When a cooper mine in the US learned of a new overburden-loading dipper that P&H Mining Equipment had developed with a Powder River Basin coal mine, the wheels were set in motion to develop a copper ore-loading dipper that would provide performance gains.
To achieve this objective P&H Mining Equipment engaged the copper mine to identify key factors such as material being loaded, dipper geometry and shovel power systems dynamics that can affect shovel dipper performance.
The company joined an Australian-based Cooperative Research Centre (CRCMining) to apply a systematic approach for testing and evaluating promising dipper designs.
According to P&H Mining Equipment dipper product manager Darryl Immel, CRCMining helped develop miniature scale models and then applied a unique testing facility to measure and analyse the relative performance of the alternative dipper designs.
“Because real-world dippers are very large and costly to build, the most efficient alternative process for P&H Mining Equipment to pursue involved developing dipper designs — and above all scale models, based upon long —time conventional dipper designs it developed for various material handling situations,” Immel told Australian Mining.
“Engineers identified several factors that needed to be applied and examined. They included dipper lip angle, dipper lip shape, dipper width and selection and spacing of ground engaging tools.
“Other factors included dig energy requirements, dig time, fill efficiency, wear zones and the overall effects of the material as the dipper engages. Also considered in the dipper design were the shovel operator experience and material bench height alternatives.”
The dipper models were then mounted to a mechanical digging ‘arm’ within a specially designed bin loaded with material that simulated copper ore in terms of its density, abrasiveness and particle size distribution.
Multiple digging cycles were then applied for each dipper scale model, with special input/ouput sensory data recording several key performance parameters. In the end, one model stood out amongst the rest for its ability to deliver significant productivity gains.
“That design is now being gainfully applied to copper mines in North America and South America,” Immel said.
The cooper dipper is designed and built with fortified ground engaging tools and amour made necessary by the hardness and abrasiveness of copper ore.
CRCMining lab tests showed average 6% increased payloads, 3.5% faster dig time and 1.4% reduced energy requirements.
The copper dipper features a rounded cutting lip profile that makes possible more efficient gathering-up of hard and abrasive copper ore.
The dipper also features optimised tooth spacing, corner shroud spacing and armoured wear protection.
P&H Mining Equipment