Crystallization

A supersaturated solution of magnesium sulfate (x_F = 0.46) is cooled in a crystallizer to 130 °F. What is the crystal hydrate formed?

How much CaCl₂ 6 H₂O must be dissolved in 100 kg of water at 20°C to form a saturated solution? The solubility of CaCl₂ at 20°C is 6.7 gmol anhydrous salt per kg of water.

If an aqueous solution of 25% w/w MgSO₄ at 140°F and is cooled to 30°F, the mother liquor concentration will be how many % w/w MgSO₄?

If an aqueous solution of 25% w/w MgSO₄ at 140°F and is cooled to 30°F, what is crystal hydrate formed?

1200 lbs of Ba(NO₃)₂ is dissolved in sufficient water to make a saturated solution at 90°C. Assuming that 10% of the weight of the original solution is lost through evaporation, calculate the crop of crystals obtained when cooled to 20°C. Solubility data for barium nitrate is 30.6% wt at 90°C and 8.6% wt at 20°C.

A Swenson-Walker crystallizer is to be used to produce 1 ton/hr of copperas crystals by cooling a saturated solution which enters a crystallizer at 120°F. The slurry leaving the crystallizer will be at 80°F. Cooling water enters the crystallizer jacket at 60°F and leaves at 70°F. It may be assumed that the U for the crystallization is 35 BTU/hr-ft²-°F. There are 3.5 ft² of cooling surface per foot of crystallizer length and a crystallization unit is 10 ft length.

Data:
Heat of solution of copperas = 4400 cal/gmol copperas
CpF = 0.7 BTU/lb-°F

Solubility at 120°F = 140 parts copperas/100 parts excess water
Solubility at 80°F = 74 parts copperas/100 parts excess water

Determine the amount of cooling water required in gpm.

In #6, what is the number of crystallizer units?

The solubility of NaHCO₃ in water is 9.6 g/100 g of water at 20°C and 16.4 g/100 g of water at 60°C. If a saturated solution of NaHCO₃ at 60°C is cooled to 20°C, the percentage of dissolved salt that crystallizes out is ____________.

A solution of MgSO₄ at 220°F containing 43 g of MgSO₄ per 100 g H₂O is fed to a cooling crystallizer operating at 50°F. If the solution leaving the crystallizer is saturated, the rate at which solution must be fed to the crystallizer to produce one ton of MgSO₄ 7 H₂O per hour is _________________.

A Swenson-Walker crystallizer is fed with a saturated solution of MgSO4 at 110°F. The magma leaves at 40°F. The feed contains 1 g seed crystals/100 g solution, with 80-mesh size. Assuming ideal growth and negligible evaporation, the mesh size of the crystals leaving the crystallizer is ________________.