Boiler used in the refining process of saltpetre (potassium nitrate, KNO3) to produce the pure, saltpetre necessary for high-grade gunpowder. Saltpetr

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Boiler used in the refining process of saltpetre (potassium nitrate, KNO3) to produce the pure, saltpetre necessary for high-grade gunpowder. Saltpetre is found abundantly as a natural product but but containing many impurities, organic such as vegetal and animal matter, or inorganic such as earthy soluble salts. Putting it in solution removes the soluble salts, and after filtration the liquor is reduced and concentrated by boiling. This is followed by cooling. This process has to be repeated several times to obtain the required level of purity. Part of the saltpetre production process used in the Gunpowder Mills established by the French state during the 19th century.

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Size: 3661px × 4788px
Photo credit: © SHEILA TERRY/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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