黑曲霉产酸调控及其浸出碳硅泥岩型铀矿石

在黑曲霉发酵液浸铀体系中，发酵液中的有机酸浓度直接影响铀的浸出率。为了提高黑曲霉发酵液对碳硅泥岩型铀矿的浸出性能，本文设计正交实验对黑曲霉的产酸条件进行优化，研究了预培养时间、微粒子浓度、接种比例、发酵培养时间对黑曲霉代谢产酸的调控作用，分析了发酵液中有机酸含量与铀浸出率的关系。结果表明，在预培养时间15 h、微粒子浓度5 g/L、接种比例4%、发酵培养时间96 h的最优实验条件下，黑曲霉发酵液中的总酸浓度为6880 mg/L，利用该条件下的发酵液浸出碳硅泥岩型铀矿，铀的浸出率达69.27%，铀浸出率与黑曲霉发酵液的总酸量呈正相关。

Regulation of Acid Production by Aspergillus niger and its Leaching Performance for Carbon-Silica Mudstone Type Uranium Ore

In the uranium leaching by fermentation broth of Aspergillus niger, the concentration of organic acids in fermentation broth directly affects the leaching rate of uranium. In order to improve the leaching performance of A. niger fermentation broth for carbon-silica mudstone type uranium ore, orthogonal experiments were designed to optimize the acid production conditions of A. niger. The effects of pre-culture time, microparticle concentration, inoculation ratio, and fermentation culture time on the acid production of A. niger were explored. The relationship between the acid production of fermentation broth and uranium extraction rate was analyzed. The results showed that the total acid concentration in the fermentation broth of A. niger was 6880 mg/L at the optimum experimental conditions of pre-culture time of 15 h, microparticle concentration with 5 g/L, inoculation with 4% and fermentation culture time of 96 h, and thus, the uranium extraction rate reached 69.27%. The uranium extraction rate was positively correlated with the total acid in A. niger fermentation broth.