PRODUCT FOCUS
Finlay
Deployed in an alluvial diamond mining company in the arid Northern Cape, Finlay’ s dual power screen machine saves water as well as improves efficiencies.
electrical power is already supplied at a fixed cost.”
The Finlay 694 + dual power screen receives the minus 40mm material from the Finlay 883 + screen and screens out the sand that is smaller than minus 3.5mm.
“ On the Windsorton site, we’ re working through many old mining sites that were worked years ago, and our gravels are situated at very shallow levels with little overburden to remove and stockpile for later rehabilitation and there is subsequently a lot of sand to contend with.
“ On average, we’ ll screen 1 680 tonnes per shift and of that, a massive 72 % goes to our four 16-foot pans, which shows the screens’ efficiency. Another upshot of this efficiency is that we can now use closer circuits on our pans, which saves us water. We used to fill our process water reservoir from the nearby Vaal River every day, but due to us taking the sand out of the gravel using the Finlay 694 + dual power screen, we now only draw water for the pans on a Monday. This equates to using the water we used for one pan before, on four pans now, which is really eco-friendly.”
The Finlay 883 + heavy-duty screen returns average fuel figures of 10.4 litres to the hour and the Finlay 694 + dual power screen averages 14.2 litres.
“ To further improve the efficiency of the Finlay 883 + screen, we have fitted an optional external air filter to counter the dust, and air filters on both machines are cleaned at the start of every shift,” Smit says.
All oversized material, along with the sand, is hauled back to the mining area that is rehabilitated continuously. The sand that is removed by the Finlay 694 + dual power screen has proved to be an ideal growth medium for both Blue Buffalo and Borseltjie grass types, which are planted in accordance with the mine’ s environmental management plan.
Schoeman points out:“ We use customer feedback from around the world to assist us in improving product lines. Machine downtime has been radically reduced due to the fact that the equipment is no longer subject to trial and error. Machines thereby run on less power, which provides environmental and cost factor benefits, with 85 – 95 % availability becoming the norm. We have upgraded our newer models to decrease the physical interaction required and we have reduced the size of wear components to make them easier to physically handle. In line with this, we have also introduced a range of special lifting devices, certified and weight tested to assist customers in the removal of wear parts. The end result is that equipment availability is greater and the return on investment is much faster.” Product automation is increasing as this provides more equipment availability. It allows for longer operational hours since the predictive elements within the equipment provide for proactive rather than reactive maintenance. Vibration and heat sensors in the bearings send alerts to the operator that something is amiss.
However, automation does not mean that the human element is removed from the process, since one still needs an operator to ensure that the process continues.
In addition to efficiency and high levels of throughput, regardless of the material being crushed, there is a growing trend towards the ability for crusher operation management to be able to remotely monitor and control crushing equipment from a smart device or cell phone. This can provide instantaneous insight into the health of the equipment, fuel consumption idle time, crushing time, and projected tonnages per hour, without having to physically be on site.
“ This allows us to observe trends and look at tolerances so that overall maintenance is reduced. Checkpoints can be immediately addressed, and we can quickly remedy root causes. We believe that the future is in the remote monitoring of equipment,” adds Schoeman.
Mobile vs static crushers
The debate on whether it is more costeffective to invest in a static or mobile crushing plant can be simplistically resolved if one considers the applications for use and the length of the crushing contract.
Typically, static crushing plants are chosen when a crushing contract is expected to last a number of years or where deposits are extensive. Static is an objective term here, as the plant can be mounted on a skid frame to provide limited mobility.
24
JULY 2018