Continuous process for producing insoluble sulfur

A continuous method for producing insoluble sulfur, comprising the following steps:

• (1) heating a sulfur to 200-700° C., then quenching the sulfur with water, aqueous solution and other solvents as a quenching agent, and then drying and solidifying the resulting insoluble sulfur at 40-80° C. for 3-15 h, to obtain a solid insoluble sulfur crude product containing 30-70% of insoluble sulfur;
• (2) crushing the insoluble sulfur crude product obtained in step (1) in water in a pulverizer into particles with a particle size of 50-400 meshes, wherein a temperature of water is controlled to not higher than 80° C. during the crushing;
• (3) purifying and refining the insoluble sulfur obtained in step (2) in an extraction column, wherein water and the insoluble sulfur crude product are pumped into an upper part of the extraction column, and a solvent is pumped into the lower part of the extraction column;
• (4) making liquid flowing out from a top of the extraction column flow into a separation tank for water and solvent to separate a water layer and a solvent layer, wherein the solvent layer is heated and evaporated to recover the solvent and sulfur, while the water layer returns to the pulverizer;
• (5) feeding the insoluble sulfur and solvent separated from the lower part of the extraction column in step (3) into a filter to separate the solvent out;
• (6) heating and evaporating the insoluble sulfur filtered in step (5) to recover the solvent;
• and
• (7) adding a filling oil into the insoluble sulfur obtained in step (6) to result in a mixture, and uniformly mixing the resulting mixture to prepare an oil-filled insoluble sulfur product.