By Marianne Arens
8 October 2013
The death of three potash miners in a mining accident in the German state of Thuringia a week ago is likely a result of management’s violation of safety procedures.
The three miners, aged 24, 50 and 56, died in a potash mineshaft near the town of Unterbreizbach. They died 700 metres underground after a controlled blast led to a massive and sudden release of a huge amount of carbon dioxide.
The men were part of a seven-member team assigned to examine the situation in the mine after the blast with the aid of gas detectors. At the time of detonation, they were several miles away from the explosion site. The wave of CO2 gas spread so quickly, however, that the men did not even have enough time to put on their oxygen equipment. Just four members of the group were able to reach a shelter in time to save their lives.
The question arises of why they were underground in the first place. The chief executive of the company running the potash mine K+S AG (Kassel), Norbert Steiner, said the advance party was situated in what was regarded as an adequately safe area in the pit system.
The mining expert Hans-Jürgen Schmidt from Sonderhausen, however, expressed his concern that the seven men were underground during the detonation. In an interview with German radio (MDR), Schmidt said, “CO2 was always a threat at the pit. This is why all miners should have been evacuated when the blast took place. This has always been the case.”
The carbon dioxide, which penetrated the salt rock millions of years ago as a result of volcanic activity, is stored either in salt crystal lattices (“intra-crystalline”) or in small gaps between the crystals (“inter-crystalline”). The gas can then be released by a blast and spread in explosive fashion. A geology encyclopedia states: “Outbreaks can assume huge dimensions and eject several hundred thousand cubic metres of gas plus tens of thousands of tons of rock salt.”
The great dangers involved in such mines are well known. Potash has been mined in this region of Thuringia for more than 125 years, and major accidents took place at the same mine in 1953 and 1958, when large amounts of CO2 were released, killing nine miners. In 1983, four miners died in nearby Hattorf, and another two in 1984. Three miners died in 1989 in Wintershall—all due to unexpected clouds of carbon dioxide gas.
The MDR quoted the former head of the Saxon mining authority, Reinhard Schmitt, who said it was known that “hundreds of thousands of cubic metres of gas could be released immediately by a blast or through a bore operation.” For this reason, such operations should only take place between shifts.
The regional district officer of the Mining-Chemical Energy (IG BCE) trade union, Friedrich Nothhelfer, hastened to line up with the K+S AG management. He told the dpa news agency, “Mining accidents such as that in Unterbreizbach are major exceptions.” The chairman of the IG BCE, Michael Vassiliadis, cynically remarked to the Frankfurter Rundschau, “The public has often forgotten that even today mining is still associated with risks.”
Despite the platitudes of the union bureaucrats, the questions remain: Why were the seven miners underground during the blasting operation? Was their presence due to economic reasons, because the blasting took place over three days in a row?
The affected potash shaft has been closed since the accident last Tuesday. Relatives and locals have gathered on a regular basis to deposit flowers and candles.
The accident is currently in the hands of the prosecutor and the mining authority, who plan to interview the four surviving miners. Immediately after the accident, the plant manager of the mine, Rainer Gerling, announced that management would review safety measures after the completion of all investigations.