Edge mill

Edge runners in an oilmill

An edge mill or a Chilean mill is a mill used for crushing or grinding in which stones roll around on their edges, on a level circular bed. It is used for milling ore and as an oil mill.^[1] Horse or oxen-driven versions were used in pre-industrial revolution America as tan bark mills to shred tree bark to derive tannins for the leather industry.^[2]

1. Principle: Works on the principle of compression and shear offered to feed by heavy steel pestle.

2. Working: The feed is placed in the motor and the motor is rotated. The pestle also rotated due to friction produced between the motor and pestle. Scrapers bring the feed to the grinding zone, and the material is reduced in size and the collected and sieved.

3. Application: Brittle and crystalline substances are reduced to powder.

4. Advantage: It is a laboratory scale mill.

5. Disadvantage: It was replaced by more advanced mills.

References

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