black copper meaning in Hindi

Examples

1. Ultramarine withstands heat, but azurite turns to black copper oxide.
2. Initially the black copper was converted to blister copper in the ISASMELT furnace.
3. This produces a " black copper phase " and a low-copper silica slag.
4. This indicates that the black copper oxide comes partially from the cuprate and partially from the PCB copper circuitry.
5. The centre spot and the rim of a chau gong are left coated on both sides with the black copper oxide that forms during the manufacture of the gong, the rest of the gong is polished to remove this coating.