Mechanism of gold collection in matte and distribution behavior of precious metals in oxygen-enriched smelting process 造锍捕金机理及富氧熔炼过程贵金属分配行为

Abstract

The distribution behavior of precious metals in high-temperature molten is affected by the thermodynamic properties of smelting systems and components. The capture of precious metals by high-temperature molten matte is beneficial to reduce the total Gibbs free energy of the system. The loss form of precious metals is similar to copper in the slag, mainly based on mechanical suspension which accounting for more than 90% of the total slag loss. The precious metal multiphase equilibrium model was modified with a mechanical suspension rate. The modified model was used to calculate the Au and Ag contents in the copper smelting process of the typical copper smelting process. The Au contents and Ag contents in matte are 13.29 g/t and 825.84 g/t, and Au and Ag contents in slag are 0.53 g/t, 33.29 g/t, respectively, which are in good agreement with the production results. Then, the distribution behavior of Au and Ag in multiphase were calculated under different concentrate components (Cu, S) and process parameters (matte grade, oxygen-ore ratio). With the increase of Cu content in concentrate, matte grade and oxygen-ore ratio, and the decrease of S content in the concentrate, the distribution ratio of Au and Ag in the copper matte decreases, and the loss in the slag increases. Therefore, reducing the mechanical levitation rate of the copper matte is beneficial to reduce the loss of precious metals in the slag and improve the recovery rate of precious metals.