I. Main Factors Affecting Cyanide Leaching Efficiency
* Oxygen concentration in the pulp solution;
* Cyanide solution concentration;
* pH value (alkalinity) of the leaching system;
* Ore properties (e.g., content of oxygen-consuming minerals such as pyrite and pyrrhotite);
* Leaching temperature, pulp agitation intensity, leaching time, grinding fineness, etc.



II. The Degree of Influence of Oxygen Concentration on Cyanide Leaching Efficiency
* Under the premise of stable control of cyanide concentration, the cyanide leaching rate and leaching efficiency of gold are mainly determined by the dissolved oxygen concentration in the pulp:
* Increasing the dissolved oxygen concentration in the solution can directly accelerate the gold leaching rate and improve the gold leaching recovery rate;
* Any factor that causes a decrease in the dissolved oxygen content of the pulp will directly reduce the gold leaching rate, resulting in poorer leaching indicators;
* When the raw ore contains sulfide minerals such as pyrite and pyrrhotite, these minerals will consume a large amount of dissolved oxygen in the solution in the leaching system, significantly reducing the gold leaching efficiency.

III. Conventional On-Site Oxygen Control Pretreatment Methods

To avoid interference from harmful elements in the ore with gold leaching, alkaline agents such as lime are typically added to the slurry before formal cyanidation leaching. Simultaneously, air is introduced for thorough agitation. This serves two purposes: firstly, adjusting the slurry alkalinity to inhibit cyanide hydrolysis, and secondly, pre-oxidizing oxygen-consuming sulfide minerals and replenishing dissolved oxygen in the slurry.

IV. Suitable Oxygen Concentration Control Range and Enhanced Leaching Process

In conventional cyanidation gold extraction processes, the cyanide concentration in the slurry is generally maintained at a high level. To significantly optimize gold leaching indicators, the core approach is to increase the dissolved oxygen concentration in the slurry.

Industrially, two common methods are oxygen permeation and high-pressure aeration to increase the dissolved oxygen content in the slurry, thereby enhancing the gold cyanidation leaching process and effectively improving various production indicators such as the gold leaching rate.

This process, which optimizes leaching effects by artificially increasing the dissolved oxygen in the leaching system, is collectively referred to in the industry as oxygen-enriched leaching.