Gold-碲 ore beneficiation technology

Both gold and silver can more or less combine with hydrazine to form a compound. The gold telluride can be floated with a foaming agent. However, since the telluride is very brittle, it is easy to be muddy during the grinding process, which makes the flotation of the telluride difficult. Therefore, when handling gold-碲 ore, it is important to perform stage flotation.

The preferential flotation principle process of gold-bismuth ore is shown in Figure 1. First, gold halides and other easily floating minerals are recovered from the ore. In the soda medium (pH=7.5~8), only pine root oil or other foaming agent is used for flotation, so that a part of the free gold enters the concentrate, and the tailings uses the sulfhydryl collector to carry out the sulfide flotation. The gold-niobium concentrate is subjected to long-term cyanidation (4 to 5 days), while the gold-sulfide concentrate is calcined, and then the calcine is cyanated.

Figure 1 Gold-碲 ore preferential flotation principle process

Another principle process (shown in Figure 2) is the separation of yttrium-containing products from mixed flotation concentrates and their cyanide tailings. If necessary, the concentrate can be reground, washed and dehydrated, and then the sulphide flotation is carried out using a hydrocarbon oil as a collector in a soda-cyanide medium.

FIG 2 Gold - Te - mixing pyrite ore - flotation process

Currently, gold-bismuth ore can be processed in the following two options.

(1) The insoluble gold is selected into the concentrate by flotation, and the concentrate is subjected to oxidative roasting, calcination and flotation of tailings for cyanidation.

(2) The ore is directly cyanated and the cyanide tailings are floated. The flotation concentrate is calcined and the calcine is cyanated.

The process of selecting the smelting process for the insoluble gold-bismuth ore in the Lake-Wuyend-Starr gold-making plant in Australia is shown in Figure 3.

Figure 3 Process for the selection and processing of insoluble gold-niobium ore in a gold processing plant in Australia

The treated ore contains 7.5 g/t of gold, and the gold is mainly a fine-grained inclusion of bismuth, with a particle size ranging from fine to 5 mm. Figure 3 shows the combined process of re-election-flotation and flotation concentrate roasting-cyanide and flotation tailings cyanidation. The ore is subjected to three-stage crushing (to less than 10 mm) and four-stage grinding to prevent the mash from being pulverized. In the grinding and grading cycle, the coarse gold grain gold is firstly recovered by the flannel chute, the coarse-grained chute feed size is 15%-1.65mm, and the sweeping chute feed size is 20%+0.074mm. The ore after grinding is used to recover insoluble gold by flotation. The flotation concentrate is dehydrated and calcined (500-550 ° C) to dissociate the gold-containing sulfides and tellurides to make them suitable for cyanidation. Since the flotation concentrate has a high sulfur content, it is separately calcined, and the calcination first recovers the monomer gold by using a chute, and then performs two-stage cyanidation. Re-select the concentrate for amalgamation .

The total gold recovery rate of the plant is 94.2%. Among them, the recovery rate of raw ore chute was 13.02%; the recovery rate of roasting chute was 20%; the recovery rate of roasting cyanidation was 57.60%; the recovery of cyanidation of flotation tailings was 3.60%.