低品位磷矿废石的细菌浸出试验研究

用硫杆菌氧化还原态硫产生硫酸来浸出磷矿,可望为低品位磷矿废石的综合利用及环境保护开辟新的途径,但是用硫杆菌浸出磷矿的浸出率较低。采用加入不同吐温类表面活性剂的方法,促进细菌与矿物的作用,用pH值的变化和浸出率来评价其效果,并对其种类和用量对嗜酸氧化硫硫杆菌的生长及浸磷效果的影响进行了分析。试验结果表明:在加入不同种类及用量的吐温类表面活性剂时,浸矿溶液中嗜酸氧化硫硫杆菌的浓度、溶液的pH、以及磷的浸出率三者具有十分一致的变化趋势。吐温类表面活性剂的分子结构及加入量为影响嗜酸氧化硫硫杆菌浸磷效果的重要因素,通过选择适当的吐温类表面活性剂并控制其用量,可促进嗜酸氧化硫硫杆菌的生长及产酸能力。吐温类表面活性剂可改善嗜酸氧化硫硫杆菌的浸磷作用,通过选择其种类并调节其用量,可获得较佳的浸磷效果。

Experimental Study on Bacterial Leaching of Low-Grade Phosphate Gangue

The leaching of phosphate ore with sulfuric acid produced by the oxidation of reductive sulfur with Thiobacillus is expected to provide a new way for the comprehensive utilization of low-grade phosphate gangue and protection of environment.However,the rate of phosphate leached from the ore with Thiobacillus is low.Different types of Tween surfactants were used to promote the interaction between the bacteria and the ore.The effects were evaluated by the variation of pH and rate of phosphate leached.The influence of the type and dosage of the Tween surfactants on the growth of Acidithiobacillus thiooxidans and the rate of phosphate leached was analyzed.The experimental results indicated that when adding Tween surfactants of different types with different dosages,the variation trends of Acidithiobacillus thiooxidans density in solution,solution pH,and rate of phosphate leached correspond to each other quite well.The molecular structure and dosage of Tween surfactants are important factors influencing the effects of phosphate ore leaching with Acidithiobacillus thiooxidans.Through selecting the type and adjusting the dosage of Tween surfactants,the growth and acid-producing ability of Acidithiobacillus thiooxidans can be improved.Tween surfactants can improve the leaching of phosphate ore with Acidithiobacillus thiooxidans.Optimal phosphate leaching effects can be obtained by properly selecting the type and adjusting the dosage of Tween surfactants.