Development of a large industrial bio-oxidation reactor in hydrometallurgy

• High dissolved oxygen level in the bio-oxidation is beneficial to improve the oxidation efficiency.
• The KYZ-B sparger is helpful to maximize oxygen mass transfer rates.
• The bio-oxidation reactor installed with KYZ-B spargers has higher oxidation efficiency.

In this paper, the characteristics of the bio-oxidation process are investigated and the design principles of an efficient bio-oxidation reactor are proposed based on the large number of laboratory tests. Methods, such as increasing the height of tank to improve dissolved oxygen content and adding affiliate aeration system to reduce the diameter of air bubbles, are taken. The new type bio-oxidation reactor installed with KYZ-B aeration system is designed and manufactured. The metallurgical performance comparison between the new bio-oxidation reactor and the traditional one was taken by industrial test in Hatu gold concentrator in Xinjiang Uygur Autonomous Region in China.The result of industrial test shows that: under the same feeding and the same content of S, Fe, As in the overflow of two bio-oxidation reactor, the feed rate in slurry of the new reactor was 3.72 m3 per hour, but he feed rate in slurry of the traditional reactor was 3.23 m3 per hour. The feed rate of reactor 2# is 15.2% higher than reactor 1#. The cyanide leaching test was taken. The gold leaching rate of the sample taken in the new reactor is 95.53%, while that of the traditional one is 95.09%. The gold leaching rate and the electron microscopy images demonstrate that the new bio-oxidation reactor has higher oxidation efficiency.