日立並びに佐賀関両製錬所に排煙硫酸工場の新設について

抄録

As a step to realize the rationalization of postwar copper smelting, the Nippon Mining Co., Ltd. formed in the spring of 1949, a plign of producing contact process sulphuric acid by treating waste gases in their two plants at Hitachi and Saganoseki smelter. The plants at Hitachi and Saganoseki smelter were respectively completed and began operation in January and February, 1951 producing 6, 000metric tons of acid Der month.
This plan is significant in that it has the following two meanings. Firstly, the construction of contact sulphuric acid plant which had been prohibited after the wer, was once again permitted by GHQ and again, that 338, 000, 000 yen equivalent to 55 per cent ofthe total construction cost was met by the counterpart fund. Secondly, the plan of producing sulphuric acid by contact process of directly treating copper smelting converter waste gasses with high fluctuation in SO₂ and gas volume was the first of its kind attempted in Japan.
This plan brought about an extremely satisfactory result in that both of these smelters succeeded in recovering sulphur equivalent to about 40 per cent of the amountin the waste gases in the form of sulphuric acid and thus at Hitachi smelter, they were able to reduce the gas polution to less than 20 per cent when compared with that of five years before its installation.
Report was made on the circumstances which led to the construction of the waste gas sulphuric acid plant and on the construction plan, outline of new plant, points of special considerations paid in connection with the plan and the outline of operation.