Page 76 - Feed Lab

Estimation of Sand & Silica Suguna Management System Ver 1.0 / SOP / FQL / P2 - 08 Page 2 of 2

burner till smoke free and keep it in a muffle furnace
o
o
at 600 C +/-20 C for 30 minutes. Cool and weigh
(B). (Picture - 13)

Note:
For sample like DORB, Rice polish, MBM, Crushed fish
/ Dry fish, add Conc. HCl and Conc. HNO should be
3
used instead of diluted acids.
Picture-7 Picture-8

REAGENTS
F1:3 Hydrochloric acid

F1:3 Nitric acid

PROCEDURE
FTake silica crucible record empty weight (A) and
tare it. Then weigh 2 gm of sample in a silica
crucible. (Picture - 9) Picture - 9
FIgnite the sample on a burner till smoke cease off.
Place the crucible in a muffle furnace and heat to
o
o
600 C +/-20 C. Kept for 90 minutes. Remove the
crucible from the furnace carefully and cool.
(Picture - 10)
FAdd 1:3 hydrochloric acid till effervescence ceases
and add 5 drops of 1:3 nitric acid. Give slight boiling
to the solution and cool for minimum 5 minutes.
(Picture - 11) Picture - 10 Picture - 11

FThe above solution transfer to the filter paper (What
man No.1/615A) into a 250 ml conical flask. Wash
the residue till it is acid free with 200 ml to 250 ml
hot distilled water. The filter paper (What man
No.1/615A) containing an insoluble material is
placed back in to the silica crucible and dry (use hot
air oven). (Picture - 12)

FThen ignite silica crucible in an electric Bunsen
Picture - 12 Picture - 13

CALCULATION
Weight of insoluble ash (B - A)
Sand Silica % = ------------------------------------------------------- X 100
Sample Weight, g

REFERENCE
1. Bureau of Indian Standard IS 7874 1975
2. Association of Official Analytical Chemist 2000.

Prepared by : Approved by :
64 Director - Technical