The flotation method is a widely used technique for the recovery of gold from gold-containing copper ores, base metal ores, copper-nickel ores, platinum group ores and many other ores where other processes are not applicable. Flotation is also used for the removal of interfering impurities before hydrometallurgical treatment, for the upgrading of low sulfide and refractory ores for further treatment. Flotation is considered to be the most cost-effective method for concentrating gold. Flotation process maximizes the enrichment of gold into sulfide minerals. The tailings can be directly discharged.
In the flotation process of the major steps that must be done include the process destruction of rock minerals, milling, flotation, drying, and smelting.
1. Crushing and Grinding stage
2. Classifying stage are the same as Gravity process.
3. Mixing and Flotation stage
The classified ore gets into mixing tank for fully mixing. At this stage, the chemical agent for foam can be added. After fully mixing, the slurry will enter into flotation machine.
When the flotation machine works, the motor drives the impeller to revolve, so the centrifugal effect and negative pressure are produced. On one hand, ample air is absorbed and mixed with mineral slurry, on the other hand, the mixed mineral slurry is mingled with additive, meanwhile, the foams are thinning, the mineral is bounded with foams, and floats up to the surface of mineral slurry and the mineralized foam is formed. The liquid surface can be adjusted with the height of adjustment flashboard so that the useful foams are scraped with the squeegee.
4. Concentrator thickening and drying
Then gold is separated from others. Since the separated ore is wet, they should be dewatered by thicker initially, and dried by a dryer.