Harsh conditions, that is what characterizes most coal mines' operations. The challange presented to Sidrasul Brazil by a mine in the Santa Catarina region, was pumping excess water from extraction, with a pH between 2.5 and 3.5 with moderately abbrasive coal particles ranging from 0.5 to 4 mm. The mine has a depth of 66 meters and a total extension of 600 meters.
Water was being pumped from the drilling front to the retention bassin with conventional horizontal end-suction pumps. Coupled to electric motors these pumps were expensive to operate and had a very short life time, burning regularly due to phase failures and dry-running. The only solution at that moment was rewinding the electric motors every 20 days on average and send the pumps back into operation! These repairs generated high costs related with the delays in the exploitation.
After analyzing the application, Sidrasul used a Grindex Minex pump. The pump was adapted to the aggressive medium with an extra polyurethane protective coating in combination with a stainless steel base and thus better suited to the customers harsh environment.
The customer's main pumping problem was solved by sizing the pump correctly for the application. The Minex pump turned out to be an ideal choice: the maintenance interval went from every 20 days to once every 6 months! The pump's air valve, allowing the pump to run dry, eliminates the need of an operator constantly baby-sitting the pump ,while at the same time the SMART motor protection protected the pump from phase failures and overheating. Grindex offered all these benefits, and more, such as ease of installation thanks to the phase shifter with 20 meters cable and the light weight design facilitating moving and transporting the pump.