Pure ammonium nitrate is a high-quality nitrogen fertilizer with a nitrogen content as high as 35%, but chemists have long been aware of its other side: under high temperatures or severe impact, ammonium nitrate has the potential to explode. This characteristic imposes strict safety controls on the storage, transportation, and use of ammonium nitrate. How can one retain the nutritional advantages of coexisting high-concentration nitrate nitrogen and ammonium nitrogen while completely eliminating the safety hazard? The answer is - invite "limestone" to be a safety partner.
Calcium ammonium nitrate (CAN) is the classic product born from this line of thinking. In production, ammonium nitrate melt is thoroughly mixed with dolomite powder or limestone powder for granulation. The addition of calcium and magnesium carbonates reduces the total nitrogen content of the finished product to about 27%, with nitrate nitrogen and ammonium nitrogen each accounting for roughly half. It is this seemingly simple physical modification that produces a qualitative change: after calcium enrichment treatment, calcium ammonium nitrate loses its explosiveness but gains the ability to ameliorate acidic soils and supplement active calcium. Many countries in Europe and America list CAN as the only high-concentration solid ammonium nitrate product permitted for direct sale as fertilizer. The water-soluble calcium it contains can effectively prevent calcium-deficiency physiological disorders such as bitter pit in apples and blossom-end rot in tomatoes, and can promote root development and cell wall robustness. From "dangerous goods" to "safe fertilizer," from a mere nitrogen fertilizer to a multifunctional product that supplies calcium and improves soil, calcium ammonium nitrate has won the trust of farmland worldwide through a chemical "reduction for stability."