The Prosecutor's office of one of Russia's Siberian regions on Monday ordered RUSAL-Krasnoyarsk to upgrade and put in operation a 2.5 million ruble ($81,000) gas purification equipment to filter the air from dust from calcining furnaces.

The factory in Krasnoyarsk belongs to the world's largest aluminum producer RusAl.

An environmental check showed that RUSAL-Krasnoyarsk failed to provide environmental quality standards and severely violated air protection laws harming the environmental situation in the Krasnoyarsk region. The Prosecutor's office has opened an administrative case against RUSAL-Krasnoyarsk to remove the violations.

"RUSAL-Krasnoyarsk has developed and approved measures (deadline Sept. 30, 2010) to remove violations of the air protection law identified by the prosecutor's office, including the reconstruction and commissioning of control equipment (a radial cyclone) to provide a more effective cleaning of gases from dust produced by calcining furnaces. The cost of the upgrade amounts to 2.5 million rubles," the prosecutor's office said in a statement.

Russian Prime Minister Vladimir Putin last month demanded a speedy completion of investigations into the blasts which killed at least 67 miners at the Raspadskaya coal mine in Western Siberia in May.

Russia's emergency officials say at least 23 miners are still missing from the two blasts that rocked the mine near the town of Mezhdurechensk on May 9.

Putin said analysis of the Raspadskaya tragedy had shown that the coal mining industry badly needed "systematic change."

The accident at the Raspadskaya coal mine is believed to have been caused by poor observation of safety regulations.

The Russian industrial safety watchdog detected over 1,400 safety violations at the mine in 2009 and in January-April 2010 and suspended production five times.

MOSCOW, July 12 (RIA Novosti)