Sodium nitrite synthesis method

sodium nitrite synthesis related introduction

sodium nitrite ( 纳米? ) , are combined to generate the nitrite ion and sodium ion inorganic salt. Sodium nitrite easy deliquescence, soluble in water and liquid ammonia, the alkaline aqueous solution, the pH of about 9, slightly soluble in ethanol, methanol, diethyl ether and other organic solvents. Sodium nitrite salty, it is be used to make false salt.

sodium nitrite synthetic methods:

1, use the lead reduction of sodium nitrate, heated to melt sodium nitrate, add a small amount of metallic lead, and continue to stir heated to lead all oxidation. The generated block cooling while divided into small pieces and lead oxide generated several times with hot water extraction. Bubbled into carbon dioxide generated lead carbonate precipitation, filtered, with dilute nitric acid and filtrate correctly, the evaporation and crystallization precipitation concentrated sodium nitrite. After suction, dry after washing with ethanol and recrystallization refined again.

2, or soda ash with caustic soda solution absorbing the eduction in nitric acid or a nitrate production tail gas containing a small amount of NO and NO2, tail gas of NO/NO2 ratio to adjust to the NaNO2 and NaNO3 in the neutralization liquid ratio below 8, the quality of the liquid in the process of absorption and should avoid acid, so as to avoid corrosion of the equipment. And the liquid of the relative density of 1. 24 to 1. 25, soda ash content is 3 ~ 5 g/L send to evaporation, absorb liquid evaporation concentration at 132 ℃, then cool to 75 ℃, precipitation sodium nitrite in crystallization, then through the separation, drying for a quick product. Reaction equations are as follows:

Na2CO3 + NO + NO2 & rarr; 2NaNO2+CO2↑

3, nitrate and nitrite production out of the exhaust gas of nitric oxide and nitrogen dioxide, using soda ash or absorption and neutralization liquid caustic soda solution, evaporation and the crystallization, then using the solubility of sodium nitrite and sodium nitrate in water to separate the two different, a quick finished product.

2 + 2氢氧化钠→ 2NaNO2+H2O

2NO+Na2CO3→ 2 nano2 + CO2

the above information is the synthetic method of sodium nitrite. If there is demand, can contact Shanghai xin chemical industry.