Bitcoin and China. NurPhoto/ Getty Images China has re-emerged as the second-biggest bitcoin miner after the US, despite Beijing's ban on crypto activity. A surge in covert operations has made it a major mining hub again, the Cambridge Centre for Alternative Finance found. China's crackdown resulted in a swift drop in global bitcoin mining, which has now recovered to hit all-time highs. For more stories go to www.BusinessInsider.co.za . China has made a comeback as a global bitcoin mining powerhouse, despite Beijing's crypto crackdown. Research by the Cambridge Centre for Alternative Finance found a surge in covert mining operations post-ban…