Charcoal fire dust compositions

Aluminium fire dust consists of melted aluminium as the active substance and melted A1 l03 as the inactive substance in a particle in the fire dust of black powder(a composition of potassium nitrate, sulphur and charcoal) charcoal is the active material along with the burning product. K SO/, K C03etc. is the inactive part. 

The fire division occurs most easily when the cohesion of the particle is weakest. With the fire dust of black pov/der-type compositions the point may be a content of about 7% sulphur. If the sulphur content is larger than that, the potassium sulfide, KiSx. content,in a particle increases to produce strong cohesion, which makes the fire division more difficult. If the content is less than that, unburned charcoal aggregates and in this case the fire division is also difficult. 

The manufacturing process of black powder type composition has a large influence on this division. The three components, potassium nitrate, charcoal and sulphur, must be intimately mixed if we hope to get good effect. For example for a composition of 58% potassium nitrate, 7% sulphur and 35% charcoal, the average life time of the fire dust from this... 

Charcoal is used for many purposes e,g. to obtain an explosive force as a fuel producing a large amount of heat and gas in combination with an oxidizer to adjust the burning rate of compositions to obtain sparks or fire dust to modify the ignition character of compositions to increase brightness of.flames or simply as a combustion agent which helps the burning of compositions. 

Pine charcoal burns in combination with ammonium perchlorate at F/O = 2 10 producing a yellow flame, but no sparks or fire dust. A mixture of pine charcoal, sulphur and potassium nitrate in the weight ratio 30 10 60 burns producing pretty. orange red fire dust. This characteristic is generally seen with other charcoals but pine charcoal produces the most pretty fire dust of all. On the other hand, the phenomenon shows that pine charcoal does not complete the reaction and produces less gas in black powder-type compositions. Therefore pine charcoal is used to produce fire dust and not to obtain force. 

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