A. Wet grinding achieves a finer product size than dry grinding
B. Its capacity decreases with increasing fineness of the products
C. Grinding cost and power requirement increases with increasing fineness of the products
D. All A., B. and C
Related Mcqs:
- A tube mill as compared to a ball mill__________________?
A. Employs smaller balls
B. Gives finer size reduction but consumes more power
C. Has larger length/diameter ratio (>2 as compared to 1 for ball mill)
D. All A., B. and C. - A tube mill compared to a ball mill__________________?
A. Has a higher length/diameter ratio
B. Produces a coarser product
C. Has a higher diameter/length ratio
D. Uses much larger balls - Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines ?
A. Compartment mill
B. Rod mill
C. Pebble mill
D. Tube mill - The value of work index does not change materially from one equipment to another. If the value of work index determined for close circuit grinding is Wi, then the same for open circuit grinding will be_________________?
A. 0.5 Wi
B. Wi
C. 1.34 Wi
D. 3.34 Wi - Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with ______________ to get the same for dry grinding?
A. 1.0
B. 0.5
C. 1.34
D. 4.34 - Use of ‘grinding aids’ is done in _______________ grinding?
A. Dry
B. Wet
C. Ultrafine
D. Intermediate - Wet grinding in a revolving mill ______________ as compared to dry grinding ?
A. Gives less wear on chamber walls
B. Requires more energy
C. Increases capacity
D. Complicates handling of the product - A _____________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end?
A. Compartment
B. Tube
C. Rod
D. Pebble - In closed circuit grinding as compared to open circuit grinding, the_________________?
A. Specific surface of product is more
B. Product has lesser size uniformity
C. Production rate at a given limiting size is lower
D. Operation is economical - Critical Speed (Nc) of a ball mill is given by (where R1 and R2 are radii of ball mill and the ball respectively) ?
A. Nc = (1/4π). √(g/R1 – R2)
B. Nc = (1/2π). √(g/R1 – R2)
C. Nc = (1/π). √(g/R1 – R2)
D. Nc = (1/2π). √(R1 – R2/g)
