Dry material mixture for a backfill, preferably a refractory concrete backfill, for producing a heavy-clay refractory non-basic product, refractory concrete backfill and such a product, method for producing same, lining, and industrial furnace, channel transport system or mobile transport vessel

A dry substance mixture for a batch, preferably a refractory concrete batch, for the production of a coarse ceramic, refractory, unfired, shaped or unshaped, non-basic product, in particular for a working casing or a backing of a large-volume industrial furnace of the aluminum industry or for a working casing of a launder transport system or a mobile transport vessel of the aluminum industry for the transport of liquid aluminum or a liquid aluminum alloy, the dry substance mixture comprising:

• a) coarse- and fine-grained aggregate of at least one refractory, non-basic aggregate material with a grain size >200 μm, preferably in a total amount of 45 to 80 ma. %, preferably 50 to 60 ma. %,
• b) meal-grained aggregate of at least one refractory, non-basic aggregate with a grain size ≤200 μm, preferably in a total amount of 15 to 50 ma. %, preferably 25 to 40 ma. %, wherein the meal-grained aggregate comprise an Al2O3 granular material,
• c) at least one anti-corrosion agent to improve corrosion resistance to molten aluminum, and
• d) optionally at least one dry binder,
• wherein the anticorrosive agent comprises at least one first dry, mealy phosphate having a softening point, determined by heating microscopy according to DIN ISO 540:2008, of 600 to 1400° C., preferably 800 to 1300° C., and at least a second dry, mealy phosphate having a softening point, determined by heating microscopy according to DIN ISO 540:2008, of >1600° C., the two phosphates each having a solubility in water at 20° C. according to DIN EN 15216:2008-1 of <50 g/l, preferably <30 g/l, more preferably <20 g/l, and
• wherein the at least one first phosphate is calcium dihydrogen phosphate (Ca(H2PO4)2), magnesium dihydrogen phosphate (Mg(H2PO4)2), calcium hydrogen phosphate (CaHPO4) or magnesium hydrogen phosphate (MgHPO4) or calcium hydrogen phosphate dihydrate (CaHPO4·2 H2O) or magnesium hydrogen phosphate trihydrate (MgHPO4·3 H2O), preferably calcium hydrogen phosphate (CaHPO4), and
• wherein the at least one second phosphate is aluminum phosphate (AlPO4).