Manganese metal was evaluated as a fuel for slow-burning delay compositions pressfilled in aluminium or compaction-rolled in lead tubes. Oxides of antimony, bismuth, copper, manganese and vanadium were considered as oxidants. Measured burn rates for binary mixtures varied between 5 and 22 mm/s but slower burning ternary and quaternary compositions were also found. The addition of fumed silica to the Mn/MnO 2 system had little effect on the propagation rate but a low level addition of hollow glass sphere significantly reduced the burn rate. Mn -MnO 2 mixtures showed reliable burning over a wide stoichiometric range. In this system the fuel and the oxidant share a common metal. They combine to form the more stable intermediate oxide (MnO) releasing considerable quantities of heat in the process.

Lead and its compounds in detonator time delays are being phased out owing to environmental and health concerns. It was found that changing from the conventional rolled lead elements to rigid aluminium tubes caused a significant decrease in the burn rate. It also impaired ignitability, especially of slow burning compositions such as SiBaSO4. Consequently, potential alternatives for the latter and also the fast burning SiPb3O4 system were sought. Bi2O3, prepared by thermal decomposition of bismuth subcarbonate, gave fast burning compositions with silicon as fuel (155 mm s−1 with 20% Si). This system was ignitable by the spit of a shock tube. The SiSb6O13 system required an initiating composition and yielded slow burning compositions. The lowest sustainable and reproducible burn rate in lead tubes, in the absence of additives, was 4.8 mm s−1. In lead tubes, it was possible to reduce the burn rate further by adding fumed silica: A composition obtained by adding 10% fumed silica (add‐on basis) to a 10% Si–90% Sb6O13 composition still burned reliably at a burn rate of 2.3 mm s−1.

Chemical time delay detonators are used to control blasting operations in mines and quarries. Slow burning Si-BaSO4 pyrotechnic delay compositions are employed for long time delays. However, soluble barium compounds may pose environmental and health risks. Hence inexpensive anhydrous calcium sulfate was investigated as an alternative "green" oxidant. EKVI simulations indicated that stoichiometry corresponds to a composition that contains less than 30 wt. % Si. However combustion was only supported in the range of 30-70 wt. % Si. In this range the bomb calorimeter data and burn tests indicate that the reaction rate and energy output decrease with increasing silicon content. The measured burn rates in rigid aluminium elements ranged from 6.9 to 12.5 mm s 1. The reaction product was a complex mixture that contained crystalline phases in addition to an amorphous calcium containing silicate phase. A reaction mechanism consistent with these observations is proposed.

The ignition temperature of the Al-CuO thermite was measured using DTA at a scan rate of 50 C.min -1 in a nitrogen atmosphere. Thermite reactions are difficult to start as they require very high temperatures for ignition, e.g. for Al-CuO thermite comprising micron particles it is ca. 940 C. It was found that the ignition temperature is significantly reduced when the binary Si-Bi 2 O 3 system is added as sensitizer. Further improvement is achieved when the reagents are nano-sized powders. For the composition Al + CuO + Si + Bi 2 O 3 (65.3:14.7:16:4 wt %), with all components nano-sized, the observed ignition temperature is ca. 613 C and a thermal runaway reaction is observed in the DTA.

The feasibility of aluminium or magnalium filled fluoropolymer Viton B as an open-burn time delay was investigated. Film samples with a thickness of 245  21 m. were prepared via a slurry casting process. Fuel filler content was varied from 20 to 60 wt.%. The films retained the elastic properties of the parent polymer except that the elongation at break decreased rapidly with increasing filler content.Sensitivity tests showed that the films were insensitive to ignition by friction and impact. EKVI thermodynamic simulations showed that, for both systems, the maximum energy output is ca. 8.3 MJ kg 1 . Energy measurements indicated that the maximum energy output occurred in the range 30 to 40 wt.%. Maximum burn rates of 82 mm s 1 and 40 mm s 1 were achieved using a magnalium and flake aluminium as fuels respectively.