Physicochemical properties and preparation method of sodium nitrate (2)

(3) Sodium sulfate preparation method

There are many sources of sodium sulfate, and it is a meaningful way to use sodium sulfate to prepare sodium nitrate

In the first step, Ca(NO ₃ ) _{2 is prepared} , and the second step is an irreversible reaction, but a small amount of sulfate is often left in the product

The second way is to use the reaction between Glauber's salt, ammonium bicarbonate , and ammonium nitrate to achieve:

This method produces NaNO ₃ , the sodium conversion rate is as high as 98%, the ammonia conversion rate is also over 80%, the purity of the product NaNO ₃ can reach 99.

The third way is the direct reaction of Glauber's salt with nitric acid:

Na ₂ SO ₄ +HNO ₄ →NaHSO ₄ +NaNO ₄

By adding lime containing CaCO ₃ to the solution , the generated NaHSO _{4 is} removed

(4) Preparation method of boron-containing ore

This kind of method utilizes boronite, boronite or boronite firstly react with caustic soda solution, leaching to generate sodium metaborate, then dissolving it with nitric acid, and then cooling, crystallization, centrifugal separation, purification, drying and other processes.

In addition to using boron-containing ore as raw material, it can also be directly prepared by reacting borax with HNO ₃ :

Na ₂ B ₄ O ₇ ·10H ₂ O+2HNO ₄ →4H ₄ BO ₄ +2NaNO ₄ +5H ₂ O

The reaction is easy to proceed

(5) Sodium formate preparation method

This method is reported in a Polish patent

In the method, sodium formate is used as a starting material to obtain sodium oxalate at high temperature , and finally sodium oxalate and nitric acid are reacted on a cation exchange resin to obtain two important chemical raw materials, oxalic acid and sodium nitrate