Mined Ore

Mining and at least the primary crushing will take place underground at each of the two mines. The crushed ore will be transported to the surface and the processing facility.  W ater is used in drilling and handling of the ores in the mine to reduce dust.

Crushing/Grinding

At the concentrating plant, the low-sulfur ores (with 1 – 2 % sulfur content) will be stored for a short time in small stockpiles or ore bins before additional crushing and grinding.  To facilitate grinding and eliminate dust, the ore continues to be mixed with water. The slurry next feeds into the flotation cell.

Flotation Separation

In the flotation cell, frothing agents, air and agitation will create bubbles that are coated with reagents, which collect the metallic sulfides at the top of the cell where they will be scraped off.  The remaining 91 - 95% of material, the tailings, will have sulfur levels of .05 – .08 %, or about that of everyday rocks.  About half these tailings will be stored in engineered tailing impoundments on the surface; the remainder will be stored underground for structural strength in the empty mine. 

Concentrate

The concentrate that is floated to the top will be about 5 - 9% of the original material and will contain as much as possible of the valuable sulfide minerals. 

Platsol™ Process

A proprietary pressuring-leaching process will separate the metals from the sulfur.

Liquid/Solid Separation & Neutralization

The liquids and solids will be separated and the solids will be disposed of in the engineered facility.  The sulfur will be oxidized to sulfate.

Ni/Co Precipitate

The nickel and cobalt will be precipitated from the liquids, and after separation of the precipitate, the metals will be sent to refineries for further processing.

Cathode Copper

The copper will be electrolytically plated out to form sheets of cathode copper, which are more than 99% pure.

PGM/Au Precipitate

The PGMs and gold will be precipitated and sent for further refining.

Sulfur Treatment with Limestone

The sulfate will be reacted with limestone or lime to form gypsum, the same material used in wallboard.

Remaining Solids

The gypsum and small amount of other residues wall be disposed of as  backfill in the mine or in the engineered surface impoundment.