Stock Photo: There are several mines operational in Bulgaria among many mines which generate different elements such as zinc and lead Factories near the mines process the resoucres and make seperate the different elements and compact them The working conditions are ex
Stock Photo: 1566-1080641 There are several mines operational in Bulgaria among many mines which generate different elements such as zinc and lead Factories near the mines process the resoucres and make seperate the different elements and compact them The working conditions are ex