Fractal Study Of Superfine Quartz Powder Based On Ball Mill

The superfine quartz powder has an important role in every important area of national economy. But now, with the improvement of the technology of the superfine quartz powder, the existing methods of powder evaluation are not suitable to occasion. In this paper, the method of superfine quartz powder evaluation is studied to improve the existing evaluation system, based on fractal theory.Firstly, the mechanism of grinding for powder is analyzed based on the experimental data, started with the principle and the influence factors of preparation of ultra-fine quartz powder by high energy ball milling and combined the fractal theory. This analysis helps to find the fact that the powder grinding process has fractal character, which is the condition for the fractal study on the superfine quartz powder.Secondly, fractal model for size distribution of powder is built, based the basis concept of fractal dimension. The assumption that the size distribution dimension can characterize equality, dispersibility and size of powder is putted forward and proved, by calculating the size distribution dimension and analyzing the calculated results. Then, the characterization principle of size fractal dimensions to powder granularity character is proposed.Thirdly, the BP neural network process parameters model which describes the relationship between the key process parameters of the preparation of superfine quartz powder and size distribution dimension is built, based on the BP neural network. The generalization ability and the application performance of Neural Networks are both improved by imputing sample data and using noise, Bayesian and neural network ensemble. And the forecast of the size distribution character is achieved.Lastly, box-counting algorisms and circumference-area method for border fractal dimension are both improved and the improved method can applied in computer automation to calculate border fractal dimension. By analyzing the calculated result, the fact that border fractal dimension can characterize the irregular rate of size shape is proved. Meanwhile, the calculation method for the surface fractal dimension is studied and the physics meaning of the index in three-energy consumption theory model is clarified. It indicates that the surface fractal dimension can not only character the Complexity of size surface, but also reflect the energy consumption character in grinding process by integrating the three energy consumption theories.