The Research Of Stabilizer And Extractant On Preparation Of Insoluble Sulfur By Low Temperature Molten Method

This paper gave a relatively comprehensive review in technical progress and development prospects of insoluble sulfur (IS). Based on the low temperature molten method for insoluble sulfur production, effects of polymerization conditions, initiators, stabilizers on IS yield were investigated. The results show that the suitable conditions for sulfur polymerization are at reaction temperature 260℃, reaction time 60min. Addition of initiator into polymerization system can increase IS yield in product and the proper initiator added into polymerization system is Na2S2O8/FeCl2 (mass ratio 4:1 and 0.5m%). The appropriate stabilizer added in the system is KI (0.2%). In this case, IS content in polymerization product can reach 44.54%. Based on measuring solubility of a few solvents, the mixture with tetrachloroethylene and 1,1,1-trichloroethane (1:1 volume ratio) was screen out as extractan for IS and have both good solvency and extraction effect for sulfur. The proper extraction conditions are at 55℃of temperature,15min of extraction time,12:1 of solvent ratio. Compared with CS2, the extractant has low toxicity and simple recovery method. Therefore it is hopeful to replace carbon disulfur. Effct of different treating oils and SN-1, SN-2 stabilizers for IS on thermal stability of IS product was investigated. The results show that naphthenic rubber oil is the best choice. The thermal stability can reach more than 90% and can fully meet the requirements of HG/T2525-93 when SN-1, SN-2 are added in the IS product by 0.1% and 0.08% respectively during treating oil for IS product.