1.2.5, 6.4.4, 3.8.4, 4.3.2, 8.8.5
Pyrophoricism in Metals. Henry Allen. Metal Treatment and Drop Forging, 26, No. 160, 31-32 (1959) January.
It has been observed that if magnesium die-castings are immersed for a prolonged period, in chromic acid solution, an ignition risk arises. It is recommended that magnesium die-castings be washed immediately on removal from the solution in cold water, afterwards being coated with mineral oil. The theory is that the prolonged immersion in the chrome creates a finely divided condition and that with magnesium die-castings, for instance, a precipitate is formed, such as a magnesium-aluminum compound in a fine particle form. When dried in air, the large surface of the powdery film exposed to oxidation with consequent evolution of heat, may touch off spontaneous ignition. There are some hazardous chemical combinations also, to take an illustrative case, methyl chloride in contact with aluminum can form spontaneously combustible aluminum methyl....
