Fireworks Materials (Ⅲ)

                     Copper Oxides

   Both copper (I ) and spacing copper ( II ) oxides are used now for ignition and  starter compositions in conjunction with silicon and lead (IV) oxide. However the availability of good halogen donors and the disadvantages of  Paris  Green have caused a revival of the use of copper oxide for making blue colors.

                      Dextrin (C6H10O5)n

  As it is soluble in water and has good adhesive properties, it is used extensively as a binder in fireworks. It is fairly usual to add a few percent of the dry powder to a star composition during the mixing operation and then add water prior to star formation.

                     Dyestuffs

  The quality of the materials used for smoke production is important, particularly the particle size of the dyes and their freedom from inorganic salts.

                    Flour

  It was also used in some compositions to retard the burning speed.

                    Shellac

  Shellac, acaroids resin and copal gum are all used as fuels, mainly for the production of color.

                   Hex a c h l o r o b e n z e n e, C6CL6

  Extensive use of this material as a chlorine donor in color mixtures appears to have been made in the past. This substance is the well known insecticide.

                       L r o n , Fe

  There can be little doubt that iron has used in fireworks from the earliest times. Apart from the steel dust for the manufacture of sparklers, the best iron for fireworks is the ordinary iron borings which have been broken down to a rough powder which will pass 20 mesh. The long needle like fragments give the best effects.

                    L r o n Oxides

   The black magnetic form, fe3o4 is used the r mite and incendiary compositions and the brown form fe2o3 has been used in first fires and ignition compositions where high temperatures are needed.

                    Lead Oxides

   The  red form,pb3o4 and the chocolate colored dioxide, pbo2 have been used in first fires and ignitions for military purposes, and  are potentially useful for fireworks also. Combined with magnesium, it is used for crackling micro stars

                  
Magnesium . Mg

On the other hand, it is indispensable in situations where it is essential to gain high candle power in signal flares.

                     Magnesium Mg/AL

  Magnesium is used in fireworks for a variety of purposed;

  1 . in coarse powder of about 30-50 mesh the metal produces a sharp crackling noise in colored flame fountains. The presence of  c r y o l I t e seems to enhance this effect.

  2 . Dust free coarse powders produce pleasant sizzling effects in some stars.

  3 . the finer powders from 120 mesh onwards are used to enhance colored flames, produce some silver effects and to produce the newer blinker strobe effects. Come from magnesium burning with the nitrates of barium or strontium where the irrational burning can be varied with catalysts