Abstract: A buttress (52) for buttressing an axial end (34) of a partition (36) in a multiple-chamber heat exchanger (28) comprises an integral solid cast from a refractory material. A thick axial end (55) of the solid is provided for compressive engagement with an end (34) of the partition (36). A thin axial end (56) opposite the thick end (55) is provided for compressive engagement to a kiln shell liner (54). A radially outer surface (77) engages an inner surface (14) of the kiln shell (12). A radially inner surface (58) of the buttress (52) slopes generally from the thick end (55) to the thin end (56), such that compressive force exerted on the thick end by the partition (36) is transmitted through the buttress (50) to a liner (54) of the kiln shell (12).