Yoctolux Collieries in Mpumalanga has achieved improved yields and production throughput with the installation of a Cavex® 500CVXT20 DM cyclone from Weir Minerals Africa.
Part of the Tala Group, the opencast coal mine was looking to improve the performance of its dense media separation (DMS) circuit in its Wash Plant 1. The existing 610 mm cyclone, installed during the mine’s initial design phase, had an operational life of only six months between refurbishments.
Members of the Weir Minerals Middelburg branch and hydrocyclone product team conducted a site audit, revealing that the incumbent cyclone was operating inefficiently. A wash-ability analysis showed that an improved yield could be achieved using the Cavex hydrocyclone technology on the DMS circuit. The customer specified that the product would have to offer improved separation efficiency, increase wear life and match the existing cyclone footprint.
Following a proposal that included dense media (DM) hydrocyclone simulations, a Cavex 500CVXT20 DM hydrocyclone was installed in August 2017. Manufactured from mild steel, it is lined with 25 mm slip-casted radius ceramic tiles manufactured 92% alumina content.
To date, the hydrocyclone has achieved higher separation efficiency through an average 15% yield increase. It has achieved an overall average of 75% yield for both of the mine’s coal types – grains and peas. This compares favourably to the 65% achieved previously by the competitor’s cyclone.
There has been a 49% throughput increase in production tonnage, from 78 tonnes per hour to 116 tonnes per hour as a result of the reduced turbulence in the hydrocyclone’s design. The mine has also seen significant wear life improvement, with the Cavex DM hydrocyclone requiring only a spigot replacement after nine months.
So satisfied was the management at Yoctolux Collieries that they placed an order for an additional Cavex 500CVXT20 DM hydrocyclone in May 2018. This replaced the competitor’s cyclone on Wash Plant 2. The replacement was based on the improved metallurgical and operational benefits obtained by the Cavex hydrocyclones.