New York Times: Less than a year ago, officials were pressing mines and factories along this limestone belt of northern China to shut down or move away to clear the air of dust and smog for the Beijing Olympics. Now, amid the global economic downturn, priorities have shifted. Cumbersome environmental reviews have been accelerated, state bank loans are flowing freely again and workers are welding the grinding mills of Sanhe Yongsheng Cement, one of the new cement plants under construction not …