Sulfuric acid slag gold extraction technology
At present, China has obviously been the gold exploration and use of resources can not keep up production requirements of the situation, which restricts the improvement of China’s gold production, at the same time, from the gold-bearing wastes and the recovery of refractory gold ores and technical support policies are not ideal, This part of the gold resource has not yet been fully utilized. sulfuric acid slag recovery of gold-bearing pressing technology development(Used Stone Crusher).
China’s annual gold produced hundreds of tons of sulfuric acid slag, currently only greater than 3 g / ton slag can be used each year, only 7.5 million tons of processing power, and the remaining slag or waste disposal or to more than ten million Queensland / tons sold to cement plants as raw material? contained gold lost in vain, very regrettable.
Technical literature from abroad to see, from the cinder gold recovery technology is also limited to cyanidation process, re-elected, flotation, magnetic separation, thiourea process etc in the research stage.
The current cyanidation process is only suitable for processing gold grade higher than 2.5 g /? Tons of sulfuric acid slag, low-grade and then the profit is too low, investment is difficult to recover in the short term, so despite good social benefits, but economic efficiency is not gold extraction plant was built without enthusiasm; heap leaching method, while the cost of production can reduce, but not continuous production and winter can not produce, so this process is difficult to promote; re-election, magnetic separation and flotation recovery can burn Queensland residue part of gold, but the recovery rate as high and cyanidation of the concentrate produced from recycled gold in the recovery time is not ideal, it is difficult to promote. Thiourea leaching method and the high cost of pharmaceutical conditions difficult to control, the solution is still satisfactory gold recovery methods, still in the exploratory stage, is still far from industrial applications.
We believe that the impact of gold from the slag in the two main factors, one investment is too large, and second, high production costs. If you can solve these two problems, low-grade sulfuric acid slag gold extraction technology will be successfully promote.
Through our technology to promote the use of cyanidation study found that the process has the following problems(Used Stone Crusher For Sale):
(A) Changchun Gold Research Institute of years of research shows that sulfuric acid slag does not have to wear cyanide leaching rate can be guaranteed, with the purpose of paragraph miners grinding just to ensure the cyanide reaction slurry was stirred evenly, do not sink tank. ground miners segment investment of more than 40 million production costs as high as 15 yuan / ton, if the way to cut through the other steps, cyanidation of Queensland investment and production costs will drop dramatically.
(B) As by discharge after the grinding thickener overflow the washing – to remove cinder dissolution of iron and copper impurities in the grinding process can not add cyanide? So the poor can not be fully recycled liquid, poor liquid discharge treatment not only production costs, but also cause environmental pollution, in some areas of high environmental quality, environmental protection department will not approve construction of cyanidation plant.
(C) the number of sulfuric acid plant was built in the city?, Not enough space to build larger tailings. Using the current cyanidation process, whether used with zinc replacement, or CIP, must be the end of the separation filter cyanide the residue, the residue with a motor vehicle to transport it to another place. Filter section in increased investment, because of grinding the slag fine particle size increased the difficulty of filtering, an increase of production costs.
(D) make poor use of zinc replacement fluid zinc concentration increased, the leaching conditions deteriorate, resulting in lower gold recovery; as cinder hardness, wear and tear with a large carbon CIP, gold loss, and increased production costs.
(E) the maximum cyanidation reaction time is not long enough, usually at least 16 hours, which requires the construction of a large volume of leaching tank, investment increases, power consumption increases, plant size increases.
In summary, low-grade sulfuric acid from the cinder of gold leaching must develop new technology or new technology, investment and reduce costs. The specific studies include the following way:
1, using the new extraction equipment, not grinding to ensure the smooth progress of the leaching reaction. And leaching power consumption does not increase or increase less.
2, the use of fast leaching leaching method, the leaching time is only a few hours or less. Increase the leaching effect of stirring intensity to ensure that, due to short reaction time, the unit power consumption does not increase much.
3, using the whole cycle of poor fluid process, nothing more than rows of waste water, waste water treatment cost savings, savings leaching agents.
4, with the fixed bed adsorption recovery of gold from your solution, no washing or CIP section in steps, dip directly after filtration, improve your concentration so that the absorbent liquid gold on gold grade increase, reducing equipment investment and production costs.(Used Stone Crusher Plant For Sale)
Through extensive research and testing, select a water chlorine method process.? Small test results show that the leaching rate is higher than the cyanide method,? The reason is that the process of cyanide on the gold surface of the slag particles hinder gold leaching and diffusion of membrane . The nature of the residue by burning – cyanide tailings acid when the calcination temperature of vital importance.