Chemical formula: NaOH
Purity: %1±50 | %1±31
Other Names: Caustic soda, Alkali, Alkaline Soda, Sodium Hydrate, Sodium Hydroxide
Product grade: 1. Industrial Lye
The color of the liquid is clear and transparent and has no odor. It dissolves easily in water and ethanol, methanol and glycerin in equal proportions.
Although chemists had long suspected that alkaline soils were oxides of metals, the nature of sodium and potassium had not been studied until the early 19th century. Even LaVazia did not have a clear idea about what the main component of Soda Ash and Potash was and guessed that nitrogen was one of the constituents of these materials. This mistake appears to be derived from the similarity between sodium and potassium salts with ammonium salts.
The point of determining these components is that of Humphrey Davy, an English scientist. At first, he was frustrated by the failure, meaning he could not extract the metal from the Soda Ash and Potash with the help of a galvanic cell. He soon realized his own mistake and realized that by using a saturated aqueous solution, the presence of water prevented the breakdown of salts. In October 1807, Davy decided to melt the waterless potash, and as soon as he started electrolysis with this melt, small mercury -like, metallic-looking beads appeared on the negative pole in the molten material.
Some grains were immediately blasted and produced a bright flame, while others did not fire but became opaque and covered with a thin white cortex. Davy concluded from several analyzes that the grain was the material he was looking for and that it was highly flammable potassium hydroxide or Potash. Davy carefully examined the metal obtained from the electrolysis and found that when combined with water, the flame produced by the burning reaction is hydrogen released from water. When Davy performed the necessary tests on potassium hydroxide metal, he contemplated searching for sodium hydroxide and, using the same method, succeeded in separating another alkali metal, sodium.
Electrolysis of aqueous solution of sodium chloride produces both chlorine and Sodium Hydroxide.
Approximately, there is a 300-million-ton demand for salt annually, around the world. Salt rock, or sodium chloride, deposits have many reserves around the world. These deposits usually contain pure sodium chloride and are generally several hundred meters deep (some are about 3000 meters deep) and have a thickness of about 300 to 500 meters. The existence of these mines dates back to about 200 million years ago due to seawater evaporation.
Often, these materials are extracted by pumping high-pressure water into existing salt rocks. Part of the salt solution obtained in this type of extraction is evaporated to produce dry salt.
Although most salt rocks occur in saltwater, some of these rocks also have mines and must be extracted from the mother's mines.
The small amount of salt extracted from the salt mine is in stone and the most of it is mined from the surface of ground soil. The salt (sodium chloride) is transferred to a large silage before being decomposed into chlorine and sodium hydroxide for storage. Saturated brine is purified before electrolysis. This method produces deposits of calcium, magnesium and other destructive cations, sodium carbonate, sodium hydroxide and other substances. The solids suspended in brine are refined and removed during the filtration process.
The salt obtained during the extraction process must be purified prior to electrolysis and purified from chemical deposits of calcium, magnesium and other harmful cations by the addition of sodium carbonate and other reagents. Suspensions in brine are also separated by filtration and purification processes. Finally, the resulting salt is stored in niches before the alkali chlorine process begins.
There are currently three electrolytic processes used to produce this substance, the concentration of caustic soda obtained from each process being different:
1. Membrane cells: The caustic soda concentrate produced by this method is about 30 %, which usually gets condensed up to 50% by pressure and evaporation.
Mercury cells: The caustic soda concentrate produced by this method is about 50% by weight, which is usually sold in markets around the world. The concentration of this solution can be increased by evaporation up to 75% and then by solidification at a temperature of 477 to 577 ° C. It is then sold as solid sodium hydroxide or Soda Ash or Soda granula.
Diaphragm cells: The gross caustic soda produced by this method, called DCL, contains 10 to 12% sodium hydroxide and 15% sodium chloride. To achieve the 50% sodium hydroxide solution usually required, DCL must be regulated by evaporating units that are much larger and more complex than similar items in the membrane cell method.
A huge amount of salt precipitates in this process which usually absorbs back into the salt solution, stored in cells and is used again. Another point of view is that the sodium hydroxide, produced by diaphragm cells is tainted by 1% which makes it not usable for many purposes.
Applications of Liquid Caustic Soda
Liquid profit plays an important role in various industries, some of which are:
Paper and pulp: Worldwide, the most widely used of Caustic Soda are in the paper industry. Used in pulp and whitening processes, inks are made from recycled paper as well as water treatment.
Fabric: The textile industry uses caustic soda to process flax and dye synthetic fibers such as nylon and polyester.
Soap and detergent: In the detergent industry, sodium hydroxide is used for soap, a process that converts grease, wax and vegetable oils into soap. It is also used to produce anionic surfactants, which is an essential ingredient in most detergents and detergents.
Bleach production: In these industries, the use of caustic soda is used to produce bleach. Bleachers have many industrial and domestic applications such as fat cutting and mold and mold control.
Petroleum Products: Lye is used to discover, produce and process oil and natural gas.
Aluminum production: In the aluminum industry, sodium hydroxide is used to dissolve bauxite ore, the raw material of aluminum production.
Stability and warehousing:
The caustic soda solution is a stable liquid, but its shelf life depends on storage conditions. If lye is exposed to air, the quality of the product will change over time as the liquid absorbs the carbon dioxide from the surrounding air and forms solid sodium carbonate (Na 2 CO 3) particles. Iron is also absorbed by NaOH if the solution of NaOH is stored in steel containers or coated steel tanks whose coatings are damaged, thus minimizing its exposure to air and reducing the amount of direct contact with metals containing iron, extending the service life of sodium hydroxide solution.
Safety data sheet:
Due to the high pH of sodium hydroxide and the harmful effects it has on the human body, safety precautions should be taken when using this product.