Rapid hardening, ultra-high early strength portland-type cement compositions, novel clinkers and methods for their manufacture which reduce harmful gaseous emissions

Abstract

Clinkered materials containing high concentrations of {(C,K,N,M)4 (A,F,Mn,P,T,S)3 Cl,{overscore (S)})}(crystal X), and {C2S)3 (C{overscore (S)})3Ca(f,Cl)2} or C9S3{overscore (S)}3Ca(f,cl)2 (crystal Y), and/or {C5S2{overscore (S)}) (crystal Z) directly from the kiln, rapidly hardening ultra-high early strength cement including these clinkered materials, methods for forming and using said compositions and the cements so produced are claimed. The methods include the steps of forming a mixture of raw material containing CaO, MgO, Al2O3, Fe2O3, TiO2, Mn2O5, SiO2, SO3, Na2O, K2O, P2O5 and F, respectively designated C, M, A, F, T, Mn, S, {overscore (S)}, N, K, P and f, and heating said mixture to an elevated temperature between 900° C. and 1,200° C.; before determining average amount of crystals X, Y, and Z. Final mixtures comprising these clinkers and hydraulic or portland type cement are made to produce cement compositions having crystal X concentrations of approximately 5% to 35% by weight, crystal Y concentrations of approximately 5% to 40% by weight, and/or crystal Z concentrations of approximately 5% to 40% by weight, with the remainder being hydraulic or portland type cement. The cements so produced are rapid hardening and exhibit high strengths ranging from 2,000 psi to 7,000 psi in one hour, 6,000 to 8,000 psi in one day and 9,000 to 12,000 psi in 28 days. They are sulfate and seawater attack resistant and have low heats of hydration, minimal shrinkage, and high water impermeability. The methods claimed also results in significant reduction in gaseous emissions including SOx, NOx and COx.

Dependencies are inferred from the claim text.