Optimization of coal overburden excavation considering variable geomechanical properties and states of excavator teeth

We examine the impact of overburden geomechanical properties on the velocity of the excavator rotary movement Vb and on the excavator current consumption Imax for two different states of excavator teeth: new excavator teeth and worn-out teeth after minimum 250h of work. The analysed dataset is collected from recordings made by the bucket-wheel excavator SchRs 900 25/6 operating at “Tamnava Eastern field” open-pit coal mine in Serbia. The following geomechanical properties of the overburden are examined: grain size composition, unit weight, cohesion and angle of internal friction. Using multiple linear regression analysis, we develop explicit mathematical correlations between Imax and Vb and the overburden properties in a form of nonlinear equations for the case of new excavator teeth, while statistically significant correlation for the worn-out teeth is obtained only between overburden geomechanical properties and Imax. Results obtained indicate the existence of statistically significant two-factor interactions with positive effect of overburden unit weight and angle of internal friction on Imax and Vb, while cohesion is generally inversely proportional to the analysed outputs. Analysis performed enables optimized planning of the excavator performance regarding its productivity during the overburden excavation.

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Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023)