Fick’s law in transport phenomena relates to which physical process in fluids or solids?
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AEnergy consumption in comminution
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BFinal particle size prediction
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CFeed size specification
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DNone of these (it describes molecular diffusion)
Answer
Correct Answer: None of these (it describes molecular diffusion)
Explanation
Introduction / Context:Fick’s law is a cornerstone of mass transfer. It states that diffusive flux is proportional to the negative gradient of concentration, analogous to Fourier’s law for heat conduction.
Concept / Approach:Fick’s first law: J = −D * (dC/dx), where J is molar flux by diffusion, D is the diffusivity, and dC/dx is the concentration gradient. Fick’s second law accommodates transient diffusion by combining the first law with the continuity equation. These do not address particle size, feed size, or energy in crushing; they govern molecular transport in gases, liquids, and solids.
Why Other Options Are Wrong:Energy/particle size items belong to comminution, not mass diffusion.
Final Answer:None of these (it describes molecular diffusion)