 On returning to the Netherlands, he is said to have acted as assistant to Johannes Diderik van der Waals, physics professor at the University of Amsterdam.From 1879 to 1882, Delprat worked in Spain at the Tharsis Sulphur and Copper Mines.In 1898, chairman E. N. Wigg of Broken Hill Proprietary invited Delprat to Australia to become Assistant General Manager of BHP.