By TODD RICHMONDMADISON, Wis. (AP) â¿¿ Republicans in the Wisconsin Assembly approved a polarizing mining bill Thursday and sent the measure to Gov. Scott Walker for his signature, completing a long push to help a Florida-based company open a giant iron mine near the shores of Lake Superior over environmentalists' objections. Minority Democrats dragged out debate for nearly nine-and-a-half hours but were powerless to stop the measure. Republicans finally approved it on a 58-39 party-line vote. The bill already has cleared the Senate. It now heads to Walker, who has touted the proposal as his key job creation plan. He is expected to sign it into law early next week. "On behalf of the unemployed skilled workers in our state who will benefit from the thousands of mining-related jobs over the next few years, I say thank you," Walker said in a statement. It's still unclear whether the bill will survive legal scrutiny, though. Conservation groups and the Bad River Band of Lake Superior Chippewa contend the bill eviscerates environmental protections and are considering lawsuits. Still, the vote was cathartic for Republicans. They've been working for two years to pass a bill to help Gogebic Taconite dig a miles-long open-pit iron mine in the Penokee Hills just south of Lake Superior. The GOP has played up the mine as a huge economic engine, saying it would create hundreds of jobs for the impoverished region and thousands more across the state's heavy equipment manufacturing sector. But company officials have refused to move forward until lawmakers eased the regulatory path for them. Republicans introduced a sweeping bill that would have overhauled the state's mining rules in late 2011. Conservationists and Democrats contended the measure relaxed environmental standards and opened the door for pollution that would ruin one of the last pristine areas in the state.