Preparation method of sodium dichloroisocyanurate

Sodium Dichloroisocyanurate

[Alias] Youlujing, abbreviated as NaDCC

[Structural formula]

[Physical and chemical properties] White powdery crystals with chlorine odor.

[Preparation method] There are three main production processes of sodium dichloroisocyanurate: dichloroisocyanuric acid neutralization method (chlorination method), sodium hypochlorite method, trichloroisocyanuric acid metathesis method (also called neutralization method)

(1) Dichloroisocyanuric acid neutralization method (chlorination method)

Cyanuric acid and caustic soda are mixed into an aqueous solution at a molar ratio of 1:2, chlorinated with chlorine to generate dichloroisocyanuric acid, and the slurry is filtered to obtain a dichloroisocyanuric acid filter cake that can be fully washed with water to remove the sodium chloride in the filter cake , To obtain dichloroisocyanuric acid

The wet dichloroisocyanuric acid is mixed with water in the slurry, or put into the mother liquor of sodium dichloroisocyanurate, and caustic soda is added dropwise at a molar ratio of 1:1 for neutralization reaction

(2) Sodium hypochlorite method

Firstly, caustic soda reacts with chlorine gas to generate a sodium hypochlorite solution of appropriate concentration.

(3) Trichloroisocyanuric acid double decomposition process

Cyanuric acid and caustic soda are made into trisodium cyanurate at a molar ratio of 1:3, which is chlorinated with chlorine at an appropriate temperature to generate trichloroisocyanuric acid, which is centrifuged to obtain wet trichloroisocyanuric acid.

Trichloroisocyanuric acid, cyanuric acid and sodium hydroxide solution are in a molar ratio of 2:1:3, and the metathesis reaction is carried out at 30～40℃.

(4) Dry

The prepared sodium dichloroisocyanurate products mainly have three forms, anhydrous compounds, monohydrate compounds and dihydrate compounds.