A Novel Process For Super Mill And The Milling Experiments Of Minerals

This paper described the development and present actuality of superfinepulverization technology, it also discussed influential factors of mineralsuperfine pulverization and the factors that influencing the powder granularityduring process of superfine pulverization, we produced the action frequencyand action force as influential factors originally. With increasing the actionfrequency the quantity of crushed product in the same time span also increasedenormously, this made the product more likely to be crushed than aggregation.The greater the action force used during the process of increasing actionfrequency (decreasing diameter of medium) the better mutual action amongproducts. We used those knowledge to design a new kind of ball mill. After aperiod of work , we finished the work of design, accessories producing,installation and debugging. We also used this new kind of ball mill inexperiment.We used home-made ball mill to produce a large quantity of superfinemineral power. superfine power were analyzed by TEM and XRD. Quartzpower presented grain shape with average diameter at 35nm(with a littleaggregation);antigorite power presented chain shape with average diameter at80nm; mica and graphite power presented flake shape with average diameter at100nm (graphite flake looked like piece goods); The SEM images of kaoliniteand bentonite presented flake shape (bentonite flake were less than 10nm); TheSEM images of diatomite power showed that they were composed ofnanometer power(less than 10nm) and aggregated. Produced automobile dyeTiO2 were nanometer product and could transform from anatase to rutile using30% of wet process pulverization. The mechanochemical change ofhome-made ball mill pulverize 4h was the same as the change of sintering 4h at900℃, but this change did not happen with planetary mill 20h in the samecondition. The main characteristic of home-made ball mill was the different structurefrom other ball mill, so the movement track of medium and action forceinfliction mode were also different. planetary mill used impactpulverizationaction, the action force was large , the action frequency was low,the medium abrasion to much with large diameter product; home-made ballmill was a kind of ball mill which with low action force , high action frequency,less abrasion and small product diameter. In our experiment, the planetary millwas fixed at 426rpm rotate speed and centrifugal acceleration of 33g (g-acceleration of gravity); home-made ball mill was fixed at 150rpm rotate speedand centrifugal acceleration of 6.5g. Laser sixers and XRD showed that thehome-made ball mill was better than planetary mill in pulverization efficacy ofquartz, this proved our hypothesis. The images of XRD proved that automobile dye TiO2 did not occuramorphous phase during the process of mechanochemical phase transition inthe condition of home-made ball mill in wet atmosphere. This result wasdifferent from planetary mill in dry atmosphere. This proved that home-madeball mill could make full use of the energy of pulverization which was alsodifferent from traditional planetary mill. We introduced a new mechanism ofTiO2 phase transition in the process of pulverization: home-made ball millcould provide moderate and continuous shearing stress. Under the action of...