Application

The Uses of Sodium Sulphate

Sodium sulphate plays an important role in reactive dyeing by improving the affinity of the dyestuff towards the fiber, acceleration ofthe dyestuff’s association and lowering its solubility. The presence of gas particle within the common salt might cause corrosion of the instrumentation. Hence, sulfate is usually most popular over common salt.

Detergent
Sodium sulphate is used in powdered detergents as filler because phosphates, which were traditionally used as fillers in powder detergents. Sodium Sulphate is added to change the consistency of the detergent, to make it more pourable, more soluble and to help it disperse evenly. Sodium sulphate is added to make the detergent powder flow freely. Without it, the detergent would stick together and become one big block. Sodium sulphate is widely used as desiccant which are able to bind multiple molecules of water, forming “hydrates”. This effectively locks up any moisture that enters the detergent, maintaining a dry, free-flowing powdered detergent.

Glass
Sodium sulphate is used in making bottle, sheet, and plate glass in order to provide the necessary alkali base and because it is cheaper than soda ash, which is the standard source of alkali. Sodium sulphate prevents scum formation in the molten glass during refining, and also fluxes the glass. Also acts as a fining agent in molten glass, removing small air bubbles and imperfections during the blowing and casting processes. In making glass the several ingredients, such as sand, soda ash, salt cake, coke, and niter, are weighed out in the proper proportions, mixed in mixing machines, and transferred to the pots in furnaces heated by gas. Glassmakers desire salt cake with less than 1 per cent of either sodium chloride or sulphuric acid, less than 0.4 % of iron and aluminium oxide, less than 0.5 % of matter insoluble in water, and less than 0.2 % of magnesium sulphate.

Pulp & Paper
Sodium Sulphate is used in manufacturing of pulp in Kraft process. The sulphate process of reducing wood to pulp is so named because it involves the use of sodium sulphate, but this substance is used only in making the sodium sulphide that is one of the active chemicals in the process, the other being sodium hydroxide. The process might more properly be called the sulphide process. It is used in treating all the long-fibered woods. As a matter of fact, however, sulphate pulp can be more easily bleached than soda pulp. The cost of labour in the sulphate process is slightly higher than in the soda process, on account of the smelting operation; on the other hand, the raw material is cheaper. Salt cake for this process should be ground and should contain at least 95 per cent of anhydrous sodium sulphate.

Commodity Industry
Sodium Sulphate is used in manufacturing of pulp in Kraft process. The sulphate process of reducing wood to pulp is so named because it involves the use of sodium sulphate, but this substance is used only in making the sodium sulphide that is one of the active chemicals in the process, the other being sodium hydroxide. The process might more properly be called the sulphide process. It is used in treating all the long-fibered woods. As a matter of fact, however, sulphate pulp can be more easily bleached than soda pulp. The cost of labour in the sulphate process is slightly higher than in the soda process, on account of the smelting operation; on the other hand, the raw material is cheaper. Salt cake for this process should be ground and should contain at least 95 per cent of anhydrous sodium sulphate.