Bismuth Chromate in Delay Compositions

  • R.G. Sarawadekar Explosives Research & Development Laboratory, Pune.
  • S. Jayaraman Explosives Research & Development Laboratory, Pune.
Keywords: Barium chromate, Bismuth chromate hydrate, Explosion temperature, Calorimetry


Barium chromate is used as a secondary oxidiser in delay compositions which slows down the rate of the reaction. The composition containing barium chromate potassium perchlorate and sulphur along with the binder, gives inverse burning rates up to 4.5 s/cm. If barium chromate is substituted by bismuth chromate hydrate, the rate of reaction is slowed down further to 11.8 s/cm. Various compositions were prepared by changing the percentage of barium chromate and bismuth chromate. The energy of activation was determined to be 14.5 kcal/mole for the composition with 40 per cent bismuth chromate. The explosion temperature for a delay of 5 s was observed as 480 degree centigrade. These compositions were subjected to impact and friction sensitivity tests to determine the safety aspects. This paper presents the results of burning rate calorimetry, explosion temperature and the sensitivity data of some delay compositions containing bismuth chromate.

Author Biographies

R.G. Sarawadekar, Explosives Research & Development Laboratory, Pune.
Dr RG Sarawadekar o btained his PhD in Physical Chemistry from Shivaji University , Kolhapur ,in 1931 and is working at ERDL, Pune . His research inte rest includes the pyrotechnic compositions and their applications in the various pyrotechnic devices. He has about 10 papers
to his credit.
S. Jayaraman, Explosives Research & Development Laboratory, Pune.
Mr S Jayaraman is working at ERDL, Pune . He obtained his MSc in Chemistry from Annamalai University. He has been engaged in the development of various electro-explosive devices and pyrotechnic compositions for Defence applications during the last 23 years.
How to Cite
Sarawadekar, R., & Jayaraman, S. (2013). Bismuth Chromate in Delay Compositions. Defence Science Journal, 42(3), 177-181.
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