What is the amount of sea coal needed in cast irons for large green casting moulding sands?
A. 10%
B. 15%
C. 20%
D. 25%
A. 10%
B. 15%
C. 20%
D. 25%
Right option is A. 10%
Explanation: Sea coal otherwise is used in small numbers for binding. Sea coal is used for surface appearance improvement. It is used about 10% in cast iron moulding sands for large green casting sands.