proposal for open pit mining
PolyMet Mine Proposal | Mining TruthNov 13, 2015 . PolyMet's Minnesota mining project proposes to develop an open-pit mine to extract copper, nickel and other metals.proposal for open pit mining,Environmentalists Criticize Open Pit Sulfide Mine Planned for .Dec 21, 2015 . Aquila describes the proposed mine as “gold- and zinc-rich” but their . Back Forty proposal for years, contending that an open pit sulfide mine,.Proposal of an environmental sustainability index for open-pit mines .1Engenheiro Ambiental, Doutorando em Engenharia de Minas Universidade Federal do Rio Grande do Sul - Departamento de Engenharia de Minas Porto.