Study On A New Process For Insoluble Sulfur Production

Insoluble Sulfur, or IS for short, is also referred to as sulfur mu. It is formed through ring opening polymerization of ordinary sulfur and named for its insolubility in carbon disulfide. IS is widely used in the production of radial tyres as the vulcanizing agent of rubber. With its high dispersibility and high temperature stability, IS could effectively avoid rubber blooming in rubber compounding process and has good vulcanizing effect. With the domestic demand for radial tire increasing, the demand for IS increases as well. It is of great economical and social benefit to produce IS from ordinary sulfur.This paper prepared IS from ordinary sulfur in the process of which sulfur vapor is quenched in various organic hydrocarbons. The quenching fluids included D30 solvent oil, aviation kerosene and hydrocracking tail oil. The effect of reaction temperature, reaction time and temperature of the quenching fluid on the yield of IS and its high temperature stability was investigated. Results showed that aviation kerosene exhibited the best quenching effect and the high temperature stability of IS got with this fluid could reach 69.03%. The optimum process conditions were as followings:IS stabilizer of 1%, reaction temperature of 450℃, reaction time of 20min, quenching fluid temperature of 20 ℃.The dispersity of the IS was determined by comparing with IS90 produced by a domestic factory. This experiment was carried out as followings:mix SBR with IS, compression molding, use optical microscope to observe. Different parts of the compound rubber were selected for vulcanization test with the rubber process analyzer and the vulcanization curve was made to evaluate vulcanization effect. Results showed that IS prepared in this paper had high dispersity and uniform vulcanization effect.This paper designed and set up a pilot unit according to the results of basic research. Water quenching test was conducted to investigate the effect of industrial factor on IS production process. Results indicated that this process is feasible for industrial production. An IS production unit of 10000 tons/year was designed according to the results of basic research and pilot experiment. This process includes four major parts:raw material pretreatment process, quenching process, post-processing and waste recycling process. The energy consumption of the whole process is about 1882 kW·h/t according to material balance and heat balance calculation.3 heat exchangers,7 pumps and 4 multi-functional drying machines were selected out in this paper based on the requirements of IS production. The design conditions and requirements for non-standard equipment in this process were also determined.