The world’s mountain of discarded flat-screen TVs, cellphones and other electronic goods grew to a record high last year. An annual study released Thursday estimated the amount of e-waste that piled up globally in 2019 at 53.6 million metric tonnes, almost 2 million tons more than the previous year. That's about as heavy as 350 cruise ships the size of the Queen Mary 2. Among all the discarded plastic and silicon were large amounts of copper, gold and other precious metals. While about a sixth of it was recycled, the remainder of those valuable components _ worth about $57 billion _ weren’t reclaimed. The authors predicted that global e-waste could grow to 74 million tons by 2030.