The gold extraction process of placer gold mainly depends on the chemical composition of gold-bearing mineral raw materials, mineral composition, natural gold particle size and product requirements.
Regardless of the process and process used, when the selected raw materials contain coarse-grained monomer dissociated gold, generally before flotation and oxidation, methods such as amalgamation, re-election or single-cell rapid flotation are used to recover the monolith in time and as soon as possible. bulk dissociated coarse-grained gold. As long as conditions permit, gold should be produced in the mine as much as possible to produce alloy gold or pure gold. On-site gold can not only reduce the transportation of intermediate products, but also accelerate the sales of products, which is conducive to capital turnover.
Placer gold ore beneficiation process:
The beneficiation principle of placer gold ore is to use the gravity separation method to recover gold and its associated heavy minerals from the raw ore sand to the maximum extent, and then use the combined operations of gravity separation, flotation, amalgamation, magnetic separation and electrostatic separation to Gold and various heavy minerals are separated from each other to achieve the purpose of comprehensive recovery. Placer gold sorting is generally divided into processes such as crushing and screening, desliming and sorting.
1. Fragmentation and screening
Many placer gold deposits contain cemented mud balls, some of which have a particle size greater than 100 mm. If the mud balls are not disintegrated, they will be removed together with waste rocks during the screening process, resulting in gold loss. In addition, the cement can also be cemented on gravel or pebbles, and if it is not disintegrated, it will also cause gold loss during the sieving process.
2. Desliming
Materials smaller than 0.1 mm in placer gold generally do not contain gold or contain very little gold. Gold smaller than 0.1 mm is commonly known as floating gold, which is difficult to recover during the sorting process, while the ore slime of the same particle size interferes with the sorting process, especially the mechanical sorting process. Therefore, in the gold placer mechanical concentrator, always try to remove the slime less than 0.1 mm. Desliming equipment commonly used in production is desliming buckets of various specifications. However, the chute gold separation allows wide material particle size and large processing capacity, so desliming is usually not performed before sulfur separation.
3. Selection
Practice has proved that the gravity separation method is the most effective and economical method for processing placer gold. Since the particle size composition of gold in placer gold is different, the effective particle size limits of materials processed by various gravity separation equipment are also different, so the reasonable separation process of placer gold should be the joint operation of several gravity separation equipment. Separation of gold placer
Practice has proved that the gravity separation method is the most effective and economical method to deal with placer gold ore. Because the particle size composition of gold in placer gold ore is different, the effective particle size limit of materials processed by various gravity separation equipment is also different, so a reasonable placer gold ore The sorting process should be a joint operation of several sorting equipment.
The gold-bearing concentrate obtained in the roughing section has a gold grade of 100 g/t. Heavy sand minerals are hidden at 1-2 kg/ton. There are currently three methods for the treatment of gold-bearing coarse concentrate:
1. Wash out the gold grains with a manual gold pan and discard them with heavy sand;
2. Use a mixing cylinder for internal amalgamation, and discard the heavy sand after obtaining the amalgam;
3. After the gold is extracted by manual washing or amalgamation, the heavy sand is sent to the concentration plant for processing, and various heavy sand minerals are recovered by magnetic separation, electric separation and other methods.
The recovery rate of placer gold beneficiation: two-stage chute separation is 70% to 74%, chute roughing, jig sweeping, shaking table selection process is 85% to 90%.
