Design and Testing of a Pilot Plant for So2 Removal from Smelter Gas.
McKinney WA; Nissen WI; Rosenbaum JB
Met Soc AIME 1974 Feb; :13 pages
Design considerations are presented for a pilot plant employing the Bureau of Mines citrate process to remove sulfur dioxide from smelter stack gas. The plant was constructed by the Bureau and is being operated jointly by the Bureau and the Bunker Hill Company at the lead smelter in Kellogg, Idaho, to assess the feasibility of the citrate process for sulfur dioxide emission control. Nominal capacity of the Kellogg pilot plant is 1,000 scfm of 0.5 percent so2 gas yielding about 1/3 ton sulfur per day. Sulfur dioxide is absorbed from cooled and cleaned smelter gas in a 2.5-Foot-diameter by 30-foot-high packed tower using about 10 gpm of a countercurrent flowing citric acid-sodium citrate-sodium thiosulfate solution. The absorbed so2 is reacted in three 100-gallon stirred closed vessels with added h2s, thus precipitating elemental sulfur and regenerating the citrate solution for recycle. Sulfur is removed from the slurry by oil flotation, melted in a heat exchanger, and then separated from the occluded citrate solution and oil in a settler at 35 psi and 135 deg. C.
Met. Soc., AIME, February 1974, TMS Preprint A74-85, 13 PP.