Since Burrage did not have the capital to develop a mine, he approached the Guggenheim Brothers. They examined his claims and estimated reserves at 690 million tonnes grading 2.58% copper. The Guggenheims also had a process for treating the low grade ores developed by Elias Anton Cappelen Smith and were immediately interested, organised the Chile Exploration Company (Chilex) in January 1912 and eventually bought out Burrage for US$25 million (or $ million today) in Chilex stock. E. A. Cappelen Smith, consulting metallurgist for M. Guggenheim's Sons, worked out the first process for the treatment of Chuquicamata copper oxide ore about 1913, and directed a staff of engineers operating a pilot plant at Perth Amboy, New Jersey, on three shifts for an entire year.