Barium sulfide data

D6. We are removing barium sulfide BaS from insoluble solids (see Problem 14.D14 for data) in a batch washing process. We initially have 10.0 kg of wet solids (each kg dry insoluble solids carries with it 1.5 kg underflow liquid). The initial underflow liquid is an aqueous solution with 0.05 mass fraction BaS. The wet solids are mixed with 10 kg of pure water, the solids are allowed to settle (each kg dry insoluble solids carries with it 1.5 kg underflow liquid), and the overflow liquid is removed. This process is then repeated twice using 10 kg of pure wash water each time. Assume that liquid density is constant and that the underflow liquid held by the solids has the same concentration of BaS as the overflow liquid. 

D15. We are removing barium sulfide BaS from insoluble solids (see Problem 14.D14 for data). We are processing 1000 kg h of dry insoluble solids plus the underflow liquid carried with the solids. The entering underflow liquid is 15 wt % BaS. A 99% recovery of the BaS is desired. The entering solvent (water) is pure. Use a countercurrent process. 

SAFETY PROFILE Confirmed carcinogen with experimental carcinogenic and tumorigenic data. Poison by intratracheal, intravenous, and subcutaneous routes. Mutation data reported. Can react violently with fluorine, hydrogen peroxide, hydrogen sulfide, iodine, barium oxide + air. See also NICKEL COMPOUNDS. 

In the noncyclic compounds for which structural data are available, a dihedral angle of about 90° occurs between the planes of the valencies of adjacent sulfur atoms. Reported values lie between 74° in cesium hexa-sulfide (3) and 108° in barium pentathionates (119). In six- and particularly in five-membered cyclic disulfides, the angle is smaller, and may for steric reasons also become larger, but planar, tram groups with 180° dihedral angle have not been observed. 

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