Calcium chloride dihydrate is also known as glacial calcium. There are no colored crystals. General product is milky white, hoary or take yellow flaky or small solid, flavour is slightly bitter and astringent. The relative density is 1.85g/cm3(20°C). Soluble in water, dissolved in alcohol, insoluble ether. Its solution is neutral or slightly base. It has corrosion. When it is heated to 260℃, it is dehydrated. Strong deliquescence. The water vapor distillation wastewater (containing 100 g /L calcium chloride) in ammonium bicarbonate production by ammonia-alkali process was cleaned, responded, volatilized and separated from the sodium oxide. Then the hydrolysate was responded and extracted again. When the calcium chloride content reached 70%, it was made by refrigeration.