A 20% wt solution of NaSO4 at 200°F is pumped continuously to a vacuum crystallizer (meaning no water is evaporated) from which the magma is pumped at 60°F. What is the composition of this magma, and what percentage of NaSO4 in the feed is recovered as NaSO4-10H2O crystals after this magma is centrifuged? The solubility data of NaSO4 is as follows:
From table 2-122 (CHE HB), solubility of Na2SO4·10H2O:
T (°C) 10 15 20
g/100 gH2O 9.0 19.4 40.8