Technique for producing sodium nitrate by chilisaltpeter adverse current circulation leaching

Abstract

The invention relates to a process for producing sodium nitrate by using nitratine reverse-flow circulation extraction, which comprises steps as follows: (1) breaking ores into the grains smaller notlarger than 5cm, (2) reverse-flow circulation leaching: after 2-6 stages of reverse-flow circulation immerge, the sodium nitrate content of extraction solution is increased from 300-380g / l to 390-500g / l, (3) separating, washing and drying at low temperature that exchanges heat between the extraction solution and low-temperature separation mother liquid, to reduce temperature, mixing and reducing temperature to -10-20DEG C, and keeping temperature for 100-140min, separating solid and liquid, filtering and washing via a saturated sodium nitrate, according to the mass ratio between product and sodium nitrate solution as 6 / 1-5 / 1, then drying to obtain sodium nitrate product, and feeding the separated mother liquid into the step (2), to process next circulation. The invention can save water more than 40%, and save energy more than 25%, while the single-process collecting rate is more than 25% and the total collecting rate of sodium nitrate in ore is more than 95.0%. The product obtained bylow-temperature separation contains sodium nitrate more than 92%, and the washed product contains sodium nitrate more than 98%. The invention can use low-grade nitratine mine to produce sodium nitrate.

Description

1. Technical field: [0001] The invention relates to a production process of sodium nitrate, in particular to a process for producing sodium nitrate with sodium nitrate. 2. Background technology: [0002] Sodium nitrate is a colorless transparent or light yellow rhombic crystal, which can be used as chemical analysis reagent, oxidant, chemical fertilizer, fireworks, nitric acid, dye synthesis, etc. It is mainly used in the manufacture of potassium nitrate, explosives, picric acid and other nitrates. It is also widely used in glass industry, enamel industry, dye industry, pharmaceutical industry and agriculture. It is an important inorganic chemical raw material. [0003] In the known technology, the process of directly using sodium nitrate to process and produce sodium nitrate is based on the saltpeter ore containing relatively high sodium nitrate, and the content is even more than 60%. In this case, water can be directly added to the ore for leaching. The sodium nitrate pro...

AI Technical Summary

Problems solved by technology

However, the water consumption of this process is still relatively large, and the wind is greatly affected during spraying and leaching, the concentration of sodium nitrate in the leaching solution is low, the investment in the construction of beach-dried salt fields is relatively large, and the energy consumption for producing sodium nitrate from salt field semi-finished products is relatively high.