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.The equation used to simply state the first and simplest type of delay reaction can bewritten as:+ + > +In the experimental section later in the paper are simple experiments thatprove the mixture of potassium sulfate and aluminum is capable of explosive burningif some potassium sulfide is present.Aluminum can exothermically and explosivelyreduce all sulfates to sulfides but in the case of potassium sulfate it is usually a slowreaction similar to the flitter effect and is indeed typically taking place in most flitterstars whose formulas have the three formula ingredients of black powder type mix-tures and aluminum.The presence of potassium sulfide causes a change in reactiontypes and reaction speed.Please see the test tube experiments.26Before the reaction indicated in the last equation has occurred to more thanhalf the potassium sulfide (typically about one fifth to one third) the flash reactionoccurs.The3 + 8 > + 4Notice the brackets are gone.Here is the high light output flash.Incidentally,the reaction can be used to make firecrackers but it is disappointing and difficult toinitiate properly.In all but the last equation the aluminum has been essentially inert.The tem-perature of the molten material has been about 850°C; aluminum melts at 660.37°C.The aluminum particles can easily be recovered from the molten spritzels by dissolv-ing the spritzel in nitric acid.The aluminum can be filtered out or separated bysedimentation or centrifuging.Microscopic examination of the spritzels after quick freezing on microscopeslides will allow the examination of the aluminum.The spritzels can be frozen oncontact with slides at room temperature.The four hundred Celsius degree or moredrop in temperature is nearly instantaneous, so fast that the materials do not sortthemselves out well enough to produce crystals visible at one hundred diameters.The spritzels are extremely hygroscopic.They will often have picked up enoughwater from the flame and air that reactions will occur within 3 seconds from collec-tion.Spritzels which contain higher oxides of potassium are as hygroscopic as phos-phorus pentoxide, which is the world standard for total desiccation.All handling andanalytical work must take into account this exceedingly hygroscopic condition.Mostof the work reported here was done at humidity of six percent or less, which is lowenough to dry calcium chloride, the most common laboratory desiccant.The potassium sulfides hydrolyze in the water they absorb from the atmos-phere to form potassium hydroxide solution which dissolves the aluminum.A drop ofwater placed on a fresh spritzel will quickly cause the reaction.Hydrogen andhydrogen sulfide bubbles will be observed.By covering the splatter of frozen spritzelwith oil, air and moisture can be occluded for enough time for observations.(Remember that oils often dissolve a percent or so of water.) The spritzel can beground away with emery paper of 200 grit, then 400 grit, and then 600 girt, alwaysunder oil.Often a small hand lens is enough magnification to see the shiny aluminumparticles.Aluminum particles become more spheroidal.Flake aluminums often meltand leave very thin sheets of aluminum around a globule which contains most of themass of the aluminum in the particle.These particles somewhat resemble fried eggs.A few grams of these fried egg-shaped aluminum particles were found to be easier toignite than the original form.Much more sophisticated chemical testing can be done,27but the findings are that no important consumption of aluminum occurs until theflash reaction.Equation #3 is found never to go to completion; as soon as enough sulfate ac-cumulates Equation #4 is activated and the droplet is blown apart violently.Inpoorly formulated, mixed or formed glitter, one can observe spritzels which are notentirely reacted.These spritzels, if large enough, yield interesting debris for micro-scopic study.Winokur calls this burning of the spritz reaction comma or asymmetricalflashes.The reasons for such performance are obvious under the microscope.Theaccumulation of sulfate in a high viscosity spritzel, or one which contains large par-ticles or aggregates of particles which block mixing in the droplet, produce unevendistributions of sulfate and aluminum in the droplet.Thus when the explosive reac-tion occurs, the explosive is poorly mixed and the slower burning or nonburning par-ticles act as casings or loads to be driven by the microscopic explosions.The small(less than 2 cm) lacy effect I call spurets, and if two centimeters or larger,Lacy implies crisscrossing.The phenomena is radial and spur-like.The coma effectmentioned by Winokur is similar but more often occurs when the viscosity of thedroplet is high and physical obstructions, often metal particles of aluminum too largeto burn quickly, are thrown from the droplet.There is microscopic evidence thatafter the spritz flashes, the particles in the unreacted mass are heated greatly and thatthis increase in temperature causes a shift in type of reaction to that of aluminum flit-ter burning reactions.This is not completely investigated.Present data indicates thatthe thickness of the melt covering the aluminum particles is the differentiating factorbetween flitter and glitter, where the molten sheath is composed of sulfides
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