Russian mine sets longwall production record twice in one year
A coal mine in Russia recently earned recognition for a longwall production record — 1 567 000 tonnes (1,727,322 tons) of raw coal in one month from a single longwall face. The achievement was impressive for a number of reasons: It surpassed the world record for monthly coal production from a single longwall system. The record the mine broke was its own, set just 3 months earlier. And most importantly, the record was achieved without a single lost time injury — an accomplishment made possible by the mine’s strict adherence to national safety laws and a culture that makes safety a top priority.
Relying on productive equipment
The Russian Yalevskogo mine in Siberia, formerly known as Kotinskaya, is operated by the Siberian Coal Energy Company (SUEK). The mine is located in the Kuzbass region, the source of much of the country’s coal experts, where SUEK operates 10 longwall faces in underground mines as well as two surface coal mines. Yalevskogo currently has two longwall faces and mines in two seams: Seam No. 50 and Seam No. 52. The longwall systems at the two faces average cutting heights of approximately 4 meters (13 feet).
The longwall system includes a Cat® AFC PF6 armored face conveyor (1142 mm outer width) as well as a Cat BSL PF6 beam stage loader (entry conveyor) — both armed with Cat controlled start transmission CST drives. The beam stage loader includes a SK11/14 crusher with 400 kW (536 hp) installed power. Pan width is 1,342 mm (0.05 in). The longwall face at Yalevskogo mine is equipped with customized two-leg Cat roof supports, each with a width of 1.75 meters (5.75 feet) and support capacity of 725 tonnes (800 tons).
In 2016, SUEK ordered additional Cat longwall equipment for a face extension from 300 to 410 meters (984 to 1,345 feet). For this extension, the installed power of the face conveyor was upgraded to 3 x 1.000 kW (1.341 hp) with new Cat CST65 drives. The extended longwall started operating in April 2017 in the 3.8-meter-thick (12.5-foot-thick) Seam No. 50. The mine set a new production record of 1 407 300 tonnes (1,551,283 tons) in the seam just a month later, followed by a new world record in August 2017.
“To produce a record amount in only one month, it took a customized longwall system designed for high availability and efficiency,” says Frank Theml, a Caterpillar Underground commercial manager in CIS/Mongolia. “They needed face and entry conveyors especially designed for high performance, and we’re proud that we were able to provide them.”
Previously, the widest longwall face in Russia was 300 meters (980 feet). For this extended longwall, SUEK combined three different types of Cat roof supports from other longwall faces.
“The challenge for Caterpillar was to match the armored face conveyor to these different roof support types,” says Theml. “This was necessary because of the tip-to-face distance — the distance between the canopy and the coal face.”
The tip-to-face distance is a critical measurement in order to maximize roof integrity and limit dilation. “The smaller the distance, the better the result,” says Theml. “This distance is strictly limited by national law.”
For the different roof support types, Caterpillar manufactured custom-specific clevis mountings — the connection between the AFC line pan and roof support base — in order to ensure that all face roof supports have the same tip-to-face distance, adhering to regulations.
Focusing on safety
While SUEK and its nearly 800 workers are proud of their accomplishments, they are most proud of the fact that they broke the record without any lost time injuries on the face and in full compliance with national safety laws.
The safety focus at SUEK Company operations starts at the top. The company’s Board of Directors supervises a committee that coordinates labor protection and industrial safety at all SUEK sites, and the company develops and implements educational programs for personnel. Safety contests are held on a continuing basis, with Yalevskogo mine regularly winning these challenges.
Internal safety standards apply to everyone at the mine, including contractors like Vostochnaya Technica LLC (VT), the local Cat Dealer in Siberia, Yakutia and northeast Russia.
“Ensuring safe working conditions and minimizing any risks connected with the coal mining process are the top priority for SUEK Company,” says Andrew Ravnyushkin, a technical director at VT. “When we are working on site, we follow the same strict standards that SUEK has for its own people.”
The mine meets advanced international standards and continually strives to decrease the safety incident rate, undergoing regular audits to ensure they meet the requirements.
These requirements are taken very seriously at Yalevskogo. “The safety rules are strictly followed,” says Ravnyushkin. “That plays a big part in the reduction of risks of injuries and accidents.” SUEK uses a specialized software to keep records during every shift and diligently monitors the number of registered and corrected violations.
The mine also takes advantage of new start-up instrumentation, which eliminates any possibility of accidental or unauthorized disconnection of the protective devices, and has a dispatcher in the central office with responsibility for monitoring the status of the system in real-time mode.
Taking advantage of automation
While a number of safety features are incorporated into the longwall system, the biggest safety benefits come from automation, which removes personnel from the hazards of the longwall face.
The longwall at Yalevskogo is fully automated. All three types of roof supports were upgraded with a Cat PMC-R roof support control unit. The automation system also incorporates a Cat PMC-D drive control, a Cat PMC-V for visualization and parameter setup of the drive system, and a Cat MCU2 master control unit for visualization and control of the longwall operation with an explosion-proof underground computer. Through data transmission in real time via optical fiber cable/modem, the whole system can be controlled from a mining control center located at the surface.
When the longwall system is activated, warning signals give the crew the opportunity to leave the area in advance. Signals also sound before a roof support starts moving.
The electrohydraulic roof support control system for Yalevskogo offers special operating modes to boost both productivity and safety. The system can reactivate some regions of the face and resume production even when the face has been put into a safe condition in response to the detection of an electrical fault. Strict conditions must be observed before reactivation.
Conveyor moving is performed in groups up to 15 pans, which shortens the time for this operation and reduces the number of people involved in the process. In addition to the safety benefits, this also increases overall productivity.
Building a partnership for support
VT and SUEK work together on equipment support at Yalevskogo as well as several other SUEK mines, including Rubana, Kirova and Talkdinskaya-Zapadnaya 1 and 2. VT has been a partner to SUEK since taking over service for the longwall equipment previously manufactured by Bucyrus.
The mine’s own technicians handle regular equipment maintenance, but SUEK relies on VT to provide consulting as well as to monitor the maintenance performance and participate in repairs when needed. A VT workshop is located just 70 kilometers (44 miles) away in Novokuznetsk.
VT is also responsible for performing Scheduled Oil Sampling and inspecting the condition of wear parts to ensure the longwall system is operating at peak performance and to head off any potential failures.
SUEK relies on VT to perform major upgrades, rebuilds, repairs and replacements. “VT prepares all the necessary parts in advance and carries out maintenance during the longwall changeovers,” says Ravnyushkin. “Our own technical personnel, together with technicians from the mine, monitor the condition of the equipment and perform all the necessary maintenance.”
SUEK recognizes the role of the combined maintenance team in enabling the record-breaking production at Yalevskogo, citing the timely and high-quality technical service and the dependable productivity of the longwall system and roof supports.
Looking to the future
Building on the success of its first 400-meter (1312-foot) longwall face, SUEK has already placed an order for another complete armored face conveyor system to equip its second extended face. The longwall will operate in Yalevskogo Seam No. 52, with commissioning planned for early next year.
The new system consists of a Cat AFC PF6/1142 with three drives of 1000 kW (1,341 hp) each, along with Cat CST65 gear boxes, a Cat PF6/1342 beam stage loader with a Cat SK11/14 crusher and a belt return unit. The AFC system will go into operation with Cat roof supports.
The order marks continued growth of SUEK’s Cat longwall equipment. The company currently operates four longwall faces with Cat roof supports and has nine complete Cat AFC systems.