The preparation method of methylene dithiocyanate

Abstract

The invention relates to a preparation method of methylene dithiocyanate. Ammonium thiocyanate, dichloromethane, methanol and water are put into a reaction kettle at a weight ratio of 2:2:1:0.1:5, and auxiliary When the temperature rises to 90°C and the air pressure is 0.4MPa, the synthesis time is more than 6 hours; then the above-mentioned composition is put into a crystallization kettle, cooled with water in the crystallization kettle, and Stir at the same time to accelerate cooling; then put the material in the crystallization tank into a filter for vacuum filtration; then use water twice the weight of the vacuum filtered product, add detergent to stir and wash; finally refine and crystallize the washed product to produce To obtain methylene dithiocyanate products. The ammonium thiocyanate synthesis method is used to improve the utilization rate of resources, reduce environmental pollution, and reduce production costs. The propulsion type agitator is used to fully dissolve the water and oil, and the reaction is thorough. The reaction is complete by using additives, and the product yield reaches 80%.

Description

technical field [0001] The invention belongs to the technical field of green and environment-friendly circulating water treatment chemical preparation method, and relates to a kind of industrial circulating water sterilization suitable for power plants, chemical plants, fertilizer plants, steel plants, printing and dyeing plants and oil refineries, and also suitable for sewage A method for preparing methylene dithiocyanate that is sterilized and recycled for use in central air-conditioning and other water systems for sterilizing and inhibiting bacteria. Background technique [0002] my country ranks more than 100 in the world in the amount of fresh water per capita, and is listed as one of the 13 water-poor countries by international organizations. With the rapid development of the national economy, the situation of water shortage is becoming more and more serious. It is more and more necessary to save water and emphasize the use of circulating water. The special environmen...

AI Technical Summary

Problems solved by technology

At present, the reaction pressure is low in industrial production, and a large part of dichloromethane is gas, which cannot be fully contacted with the aqueous solution of sodium thiocyanate, and adding a phase transfer catalyst has no effect on it, so the production rate has always been low.