Whole mud cyanide leaching is an ancient and reliable gold extraction process, which is widely used in production today. In recent years, in order to increase gold production, realize gold production on site, and increase the production efficiency of enterprises, various gold mines have expanded the application scope of their all-mud cyanide leaching process.
The embedded particles of gold in various ores are mostly medium and fine-grained gold, and the occurrence state of gold is mainly intergranular gold and fissure gold. This embedded state is conducive to full mud cyanide leaching, but there is still a small amount of fine particles wrapped in gold in various ores, which will have a certain impact on the leaching rate of gold. The mineral research results show that each ore type is a relatively difficult gold ore to leach, and a large amount of cyanide is consumed during cyanide leaching, which affects the leaching rate of gold.
The conventional all-mud cyanide leaching process not only consumes a lot of cyanide, but also has a low leaching rate for medium- and high-sulfide gold ores that contain a lot of harmful impurities such as copper, arsenic, and sulfur. Adding lead nitrate for pretreatment before leaching can reduce cyanide loss and increase the leaching rate.
Adding lead nitrate before leaching can reduce the content of soluble metal particles in the slurry, thus reducing sodium cyanide consumption. In gold mines, take the ore-type high-flavor pyrrhotite-type gold-2-copper ore as an example. The content of pyrrhotite reaches 23130%. In the molecular structure of pyrrhotite, there is a weakly bonded sulfur atom that is easily oxidized to form soluble sulfide, which consumes a large amount of cyanide during the cyanide leaching process and prolongs the pretreatment time. And the addition of lead nitrate can reduce the presence of sulfide ions in the slurry and the settled soluble sulfide, thereby reducing the consumption of sodium cyanide and improving the leaching rate.
Post time: Dec-06-2023
