The Goro plateau is one of the major areas of lateritic New Caledonia. It consists of oxidized ores of two categories:

Lateritic ore (upper profile), richer in iron oxides.

Saprolite ore (lower profile), or magnesium- silicate mineral.

Ore mining on the Goro plateau is made in a open pit mine, worked “in seats.” The first phase of the operation of the mine began with the work of the mining exercise and pit pre-production to prepare the mine to the commercial phase.

15 meters of rock called “sterile” must be stripped before the excavators encountered layers yellow laterite and saprolite containing the analytes: nickel and cobalt.

The extracted ore is sent to the processing unit where it is prepared.

After the rejection of large rocks, earth and rock ore from the mine operation (Limonite and Saprolite) are pulped by adding water and stirring. The ore slurry is transported through pipes to the factory, located below the mine.

The pulp is then decanted to obtain, first, a slurry of ore, said thickened pulp, and, on the other hand, water, which is recycled to the mine to produce again the pulp.

The thickened pulp is then treated by addition of acid: this will have the effect of extracting metals from solid minerals and liquefy. The thickened pulp is gradually heated up to 260° at a pressure of 45 bar which prevents the water from reaching the boiling point.

It then undergoes a process of leaching, called leaching. It is injected in an autoclave at 270°C where it is brewed with sulfuric acid. Certain metals such as nickel and cobalt are dissolved, while the iron content in the pulp, for example, remains in a solid state in the form of hematite (iron oxi ........