# Powder mill > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Powder_mill > Markdown URL: https://mediated.wiki/source/Powder_mill.md > Source: https://en.wikipedia.org/wiki/Powder_mill > Source revision: 1306345101 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Mill where ingredients of gunpowder are ground and mixed}} [[Image:Encyclopédie_-_illustration_of_a_powder-mill_(18th_Century).jpg|thumb|upright|One component of a powder-mill, taken from [Encyclopédie](/source/Encyclop%C3%A9die), published by [Denis Diderot](/source/Denis_Diderot), ''circa'' 1770.]] [[Image:Hagley Mill Equipment.jpg|thumb|A working example of the drawing above. This is a restored [edge-runner mill](/source/Edge_mill) at [Eleutherian Mills](/source/Eleutherian_Mills).]] A '''powder mill''' was a [mill](/source/mill_(grinding)) where [gunpowder](/source/gunpowder) is madeKnight, Edward H.. "Powder-mill" ''Knight's new mechanical dictionary: a description of tools, instruments, machines, processes, and engineering: with indexical references to technical journals (1876-1880)''. vol. 2. Boston: Houghton, Mifflin and Co., 1883. 1781. Print. from [sulfur](/source/sulfur), [saltpeter](/source/potassium_nitrate) and [charcoal](/source/charcoal). ==Milling steps== Crude grinding and mixing operations such as the [Frankford Powder-Mill](/source/Frankford_Powder-Mill) of [Philadelphia](/source/Philadelphia) were a [cottage industry](/source/cottage_industry) until the [Industrial Revolution](/source/Industrial_Revolution) brought improved product quality through the following procedures: * [Charcoal](/source/Charcoal) was often manufactured nearby from locally available trees, but the heating retorts were typically separated from the other buildings to minimize fire danger. Trees with low value as sources of [lumber](/source/lumber) were debarked, dried, and cut to uniform length to fit into iron retorts with [cast iron](/source/cast_iron) doors. The [retort](/source/Retort)s were carefully packed to leave as little air space as possible, and the retort doors were closed and sealed with clay to prevent entry of air as the retorts were heated by external fires. Volatile gas generated by the heating process was vented through a small [flue](/source/flue) at the top of each retort. After the external fires were extinguished, the retorts were allowed to cool before the doors were opened to remove the charcoal.{{cite book |last=Whitten |first=Maurice M. |title =The Gunpowder Mills of Gorham-Windham, Maine |publisher =Windham Historical Society |date =2012 |location =[Windham, Maine](/source/Windham%2C_Maine) |pages =15–26 }} * High purity [sulfur](/source/sulfur) usually required little preparation other than grinding to a powder. Separate '''grinding mills''' reduced cool charcoal and sulfur to fine powders. * Crude [saltpeter](/source/Potassium_nitrate) (KNO3) was [dissolved](/source/Solubility) in a pot of boiling water. After boiling, a small amount of floating glue might be added to the hot water to aid skimming off floating impurities. The hot solution was then carefully [decanted](/source/Decantation) to avoid suspending [insoluble](/source/Solubility) solid impurities settled to the bottom of the pot. The hot decanted liquid was distributed into shallow wooden vats where [evaporative cooling](/source/evaporative_cooling) would remove excess water. Purified [potassium nitrate](/source/potassium_nitrate) [recrystallized](/source/Recrystallization_(chemistry)) while the cooling solution was gently agitated with broad hoes to prevent formation of large [crystal](/source/crystal)s. * Powdered sulfur and charcoal were combined in appropriate ratios with moist saltpeter crystals, and the moist paste was mixed and compacted by kneading beneath heavy rotating wheels in a '''press mill'''.Braddock, John. ''A memoir on gunpowder: in which are discussed, the principles both of its manufacture and proof''.. Madras: Printed at the Church Mission Press, 1829. Print. * The compressed cake was transferred to a '''corning mill''' or '''kernelling mill''' to be cut into pieces of approximately correct size by [bronze](/source/bronze)- or [zinc](/source/zinc)-toothed wheels. * Kernelling mill products were sorted by size using leather [sieve](/source/sieve)s. Oversize product was