Generalized skew-normal distribution model of partition curves based on quartile

In view of the similarity between the partition curve of coal preparation and the cumulative curve of distribution function, the quartile of random distribution is often used to describe the characteristics of partition curve, the median being the separation density, quartile deviation being the probable error, quartile measure of skewness reflecting the asymmetry of the partition curve. With the help of the properties of linear interpolation and distribution function, a generalized skew-normal distribution model of partition curves based on quartile and other auxiliary parameters was built which have four or five parameters including separation density, probable error and quartile skew coefficient and so on. The introduced auxiliary parameters have a good correction to the tail of the curve. The model shows very good fitness for the partition coefficient data.