MAJ. BROGNIARTS FORMULA FOR DRY CONTENT OF LIQUID
If we know the specific gravity of the material in a liquid suspension and the density of the suspension we can calculate the dry weight of this material from:
Dry weight= (1q-1000) x S/S-1
W = dry weight of material in 1 liter of liquid
lq = weight in grams of 1 lifer liquid
S = specific gravity of dry material
Most clays have a specific gravity of 2.5.
Example: This formula is very useful. Let us suppose we have an already-prepared clay slip and we want to add 5 % iron oxide based on dry clay content. First we measure exactly 1 lifer slip and we find it weighs 1.7 kg. Now we calculate dry content of 1 liter slip using Brogniarts formula:
Dry weight = (1700-1000) x 25 /(2.5-1)= 1,166 grams
We have, say, 30 lifers slip so dry clay content in 30 lifers is:
30 x 1.166 kg = 35 kg. Addition of 5% iron oxide to dry clay content = 1.75 kg.