Oxidized gold ore refers to the ore formed by oxidation reaction of gold-bearing ore in the surface or near-surface oxidation zone due to exposure to oxygen or other oxidants. Due to its complex nature, the Mineral processing needs to be optimized in combination with the specific mineral composition.
Overview of four Mineral Processing methods for oxidized gold ore
Common Mineral processing methods include gravity separation, flotation, cyanidation and heap leaching, or a combination of multiple methods to improve gold recovery.
Gravity separation of oxidized gold ore
Gravity separation is a physical Mineral processing method that uses mineral density differences for separation and is often used for the pretreatment of oxidized gold ore. After crushing and grinding, the ore is separated by equipment such as a shaker, jig or centrifugal concentrator to obtain a gold-rich concentrate. Gravity separation has the advantages of low cost and simple process, but has high requirements for ore grade and particle size. It is a common and efficient process for processing oxidized gold ore.
Flotation of Oxidized Gold Ore
Flotation is a mineral separation method that uses the differences in physical and chemical properties of the mineral surface to separate the gold. Oxidized gold ore usually has poor flotation effect due to the lack of carriers for gold particle flotation.
Cyanidation of Oxidized Gold Ore
Cyanidation is a common method for extracting oxidized gold ore, especially for fine-grained, high-grade oxidized gold ore. After grinding, the ore is mixed with a cyanide solution (such as sodium cyanide) under alkaline conditions, and the gold is dissolved into gold cyanide through leaching reaction under alkaline conditions. Subsequently, the dissolved gold is recovered by activated carbon adsorption or zinc precipitation. Cyanidation has a high recovery rate and can extract fine gold particles, but cyanide is a toxic substance, and safety measures and environmental controls must be strictly implemented to ensure the safe handling and disposal of cyanide solutions. This method is widely used in the mining of small and medium-sized oxidized gold ores.
Heap Leaching of Oxidized Gold Ore
Heap leaching is a gold extraction process commonly used to treat low-grade oxidized gold ores. The basic process includes heap building, drip (spray) leaching, precious liquid collection and gold recovery. The ore is first crushed and screened to a particle size of -10mm to -20mm, and then piled on a heap leaching site with an impermeable membrane. The heap is built in layers or slopes to ensure that the ore pile has good permeability so that the leaching solution can penetrate evenly and fully contact the gold ore. Subsequently, the ore pile is sprayed with cyanide solution or dilute sulfuric acid, and the gold is dissolved by the leaching solution and penetrates to the bottom of the ore pile. The gold-containing solution is collected by a liquid collection system, and then the gold is extracted from the solution by activated carbon adsorption, and then the gold is recovered by desorption and electrolysis. Heap leaching has the advantages of low investment, simple operation and strong adaptability. It is especially suitable for large-scale extraction of low-grade gold ores, but the ore particle size is too fine, which may affect the leaching efficiency.
Conclusion
The oxidized gold Mineral processing needs to select a suitable extraction method according to the specific characteristics of the ore. The selection of the Mineral processing method is affected by the mineralogical characteristics of the ore, the gold grade, the available equipment and technology, and factors such as economic feasibility should also be considered. In actual operation, in order to improve the recovery of gold, mineral processing tests need to be carried out to cope with the characteristics of different ores and optimize the overall recovery rate.