An example would be the reaction of barium hydroxide with phosphoric acid because the insoluble salt barium phosphate is produced in addition to water.
From the en.wikipedia.org
Radium hydroxide is more soluble than hydroxides of other alkaline earth metals, actinium, and thorium, and more basic than barium hydroxide.
From the en.wikipedia.org
Other methods include the addition of molecular sieves or alkali bases such as potassium hydroxide or barium oxide.