At present, there are many types of vein gold ores, including gold-bearing quartz vein or auriferous pyrite-bearing quartz vein type, auriferous pyrite-bearing altered granite vein, gold-bearing polymetallic sulfide vein, oxidized gold-bearing quartz vein, gold, tungsten and arsenic-bearing quartz vein.
Due to the different ore properties of all kinds of vein gold ore, the extraction processes of vein gold are also different. The five extraction processes of vein gold mainly include single flotation process, all-slime cyanidation process and the combined gold extraction processes composed of gravity separation, flotation and cyanidation process.
Use the table of contents below to navigate through the guide:
The single flotation process is suitable for the treatment of gold-bearing quartz vein with fine gold particles, high floatability of sulfide, gold-bearing polymetallic sulfide vein and carbon (graphite)-bearing gold ore.
This extraction process of vein gold means float the gold into copper, lead concentrate, and then extract the gold from the ore concentrate, which is more economic and reasonable for the gold ore contains non-ferrous metals. It can realize the comprehensive utilization of multi-metals, enrich the gold to the sulfide minerals as much as possible, and directly discharge the tailings. But it cannot obtain the finished gold, so the application range is relatively small. It is often combined with other gold processing methods.
The gold is discovered in quartz vein ore as the fine or fine dispersed state. The ore has a deep oxidation degree and does not contain copper, arsenic, antimony, bismuth, carbon and other substances. This kind of vein gold ore is suitable for the all-slime cyanidation process.
Gold bearing ore is leached in the cyanide solution, then the activated carbon is directly absorbed from the pulp to carry the gold, and the carbon desorption is directly separated, refined and smelted. In this extraction process of vein gold, the cyanide is a highly toxic substance, which is easy to pollute the environment. At present, the harmfulless gold leaching reagents can be used to replace the cyanide reagents in the gold cyanide leaching process.
In general, the gravity separation-cyanide process is suitable for the treatment of oxidized gold-bearing quartz veins. In the vein gold extraction plant, the gravity separation method is often used as a part of the combined gold extraction process. In the grinding and classifying circuit, the combination of jig, spiral chute and shaking table are adopted to recover the dissociated coarse monomer gold in advance, so as to facilitate the subsequent cyanide operation and obtain the qualified gold concentrate.
In order to improve the rate of return on investment, the combination of flotation process and other gold extraction processes can sometimes achieve more impressive results for the different properties of vein ore.
This extraction process of vein gold is often used to treat gold-bearing quartz vein (close symbiosis between gold and sulfide) and quartz pyrite ores. Generally, the xanthate is used as collector, terpinol oil is used as the foaming agent, and the weak alkaline pulp is floated in the flotation machine to get the gold concentrate. Then the flotation concentrate is sent to cyanide leaching, the gold is dissolved by the cyanide, the complex is sent into the solution, and then the zinc powder is replaced to get gold slime, and finally the gold slime is smelted by fire to get pure gold.
The extraction process of vein gold is suitable for the treatment of the mineral that is conducive to cyanide but with good floatability (containing sulfur, iron, arsenic and other impurities), a small amount of gold with such minerals. For the flotation concentrate containing high arsenic sulfide, the impurities (such as sulfur, iron, arsenic) is enriched into the concentrate, and become the refractory concentrate with high sulfur high arsenic, while it also cannot be directly sent to the cyanide leaching, the flotation gold concentrate can be first sent to oxidizing roasting for removing the arsenic and sulfur. So the calcine structure is loose, which is more advantageous to the leaching of gold and silver.
This extraction process of vein gold is focused on the flotation method, which is suitable for the ore that the gold has the closely symbiosis with sulfide and can only be recovered by smelting method. Besides, it is also suitable for the gold-bearing quartz vein with misproportion dissemination. Compared with the single flotation process, it can obtain a higher recovery rate.
The flotation concentrate is obtained by the flotation separation of the raw ore, and the sulfide part of the flotation tailings often exists in the form of connective body with gangue. Except the gold is wrapped in the sulfide as the fine grains, the gold is also often exists as the coarse monomer gold and micro-fine monomer gold. It is difficult to recover the intergrowth between coarse-grained sulfide and gangue, coarse-grained natural gold from tailings by the flotation, but the gravity separation process can recover this part of gold better.
In order to separation the vein gold ore more reasonably, it is suggested to carry on the mineral processing test, comprehensively analyze the nature of the ore, and conclude the scientific mineral processing test report, thus to select the what extraction process of vein gold, thus to achieve the ideal investment returns.