Caustic soda liquor

There is a so-called dry mercerisation process [275] in which the fabric is padded with caustic soda liquor at 20-25 °C and then dried in a stenter at about 130 °C. An immersion time in the pad trough of 7-10 seconds is sufficient but the goods need a total saturation time in the alkaline liquor of 30-40 seconds, i.e. from the nip to entry into the drying zone. 

A single-effect evaporator is used to concentrate 0.075 kg/s of a 10 per cent caustic soda liquor to 30 per cent. The unit employs forced circulation in which the liquor is pumped through the vertical tubes of the calandria which are 32 mmo.d. by 28 mmi.d. and 1.2 m long. Steam is supplied at 394 K, dry and saturated, and the boiling-point rise of the 30 per cent solution is 15 degK. If the overall heat transfer coefficient is 1.75 kW/m2 K, how many tubes should be used, and what material of construction would be specified for the evaporator The latent heat of vaporisation under these conditions is 2270 kJ/kg. 

As soon as in 1785, a solution of chlorine gas in water was used to bleach textiles. Potassium hypochlorite (Eau de Javel) was prepared by Berthollet in 1789. In 1820, Antoine G. Labarraque replaced potash liquor by the cheaper caustic soda liquor and thus was bom sodium hypochlorite. At the end of the 1820s, Robert Collins, then Oliver Wendell Holmes showed that puerperal (childbed) fever frequency decreased when midwives wash their hands... 

In a typical manufacturing process, sodium silicate solution of a weight ratio of 2 and caustic soda liquor (50 wt%) are mixed together to give a solution of metasilicate ratio (see Figure 22.10). Solid sodium hydroxide may be used instead of caustic soda liquor. This solution is concentrated to a... 

Sodium hydroxide (caustic soda) and Sodium hydroxide solution (45-50%) (caustic soda liquor)... 

Mercury cell caustic soda liquor is a high-grade product, low in chloride and chlorate impurities and, because of its traditional associations, known as Rayon grade. It is produced directly by amalgam decomposition at the strength at which it is sold. This usually contains 46.8% NaOH (i.e. 100Tw caustic liquor). 

Caustic soda as a liquor is preferred because delivery can be made in bulk, handling costs are low and no redissolving equipment is required. The overall cost per ton of caustic soda is lowest with the liquid form. Commercial caustic soda liquor is marketed at a strength of about 47%, corresponding to a eutectic point of +6 C on the freezing point curve. Transport and storage difficulties due to freezing in cold weather are thus minimised. 

General quality specifications for caustic soda and caustic soda liquor are given below and these may be used to establish a raw material specification with a supplier. 

It is recommended to bund caustic soda liquor tanks. The bund should be able to retain 110% of the contents of the tank and should be constructed from a strong cement with a low water-to-cement ratio and should be lined with a caustic-resistant material if the temperature of the stored... 

ICI-PLC Mond Div. Technical Service Note TS/A (1984) "Sodium hydroxide. Caustic soda liquor". 

Hydrochloric acid 30% w/w Caustic soda liquor 50% w/w Sodium nitrite 100%... 

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