Jin Liu is a chemically stable precious metal. Gold is dissolved in a thin cyanide solution in the presence of oxygen (or oxidant) to form a monovalent gold complex:
4Au+8KCN+2H 2 O+O 2 →4KAu(CN) 2 +4KOH
It can also be argued that the following reactions occur when gold dissolves:
2Au+4KCN+O 2 +2H 2 O→2KAu(CN) 2 +2KOH+ H 2 O 2
2Au+4KCN+H 2 O 2 →2KAu(CN) 2 +2KOH
Hydrogen peroxide is an intermediate product formed by the reduction of oxygen in dissolved water.
Regarding the kinetics of gold dissolution in cyanide solution, the diffusion theory states that when gold is immersed in a cyanide solution, the surface of gold dissolves immediately and a saturated solution is formed on the surface of gold, and the saturated solution gradually diffuses into the interior of the solution. Due to the diffusion, the concentration of the saturated solution around the gold is lowered, and the gold is further dissolved to supplement the concentration of the solution around the gold, and the dissolution of gold is gradually formed.
During the dissolution process, the metal loses electrons from its surfaced anode region, while oxygen extracts electrons from the cathode region of the metal surface. The electrochemical dissolution that occurs is shown in the figure below.
Au→Au + +e -
Au + +2CN - →Au(CN) 2
The cathodic reaction is:
O 2 +2H 2 O+2e - →H 2 O 2 +2OH -
The dissolution rate of gold is related to the concentration of cyanide in the solution and the concentration and diffusion of oxygen. It is related to the surface area of ​​the cathode and anode where the reaction takes place and the concentration of cyanide and oxygen on the surface of the unit gold, and the inside of the solution and the saturated liquid. The thickness of the diffusion is related. When the cyanide concentration is low, the dissolution rate of gold depends only on the oxygen concentration. From a process point of view, the ratio of the dissolved oxygen to cyanide concentration should be controlled. The oxygen content in the free cyanide and the solution in the slurry must be analyzed and controlled at the same time, so that the molar ratio is equal to 6, in order to ensure the ideal leaching effect and The dosage of the medicament is small.
Box shear machine is horizontal structure, the equipment is driven by hydraulic pressure. Compared with mechanical shear machine, it has the characteristics of small size, light weight, small inertia, low noise,stable movement, flexible operation and large shear section. With the integrated control of hydraulic and electronics, single and continuous action conversion can be implemented, which is simple and convenient to use. In shearing, the material cut does not need manual support, as long as according to the shearing speed, the shearing material can be continuously added to the equipment bin.
1) Independent research and development, independent brand, mature technology.
2) Imported accessories, lower operating costs, higher quality, energy-saving and efficient.
3) Fully enclosed structure, high safety performance, low probability of work-related injuries.
4) Car-mounted mobile customization to meet the needs of changing sites.
5) Integrated installation-free, ready-to-use.
6) PLC control, manual automatic operation, automation free of manual work.
7) Electric power system and diesel system should be operated in a two-pronged way.
8) Cyclic design, long working hours, low human capital requirements.
9) Wide range of application, less restrictions on material delivery, high safety performance.
10) Independent design, long service life, high shear force.
Horizontal Shear, Horizontal Shearing Machine, Container Shear, Horizontal Metal Shear, Horizontal Scrap Shear
Jiangyin Metallurgy Hydraulic Machinery Factory , https://www.ecometalrecycle.com