Abstract: A regenerative heat exchange system comprises a multiplicity of refractory members laid in adjacent parallel rows to form one course in the system, each refractory member being so shaped such that the adjacent refractory members of one row co-operate to form a gas passageway or duct through that first course, the refractory members of an adjacent course being similarly arranged in parallel rows with the refractory members turned through 90.degree. with respect to the refractory members of the first row and being offset therefrom, the adjacent members in each row in the second course again cooperating to form a gas passageway or duct through the adjacent course, each gas passageway or duct in the adjacent course constituting a continuation of a respective gas passageway or duct in the said one course.

Abstract: A solid-solid bonded basic refractory having a chemical composition (calculated as the oxides) consisting essentially of MgO in the amount 25% to 97% by weight, CaO 0.9% to 44% by weight, ZrO.sub.2 2% to 57% by weight, and SiO.sub.2 0.5% to 23.5% by weight, the said basic refractory containing a silicate and an alkaline earth metal zirconate, the CaO/SiO.sub.2 ratio being greater than 1.4, there being at least one part by weight of said alkaline earth metal zirconate for each three parts by weight of said silicate, and the CaO to SiO.sub.2 + ZrO.sub.2 ratio being between 0.32 and 1.40, said alkaline earth metal zirconate being capable of co-existing with any basic solid refractory phase at a temperature of at least 1700.degree. C in which solid-solid bonding is maintained between said zirconate and said solid refractory phase in the presence of a liquid phase at a temperature of at least 1700.degree.

Abstract: A lance for injecting fluid materials into molten metal comprising a length of metal tube having anchors secured to the outer surface of the tube and projecting from the tube, the anchors being spaced in the longitudinal and circumferential directions, and supplementary anchors suitably secured to the tube between the first anchors, there being applied over a major portion of the length of the tube a refractory coating, which refractory coating is held to the tube by the first anchors and the supplementary anchors.