5 Gold Beneficiation Ways to Improve Your Recovery Rate
Brief in gold mining
Gold ore is divided into placer gold mine, Carlin-type gold mine, volcanic gold mine, rock gold mine, and iron cap gold mine.
The most commonly treated gold mines are placer gold mine and rock gold mine:
- After pretreatment, desilt and wash the ore, and then use the method of gravity, which can be obtained the placer gold mine.
- Rock gold mine disintegrates the gold particles through crushing and grinding and then realizes the separation through a certain gold beneficiation process.
Gold Mining Process
Ⅰ. Crushing and screening stage
Generally, gold ore is low in content and complex in composition. The commonly used separation process of crushing and screening in the industry is mainly composed of three-stage and a closed-circuit process, that is, crushing the mineral to a proper size through coarse crushing, medium crushing, fine crushing, and screening.
Ⅱ. Grinding Stage
The grinding operation of rock gold mine usually adopts one section or two sections with lattice and overflow ball mills.
The second stage grinding operation forms a closed circuit with a spiral classifier or a hydro cyclone to ensure the grinding fineness.
In view of the shortcomings of traditional mills, such as fast wear and large energy consumption and other large-scale mining machine manufacturer of ball mill in a series of transformation, adopt new wear-resisting rubber lining board, sliding bearing with improving the mill operation efficiency, and also prolong the service life of the equipment, create economic benefits for enterprises.
Ⅲ. Beneficiation stage
Placer gold mine and rock gold mine is the most common gold beneficiation types.
The gold concentrate content of placer gold ore is high and mostly exists in the form of sand particles. Therefore,the gravity process is mostly used in the beneficiation process. After pretreatment, desilting and washing the ore,and then using the method of gravity, which can be obtained the placer gold mine.
Rock gold mine mainly selects a suitable gold selection process according to ore composition. Commonly used two kinds of gold process: flotation separation gold process, gravity separation gold process.
Gold Mining Methods
Ⅰ. Cyanide gold process
- Ag: Au > 5:1 in ore;
- Easy solid-liquid separation;
- Cyanidation of flotation concentrates.
Cyanide gold mining process can be divided into stirring cyanide and percolation cyanide.
- Stirring cyanide is used to process tailings after gravity, mercury mixing and flotation of gold concentrates, or for full mud cyanidation.
- Percolation cyanide is used to treat flotation tailings and heap leaching of low-grade gold ore.
it is one of the main methods of gold processing from gold ore.
- 1Contact finely ground ore with a solution containing cyanide;
- 2Separate solid from the clear solution;
- 3Recover precious metals from the solution with zinc powder by precipitation.
Video of cyanide gold process production line
Ⅱ. Carbon pulp gold mining process
An oxidized ore with a high content of slime
Low investment and simple operation.
The gold slurry process of carbon slurry method (CIP and CIL) is to put activated carbon into cyanide ore slurry, adsorb dissolved gold on activated carbon, and then extract gold from activated carbon.
CIP: cyanide leaching first, then adding activated carbon to adsorb gold in the slurry;
CIL: adding activated carbon to the leaching tank, leaching and adsorption are carried out at the same time.
Video of carbon pulp gold process production line
Comparison of CIP and CIL:
The CIP process is longer than the CIL process, but the CIL process has large carbon storage and low carbon concentration.
The amount of backlog metal in the CIP process is large, and the distribution of the amount of metal backlog in the two processes is different. The distribution of backlogged metal on activated carbon in the CIP process is basically the same as that in the solution, but in the CIL process, the metal mainly accumulates on the activated carbon. The gold content of the solution in the process is also different.
CIL process is immersed and adsorbed at the same time, and new dissolved gold continuously enters the solution, so the gold in the solution is continuously replenished, and the gold content in the solution is relatively high;
CIP process is a single adsorption, and the supplement of dissolved gold in the solution is very small, so the grade of gold is lower.
Ⅲ. Resin pulp gold mining process
Raw ore and concentrates.
