Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Herbert Heinisch

Walter Engel

Klaus-Dieter Thiel

A method for producing phase-stabilized particulate ammonium nitrate (AN) through integration of a diamine complex of the metals copper, nickel or zinc into the crystal lattice of AN, wherein AN is reacted with inorganic CU, Ni and/or Zn compounds, is characterized in that carbonates and/or hydroxide carbonates and/or hydroxides are added as inorganic compounds of the metals Cu, Ni and/or Zn. Moreover, additives are added to reduce the melting temperature of AN.

Process for producing phase-stabilized ammonium nitrate

In the production of spherulitic nitroguanidine having a high bulk and tap ensity nitroguanidine is dissolved in dipolar, aprotic solvents, e.g. DMF, DMSO, NMP, etc., by heating to above the saturation temperature t.sub.s and the supersaturated solution is cooled with a controlled temperature gradient (.degree.C./min), crystallization being assisted by the addition of particulate, spherulitic material. In order to obtain spherical nitroguanidine with high yield in a continuous process and with mother liquor reuse, during the heating to above the saturation temperature t.sub.s, spherical control particles with a diameter of 5 to 500 .mu.m are regularly added to the solution in a quantity of 0.05 to 5.00 mass %. The particle size is chosen in such a way that, as a function of the solution behaviour of the nitroguanidine used and its concentration, on dropping below the saturation temperature spherical control particles are still present in the indicated quantity in the supersaturated solution.

Process for the production of spherulitic particles

A method of preparing compact nitroguanidine of high bulk density by crystallization from an initially hot nitroguanidine solution. The solution is cooled, while being agitated, at a temperature gradient of at least 3.degree. C./minute, with the crystallization taking place, only at temperatures less than 50.degree. C., from a supersaturated solution. The solvent for the nitroguanidine solution is selected from the group consisting of polyhydric, lower aliphatic alcohols, the mono- or dialkyl ethers of these polyhydric, lower aliphatic alcohols, dimethylformamide, dimethyl sulfoxide, or mixtures thereof. The formed nitroguanidine, in addition to having a high bulk density, has a compact form which makes it possible to prepare a slurry from nitroguanidine and to be able to process nitroguanidine as a composition amenable to casting.

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Ettlingen, Germany

Herbert Heinisch