Ball mills and tube mills with flint or porcelain balls are used for size reduction of_______________?
A. Asbestos
B. Rubber
C. Non-metallic ores
D. Limestone
Mechanical Operations
Grinding characteristic of a material is given by its___________________?
Grinding characteristic of a material is given by its___________________?
A. HGI
B. Angle of repose
C. Shatter index
D. Abrasion index
Which of the following is not categorised as a “mechanical operation”?
Which of the following is not categorised as a “mechanical operation”?
A. Agitation
B. Filtration
C. Size enlargement
D. Humidification
For Indian standard (IS) screens, the mesh number is equal to its aperture size expressed to the nearest deca-micron (0.01 mm). Aperture width of IS screen of mesh number 50 will be approximately _____________ microns?
For Indian standard (IS) screens, the mesh number is equal to its aperture size expressed to the nearest deca-micron (0.01 mm). Aperture width of IS screen of mesh number 50 will be approximately _____________ microns?
A. 5
B. 50
C. 500
D. 5000
Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of ____________ mm?
Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of ____________ mm?
A. 0.007
B. 0.30
C. 50
D. 0.014
____________ mills fall in the category of tumbling mills ?
____________ mills fall in the category of tumbling mills ?
A. Ball and pebble
B. Rod and tube
C. Compartment
D. All A., B. & C.
____________ conveyor is the most suitable for long distance transportation of cold, nonabrasive granular/irregular shape/fine materials?
____________ conveyor is the most suitable for long distance transportation of cold, nonabrasive granular/irregular shape/fine materials?
A. Bucket
B. Belt
C. Screw
D. Apron
A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is_________________?
A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is_________________?
A. 0.50
B. 0.58
C. 0.68
D. 0.62
Run of mine (ROM) coal is crushed by a _________________________ for use in domestic ovens?
Run of mine (ROM) coal is crushed by a _________________________ for use in domestic ovens?
A. Jaw crusher
B. Hammer crusher
C. Ball mill
D. Tube mill
Sizing of very fine particles of the order of 5 to 10 microns is done by elutriation, which is a _____________ operation?
Sizing of very fine particles of the order of 5 to 10 microns is done by elutriation, which is a _____________ operation?
A. Clarification
B. Sedimentation
C. Flocculation
D. Classification