Computer Image Processing Technology In The Dressing-line Particle Size Measurement

Particle size monitoring and analysis has always been a very important research task in environment conservation,chemical industry, medicine industry and metallurgy ,powder engineering ,mineral processing,etc.All the material and products in all these fields arc made up of particles,and the particle size and distribution is one of their most important characters. In mineral processing,the result of online particle size measurement of product in grinding operation is not only an important parameter for its computer automated control but also an important gist for workers to manipulate properly. The realization of grinding product's online measurement can ensure that the grinding operation has qualified products and brings higher economic index. With the development of science , online particle size measurement has many methods and technology which contain high technology more and more.It alse develops with a trend from traditional methods towards hi-tech methods.With the price of computer and camera decreasing,and with digital image processing technology developing ,we have no technical obstacle to develop a online particle sizer based on digital image processing technology which has more advantages than other machine.All the courses are controlled by a computer ,the results are given stablely and quickly without manual operation .So this paper researchs into concentration plants' online particle size measurement system.Normally, what follows is an image analyzing system's working process:theparticles are converted to digital by CCD camera and picture collecting card after theyare imaged by microscope;Then the digital picture is processed with computers andan image processing soft ,which includs picture's preprocessing,edge detection,sizeanalysis,and finally gives or types the size distribution.Picture preprocessing filtersthe noise .increases the brightness contrast and highlights the edge,which can bedone by some simple processing methods.The key problem to realize online particlesize analysis based on digital image processing technology is image segmentationand to segmentalize or get rid of the linking particles.Specialists have these twoproblem deeply studieded and almost have it solved basically.This paper has made a research and discussion on filtering methods.image segmentation,edge coding and size analysis of the particle colored image.which helps to develop a particle size analysis soft. The soft can get up to 16 size grades's down -sieve product's accumulation rate.contrasted with the real distribution ,the result improves that the soft gets a accuracy more than 85%.It takes less than five seconds to analyse a 1600×1200 image,more less than 1 minute which was expected.One minutes is thought to meet the need of the real time concentration online particle size analysis.So,the computer digital image processing technology will offer powerful academic and technical foundation for concentration plants' online particle size measurement,and will make a contribution to improving china's concentration automation level as well.