In 1916, a special council was created to operate the mines, introducing new technology and safety improvements. A record production of 82,000 mercury flasks was reached in 1941, just after the Spanish Civil War, using prisoners of war as forced labor. This amount is comparable to the 3.000.000 kg that were produced by China in 2018. The price for mercury decreased from a peak of US$571 in 1965 to US$121 in 1976 making economic planning difficult. In 1981, the Spanish government created the company Minas de Almadén y Arrayanes to operate the mine. In 2000, the mines closed due to the fall of the price of mercury on the international market, caused by falling demand. However, Almadén still has one of the world's largest mercury resources.