Preparation method of sodium sulfide

Abstract

The invention discloses a preparation method of sodium sulfide, the preparation method comprises the following steps: a, adding raw coal powder and anhydrous sodium sulphate into a mixer to obtain a mixture for standby use; b, spraying the mixture into a calcining furnace to obtain sodium sulfide alkali billet for standby use; c, thermally melting the sodium sulfide alkali billet into a liquid toobtain a reducing leaching solution; d, evaporating the reducing leaching solution to about 250 g / L to obtain a sodium sulfide semi-finished product leaching solution; e, removing heavy metal ions inthe leaching solution until the total content of metal ions in the leaching solution is less than that of 10ppm filtrate; f, pumping the filtrate into a crystallization tank, and performing rapid vacuum freeze-crystallizing and centrifugal dehydration to obtain high-purity sodium sulfide. The raw coal powder is ground and crushed, so that the contact area of the raw coal powder and the anhydrous sodium sulphate is bigger, the reaction is more sufficient when heating and reducing, and the yield of the sodium sulfide is improved; by negative pressure calcination and temperature control, the content of soluble impurities of the product can be reduced, the conversion rate of raw materials can be improved, consumption is reduced, and the effect of energy saving and consumption reduction can beobtained.

Description

technical field [0001] The invention relates to the technical field of sodium sulfide preparation, in particular to a preparation method of sodium sulfide. Background technique [0002] Sodium sulfide is also called smelly alkali, smelly soda, yellow alkali, and alkali sulfide. Sodium sulfide is an inorganic compound, and pure sodium sulfide is a colorless crystalline powder; it has strong moisture absorption and is easily soluble in water; the aqueous solution is strongly alkaline; it will cause burns when it touches the skin and hair; therefore, sodium sulfide is commonly known as alkali sulfide. At present, there are two main production methods of industrial sodium sulfide in my country, one is the main production method - Glauber's salt calcination method; the other is the secondary production method - precipitation of barium sulfate and secondary production of sodium sulfide. The existing mixture of Glauber's salt and coal powder is only simple mixing, and Glauber's sa...

AI Technical Summary

Problems solved by technology

The existing mixture of Glauber's salt and coal powder is only simple mixing, and Glauber's salt is usually irregular flakes or granules. Simple mixing has a small contact area. Powder calcination is not complete, a large amount of waste gas is produced, and the output of sodium sulfide is low

The above two kinds of industrial sodium sulfide produced have the problems of many impurities and high iron content, which will affect the quality of the final product during the application process.