Decoppering

Decoppering is the act of removing copper and it is most commonly used in the context of the removal of copper residues from the rifling of gun barrels.{{Cite journal |last=Page |first=A.L. |last2=Chang |first2=A.C. |date=January 1993 |title=Lead Contaminated Soils: Priorities for Remediation? |url=http://dx.doi.org/10.1089/hwm.1993.10.1 |journal=Hazardous Waste and Hazardous Materials |volume=10 |issue=1 |pages=1–2 |doi=10.1089/hwm.1993.10.1 |issn=0882-5696}}

Decoppering agents are frequently added to smokeless powder propellants. Decoppering is most important for large guns (especially naval guns), but the additives are used even in medium and small caliber guns.{{Cite journal |last=Zheng |first=Yulin |last2=Wan |first2=Yongshan |last3=Zhang |first3=Yue |last4=Huang |first4=Jinsheng |last5=Yang |first5=Yicheng |last6=Tsang |first6=Daniel C. W. |last7=Wang |first7=Hailong |last8=Chen |first8=Hao |last9=Gao |first9=Bin |date=2022-09-30 |title=Recovery of phosphorus from wastewater: A review based on current phosphorous removal technologies |url=http://dx.doi.org/10.1080/10643389.2022.2128194 |journal=Critical Reviews in Environmental Science and Technology |volume=53 |issue=11 |pages=1148–1172 |doi=10.1080/10643389.2022.2128194 |issn=1064-3389|pmc=10116781 }}

The most common decoppering additives are:

• Tin metal and compounds, e.g. tin dioxide
• Bismuth metal and compounds, e.g. bismuth trioxide, bismuth subcarbonate, bismuth nitrate, bismuth antimonide; the bismuth compounds are favored as copper dissolves in molten bismuth, forming brittle and easily removable alloy
• Lead foil and lead compounds, although concerns have been raised about lead toxicity