Shares of two of the world's biggest lithium miners,U.S.-based Albemarle (NYSE:ALB) and Chile-based Sociedad Quimica y Minera de Chile (NYSE:SQM) have been falling after Chile's President Gabriel Boric unveiled plans to nationalize its lithium sector in a bid to boost the economy and protect biodiversity. Chile is the second-largest lithium producer in the world of the lucrative metal and also holds the largest reserves. Under Boric’s plan, the government will negotiate with ALB and SQM for a larger stake…