This is another important supply made by the WEG´s Russian Commercial Operation (WRU) for the customer PJSC Polyus Gold, in the Magadan Region, the largest gold producer in Russia.
The scope of supply included a pair of Slip Ring Motors of 9000 KW at 1000rpm, and another two motors of 7500 KW also at 1000rpm and fully designed to be interchangeable with the old existing motors providing a smooth drop-in replacement.
The motors will be applied, in pairs, at huge SAG and Ball mills that operate through dual pinion drive summing their power to each mill.
Historically, the customer was facing a troublesome operation due to a number of different reasons such as mechanical fits, overheating of antifriction bearings and electrical overload events.
With prompt attention to the customer, the WEG team evaluated different options in order to offer the most reliable product. A robust design of slip ring rotor motors was recommended including reliable features such as fixed or liftable brushes, internal or external slip ring chamber and different series of sleeve bearings or antifriction bearing in oil bath.
The final design was approved after customer inspection at WEG headquarters facilities in Brazil and a technical visit to a cooper mine in Chile where similar WEG motors are successfully operating.
A key factor for this project was the local WEG specialists in the market providing fast response to the customer and listening carefully to the customer needs.
The WEG Slip Ring Mining motors were designed in such a way to allow another technical key factor for this project where they can operate both as a slip ring motor or as an induction motor fed by inverter when the temperature is very cold (-50°C) and the ore inside the mills gets frozen and then the mills speed can be automatically controlled.
The electric motors were delivered in July 2020. Due to sanitary restrictions, the commissioning was postponed to December and work was carried out from November 15 to December 23, 2020.
About Polyus Gold Mine – Natalka
PJSC Polyus is the largest gold producer in Russia and is among the top 10 gold producers globally with one of the lowest cost profiles.
The Company also holds the world’s third largest gold reserves with 61 million ounces of proven and probable gold reserves underpinning its strong growth profile.
Polyus´ main operations are located in Krasnoyarsk Territory, Irkutsk Region, Magadan Region (Natalka) and the Republic of Sakha (Yakutia) and include 5 operating mines, alluvial operations and several advanced development projects.
The target for Natalka is 1200 tons of ore per hour, and the average in 2019 was 1400 tons per hour. In the fourth quarter, hourly productivity usually exceeded 1500 tons!