Lead oxychloride

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Lead oxychlorides are compounds of lead that contain chlorine and oxygen or hydroxide (overall formula often written as PbClO(OH)). They occur in nature in several minerals, including mendipite (Pb3Cl2O2) and the white minerals laurionite and paralaurionite (PbCl(OH)); other natural examples include damaraite, rickturnerite, and asisite.

Historically, their main use was as pigments in lead paints. The lead oxychlorides were fused with other lead compounds, ground into a fine powder, and mixed into drying oils like linseed oil to make pigments such as Pattinson's white (a mix related to PbCl2 and Pb(OH)2) and Turner's yellow (a lead oxychloride pigment). Turner's yellow has several other names, including Patent yellow, Cassel yellow, Montpelier yellow, Kassler yellow, mineral yellow, and Verona yellow.

In the late 19th century, lead oxychlorides were briefly used to make electrodes for lead–acid batteries. Charles Francis Brush patented a method in 1876: pulverized lead oxychloride (and later lead sulfate) was packed into depressions of a grooved lead sheet, the sheet was covered with paper, and placed in a salt or acid solution with a zinc plate. The arrangement was electrolytically reduced to sponge lead to form a usable electrode. If used as the positive electrode, the sponge lead would become lead peroxide during the initial formation charge. This method was replaced by the Faure pasting method in 1880.