Four miners have been killed in an explosion that caved in part of a coal mine in the northern Mexico border state of Coahuila.

China's coal mine safety watchdog said on Friday it had completed a manned experiment of a permanent underground chamber that can shelter miners in case of an accident as part of its efforts to reduce mining casualties.

Workers at Freeport-McMoRan Copper & Gold's (FCX.N: Quote) Grasberg mine in Indonesia plan to stage a strike in coming days after talks with the company failed to resolve a pay dispute, a move that could tighten global copper supplies and lift prices. A strike would be the second in two months at Grasberg, the world's third biggest copper mine that also has the biggest gold reserves, after an eight-day stoppage in July caused production losses and helped push copper prices to three-month highs

Discovery Air Innovations (DAI), a wholly-owned subsidiary of Discovery Air Inc. and Hybrid Air Vehicles Limited (HAV) have signed an agreement under which DAI will be the first customer for HAV’s Commercial Heavy Lift program.

Shaanxi Coal Industry plans an initial public offering in Shanghai to raise up to 17.3 billion yuan ($2.7 billion) in what could be China's biggest IPO this year. The China Securities Regulatory Commission (CSRC) said late on Thursday that it would review Shaanxi Coal's IPO application on August 29.

Gold prices were staging a rally Friday, shrugging off an almost three-day selloff, after Ben Bernanke left the door open for more monetary easing.

Confirming details leaked to the Washington Post on Wednesday the US State Department said on Friday a proposed $7 billion extension of the Keystone pipeline to US Gulf Coast refineries would not likely boost the amount of crude produced from Alberta's oil sands, suggesting it would have limited impact on the environment. A final decision on the controversial pipeline could come as soon as the end of the year. The news comes as demonstrators in front of the White House continue being arrested in efforts to convince President Barack Obama of Keystone XL’s dangers. The price Canada can charge for crude exports to the US is falling further behind the international benchmark because of a glut in the Midwest and some hedge funds have started to bet that the spread could go as high as $50/barrel leaving Alberta producers millions of dollars out of pocket per day.

A proposed open-cast coal mine on West Coast conservation land has gained resource consents because of its economic benefits. West Coast Regional Council released the decision yesterday to grant consents for a subsidiary of Perth-based Bathurst Resources Ltd to mine 200 hectares in the Mt Rochfort Conservation Area on Denniston Plateau, near Westport.

In a sign that consolidation in the uranium sector is gathering pace, world number one uranium producer Cameco announced on Friday it is extending a $527 million cash offer to shareholders of Hathor Exploration, after talks with the board of the junior explorer failed to result in a deal.