Abstract The present invention is an improved one of U.S. Pat. No. 3,782,992 and relates to a process for regulating setting time of hydraulic cement which comprises clinker containing 5 - 60 percent by weight of 11CaO.7Al2O3.CaX2, more than 5 percent by weight of 3CaO. SiO2, anad further 2CaO.SiO2 solid solution and 4CaO.Al2O3.Fe2O3; anhydrite with or without hemihydrate; at least one selected from the group consisting of sugars, sodium hydrogen carbonate, water-soluble phosphates, carboxylic acids, silicofluroides, sodium silicates, ligninsulfonate, sulfuric esters of higher alcohol and alkylsulfonates, whereby the anhydrite is contained in an amount that Al2O3/SO3 weight ratio of Al2O3 in the clinker and SO3 in the anhydrite is 0.7 - 1.8 and hemihydrate is contained less than 5 percent by weight based on SO3.
A process claimed in claim 1, wherein the cement comprises anhydrite and hemihydrate.
Claim 2
Dependent Claim
18 words
A process claimed in claim 2, wherein the cement comprises less than 5 percent by weight of hemihydrate.
Claim 3
Dependent Claim
27 words
A process claimed in claim 1, wherein the cement comprises 0.01 - 1.00 percent by weight of at least one member selected from oxyacids and dicarboxylic acids.
Claim 4
Dependent Claim
79 words
A hydraulic cement composition, consisting essentially of: 5 - 60 weight percent of 11 CaO.7Al2O3.CaX2, wherein X represents a halogen atom, more than 5 weight percent of 3 CaO.SiO2 solid solution and further 2 CaO.SiO2 solid solution and 4 CaO.Al2O3.Fe2O3; anhydrite; and 0.01 - 1.0 weight percent of a carboxylic acid, wherein the anhydrite is contained in an amount such that the Al2O3/SO3 weight ratio of Al2O3 in the clinker and SO3 in the anhydrite is 0.07 - 1.8.
Claim 5
Dependent Claim
17 words
A hydraulic cement composition as described in claim 5, wherein the cement composition comprises anhydrite and hemihydrate.
Claim 6
Dependent Claim
21 words
a hydraulic cement composition as described in claim 6, wherein the cement composition comprises hemihydrate less than 5 percent by weight.