Norlite lightweight aggregate, in combination with high alumina cements, such as Lumnite or Ciment Fondu, will produce concretes which will withstand temperatures up to approximately 2000 · F.
There are many advantages of using Norlite as a refractory material, including: immediate availability, high thermal insulation, high structural strength, light weight, low expansion and contraction, fuel savings, reduced maintenance and installation costs, ease and speed of new erection or repairs, abrasion resistance, and minimum spalling, even under severe abuse.
Using mix proportions of 1:4 up to 1:6 will obviously vary the strength and weight. For instance a 1:6 mix has significantly lower strength but it also has somewhat lower unit weight. This reduced unit weight provides improved insulating properties. While the insulating properties of Norlite/Lumnite concrete are not as good as could be achieved by using some of the very light lightweight aggregates such as perlite or vermiculite, they combine good strength as well as corrosion and abrasion resistance with their insulating value and are used for lining stacks, ducts and breechings, as well as in and around process vessels in petroleum and petrochemical industries.