New Delhi, Sep 25 : The Chinese authorities said on Friday that all cryptocurrency -related businesses are illegal and called for the exit of cryptocurrency mining projects. -related businesses are illegal and called for the exit of cryptocurrency mining projects. Up to three-quarters of the world’s supply of bitcoin has reportedly been produced in China, but the process consumes vast amounts of electricity, and energy produced by coal-burning plants is a massive contributor to air pollution, Global Times reported. Over the past several months, several large virtual currency mining centres in China, including in southwest China’s Sichuan Province and north…