Method for reducing particle size of foaming agent

Abstract

The invention discloses a method for reducing the particle size of a foaming agent. The method comprises the following steps: (1) adding water into a biurea solid to prepare a biurea suspension liquid of which the water content is 30% to 50%; (2) adding a defoaming agent of which the mass is 0.1% to 5% of the mass of the biurea into the biurea suspension liquid and adding a catalyst sodium bromide of which the mass is 1% to 5% of the mass of the biurea and a catalyst aid, namely an iron agent of which the mass is 0.5% to 2% of the mass of the biurea, and uniformly stirring; (3) continuously adding an excessive amount of an oxidant into the solution, continuously stirring at the temperature of 30 to 80 DEG C, and further stirring for 15-30 minutes after the oxidant is completely added dropwise; (4) after the reaction is ended, filtering and washing the solid, drying in an oven at the temperature of 105 DEG C until the solid is constant in weight, filtering and recycling the mother liquid. The method disclosed by the invention has the beneficial effects that the defoaming agent is taken as an additive, so that a remarkable particle size reduction effect is realized, and particles can be reduced from 40 micrometers to about 25 micrometers in particle size.

Description

technical field

[0001] The invention relates to the field of ADC foaming agents, in particular to a method for reducing the particle size of the foaming agent. Background technique

[0002] The production methods of ADC foaming agent include urea method, Rasig method and ketazine method. The urea method is the most commonly used method in China, which is to react urea and sodium hypochlorite to produce hydrazine hydrate, then condense hydrazine hydrate with urea to form biurea, and biurea and oxidant to form ADC foaming agent. At present, chlorine gas is generally used as the oxidant in the production of ADC blowing agent in China. However, the production of chlorine gas will produce a large amount of hydrogen chloride, which will cause corrosion to the equipment. The green and environmentally friendly hydrogen peroxide oxidation has always been favored by the ADC blowing agent production industry, but its cost is high, and there will be problems with too coarse particle s...