Diamond mining group Alrosa has called off its search and rescue operation for eight workers at its Mir deposit in Yakutia, Russia.
The search for the workers began on August 4 when Mir’s underground section flooded and continued 24 hours a day for three weeks.
On Saturday, August 26, a sudden rush of water entered the mine, with the company now rendering the rescue mission “impossible to continue”.
“It is with a heavy heart that I am forced to announce that there is no more hope that we can find the missing miners alive and bring them to the surface,” says Alrosa president, Sergey Ivanov. “We are deeply shocked by what happened. This is a great tragedy for the whole company.”
He continues: “Unfortunately, knowing that we have done everything possible to rescue the people cannot be a comfort to their loved ones. As the head of the company, I guarantee that the miners’ families will receive the necessary support and financial aid – timely and in full. On behalf of Alrosa, I would like to express my sincere condolences to the families, relatives and friends of the miners. We mourn with you.”
Alrosa will pay to the missing miners’ relatives a compensation of RUB 2 million.. These funds have been allocated by Alrosa (in excess of payments under the Collective Bargaining Agreement) and the contractor organization Belspetsmontazh LLC. In addition, the miners’ relatives will receive insurance payments and payments from the budgets of various levels, including those of the Republic of Sakha (Yakutia) and the municipal entity Mirny District. The families of the workers from the Belgorod Region will also receive payments from the Administration of the Belgorod region, and the families of the miners who lived in Mirny – from the budget of the Municipal Entity Town of Mirny.
The legal status of the miners remaining underground after the end of the search and rescue operation will be considered by the court in the near future.
Alrose has published the following report detailing its rescue operation and why it had to come to be called off:
The search and rescue operation at Mir underground mine continued for three weeks. The rescue works were carried out 24 hours a day in three shifts. A total of 320 people were involved in the operation: 170 specialists of the Emergencies Ministry and about 150 employees of Alrosa. The miners and rescuers spent a total of more than 360 hours underground.
The search was conducted at a depth of 550 and 600 meters, the total volume of the rock extracted amounted to 19.5 thousand cubic meters, the length of the cleared mine workings was 1,191.5 meters. Over 30 units of equipment, aviation, divers and rock climbers were involved in the search. To ensure the rescuers’ safety and prevent flooding of the levels where the search was on, two groups of additional pumping units were installed in the underground mine.
The search became more complicated on August 18, when the water coming from the Metegero-Ichersky aquifer complex stopped discharging into the underground mine and started accumulating at the bottom of the open pit. The inflow in the open pit mine was about 1,200 cubic meters of water per hour, of which about 1,000 cubic meters discharged into the underground mine, and 200 cubic meters accumulated at the bottom of the open pit every hour. It created a danger of instantaneous breakthrough of accumulated water into the mine shaft and endangered the lives of miners and rescuers working underground. Federal norms and regulations in the sphere of industrial safety prohibit rescue operations in such conditions, so the search for the missing people was suspended at 4.00 pm on August 19.
All possible measures were taken to organize a controlled discharge of water in order to avoid the immediate inrush of water from the open pit into the underground mine. At an emergency meeting on August 20, it was decided to conduct a series of focused local explosions. Rostechnadzor issued a relevant permit. Blasting operations continued for five days, but it turned out impossible to achieve a controlled discharge of the whole volume of water into the underground mine.
On August 25, at 4.00 pm, the water accumulated in the open pit mine was 33,000 cubic meters. By that time, when the water in the mine shaft reached the mark of –222.2 the sensors of the automatic start of the first pump of the cage shaft were activated. The pumps on level –210 were supposed to maintain the water in the mine shaft at a certain level, protecting it from flooding.
Later in the day, based on the information about the volume of washouts in saline rock, the expert group of geotechnicians started recalculating the actual stability margin factor of the lower pit bench under which the mine workings are located. The analysis showed that the stability factor of the lower bench of the southwest wall of the open pit had already passed the critical level. If the blasting operations continued, they could result in a collapse of two lower benches of the open pit, so their further use was recognized as impossible.
Moreover, the analysis showed that washouts totaling more than 100 thousand cubic meters were already formed in the saline rock, and, based on the assessment of the intensity of dissolution of saline rock with the existing brine flow dynamics, this volume can increase at high rates. In this situation, pumping of the water from the mine shaft will result in an uncontrolled increase of erosion. Based on this, at a meeting of the Emergency Response Center, it was decided to shut down the pumps and stop the search and rescue operation.
By this time, three weeks have passed since the accident. Medical experts believe that people cannot survive for such a long time without drinking water, food, in the conditions of high humidity and in the mine flooded with a mudflow that has a high content of hydrogen sulfide and salts.