Ultrafine grinding

Y. H. Chia and P. Somasundaran, in Ultrafine Grinding and Separation of Industrial Minerals, S. G. Malghan, ed AIME, New York, 1983. 

A most useful feature of the agglomeration technique is its ability to work with extreme fines. Even particles of less than nanometer size (ca 10 ° m) can be treated, if appropriate, so that ultrafine grinding can be appHed to materials with extreme impurity dissernination to allow recovery of agglomerates of higher purity. A number of appHcations of Hquid-phase agglomeration have reached either the commercial or semicommercial pilot scale of operation. 

Ultrafine grinding is carried out batchwise in vibratoiy or ball mills, either diy or wet. The purpose of batch operation is to avoid the residence time distribution which would pass less-ground material through a continuous mill. The energy input is 20-30 times greater than for standard grinding, with inputs of 1300-1600 kWh/ton compared to 40-60. Jet milling is also used, followed by air classification, which can reduce top size Below 8 [Lm. 

H. Heegn, On the Connection between Ultrafine Grinding and Mechanical Activation of Minerals, Aufbereitungs-Technik, 1989,... 

Herbst and Sepulvida, "Fundamentals of Fine and Ultrafine Grinding in a Stirred Ball Mill", Proc. Powder Bulk Solids. Conf., Chicago, Illinois, May, 1978. (Unpublished Seminar)... 

The greatest advancements in grinding technology in the recent past have been made in ultrafine grinding... 

The coal particle size in a COM is depoident on the appUcadon and equipment to be used in the transportation, storage, and combustion. For r fplicadons as an oil replacement in ntility or industrial boilers or process heaters, where good atomizadon and stable flames are required, coals are typcally ground to 70%-80% -200 mesh (74 pm). Ultrafine grinding to sizes as low as 10 pm can improve... 

Given the multitude of existing comminution processes, we shall discuss two coarse, two fine, and three ultrafine grinding methods. 

A hammer mill for ultrafine grinding vith intermediate classification is known as the Mikro-Atomizer. In this model, a set of swing hammers is mounted between two rotor discs in the same fashion used in conventional hammer mills. In addition to the hammers, the rotor shaft carries two fans in... 

Gusew, G. M., D. K. Arkhipenko, E. F. Doilnitsyn, and V. M. Klyarovskiy, 1969. Effect of ultrafine grinding on micas and their argon content. Geochem. Internat. 6 80-88. 

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