Barium Carbonate

BaCO3. Found in nature as Witherite. It is made pure by adding ammonium carbonate and a little ammonia to a solution of barium chloride; the precipitate is then washed carefully by decantation. The carbonate usually found in the market is made by precipitating a solution of the crude sulphide with sodium carbonate, or by heating sodium carbonate with heavy spar. heavy spar. Made in either of these ways, it always contains impurities. It is used in analytical operations and for the preparation of other salts. It is poisonous, as are other salts of barium except the sulphate. It is used for sizing cotton warps and as rat poison.