When he was 15 years of age, Arthur Collins traveled with his father and brothers Henry and George to Andalusia, Spain, in the great mining region of Rio Tinto, where Joseph Collins was appointed chief chemist and assayer of the Peña del Hierro copper mine. Under his father, Arthur began his practical work in the laboratory and continued his studies in chemistry and mineralogy, and was soon employed as assayer and underground surveyor by the Peninsular Copper Co., in Southern Spain. Joseph H. Collins and his sons returned to England in 1885, where Arthur was put in charge of an experimental smelting works near Breage, in Cornwall.