Microorganisms Effect On Leaching The Potassium From Red Mud And Leaching The Phosphorus From Phosphorus Tailings

In this paper,the study object was the red mud and phosphate tailings.We used silicate bacterial leaching the potassium from red mud and acidithiobacillus ferrooxidans leaching the phosphorus from phosphate tailings.The experiments were setted from different leaching time,temperature,pH,rotation speed,the red mud mud dosage and the phosphorus tailings dosage as variable factors.Through the single factor experiments could get a more significant impact factors,and we could use the orthogonal experiments to optimize the leaching conditions.Then assessed the potential for liquid fertilizer which the red mud and phosphate tailings leaching mixed solution.The following conclusions are summarized in this paper.As follow:(1)The growth curve of microorganisms showing that the silicate bacteria grow fastly.After culture 24 hours,the silicate bacteria entered its logarithmic growth phase and 60 hours growing reach a stable period.But the growth of acidithiobacillus ferrooxidans than silicate bacteria is more slowly.After culture 42 hours,the acidithiobacillus ferrooxidans entered its logarithmic growth phase and 66 hours to reach a stable period.(2)The results of the single factor experiments showed that the medium speed(90~180 r·min-1)had little effect on the leaching of potassium from red mud through silicate bacteria,while time,red mud dosage and temperature are more significant,and the phosphate tailings dosage,leaching temperature,leaching time,the shaking speed on the influence of phosphorus in phosphate tailings were more significant than pH.(3)Through the orthogonal experiments,the best process conditions about silicate bacteria leaching of potassium from red mud: the red mud dosage was 1 g·L-1,the temperature was 32.5℃,the extraction time was 3 days.The best process conditions about acidithiobacillus ferrooxidans leaching of phosphorus from phosphate tailings: The leaching temperature was 35℃,phosphate tailings dosage was 15 g·L-1,the rotation speed was 180 r·min-1,leaching time was 8 days.Under the optimum leaching conditions,the leaching rate of potassium in red mud was 84.67%,and the leaching rate of phosphorus from phosphate tailings was 93.4%.(4)Through assessed the potential of the red mud and phosphate tailings leaching mixed solution produced liquid fertilizer,showing silicate bacterium and acidithiobacillus ferrooxidans despite higher leaching rate on red mud and phosphorus tailings,but due to the low content of phosphorus in phosphate tailings and potassium in red mud.Therefore,the preliminary preparation of the mixed liquid in spite of has a certain amount of phosphorus and potassium nutrient elements,but due to the low concentration,it can’t be directly sold as liquid fertilizer.