- Large adsorption capacity;
- Good abrasion resistance of resin;
- Not affected by organic pollution;
- Easy desorption conditions, simple regeneration.
Poor selectivity of adsorption
Adsorption of gold from ore pulp using ion exchange resin. The process used in resin recovery is similar to carbon, but the gold is adsorbed onto solid spherical polystyrene resin beads rather than activated carbon grains.
- The gold ore with fine grain and good flowability.
- The polymetallic gold sulfide ore and carbonaceous ore.
It mainly includes several stages, such as dosing, stirring, aeration, and foam scraping.
It is widely used in the process of rock gold mines in the gold beneficiation. According to the difference in the physical and chemical properties of the mineral surface, it is processed with flotation reagents to make the useful minerals selectively attach to the bubbles, achieving the flotation separation.
Video of flotation separation gold process production line
Ⅵ. Gravity separation gold mining process
It is mainly used to separate materials by different specific gravity and different settling speed in the medium.
1. Jigging gold mining process
- Coarse mineral particles
- The size range of metal mineral processing is 0.007mm-50mm.
- For placer gold processing with specific gravity difference ≥1.25 and ore monomer dissociation, the minimum particle size can reach 0.04mm.
Simple process, the large processing capacity of equipment, and the final product can be obtained once processing.
The jig is the main equipment for jig gold selection. The jigging process is to mix mineral particles with different specific gravity and stratify them according to specific gravity in the variable speed medium flow with vertical movement. The minerals with small specific gravity are located in the upper layer, while the minerals with large specific gravity are located in the lower layer, and the layered materials are discharged respectively by the effect of machinery and water flow.
Video of jigging gold process production line
2. Shaking table gold mining process
The main equipment of the shaking gold process is the shake table, which is used to process other equipment in the horizontal medium flow.
The shaking gold process is suitable for processing finer minerals.
- Coarse sand bed: material size less than 0.5mm.
- Fine sand bed: particle size at the range of 0.5-0.074mm.
- Sludge bed: particle size of 0.074-0.037mm.
- The range of ore feeding size in the rocker gold process is generally between 3~0.019mm;
- Stable and reliable;
- Easy to manage and process the required ore at once.
The transmission mechanism is used to drive the bed surface to do the longitudinal reciprocating movement, the washing flow and differential movement of the bed surface. The ore particles are stratified perpendicular to the bed surface and separated parallel to the bed surface in reciprocating motion, which makes the material of different particle size be discharged from the different sections to achieve separation.
Video of shaking table gold process production line
3. Chute gold mining process
The main equipment of the chute gold process is the spiral chute, which is the equipment for using the slope water flow to achieve separation.
Fine material with low mud content and the material size is 0.6 ~ 0.03mm.
Benefits:Simple structure, large processing capacity, and low comprehensive cost.
With the effect of the combined force of water flow, mineral gravity, friction between the ore particles, and the bottom of the tank, the ore particles are settled in different areas in the tank according to the specific gravity. The ore particles with small specific gravity are carried away by the water, leaving ore particles with larger specific gravity, which achieves separation.
Gold mining equipment manufacturers
Metso Company-cyanide and carbon pulp gold process manufacturer
Metso company is a world-leading industrial company offering equipment and services for the sustainable processing and flow of natural resources in the mining, aggregates, recycling, and process industries.
SGS Company-resin pulp gold mining process manufacturer
SGS Company is a multinational company headquartered in Geneva, Switzerland which provides inspection, verification, testing, and certification services. It’s ranked by Forbes as one of 2017 Top Multinational Performers.
FTM Machinery-Flotation and gravity gold mining process manufacturer
Henan Fote Heavy Machinery Co., Ltd. (FTM) has a rich experience in the design of gold mining equipment processes. It has completed gold mining design in Tanzania, India, South Africa, the United Kingdom and other regions. According to the actual needs of customers, FTM can provide mining design, equipment manufacturing, installation, commissioning and other services.