Area of sinkholes
The sinkhole phenomenon at potash mines is not uncommon, but for publicly traded company Uralkali it is a real troublemaker. The most serious sinkhole took place in 2006, when Uralkali was forced to close the Berezniki-1 mine after it was flooded with brine inflow.
A number of other sinkholes in Berezniki followed, including one in the middle of the town this February, according to media reports. That sinkhole ripped through the ground near a local school that had been shut down and “quarantined” in 2007 following previous incidents, the GorodBerezniki news portal reported.
The causes of the most sinkholes remained unclear. The crater could have “appeared on the location of a hole that has been here always,” regional mining institute director Alexander Baryakh was quoted by Valekse news portal as saying, adding that it has not yet been determined what caused the original hole.
The sinkhole may or may not have been caused by abandoned mines that had operated in the district between 1857 and 1953, the head of the Aleksandrovsk administration’s environment and natural resources department, Yuri Letov, was quoted as saying.
Uralkali is a Russian potash fertilizer producer and exporter. It is traded on the London Stock Exchange and Moscow Exchange using the symbol, URKA. The Company’s assets consist of 5 mines and 7 ore-treatment mills situated in the towns of Berezniki and Solikamsk (Perm Region, Russian Federation). Uralkali employs 11,300 people (in the main production unit). The company produces standard and granular potassium chloride (KCl) and supplies it (through its own trader Uralkali Trading) to over 60 countries.
The phenomenon is relatively common in the area due to the number of abandoned and working potash mines, some of which are just a few hundred metres from the surface.
Another sinkhole – which is 5 metres in diameter – was discovered during monitoring of the zone of transitional period panels, the hazardous area of the minefield of the flooded Berezniki-1 mine. The hazardous area of the transitional period panels has been fenced off and access has been restricted since 2013.
The zone of transitional period panels is an area in the town of Berezniki measuring 800 by 800 metres, surrounded by Reshetov square, Kotovsky street, and Gastello street. In 1944-46 and 1963-64, carnallite B seam was mined in the transitional period zone; in 1948-54, sylvynite AB seam was mined there.
Most recent researches claim that a huge sinkhole which has appeared near a mining town in the Perm region of Russia has tripled in diameter in the last 10 months. The giant hole, near the town of Solikamsk, is now 120m (400ft) across and up to 80m (250ft) deep.
When it was first discovered last November (2014) the sinkhole measured 20m by 30m. Although the exact cause of the sinkhole isn’t known, scientists believe it is probably linked to a nearby potash mine, the largest in the world, which uses seawater.
News of the sinkhole caused shares in Uralkali, the firm which owns the mine, to plunge last year. Now the company – the world’s largest producer of potash – has suspended operations at its Solikamsk-2 mine and sent its 1,300 workers home.