Autoclaved Oxidation Leaching of Sulfide Concentrate Containing - Gold Arsenic (III)

As for the dynamics of the oxidation autoclave pyrite leaching process also made a number of studies. In these studies, the results of the studies by Maxxen and Xannep , TepnaxXene and nannexcll were the most detailed and reliable. Because of these research   The main conclusions derived from one another study - induced. In this paper, we strive to compare the oxidation kinetics of pure pyrite with the oxidation kinetics of similar products obtained by simultaneous oxidation of pyrite and arsenopyrite .

Figure 3 , a is under different temperature conditions (acid concentration is 26.4 grams / liter, partial pressure of oxygen is 2 atmospheres) oxidation kinetics of pyrite. The equation of AppHHy . illustrates the relationship between the velocity and temperature of the oxidation process. The apparent activation energy is 11.5 kcal / gram and demonstrates that the oxidation process is carried out within the kinetic range. The effect of partial pressure of oxygen on the oxidation rate of pyrite is shown in Figure 3 , 6 (temperature is 130 °C , the acidity of the solution is 26.4 grams / liter of sulfuric acid). Pyrite differs from arsenic pyrite in that its oxidation rate is proportional to oxygen pressure. It all previous research data - delivered, pyrite and other sulfide is different - an important feature. Increasing the acidity of the solution has less effect on accelerating the oxidation process.

  Therefore, it should be noted that the presence of arsenopyrite does not change the basic regularity of pyrite oxidation.

From the process point of view, the reaction rate is much pyrite to oxygen than arsenopyrite slow, reaction order and higher, which - is very important point. This allows us to draw important conclusions in the process: ( 1 ) When selecting the autoclave leaching parameters, we should first consider the possibility of rapidly and fully oxidizing pyrite, which is the most difficult to treat sulfide. 2 ) The loss of gold due to incomplete oxidation of sulfides is mainly due to the insufficient oxidation of pyrite, rather than the incomplete oxidation of arsenopyrite.

In the autoclave leaching process test, several gold-containing concentrate samples of the following composition were used. In the concentrate sample, iron is 24.2~34.3% , sulfur is 21.8~273% , arsenic is 4.9~9.4% , gold is 31.3~ 43.0 grams / ton. The gold in all samples was in a fine-grained state and was symbiotic with pyrite and arsenopyrite. Some samples also contain 4 to 5% carbon, which increases the impermeability of the process.

The autoclave leaching is carried out in the "Visnikovsky" type titanium autoclave with a volume of 1 liter with 5 liters . Water is used as the original liquid phase. 36~80% iron (mainly in Fe ³⁺ state), 80~98% sulfur and 12~40% arsenic are transferred into the autoclave leaching solution. The yield of the insoluble autoclaved leaching slag fluctuates between 54 and 80% . The autoclaved leaching residue is sent to adsorb cyanide (using an AM--26 anion exchanger) or subjected to ordinary cyanidation treatment after washing and lime treatment.

The results obtained prove that the temperature, oxygen partial pressure and leaching time during autoclave leaching are the main factors determining the gold recovery rate. After the autoclave leaching under the optimum conditions, the gold recovery rate when the autoclaved slag is adsorbed and cyanated can reach 90 to 95% . This is 2~3% higher than the conventional cyanidation of the hot dip slag.

The advantage of using the autoclave leaching method over the calcination process is that the gold recovery rate is higher.

PSU Mould

Polysulfone Injection Molding, PSU Injection Molding, PSU Plastic Injection Molding, PSU Material,  PSU molding, PSU Mould

Dongguan Hongke Plastic Precision Mould Co.,Limited , https://www.scientificmolds.com