Sodium Nitrate is a chemical compound with chemical formula NaNO3. It has the common name of Chile saltpeter or Peru saltpeter, because of its large deposit founded in each country. The mineral form of this chemical is called nitratine, nitratite or soda niter.
- Sodium nitrate has a transparent white color, but it can change to yellow, gray or brown when it came in contact with impurities. It is highly soluble in water and its solubility is high in ammonia. Sodium Nitrate melts in 308°C and at higher temperatures it will decompose into NaNO2 and O2.
- It occurs naturally in Chile and Peru, where nitrate salts are found in mineral deposits called caliche ore. Since 1940, a conversion process that’s founded by Fritz Haber and Carl Bosch created synthetic Chilean saltpetre, which was used as the natural matter in the production of gunpowder and other ammunitions and resulted in dramatic decline in demand of sodium nitrate from natural sources.
- Some of sodium nitrate applications are as nitrogen fertilizer, an ingredient in firework, gunpowder, substitute for potassium nitrate in black powder propellant, and also as raw material to make synthetic resin if it is reacted with iron hydroxide. It is also used as a food stabilizer and additive to preserve fish , meats, hot dogs, smoked fish and luncheon meats. In fireworks manufacture, it is used to replace potassium nitrate. And now, more recently, sodium nitrate is also utilized for heat storage and heat transfer in solar power plant applications.
There are two ways in which sodium nitrite is produced in the industry. One is by reduction of nitrite salts, and the other by oxidation of nitrogen oxides. A more widely accepted method for producing sodium nitrite is by making nitrogen oxides react with an alkaline solution in presence of a catalyst. The manufacturing process of sodium nitrite is by reacting sodium hydroxide with nitrogen dioxide and nitrogen monoxide. Product of this reaction is sodium nitrite and water. Sodium carbonate also can use as sodium hydroxide substitutes. The overall reaction of manufacturing sodium nitrite is shown below: 2NaOH + NO2 + NO → 2NaNO2 + H2O The manufacturing process of sodium nitrite comprises the steps of –
- Absorption of nitrogen oxide in sodium hydroxide or sodium carbonate liquid The nitrogen dioxide and nitrogen monoxide can be obtained from the manufacturing process of ammonia. It is preferable to use excess nitrogen oxide than nitrogen dioxide to increase the production of sodium nitrite and minimize the production of sodium nitrate. The absorption reaction of nitrogen dioxide and nitrogen monoxide in sodium hydroxide produce sodium nitrite solution.
- Sodium nitrite solution that obtained then being cooled to crystallize. The product is suspensions that contain solid crystalline sodium nitrite in water. To increase the concentration, suspension is being heated until containing water evaporated. The evaporation process separates crystalline sodium nitrite from mother liquor.
- Production of medicines- In cases of cyanide poisoning, sodium nitrite is treated with sodium thiosulfate.
- Production of dyes- Used in the production of organonitrogen compounds. It is used for converting amines into diazo compounds thereby helping in production of azo dyes.
- Used as a corrosion inhibitor in process industries.
- Sodium nitrite has been found to inhibit the growth of microorganisms, thus used as a food preservative. Sodium nitrite as food preservative has infact improved food safety, extended storage life and improving desirable color/taste.
- Lipid oxidation is common in meat products, wherein the fats in the cut meats are degraded. Using sodium nitrite has helped in preventing lipid oxidation.
- Sodium nitrite is common in fertilizer, as well as it has the characteristic properties of herbicides and insecticides. It is preferred over the other compounds because it can help kill off living organisms that pose a threat to plant life without harming the flora itself.
- Sodium nitrite is used as a bleaching and dyeing agent. It is used to make basic dye, acid dye, and direct dye, and sulfur dye, diazo and azoic dyes
- It is also used as an inhibitor of polymer, anti-freeze liquids, lubricants, rubber-processing, pulp-and-paper industries, industrial and household cleaners, and as a raw material in the production of products such as caffeine and saccharine.
- Other applications of sodium nitrite are manufacturing of nitroso compound, metal coatings for detinning and phosphating, corrosion inhibitor, photography, inhibitor of polymer, pulp and paper industries, lubricants, industrial and household cleaners, anti-freeze liquid, rubber processing, raw material for caffeine and saccharine production, water treatment, etc. Moreover, Sodium nitrite is often used as dyeing and bleaching agent in textile industry.
|Molecular Weight||:||84.99 g/mol-1|
|Appearance||White Crystals Powder|
|NaNo3(On Dry Base)||%||99 (min)|
|Chloride as CL||%||90.2 (max)|
|Alkalinity (as Na2CO3)||%||0.1 (max)|
|Sulphate (as SO4)||+0.08 (max)|
|Sulphate (as SO4)||%||0.08 (max)|
|Insoluble in matter||%||0.03 (max)|