Shaoguan Smelter Low Concentration Flue Gas Double-absorption Sulfuric Acid Process

The present state and development of the production technique of sulphuric acid are summed up, the fundamental principle of acid making is elaborated on from the aspect of thermodynamics and dynamics in the paper and the merits and drawbacks of the double-conversion and double-absorption technology are analyzed in detail theoretically. Combined with the real production status in Shaoguan Smelter and the development of sulphuric acid industry on new equipments and materials, feasibility analysis is made on the application of the acid making technology of double-conversion and double-absorption to the acid making process from the sintering fume with low concentration of SO₂.Through taking the measures of adopting spherical crown converter with high heat storage, imported catalyst, the new type heat exchanger with high coefficient of thermal transmission and high-temperature absorption technology, adding an afterburner, strengthening the heat insulation of the system and reclaiming the compression heat of the SO₂ blower successfully, we adopted the double-conversion and double-absorption technology to make acid under the condition that the concentration of SO2 in the fume is as lower as 4 percent.After careful and scientific application of measures taken in the feasibility study, the modification project was put into production successfully and all the technical and economical indexes reached or exceeded the design indexes successfully, which achieved good economic, environmental protection and social benefit. Therefore the modification has made great contribution to the sustainable development of Shaoguan Smelter.The project, initiated domestically, opens the door for the application of the double-conversion and double-absorption technology to make acid from the sintering fume with SO2 at low concentration, thus it is of great value to popularize in china.