Page "Gunpowder" Paragraph 83

The current standard composition for the black powders that are manufactured by pyrotechnicians was adopted as long ago as 1780.

Proportions by weight are 75 % potassium nitrate ( known as saltpeter or saltpetre ), 15 % softwood charcoal, and 10 % sulfur.

These ratios have varied over the centuries and by country, and can be altered somewhat depending on the purpose of the powder.

For instance, power grades of black powder, unsuitable for use in firearms but adequate for blasting rock in quarrying operations, is called blasting powder rather than gunpowder with standard proportions of 70 % nitrate, 14 % charcoal, and 16 % sulfur ; blasting powder may be made with the cheaper sodium nitrate substituted for potassium nitrate and proportions may be as low as 40 % nitrate, 30 % charcoal, and 30 % sulfur.

In 1857 Lamont DuPont solved the main problem when using cheaper sodium nitrate formulations when he patented DuPont " B " Blasting powder ; after manufacturing grains from press-cake in the usual way, the powder was tumbled with graphite dust for 12 hours, forming a coating on each grain which in this case reduced its ability to pick up moisture.