4 Gold reselection methods

01 Gold single gravity beneficiation process

1.1 Features

This process is relatively simple, that is, after crushing and grinding, the chute is used to recover the gold.

1.2 Application

The single-strength beneficiation method is mainly used to select simple gold ore containing single gold, such as iron-bearing quartz vein type gold ore. Depending on the particle size of the gold in the ore, primary or primary grinding is used. Stage grinding is generally used for gold ores with uneven gold particle size distribution.

02 Gold re-election - amalgamation combined process

2.1 Features

The combined process of gravity concentration and amalgamation is a typical process for processing high-grade vein gold ore in placer gold and small concentrators.

After crushing and grinding, roughing is carried out through the chute, the chute tailings enter the classifier, the concentrate enters the vibrating screen for screening, the vibrating screen concentrate enters the amalgamation barrel, the vibrating screen tailings and the classifier return to the sand, and then the ball mill is used for grinding and classification. The machine overflow is discarded as tailings, the shaker concentrate is amalgamated, and the mercury-containing mixture is graded to smelt gold. If the shaker concentrate is mostly conjoined gold, the coarse concentrate needs to be reground, and then selected with a shaker to obtain most of the single-gold shaker concentrate.

2.2 Application

The combined process of gravity concentration and amalgamation is only suitable for relatively simple gold ores, such as gold-bearing pyrite veins (gold-bearing quartz veins, in which gold is symbiotic with a small amount of pyrite, galena, sphalerite, etc.). The ore gold particles are relatively coarse, and the gold coexists with a small amount of sulfide, and the recovery rate of gold can generally reach more than 80%.

03 Gold gravity separation cyanidation combined process

3.1 Features

The combined process of gravity separation and concentrate cyanidation is to crush the ore, re-select the gold concentrate, regrind the gold cyanide concentrate, and recover the gold.

The combined process of tailings gravity concentration and cyanidation is to crush the gold ore, and use a jig or chute to recover large particles of single gold or coated gold in the classification circuit. When the classifier overflows, the heavy separated tailings will be cyanated. The gold in the pulp is then recovered.

3.2 Application

The combined process of gravity separation and concentrate cyanidation is mainly used to treat gold-bearing sulfide ores. Gravity operation can be set up in the grinding and classification cycle to extract coarse-grained gold or gold-containing sulfide; the gravity-selection operation can also be placed after the overflow of the classifier, and a vibrating screen is used to extract fine-grained gold or sulfided gold to connect organisms. This process can be used for general siliceous schist gold deposits, conglomerate gold deposits and quartz conglomerate gold deposits.

The tailings gravity separation-cyanation combined process is mainly used for the treatment of coarse-grained gold, and is suitable for refractory oxidized gold ores suitable for cyanation. It has the advantages of shortening the cyanation time, reducing the amount of cyanation, reducing the cost of cyanation, and improving the recovery rate of total gold.

04 Gold gravity separation and flotation combined process

4.1 Features

The main feature of the combined gravity separation-flotation process is that it can handle pulp with a wide range of particle sizes, and no classification is required before sorting. It can comprehensively recover a large proportion of symbiotic minerals, which can effectively improve and improve the total recovery rate of gold.

4.2 Application

The combined process of gravity separation and flotation is widely used. It can process both gold-bearing quartz vein sulfide ore and gold-bearing polymetallic sulfide ore.

At present, a hydrocyclone is commonly used to form a mixed preferential flotation process, that is, the ore from the rod mill is re-separated through a three-stage hydrocyclone to obtain a mixed coarse concentrate, and the coarse concentrate is combined with flotation to concentrate. After grinding, the multi-metal copper and zinc are preferentially flotated to obtain a good sorting effect. Typical South African gold ore also uses a combination of gravity separation and flotation.