Mercury, flotation and cyanidation of coarse gold sulfide ore

Vein gold ore in Victoria, Australia Walter Ganguly (Wattle Gully) gold mining company handled, native gold particle size from extremely fine particles of gold to more than 20mm, of which about 80% of the gold particles greater than 0.15mm (100 mesh). And containing 1% to 2% iron ore and gold-containing arsenopyrite. The processing flow is shown in Figure 1.

Figure 1 Wattle Gully Gold Mine Process

After the ore is broken, it is ground by a ball mill (and simultaneously mixed with mercury ) to 0.98 mm (-16 mesh), and then treated with a mercury-mixed plate. The mercury-mixed tailings are recovered on the Wilfley and Phoenix-Weir shakers and then recovered through the chute to recover fine-grained sulfide, gold and mercury lost from the mercury-mixed plates. With amalgam.

The concentrate produced by the shaker and chute is cyanide milled in two 1.5m Forwood Down grinding discs and combined with a Dover screw in three 4.8m x 2.1m mixers. The pipe is stirred and cyanated. The cyanide solution is precipitated by zinc , and the precipitate is acid-washed and then cast into a mixed gold bar.

The mercury amalgamation board is properly treated daily, and the amalgamation sedimentation tank is cleaned every two weeks. The cleared amalgam is processed in the Berdane chute and then steamed and cast.

The ore contains 12.6g ∕t of gold, and the total recovery rate is 87.9%. Among them, the recovery rate of mercury amalgamation is 73.2%, and the recovery rate of cyanidation is 14.7%. The tailings contain 1.5g ∕t of gold, which is equivalent to l2% of the gold content of the factory feed.

The above process has been used by some small factories to process a small amount of ore. However, due to the complex structure of the ore, the recovery rate of gold is not high. In order to reduce the gold content of tailings and reduce production costs, the new plant will use the process of Figure 2.

Figure 2 Improved process of the Walter Gurley Mines

The ore is crushed to 80% -13mm and ground to 65% -0.074mm (200 mesh) in a grinding process consisting of a ball mill and a cyclone. Sodium carbonate was added to the mill during ball milling to maintain the pH at around 8. The concentrate produced by the pulp treated by the Denver jig is stored in the mine bin, and then the mercury is delivered in batches from the discharge tray every 1-3 days. The concentrate is cyanated after being mixed with mercury and is not sent to flotation, because it contains lime which will affect the recovery of gold and gold-containing sulfides in the flotation.

The heavy-grain products enriched by the cyclone tailings are sent to the ball mill, and the cyclone is overflowed and adjusted to be subjected to coarse selection, sweeping and selection. The flotation reagent is dibutyl xanthate and gas foaming agent 65. The flotation tailings are filled downhole or discarded after dewatering.

The flotation concentrate is approximately 2% of the plant's feed weight. Most of the flotation reagent and the soluble salts present are removed by filtration. Then, it is slurried with cyanide lean liquid, aerated for 4h, and the filter cake is further cyanated in 3 stages of 4~8h (adding lead oxide to cyanide solution). The cyanide residue is washed with water and discarded. The plant uses a 1.6m x 1.2m disc vacuum filter for filtration. After the cyanide solution is clarified and degassed, the gold is precipitated by Merrill Claude. The consumption of pharmaceuticals was Aero Brand NaCN7.3kg∕t, CaO2.5kg∕t. Compared with the old factory process, the recycling rate of the new plant is increased by more than 1g∕t.

Lake View and Star Ltd. use a process of flotation followed by cyanidation to handle complex and difficult ore. After the ore is ground, the lining of the wool (24h replacement) is used to produce the concentrate to deliver the mercury. The slurry is further added with flotation such as xanthate, and the flotation tailings are cyanated and then cyanidated. The flotation concentrate is calcined to separate the gold from the telluride and then sent to the chute to recover the coarse gold. The chute tailings are cyanated after washing. The ore contains 8.1 g of gold and the total recovery rate is 92.5%.

Great Boulder Mining Co., Ltd. uses the process of first cyanidation flotation to process the ore of Kalgoorlie, and the re-election process has been cancelled since 1949. The process is to cyanide and filter the ore and cyanide solution, the filter cake is re-pulped and inflated in the gas-filling tower through SO ₂ , and then the excess SO ₂ is removed from the mixer for flotation. Flotation concentrate calcined, washed After most of the soluble salts of iron and copper cyanide was removed again. The ore contains gold 9g ∕t, and the total recovery rate is 91.5%.

Duplex Stainless Steel Tube

Duplex Stainless Steel Tubes / Pipes, are made by Duplex stainless steels, can be both seamless and welded tubes.