thyssenkrupp Industrial Solutions will present its new mobile stacking bridge lizard® at Bauma 2019 which was earlier presented at the IM In-Pit Crushing and Conveying (IPCC) conference in Santiago, Chile in 2018. This unique solution for heap leaching and dry tailings stacking combines two proven technologies – the conveyor bridge and the tripper car – in a new way. The lizard decouples the crawler-mounted tripper car from the conveyor bridge, enabling it to be controlled independently of the bridge.
“Decoupling the tripper car from the conveyor bridge has several advantages: The transitions between the bridge segments are easier as there is no stress from a traveling tripper car on top of the bridge. As the loads on the bridge sink, the overall construction of the bridge outweighs the additional chassis and structure of the tripper car. This way the product saves weight and costs accordingly. In addition, a larger dump height and longer outreach are possible.”
“Especially with longer conveyor bridge systems the lizard pays off with lower investment cost and less fatigue issues on the bridge structures,” says Stefan Ebert, Global Product Lifecycle Manager. “Since the tripper car is not traveling on the bridge, the loads for dimensioning the bridge are significantly reduced,” explains Burhan Osmani, engineer at thyssenkrupp Industrial Solutions and the inventor of the lizard.
Operators benefit from a slimmer, lighter bridge structure, lower bridge height, smaller bridge crawlers and lower ground pressure. The same lightweight design can also be used for the reclaiming bridge. Fatigue issues otherwise caused by cyclic loads from the tripper car are completely eliminated. This significantly reduces maintenance requirements and increases availability.
A key advantage of the lizard is its multi-crawler chassis. thyssenkrupp used its expertise in this area to develop a unique solution that improves productivity: A multi-crawler chassis with no override control, the so-called “float system”, is attached to the tripper car. The double crawlers with no steering cylinders ensure unrestricted maneuverability in all directions. The system can be attached to any crawler to avoid the large turning circles of conventional gearing systems. “To be able to flexibly control the mechanically independent multiple crawlers is a game changer in mobile mining equipment,” says Paulo Costa, Head of Mining Systems.
The float gearing system allows the lizard to be operated flexibly: When a stacking row is completed, the tripper car is at either the front or rear end of the bridge. Before moving to the next stacking row, the tripper car has to turn its crawlers through 90 degrees in the direction of bridge movement without impacting the performance of the system. In this way the tripper car and the stacking bridge move backwards or forwards as one stacking system depending on the stacking plan.