Submicron Potassium Perchlorate: a Key Component to Reach Detonation in Binary Mixtures with Titanium Hydride

Abstract

The pyrotechnic compositions made up of potassium perchlorate (KClO 4 ) and titanium hydride (TiH 2 ), known as THKP, have a fast deflagration velocity (~500 m/s), along with low sensitivity and high stability. In this research, a new kind of THKP was formulated from a submicron powder of KClO 4 (50-400 nm) prepared by the Spray Flash-Evaporation (SFE) process. The use of fine KClO 4 not only ensures better oxidation of TiH 2 , but also leads to a transition to detonation in the THKP. This transition is observed in loose powders placed in small diameter tubes (3 mm). The distance of transition is relatively short (17-22 mm) and increases with the KClO 4 content of the THKP mixture. The detonation front propagates steadily, at a velocity of~1250 m/s in THKP powders with 86 % of porosity. The shockwave velocity varies little with the perchlorate content in the domain of composition studied (55-74 wt.% of KClO 4 ). Conversely, in the classical THKP mixtures prepared from micron-sized KClO 4 and tested in the same conditions, no transition to detonation is observed; the combustion slows down and eventually stops. Finally, owing to their high sensitivity thresholds to impact (S Imp. � 44.7 J), friction (S Fr. � 192 N), and electrostatic discharge (S ESD � 34.7 mJ), THKP mixtures prepared from submicron KClO 4 can be classified as low-sensitivity primary explosives.

Ultrasound-Assisted Adsorption of Perchlorate Using Calcined Hydrotalcites and the Thermal Stabilization Effect of Recycled Adsorbents on Poly(vinyl chloride)

“…In recent years, perchlorate (ClO 4 – ) as an emerging trace contaminant has been detected in water and soil resources, as well as foods, and can influence the thyroid’s uptake of iodide, resulting in the dysfunction of certain metabolic processes. − The use of perchlorate is mostly related to military and aerospace activities, such as oxidizers in solid fuel rocket propellants, explosives, and pyrotechnics. − Perchlorate is widely regarded as a persistent pollutant in groundwater and surface water due to its high solubility, nonreactivity, and nonvolatility . Various approaches including physical, chemical, and biological treatments and combination technologies have been developed for the removal of perchlorate. − Considering cost effectiveness and treatment efficiency, the adsorption process is very attractive for water treatment. − Hydrotalcites also known as layered double hydroxides (LDHs, [M 1– x 2+ M x 3+ (OH) 2 ]­[A x / n n – · m H 2 O]), are high-performance adsorbents used to remove anions , and also have application prospects as antibacterial agents, flame retardants, anticorrosion agents, drug delivery vehicles, stabilizers, solar cell components, pollutant removal materials, catalysts, and sensors .…”