What is sodium sulfide used for? What is the difference between yellow and red tablets?

Sodium sulfide, also known as stinking soda, stinking soda, alkali sulfide, is an inorganic compound, hygroscopic, soluble in water, aqueous solution is a strong alkaline reaction, touching the skin and hair will cause burns, so sodium sulfide is also known as alkali sulfide. The color of industrial sodium sulfide is pink, brownish-red and earthy-yellow due to impurities. This article will introduce the industrial use of sodium sulfide and the difference between different colors.

purpose

Dyestuff industry: used in the production of sulfide dyes, it is the raw material of sulfide green and sulfide blue.

Printing and dyeing industry: used as auxiliary dyeing agent for dissolving sulfide dyes.

Paper industry: used as cooking agent for paper.

Textile industry: used for denitrification of man-made fibers and reduction of nitrate, and mordant for dyeing cotton fabrics.

Tanning industry: used for hydrolysis to make rawhide hair removal, also used to formulate sodium polysulfide to accelerate the softening of dry leather immersion.

Electroplating industry: It is used for the treatment of conductive layer in direct plating, through the reaction between sodium sulfide and palladium to generate colloidal palladium sulfide to achieve the purpose of forming a good conductive layer on non-metallic surfaces.

Mineral flotation: Sodium sulfide is the inhibitor of most sulfide ores, the sulfiding agent of non-ferrous metal oxidized ores, and the dephosphorizing agent of mixed sulfide ore concentrates.

In water treatment: It is mainly used to deal with electroplating or other wastewater containing metal ions, using sulfur ions to precipitate metal ions to remove metal ions, such as germanium, tin, lead, silver, cadmium, copper, mercury, zinc, manganese and so on. Sodium sulfide precipitation method can recover valuable metal elements in heavy metal wastewater.

Etching: Adding appropriate amount of sodium sulfide in aluminum and alloy alkaline etching solution can significantly improve the etching surface quality, but also can be used for alkaline etching solution such as zinc and other alkali-soluble heavy metal impurities removal.

Difference between red flake sodium sulfide and yellow flake sodium sulfide

1, the difference in iron ion content, the reason why the red tablets are red, mainly because of the iron ion content.

2, the price difference, the market price of yellow tablets than red tablets more expensive.

3, the use of difference, because it contains iron ions, so there will be some difference in the use of the above. In water treatment, yellow tablets of sodium sulfide can not reach the effect of water treatment, only red tablets of sodium sulfide can be, and red tablets of iron ions in the content of at least 1500PPM to work. In the pharmaceutical industry, it is required to be free of iron ions, so only yellow tablets are suitable. And most of the other applications can be both, mainly according to the actual needs of the production enterprises.