Effect of ore properties on heap leaching gold production
Cyanide heap leaching of gold is gold ore feed. The mineralogical properties of the ore, the accompanying minerals and the grain size composition of the ore have certain effects on the heap cleaving cyanide gold extraction production. OD Turning Pipe Cutting Machine Od Turning Pipe Cutting Machine,Pipe Od Turning Machine,Steel Pipe Od Turning Machine,Tube Od Turning Machine Shaoxing Sunfong Intelligent Equipment Inc. , https://www.zjsxsunfong.com
1. Mineralogical properties The raw materials used in heap leaching and gold extraction are all piled up on the bottom pad. The leaching solution is infiltrated into the ore through the surface of the ore and the pores and cleavage surface of the ore. The gold in the ore contacts to achieve the purpose of leaching gold. Therefore, the ore's porosity is large, and cleavage and development are beneficial to the leaching process. Therefore, the densely structured primary ore is difficult to be treated by the heap leaching method, and the oxidized ore is redeposited due to weathering, and the ore becomes loose and porous, and the water permeability is good, so that the heap leaching treatment is easy.
The fineness of gold in the ore is fine, and the leaching speed of gold is fast. However, fine grain gold must be exposed to its surface in order to smoothly leach. The grain size of gold is coarse, the heap leaching time is long, and the recovery effect of gold is not good, so this ore should not be treated by heap leaching. The shape of the gold particles also has a great influence on the leaching speed of gold. When the gold particles are in the exposed flakes, the leaching speed is fast, while the leaching speed of the coarse-grain spherical gold particles is slow, and the leaching speed is fast when the gold particles themselves have open pores.
2. Associated minerals The various mineral components in the ore affect the gold immersion effect to varying degrees. Minerals that can react with cyanide in the leaching solution and consume oxygen and cyanide, or their reactants, adsorb on the surface of the gold particles, and the minerals purified on the surface of the gold affect the leaching of gold.
Iron sulfide minerals such as yellow iron, ferrous iron, pyrrhotite, etc. can chemically react with oxygen and cyanide in the leaching solution, and intermediate products can also consume oxygen and cyanide in the leaching solution.
Arsenic-containing minerals, such as arsenopyrite, realgar, orpiment, arsenopyrite, etc. can react with oxygen and cyanide consumption of chemical components effective ore leaching liquid.
Copper, zinc and other heavy non-ferrous minerals can be consumed cyanide and cyanide. The mineral and alkali reaction products are deposited and adsorbed on the surface of the gold particles, which hinders the leaching of gold. Calcium oxide acts as a protective base, and when the pH is too high, calcium peroxide is deposited on the surface of the gold particles.
When the ore contains carbon minerals, they will adsorb the leached gold and lose it in the heap, reducing the actual yield of gold.
3. Ore particle size From the viewpoint of kinetics, under the same conditions, the smaller the particle size of the ore crushing, the larger the surface of the exposed gold particles, the larger the contact surface between the liquid phase and the solid phase, and the leaching speed of gold. The faster it is.
However, if the ore particle size is too fine, it will affect the penetration speed of the leaching solution, which is not conducive to the liquid-solid separation in the heap. In severe cases, the powder ore will also hinder the uniform flow of the leaching solution in the heap, forming some dead angles and affecting the leaching effect. Fine-grained ore also affects the cleaning of the heap, causing a certain amount of gold-containing precious liquid to adhere to the ore and causing loss, and also prolonging the leaching time.