returned to the kernelling mill, while undersize product was returned to the press mill. * Sorted kernels of desired size were dried and mixed with [graphite](/source/graphite) to be tumbled in '''glazing mill''' barrels. Graphite coating reduced the tendency of grains to stick together in storage. * Glazed product was typically packaged in wooden kegs. Filled kegs were transported away from the mill as soon as possible to a [powder magazine](/source/Gunpowder_magazine) for wholesale distribution. The potential for destructive energy release from powder magazine accidents required the magazines to be distant from both the powder mill and other places of business or habitation. ==Explosions== thumb|right|This former Laflin & Rand powder mill building illustrates the protective stone walls on three sides after the weaker wooden back wall and roof have rotted away. Gunpowder is very easily ignited by [static electricity](/source/static_electricity) or [lightning strike](/source/lightning_strike)s, and most powder mills experienced occasional accidental [explosion](/source/explosion)s. Powder mill explosions typically destroyed an entire building and killed those working in the vicinity of the building. Explosions might throw flaming debris which could ignite other buildings. Successful mills were typically built as an arrangement of separate buildings to minimize the loss from any single building explosion. Buildings were separated by enough distance to minimize the risk of being damaged by an explosion in an adjacent building. Buildings were usually built of stone with one weak wooden wall and roof to direct the force and debris from an accidental explosion toward a river or an open field. ==Power supply== Powder mills were originally powered by [windmill](/source/windmill)s, [water mill](/source/water_mill)s or [horse mill](/source/horse_mill)s. Despite later availability of [steam engine](/source/steam_engine)s, the older power sources did not require a fire to generate [steam](/source/steam), and avoided the possibility of sparks which might ignite the gunpowder. Some 20th-century powder mills used electric power. Before the availability of safe electrical power, some of the most successful mills were built along rivers where water could be distributed through a [power canal](/source/power_canal) to individual buildings and intermediate products could be floated from one building to the next. The power canal offered a supply of firefighting water, and the adjacent river was a relatively safe direction to focus explosion debris. Where water transport was impractical, intermediate products were often transported in wagons pulled by [draft animal](/source/draft_animal)s. The wagons were often built entirely of wood held together with wooden pegs, and draft animals were usually unshod to avoid sparks from steel shoes or nails. ==In the United States== The 1810 census reported 208 powder mills in the United States. In 1802, the [DuPont](/source/DuPont) family started their industrial enterprises in the [United States](/source/United_States) by building the [Eleutherian Mills](/source/Eleutherian_Mills) on the [Brandywine Creek](/source/Brandywine_Creek_(Christina_River)) in [Delaware](/source/Delaware).Rideal, Charles Frederick, and Freeman Morris. ''A century of success: the history of a great industry; what it has accomplished; a record of progress and sustained work : the E.I. du Pont de Nemours Powder Co., from its foundation to the present time''. New York, N.Y.: Business America, 19111912. Print. Four mills were manufacturing 69 percent of United States gunpowder when gunpowder production peaked during the [American Civil War](/source/American_Civil_War). They were the DuPont mill, the [Hazard Powder Company](/source/Hazard_Powder_Company) of [Hazardville, Connecticut](/source/Hazardville%2C_Connecticut), the [Oriental Powder Company](/source/Oriental_Powder_Company) of [Windham, Maine](/source/Windham%2C_Maine), and the Laflin Powder Company of [Newburgh, New York](/source/Orange_Mill_Historic_District).Wilson, Mark R. ''The business of civil war: military mobilization and the state, 1861-1865'' (2006) JHU Press p.118 The [Confederate Powderworks](/source/Confederate_Powderworks) of [Augusta, Georgia](/source/Augusta%2C_Georgia) produced 6,000 tonnes of gunpowder from 1862 to 1865, but was dismantled after the war.