| This article used anhydrous calcium nitrate as starting material, dry ice bath as low temperature source to prepare calcium nitrate ammoniate Ca(NO3)2. nNH3 in liquid ammonia. Effect of experimental factors such as the addition quantity of liquid ammonia, time of ammonia evaporation and evaporation temperature as well as reaction time on content of NNH3 % of the product has been studied. Furthermore, it has also been investigated that the effect of additives on NNH3 % of product and H2O% in calcium nitrate to the synthesis of calcium nitrate ammoniate. Experimental results reveal that the optimum synthesis conditions for calcium nitrate ammoniate is at temperature of 40℃, and NNH3% and total nitrogen content (N总%) of the calcium nitrate ammoniate is 24.8% and 35.08 % respectively after complete evaporatation of the superfluous liquid ammonia. Under this condition, the synthesis time, is mainly decided by the time of evaporative superfluous liquid ammonia. And additives adding have no influence on the synthesis of calcium nitrate ammoniate. Dynamic study showes that the decomposition reaction of Ca(NO3)2. nNH3 is zero order, with activation energy of 258.42×103 J·mol-1. Decomposition rate became faster when temperature raises. By micro-capsulation technology, envelopment and mixing granulation, the stability of the calcium nitrate ammoniate have been improved apparently. Acid-base titration, K2Cr2O7 back-titration and EDTA titration were used respectively to determine the percentage of ammoniac nitrogen in the calcium nitrate ammoniate and nitrogen in nitrate form, as well as calcium. The existence Of other two ions had little influence on the analytical results. These studies might provide a rapid and accurate analysis method for large-scale industrial production of calcium nitrate ammoniate. IR and Raman spectroscopy were used to characterize the product and the spectra show that calcium nitrate ammoniate is a complex with ammonia inside.On the basis of preparation research of the calcium nitrate ammoniate, this paper also studied its application. As a by-product of nitrophosphate production, calcium nitrate could be used as starting material for the production of calcium nitrate ammoniate (Ca(NO3)2·nNH3)--a high concentration nitrogen fertilizer. Accordingly, this article also try to improve the stability of the calcium nitrate ammoniate. For example, by micro-encapsulation technology, the additives bearing low-cost, easy absorption and containing fertilizer efficiency such as soluble starch and 0.2% borax, dextrin, sulfur, and polyacrylamide were added in, it might increase the stability of the calcium nitrate ammoniate. In addition, effects of the calcium-magnesium phosphate fertilizer of outside package and the mixture prilling on the stability of the calcium nitrate ammoniate have studied as well.This research has not only provided a new technology for preparation of high concentration nitrogen fertilizer, but also opened up a new application way for calcium nitrate product, with a certain degree of social and economic value.
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