This innovation involves a process for producing sodium nitrate through the use of nitratine reverse-flow circulation extraction, with the following steps: breaking up the ore into grains no larger than 5cm; reverse-flow circulation leaching where, after 2-6 stages of leaching, the sodium nitrate content of the extracted solution increases from 300-380 g/l to 390-500 g/l; separating, washing, and drying at low temperature to exchange heat between the extracted solution and low-temperature separation mother liquid to reduce the temperature, then mixing and reducing the temperature to -10-20 C, and keeping the temperature for 100-140 min; separating the solids and liquid, filtering and washing via a saturated sodium nitrate, with the mass ratio of product and sodium nitrate solution at 6/1-5/1; then drying it to obtain sodium nitrate product and feeding the separated mother liquid into step 2. This can save more than 40 percent of the water and more than 25 percent of the energy, while the single-process collecting rate is above 25 percent and total collection rate of sodium nitrate in ore, more than 95 percent. The product obtained through low-temperature separation contains more than 92 percent sodium nitrate, and the washed product more than 98 percent. It can use a low-grade nitratine mine to produce sodium nitrate.
