Comparative analysis of caustic soda and soda ash

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Comparative analysis of caustic soda and soda ash

Different from soda ash (sodium carbonate, Na2CO3) although is called “alkali”, but actually belongs to the chemical composition of salt, and caustic soda (sodium hydroxide, NaOH) is a real soluble in water strong alkali, with strong corrosive and hygroscopic property. Soda ash and caustic soda are also called “two industrial alkalis”, both of which belong to the salt and chemical industry. Although they are very different from each other in terms of production process and product form, their similarity in chemical properties makes them substitute to some extent in some downstream fields, and their price trend also shows obvious positive correlation.

1. Different production processes

Caustic soda belongs to the middle reaches of the chlor-alkali industry chain. Its production industry has gradually been replaced by electrolysis from the caustic method at the beginning, and finally evolved into the current ionic membrane electrolysis method. It has become the mainstream method of caustic soda production in China, accounting for more than 99% of the total, and the production process is relatively unified. The production process of soda ash is divided into ammonia alkali method, combined alkali method and natural alkali method, in which ammonia alkali method accounts for 49%, combined alkali method accounts for 46% and natural alkali method accounts for about 5%. With the production of the Trona project of Yuanxing Energy next year, the proportion of trona will be increased. The cost and profit of different production processes of soda ash vary greatly, among which the cost of trona is the lowest.

2. Different product categories

There are two kinds of caustic soda commonly on the market: liquid soda and solid soda. Liquid soda can be divided into 30% liquid base, 32% liquid base, 42% liquid base, 45% liquid base and 50% liquid base according to the mass fraction of sodium hydroxide. The mainstream specifications are 32% and 50%. At present, the output of liquid alkali accounts for more than 80% of the total, and 99% caustic soda accounts for about 14%. The soda ash circulating on the market is divided into light alkali and heavy alkali, both of which are in a solid state and are distinguished according to density. The bulk density of light alkali is 500-600kg/m3 and the bulk density of heavy alkali is 900-1000kg/m3. Heavy alkali accounts for about 50-60%, according to the price difference between the two has 10% adjustment space.

3. Different modes and ways of transportation

Different physical forms make caustic soda and soda ash different in transport mode and way. Liquid alkali transport is usually made of ordinary carbon steel tank truck, liquid alkali concentration is greater than 45% or special quality requirements should be made of nickel stainless steel tank truck, alkali is generally used 25kg three-layer plastic woven bag or iron bucket. The packaging and storage of soda ash are relatively simple, and can be packaged in double and single layer plastic woven bags. As a liquid hazardous chemical, liquid alkali has a strong regional production and sales areas are concentrated in North and East China, while solid alkali production is concentrated in northwest China. The producing area of soda ash is relatively concentrated, but the selling area is scattered. Compared with soda, liquid alkali transport is more restricted, more than 300 kilometers in the car.


Post time: Nov-30-2022