A gold deposit is composed of gold bearing quartz vein and gold bearing mylonite, the former accounting for 75% and the latter 25%. The ore is seriously oxidized. The metal sulfide ore in the upper part of the ore body has been completely oxidized, which is a typical gold bearing quartz vein oxidized ore.
The main metal minerals are limonite, magnetite and hematite, followed by pyrite, occasionally chalcopyrite, sphalerite, galena, tetrahedrite, copperas, azurite, malachite, chalcocite, argentite and natural gold. Gangue minerals are mainly quartz, followed by sericite, plagioclase, chlorite and a small amount of calcite and kaolin.
The gold ore is mainly natural gold, generally in granular, strip (sheet) and veinlet forms, and a few in dendritic form embedded in quartz and limonite. The grain size of granular natural gold embedded in quartz is 0.02~0.08mm, accounting for about 65% of the total gold; The grain size of natural gold wrapped in limonite is 0.001~0.036mm, accounting for about 35% of the total gold.
As the ore is a typical gold bearing oxidized quartz vein ore with high argillaceous content, it is appropriate to use the whole peat slurry gold extraction process.
Its production process is as follows: ore crushing grinding classification concentration agitation cyanidation leaching carbon adsorption separation of pulp and gold loaded carbon desorption of gold loaded carbon electrolysis of precious liquid gold powder smelting ingot finished gold. Tailings are treated with bleaching powder and then stored in tailings pond. The main operating conditions of this process are as follows.
1. Gold cyanide leaching
The pulp concentration is 40%~50%, the grinding fineness is -0.074mm, accounting for 99%, pH=10~11, the sodium cyanide concentration is 0.03%, and the leaching time is 24h.
2. Carbon slurry adsorption
The activated carbon is almond stone carbon GH-17, with a particle size of 0.833~2.262mm, four adsorption sections, a carbon density of 9.6 g/L pulp, a carbon content of 2 kg/h, and gold loaded carbon containing about 7000 g/t.
3. Gold loaded carbon desorption
The desorption solution is 4% NaCN+2% NaOH, the desorption temperature is 95 ℃, and the desorption time is 12~14h.
4. Electrolysis of your solution
The steel wool cathode and stainless steel anode are used. The cell voltage is 3V, the cathode current density is 8-15A/m2, the electrolysis temperature is normal, and the electrolysis time is 12h.
In the three years after the production of the carbon pulp plant, various technical and economic indicators were stable, and the total gold recovery rate was more than 90%. The main raw materials consumed by the plant for each 1t of ore treatment are (kg): sodium cyanide 0.58, lime 7, bleaching powder 0.39, sodium hydroxide 0.04, activated carbon 0.09, lining plate 0.4, steel ball 5, hydrochloric acid 0.1.
