Treatment of barium perchlorate with sulfuric acid precipitates barium sulfate, leaving perchloric acid. Storage over sodium hydroxide precipitates the intermediate ether hydroperoxides. Calcium and carbonate ions react to form calcium carbonate, which precipitates, leaving fresh water. Decreased soil pH increases the solubility of phosphorus precipitates. Calcium carbonate precipitates as a solid, leaving ammonium sulfate in the solution. The cementite which precipitates from the melt forms as relatively large particles. With the addition of oxalic acid, the yttrium oxalate precipitates. Thorium precipitates out of solution as hydroxide and is removed. In this way, they prevent formation of insoluble precipitates (scale). Sodium bicarbonate precipitates as a solid from this solution. For example, addition of barium chloride, precipitates out barium sulfate. Reconstitution with sodium chloride should be avoided due to formation of precipitates. When the Bayer liquor is cooled, Al(OH) precipitates, leaving the silicates in solution. Struvite precipitates in alkaline urine, forming kidney stones. The displaced calcium precipitates mainly as gypsum.