Old Mineral Panning at Portmán

Portmán, small district in the town of La Union, is home to one of the most important mining heritage sites: Lavadero Roberto, a panning were mineral was treated to remove impurities. This large industrial complex, located outside the city center, was commissioned in 1957 and became the largest installation of its type in Europe. One of the many design modifications implemented at the panning over the years was intended to use seawater in the mineral treatment process.  To achieve this purpose, a pumping station was installed on the beach. The mineral panning capacity was expanded in 1966, resulting in more discharges to the sea and worse consequences for the environment. After its decommissioning in 1990, the mineral planning became an essential part of the mining heritage of this region, but it also revealed one of the worst environmental disasters in the Mediterranean coast. 

 

The treatment process took place in four different wards: minerals were first crushed and then transported by belt to a mill where it was ground. Later it was taken to a categorization area where the material not properly grounded was returned to the mill, in the first ward.

 

In the second ward, the categorized mineral product was driven to hoppers where it was treated with cyanide so that lead could float. The mineral was then transferred to a conditioning area where it was treated with copper sulfate to allow zinc to surface.

Lastly, pyrite was also obtained following further treatment.

 

In the third ward there were three pumps forcing the barren to pipes that discharged directly into the sea.

 

In the fourth ward there were two tanks, one containing lead and the other sphaleryte. Each tank was equipped with a pump to drive the mineral to the smelting station. In addition to the wards, there was also a mechanical mechanical workshop at the premises to work on site equipment.