{{cite web |url=https://www.nps.gov/nr/travel/Augusta/sibleymill.html |archive-url=https://web.archive.org/web/20090709185606/http://www.nps.gov/nr/travel/Augusta/sibleymill.html |url-status=dead |archive-date=July 9, 2009 |title=Sibley Mill and Confederate Powder Works Chimney |publisher=[National Park Service](/source/National_Park_Service) |access-date=10 June 2019 }} The Laflin company merged into the [Laflin & Rand Powder Company](/source/Laflin_%26_Rand_Powder_Company) after the war, and with the other three large northern mills formed the United States Gunpowder Trade Association in 1872 including the [American Powder Mills](/source/American_Powder_Mills) of [Maynard, Massachusetts](/source/Maynard%2C_Massachusetts), the [Austin Powder Company](/source/Austin_Powder_Company) of [Glenwillow, Ohio](/source/Glenwillow%2C_Ohio), and the [Miami Powder Company](/source/Miami_Powder_Company) of [Goes Station, Ohio](/source/Goes_Station%2C_Ohio).{{cite book |title =Congressional Serial Set |publisher =United States Government Printing Office |date =1912 |page =350 }} Most smaller mills were unable to compete with this trade association, popularly known as the powder [trust](/source/Trust_(business)); although regionally important mills including the [California Powder Works](/source/California_Powder_Works) of [Santa Cruz, California](/source/Santa_Cruz%2C_California), the [Equitable Powder Company](/source/Western_Cartridge_Company) of [East Alton, Illinois](/source/East_Alton%2C_Illinois),{{cite web |url=http://22box-id.com/Dunn/Western.pdf |title=.A catalog of .22 Boxes of the U.S.A. |last=Dunn |first=Tony |publisher=Roger E. Huegel |access-date=14 November 2014 |archive-url=https://web.archive.org/web/20141128200724/http://22box-id.com/Dunn/Western.pdf |archive-date=28 November 2014 |url-status=dead }} and the [Great Western Powder Works](/source/Peters_Cartridge_Company) of [Kings Mills, Ohio](/source/Kings_Mills%2C_Ohio){{cite web |url=http://www.deerfieldtwp.com/PDFs/ParksRec/KingMansionHistory.pdf |title=Ahimaaz King House and Carriage House Historic Structure Report |last=Sullebarger Associates |first=PAST Architects |publisher=Deerfield Township, Ohio |access-date=29 November 2014 |url-status=dead |archive-url=https://web.archive.org/web/20120602093009/http://www.deerfieldtwp.com/PDFs/ParksRec/KingMansionHistory.pdf |archive-date=2 June 2012 }} successfully transitioned to manufacture of [smokeless powder](/source/smokeless_powder) [cartridges](/source/Cartridge_(firearms)). As smokeless powder and [high explosive](/source/high_explosive)s replaced gunpowder for most purposes, DuPont became the major manufacturer of United States gunpowder until discontinuing production in 1971. Subsequent production for use in [pyrotechnics](/source/pyrotechnics) and antique [firearm](/source/firearm)s has been undertaken by smaller firms whose operations are often ended by the persistent hazard of accidental explosions.{{cite web |url=http://www.namlhunt.com/mlpowders8-1.html |archive-url=https://web.archive.org/web/20151021034422/http://www.namlhunt.com/mlpowders8-1.html |url-status=usurped |archive-date=October 21, 2015 |title=Black Powder in America |last=Bridges |first=Toby |publisher=North American Muzzleloader Hunting |access-date=15 June 2018 }} ==Europe== Notable European mills include: * [Ballincollig Royal Gunpowder Mills](/source/Ballincollig_Royal_Gunpowder_Mills), [County Cork](/source/County_Cork), Ireland * [Faversham explosives industry](/source/Faversham_explosives_industry), [Faversham](/source/Faversham), England * [Grenelle](/source/Grenelle) Mill - France * [Poudrerie nationale de Vonges](/source/Poudrerie_nationale_de_Vonges), Vonges, Côte-d'Or, France * [Waltham Abbey Royal Gunpowder Mills](/source/Waltham_Abbey_Royal_Gunpowder_Mills), [Waltham Abbey, Essex](/source/Waltham_Abbey_(town)), England ==References== {{Reflist}} {{commons|Powder mills}} {{Authority control}} Category:Firearm industry Category:Grinding mills Category:Gunpowder mills --- Adapted from the Wikipedia article [Powder mill](https://en.wikipedia.org/wiki/Powder_mill) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Powder_mill?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.