ABB believes it has a solution for monitoring the input and output of crushers, one of the key pieces of equipment in almost any mining operation.
Its non-contact laser level products, such as the LM80 and LLT100, provide solutions for accurate control of crusher operations, according to the company.
In rock crushing operations, one usually finds a series of rock crushers connected by conveyor belts, with each crushing stage resulting in the rocks getting smaller and smaller.
“ABB laser products provide reliable measurements and are unaffected by the continuous vibrations caused by railcars and conveyors. Lasers can deal with the presence of dust while the conveyor is feeding into the bin,” ABB says.
“They read crusher levels without being affected by these factors, thus providing inventory measurement or process control without adjustment or maintenance.”
These laser level products can do more than simply monitor crusher output; they can also be used to optimise crusher productivity.
“Feed control is crucial as crushers must be fed continuously to prevent serious damages to the equipment and to optimise productivity. It is imperative to maintain a ‘choke’ level and to avoid running the crusher empty,” ABB says.
“One must drop ‘rock on rock’ and not ‘rock on metal’.”
Throughput must also be maximised, hence the plant must quickly react to inconsistent inflows, clogging, or other problems.
This is where a rapid and accurate feedback on the material’s level in the crusher can optimise feed control and maintain the required ‘choke’ condition, according to ABB.
Industries such as mining will also often use surge bins to help maintain a controlled and/or consistent flow for the crusher. Surge bins are often bigger than needed, but can still be subject to overfilling.
“Such overfilling, if not addressed quickly, may block the whole inflow line and spill on the ground below, thus creating manual and labour-intensive clean ups,” ABB said.
“Maintaining a proper feedback loop on the surge bin (using level transmitters) is therefore as important as maintaining one on the crusher itself. In addition to impacting productivity, preparing for proper level control can allow for significant initial cost reductions when establishing surge bin requirements.”
ABB says the LM80 is an ideal solution for this type of measurement as it can be installed at different stages on the crushing line, whether composed of fixed or mobile crushing units. Each crusher can be of a different type, each design having its particular specifications and limitations. The narrow beam can be easily directed between the crusher mantle and its side wall, with the integral pointer allowing precise aiming of the laser.
“The payback associated with using the LM80 is increased production and reduced maintenance expenditures on rebuilding the crusher (due to continual rock damage),” ABB said.
The company concludes: “Laser level measurement provides users significant cost reductions, with a return on investment often measured in days or, at most, a few weeks.”