Two-layer conveying elbow with a highly wear-resistant cast sleeve as inner elbow and a pressure-bearing outer elbow. Inlet and outlet protected by CCI Big Mouth collars. The wear layer has a hardness of 67 HRC. The elbow has a reinforced back against impact wear. It is installed as a so-called IMPACT ELBOW in the last mast joint, with longer masts in the last and also penultimate mast joint.