Which expression represents Rittinger's crushing law? (Where P = machine power, m = feed rate, k = constant, D̅ sa & D̅ sb = volume-surface mean diameters of feed and product) ?
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Answer: C. P/m = K . (1/ D̅ sb – 1/D̅ sa)
Explanation
Rittinger law assumes energy is proportional to surface area created. The term 1 over D sb minus 1 over D sa represents new area. This mathematical formulation correctly reflects fine particle size reduction mechanics. Rittinger proposed his crushing law during the nineteenth century. The law relates machine power input directly to new surface generation. Volume surface mean diameters are utilized to quantify specific surface areas.
Mineral processing engineers use this law to calculate grinding mill power. It applies primarily to fine grinding where surface energy dominates work. Accurate energy calculations prevent costly motor overloads in industrial plants. Option A represents Kick law which governs coarse particle reduction processes. Option B corresponds to Bond work index scaling equations for intermediate sizes. Option D is incorrect because option C explicitly gives the correct expression.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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