Jaguar Concentrator

 The Jaguar processing plant is a copper/zinc differential flotation plant, incorporating the processes of crushing, grinding, classification, flotation, thickening, filtration and tailings disposal. The processing plant or Concentrator has been designed to treat material from the Jaguar underground ore body, at a nominal throughput rate of 400,000 tonnes per annum.

Ore from underground is carted to the R.O.M pad and blended before being loaded into the Crusher using a front end loader. The single stage crushing circuit provides a coarse size reduction stage for the ore from a maximum size of 600mm to a product of p80 (size at which 80% is smaller than) of 66.8mm. The crushers’ action not only breaks the rock but puts micro-fractures into the rock to assist the next stage in particle size reduction.

The crushed ore is conveyed to the 6.09m diameter 2.74m long, high aspect, Hardinge SAG Mill. The dual drive, variable mill’s power draw is maintained for optimal primary grinding around 900 amps, which maintains a grind size reduction from the p80 = 66.8mm of the crusher product down to a p80 = 0.800mm or 800µm discharge.

The feed, at 48 tonnes per hour, is ground in the SAG Mill and flows over a 16mm aperture screen trommel where the oversize is rejected to stockpile, and the undersize is pumped to the cyclones for classification. The hydro-cyclones classify and separate and heavy particles back to the grinding circuit while the fine particles are sent to the Flotation Circuit.

After classifying the material to a size of p80=45µ the ore slurry, now at 38% solids is conditioned for 2 hours in the copper Conditioning Tank, with lime, a frothing agent and two copper specific mineral collectors. The frothing agent Interfroth 6-3N attaches itself to the copper mineral and makes it hydrophobic. The collectors Aero 5100 and Aero 3477 seek out the hydrophobic mineral particles and with the lime form a stable froth or concentrate with the addition of low pressure air.

The conditioned slurry is sent to a high intensity flotation unit the OK 20, which produces a 15% copper grade concentrate. The concentrate is sent to the cleaners circuit which removes some of it’s impurities and upgrades it to 23.0% copper. The material that is not floated off by the OK 20 proceeds to the copper Rougher Circuit. More reagent is added and with increased air flow another copper concentrate is produced. This time the copper grade is lower and the impurities are higher. To produce a saleable concentrate from this the concentrate has to be sent to the regrinding circuit then the cleaning circuit.

The main impurities in the copper concentrate are iron and zinc species. The iron species (mainly pyrite) can be suppressed by the addition of lime, while the zinc species (mainly sphalerite) is suppressed by the depressant Sodium MetaBiSulphite (S.M.B.S). After the slurry has passed through the roughing stage it proceeds to the scavenging stage to pick up the last of the copper, before becoming zinc circuit feed. From a 3.0% copper feed, a 23.0% copper concentrate is produced recovering 87% of the total copper.

After having suppressed the zinc in the copper circuit, the pH is increased and a zinc activator, Copper Sulphate is added to float the zinc. The same collector Aero 5100 is added, which seeks out the copper adsorbed onto the zinc particles from the copper sulphate. The collector thinks the zinc is a copper particle because of the particles +1 valence state and forms a stable froth with it, the frother and lime. The zinc circuit is similar to the copper circuit, where a rough concentrate is produced in the rougher circuit, which is cleaner (has some of its impurities removed) and is upgraded in the re-cleaning circuit to a saleable product of 48.0% zinc metal. A regrinding circuit is critical in the zinc circuit as well to help liberate the Sphalerite from the pyrite and other iron species.

From an 8.0% zinc feed, a 48.0% zinc concentrate is produced recovering 78% of the total zinc. Both concentrates are individually pumped to de-aeration and density increasing thickeners, where the water is removed (and re-used in the plant) from the slurry. After entering the thickener at 5-10% solids, the slurry is thickened up to 65% solids and pumped to the Larox filters. The 2 horizontal Larox filters use hydraulic pressure to squeeze another 25% of the water from the slurry. 3 m³ of slurry is pumped into the filter at 65% solids, the majority of water is squeezed out, leaving 23 -100 kilogram cakes of concentrate to fall from the open filter at the end of the cycle 

The concentrate is moved into it’s appropriate holding bay and left to dry out until it reaches the desired moisture level for safe transport. Finally the slurry exiting the zinc circuit, after having the copper and zinc removed is pumped 1.3 kilometers to the Tailings Storage Facility where it is deposited for water reclamation.