The Application Of Microbial Reagents In Non-metallic Mineral Processing

Microbial technology in mineral processing is a rising subject including microbial leaching and microbial flotation. The former appeared in 50'th and has been used for industry application in copper,uranium and gold mines. The latter appeared in 80'th and is in the lab research stage now. Presently the research of microbial agency in mineral processing at home and abroad has focused on metals minerals,but not nonmetallic minerals,especially on architectural material (kaoline,clay ,quartz ,etc.) ,the domestic research has almost been vacancy.The microbial reagent's flotation has such advantages:no toxicity,no second pollution,low energy consumption ,be easy to achieve industrialization through biology engineering,and be bio-decomposed. Therefore ,it would have a good development.The content of this research include two parts:(1) Screening the microorganism that can produce the microbial reagent we need from the microorganism sample,select the best microorganism and optimize its culture condition .On the basis of the microbial reagent has excellent activity,distill and purify the reagent from the culture medium,give qualitative analysis of its ingredient .(2) the task is studying on microbial reagent at some nonmetallic mineral,which include microbial flocculating in some nonmetallic mineral suspension and as a new-microbial-type depressant in the kaoline flotation.The results of the enrichment culture and screening of the microorganisms that can produce microbial reagent is:33 bacterial strains were separated according to the characteristics of the bacterial communities. After screening,13bacterial strains were gained. Their flocculating activities are all over 75%.The studies of the best culture condition of the microorganisms(BF3-3) which produce the microbial reagent suggest that the best culture condition of BF3-3 is initiative pH is 7.5,culture time is 24h,culture temperature is 30 ,rotation speed 170r/min,the dosage of the culture (in 250ml flake) is 100ml. The gradients of BF3-3's culture medium is:sucrose 40g,sodium nitrate 0.5g,yeast extract 2g,MgSO47H2O 0.25g,KH2PO40.5g,initial pH 7.5.The flocculating effect of microbial reagent MBF3-3 on some nonmetallic mineral reached the traditional flocculants. Therefore ,it maybe used to flocculating some nonmetallic mineral waster water as the new generation flocculant.The study of microbial flotation at kaoline suggest the MBF3-3 microbial reagent can effectively depress kaoline.In the theory study ,the author analyzed and summarized the achievement reports and explain the mechanism of the microbial reagent's floculating and flotating in the nonmetallic mineral.