads to a far more accurate feasibility study.
- Minimizes gold grade reconciliation problems between the geological model, the mine and the plant.
- Many samples can be processed in one day as it requires little manpower and is very user friendly.
- Provides far more reliable data at the plant for the Feed Cyclone Overflow and for the Final Tail; actually, for a gold plant, the use of the Rocklabs Gravity Gold Concentrator should be considered as the benchmark system for the metallurgist.
How it works
The geologist’s log is critically important as all samples may not be necessarily processed with the Rocklabs Gravity Gold Concentrator; the following guideline should allow the geologist to make the appropriate decision:
Case #1: Maximum gold particle size below 80 μm
In this case conventional sample preparation is sufficient. Automated sample preparation facilities are highly recommended. Mineral Stats Inc. can suggest several scenarios depending on how many samples must be processed in one day.
Case #2: Maximum gold particle size between 80 and 200 μm
Crush the sample to minus 10 mesh (1.7 mm). Split a 1000-g sample using a RSD. Pulverize the 1000-g sample to about 95% minus 150 mesh (106 μm). Process the 1000-g sample in the Rocklabs Gravity Gold Concentrator. Fire assay the entire concentrate. An 8% split from the tailing is obtained that must be dried and assayed using a 30-g fire assay.
Case #3: Maximum gold particle size between 200 and 1000 μm
Crush the sample to minus 10 mesh (1.7 mm). Split a 5000 to 10000-g sample using a RSD. Pulverize the 5000 to 10000- g sample to about 95% minus 150 mesh (106 μm). Process the entire sample in the Rocklabs Gravity Gold Concentrator. Fire assay the entire concentrate. An 8% split from the tailing is obtained that must be dried and assayed using a 30-g fire assay. For plant samples, use a 5000- g sample systematically as delivered by the filter press; there is no need for sample preparation. Process the entire sample in the Rocklabs Gravity Gold Concentrator. Fire assay the entire concentrate. An 8% split from the tailing is obtained that must be dried and assayed using a 30-g fire assay.
The Rocklabs Gravity Gold Concentrator (GGC) delivers a more accurate analysis of coarse gold samples, resulting in higher yields and less waste.
Designed to eliminate the issues associated with achieving accurate analysis of coarse gold samples, the GGC separates out the true gold from a sample allowing for better grade control and optimisation of the production process. The GGC can take samples up to 10kg and separate out the coarse gold, resulting in a smaller sample for analysis.
- Only one assay required
- Continuous processing
- Rapid turnaround of samples
- Greater efficiencies in the overall production process