The present disclosure relates to a method for producing polycrystalline silicon fragments. The process includes (a) providing a polycrystalline silicon rod, (b) working the surface of the silicon rod by means of a hammer or needle hammer to remove at least a portion of a layer of the surface of the polycrystalline silicon rod, and (c) reducing the silicon rod to fragments. Wherein an amount of impact energy expended by the hammer and/or needle hammer is from 1 J to 15 J.

A glass powder production process for producing glass powder with a grain size <40 m includes feeding a fine mill with glass cullet and dry grinding the glass cullet in the fine mill, feeding the crushed glass cullet into an air classifier and air classifying the crushed glass cullet into a fine material fraction and a coarse material fraction, wherein the separation limit of the air classifier is set to a grain size <40 m, discharging the coarse material fraction from the air separator, preparing the coarse material fraction for refeeding into the fine mill, refeeding the coarse material fraction into the fine mill, outputting the fine material fraction as the end product, the glass powder. The disclosure also relates to a glass powder production device suitable for carrying out the process.

A shredder includes a shredding section that shreds paper into paper pieces, a housing section that houses the paper pieces, a bulk height sensor that detects the bulk height of the paper pieces housed in the housing section, a weight sensor that detects the weight of the paper pieces housed in the housing section, and a processor that prohibits shredding by the shredding section in response to indicating fullness of the housing section by either the bulk height detected or the weight detected.

Milling systems and methods for producing materials with a particular particle size distribution are disclosed herein. In some embodiments, a system for providing materials having a particular particle size includes a mill configured to produce grinded materials, a classifier positioned to receive the grinded materials and including a first classifier outlet and a second classifier outlet, and a screen positioned to receive the grinded materials from the second classifier outlet and including a first screen outlet and a second screen outlet. The classifier can be configured to separate the grinded materials based on a first threshold particle size. The screen can be configured to separate the grinded materials based on a second threshold particle size greater than the first threshold particle size.