Union Process has expanded its line of high-speed dry grinding attritors with the introduction of several new models in the intermediate range. The HSA attritor line is now available in a complete range of production models, including 10, 15, 20, 30, 50 and 100, as well as the HSA-1 laboratory model. The patented attritors feature a unique design concept that includes a new shaft configuration and side discharge screen. This allows the mills to use smaller media and run at higher speeds, generating a large quantity of micron-sized products continuously. Generally, the media size used in the HSA attritors is 1-3 mm; in some special cases, slightly larger media has also been used. The shaft rpm of this series ranges from 400 to 1800.