The process of separation of concentrate mineral ore in a Gold Mining in general should be done in a gradual manner, and the function of the separation process is to separate gold ore minerals from mineral impurities or mineral carrier. From the newly excavated ore from mines with very low levels of about a few grams/tonne course still needs to be upgraded to high-grade gold ore reached levels above ten grams/tonne in the way of enrichment or concentration so that it becomes feasible to extract gold. In the separation of gold concentrate has a variety of methods and means used, begin the process of separation of gold in a simple way and gold separation by using a chemical reagent and modern equipment. Gold separation processes with chemical reactions can use the system Cyanidation Method , Froth Flotation, Heap Leaching, Gold Processing With Method Carbon In Pulp and others. Except for high-grade gold ore or Gold Ore that is naturally a large grain size, so grain can be seen with the naked eye or without a microscope, because the ore of this type can easily be separated by panning or by using a gold separator machine to separate the gold ore minerals with gravity system that will separate the mineral carrier with a grains of gold ore or proceed with the amalgamation of mercury, forming amalgam gold
In a mineral ore mining in order to produce an ore concentrate to generate, it would require a phase separation of the rock minerals into the Mill. Of the separation process will produce concentrate gold from ore mined by separating valuable minerals from the dirt that covered it. The main steps in the process of separating gold to earn gold concentrate is crushing, grinding, flotation, and drying. Change the scale of destruction and milling the ore into fine sand size in order to liberate granules containing copper and gold for the separation process and to prepare the appropriate size to the next process. Once the size of the ore is reduced, the process is then performed concentration by separating minerals from mineral impurities of gold, in order to obtain higher ore grades. In Alluvial Gold Deposit, ore dug directly into the stage of the process of separating gold from mineral impurities without having to go through the mill, thus directly obtained concentrates of gold grains
In the separation of ore minerals there are two separation techniques, namely physical separation by gravity separation and chemical separation by flotation separation:
- Gravity Separation / Separation of gravity: Gravity separation is a mineral separation process based on the density difference between particles and particles of ore impurities.
- Froth Flotation / Separation flotation: Froth flotation is a separation process ore from mineral impurities by way of float ore to the surface through binding to the froth.
Gold separation process with concentration / separation by gravity methods utilizing differences in density of the density of gold with other minerals in rocks. That in general the density of gold (19.3 ton/m3) and the density of other minerals in rocks generally range from 2.8 ton/m3). Mineral carrier of gold is usually associated with minerals (gangue minerals). Associated minerals are generally quartz, carbonate, tourmaline, flourpar, and a small amount of non-metallic minerals. Gold mineral carrier is also associated with sulphide deposits that have been oxidized. Mineral carrier of gold consists of gold nativ, electrum, teluride gold, some gold alloys and compounds with the elements sulfur, antimony, and selenium. Contain adequate native gold between 8% and 10% silver, but the content is usually higher. Electrum actually another type of gold native, only the content of silver in it> 20%. If the amount of silver increases, the color becomes whiter.
Gold separation process by the method of gravity separation system would be more effective if done on the material with the same diameter as the diameter of the large differences in the behavior of light material (small density) would be equal to the weight of material (large density) with small diameter.
It is therefore necessary screening process and Classifying:
- Grizzlies, non moved screens
- Vibrating screens
- Spiral classifier
The concentration of equipment used in the of gold separation process by gravity methods of separation systems are typically used on small-scale gold mining, among others:
Panning: a separation process by means of gravity gold concentrates to produce the simplest of gold grains using a saucepan equipment trays, and the process is often done on the watershed which contained gold ore mineral content. Methods used in the gold separation process by tilting the pot of gold is in the water. While your hands are still shaking, sink, lift and out of the water and tilted back, allowing it to form a wave. Tip forward again, letting the waves travel ahead to take out of the pan. Next turn back the pan from side to side again so that the metal back on the bottom of the pan .
Example Panning Gold Equaipment , Gold Panning Machine
Example Panning Gold Equaipment , Gold Panning Machine
Sluice Box : The gold separation process may be employed on a larger scale by constructing a short sluice box, with barriers along the bottom called riffles to trap the heavier gold particles as water washes them and the other material along the box. The gold separation process with sluice boxes can be as short as a few feet, or more than ten feet. Separation of gold by sluice box more widely used to separate the ore minerals because it has the same efficiency with the concentration of the other equipment but has a simpler construction than the spiral concentrator, shake tables and jigs,
Spiral Concentrators are a gravity based concentrating device, that separates light density granular and sandy (10 mesh to 200 mesh (2 mm to 0.075 mm)) consistency material from heavier density material. In order to have a good separation of gold, there should be a difference in SG's of at least 1.0. One main benefit of spiral concentrators is they have no moving parts. The feed range, in percent solids, to a spiral ranges from 20% solids up to 40% solids. Depending upon the material characteristics, a maximum efficiency will usually be reached somewhere in this range. All that is required are some slurry pumps, the slurry to be separated and the banks of spirals with a feed distributor.
Shaking Table: The tools used in the separation process to separate gold with precious minerals worthless minerals based on differences in specific gravity of minerals through the thin fluid flow. Therefore this process is included in Flowing Film Concentration. This separation principle is that the size of the mineral should be fine because of this concentration process based on a thin fluid flow. The presence of water thrust on the same particle size but different weight of its kind, the lighter particles will experience a greater boost water from heavy particles. With the movement back and forth from the "head motion" then the heavy particle will be moving further away from the lighter particles until the particles enter the shelter. To obtain a turbulent flow of water then mounted equipment that is "riffle", thus the lighter particles will tend to jump from one riffle to riffle other than the heavy particle will only roll in the direction of the riffle. This process runs continuously so that the mineral has a specific gravity of the light can be separated. Gold separation device is very effective for separating gold from rock oxyde at 200 micron, 400 micron sulfide rocks, and 1000 micron silica. Jigging is a valuable ineral separation process with no valuable minerals based on differences in the mineral density with vertical fluid flow. In jigging occurs stratification or bedding on the particles to be separated. This happens because the particles are different from its density. Jigs is an easy alternative concentrator operated, can generally be run effectively on the largest size of 2 cm and the smallest 10 mesh.
Then the results of this process is a concentrate containing gold ore with great content, and mud washing consisting of mineral impurities in gold ore. Further processed to concentrate the gold extraction process.
Froth Flotation / Separation flotation
Flotation In Mining is a process for separating minerals from gangue by taking advantage of differences in their hydrophobicity. Hydrophobicity differences between valuable minerals and waste gangue are increased through the use of surfactants and wetting agents. The selective separation of the minerals makes processing complex (that is, mixed) ores economically feasible. The flotation process is used for the separation of a large range of sulfides, carbonates and oxides prior to further refinement. Slurry consisting of ore concentrate that has been refined (the mill) and water are mixed with reagents incorporated into a series of tank stirrer called flotation cells, where additional air is pumped into the slurry. Froth flotation ore is done by way of floating to the surface through binding to the froth by using certain chemicals and air. In addition to the separation of gold ore, prosess is widely used for some ores such as Cu, Pb, Zn, Ag, and Ni.