The goal of this project is to find a novel pyrotechnic system that will significantly eliminates the use of regulated heavy metals and polychlorinated chemicals. These pyrotechnic systems are required to be free of chlorine (perchlorate), heavy metals and strontium and weight reduced. Furthermore, they should have high color purity and luminous intensity and no hazardous solvents should be involved in synthesis and purification. To achieve these requirements, new lithium based pyrotechnical compositions with a high nitrogen content are tested. The lithium salt synthesis should be simple and easily scaled-up.

In the course of this project, more than 15 new lithium salts were synthesized and investigated. A considerable number of them were tested in pyrotechnic formulations. The opposing nature of spectral purity and light intensity resulted in the required parameters being attained, but not in a single formulation. Compared with a standard strontium formulation, the measured values of lithium flares at DEVCOM performed markedly inferior.

In the course of this project, more than 15 new lithium salts were synthesized and investigated. A considerable number of them were tested in pyrotechnic formulations. The opposing nature of spectral purity and light intensity resulted in the required parameters being attained, but not in a single formulation. Compared with a standard strontium formulation, the measured values of lithium flares at DEVCOM performed markedly inferior. 

The reason for the poorer performance of the flares is the oxophilicity (e.g. bonding/affinity to oxygen) of lithium. This results in the formation of additional by-products, which have a negative influence on the coloration. Since the flares still contain additives (paper tubes), this can also influence the performance. High burning temperatures from the fuel can also be a negative influence.

The proposed methodology would enable replacement of heavy metals and perchlorates from signal flare pyrotechnics.  However, the oxophilicty of lithium resulted in poor pyrotechnical performance, indicating that lithium salts are unlikely to be useful as colorants.

(Project Completion-2024)