In fact, the slag heap is nothing more than a heap of waste. This is where all the stone waste that had to be disposed of from the mines was collected.
The slag heap of the Oranje-Nassau IV coal mine
The slag heap is located on the north side of the former mining site. The western part, located against the buildings of Heksenberg, is the oldest part. This also contains the training mine in which miners were trained for work underground.
The minestone mountain consists of a mixture of shale rock, calcareous boulders, coal waste, light clay and sand loam particles. All these stones did not go straight up the mountain from the mine. A transfer point had been set up near the foot of the mountain (see bottom photo), where the mine stone was loaded from the mine carts into dump trucks.
The carts were then pulled over a temporary track and with the aid of a winch up the mountain to be emptied there. Part of the mining stone was dumped from the dump trucks over the side of the mountain. The rest was poured over the tip of the mountain via a conveyor belt, depending on which direction the mountain was being magnified at the time.
Because the dump site has remained unchanged over the years, a fan of tracks can be found on the south side of the mountain that the rails for the dump trucks have left behind. The mining stone was not poured directly onto the heathland.
Part of the silver sand present was excavated and sold beforehand. The quarry was known as quarry Heksenberg and was not as deep as the current Sibelco quarry. For this reason, discussion also arose about excavating the spoil heap for the remaining silver sand.
The battle for the mountain
The spoil heap of the Oranje-Nassau IV was located within the concession of the Sigrano quarry (now: Sibelco quarry). This allowed Sigrano to excavate the mountain to extract the silver sand that lay beneath it.
The plans were entirely in line with the attitude of the 1970s and early 1980s, when the remnants of the mining industry were demolished en masse to close the history of coal mining. However, attitudes have now changed.
The spoil heap of the Oranje-Nassau IV is the only stone heap still in its original state and functions as one of the few tangible reminders of the mining industry. When the plans for excavating the mountain became known, there was fierce protest in the area.
Various procedures have been followed to have the slag heap declared a protected national monument. Unfortunately, on 5 September 2005, the State Secretary for Education, Culture and Science rejected this request. Going to court was to no avail. After the District Court of Maastricht, the Council of State (March 12, 2008) also ratified this decision.
Preserve for the future
In 2008, a variant study was commissioned by Sigrano for a permit application for the extraction of silver sand under the spoil heap. In the preferred variant, the western part of the slag heap was retained to shield the Heksenberg district.
The eastern part would be excavated to be restored after the extraction of silver sand as a mining beacon, while a part would also continue to exist as a pond. Various variants were considered, in conjunction with the possibilities for nature and (water) recreation.
However, the protest from the area did not diminish. In 2018, Sibelco decided to meet the wishes of the environment. The slag heap was preserved in its entirety. This cleared the way for the municipality of Heerlen to designate the slag heap as a municipal monument in 2019. In this way, the spoil heap could be preserved as a symbol of mining for the future.
This text has been automatically translated using an online translation service.
