That's funny, I just did that same problem today! You want to use filtration to separate the sand since it is a solid and everything else is in solution. Then you use base extraction to make the CA become a salt and more soluble in water ("like dissolves like", CA is polar and so is water) versus ether (slightly polar). Then use evaporation since ether's boiling point is lower than the CA because there is no hydrogen bonding. There is an explaination after the problem set that is probably better than how I explained it.