Belite-calcium aluminate as an additive
(22) 07.05.2014
(43) 21.04.2016
(57) The present invention relates to the use of a belite calcium aluminate obtainable in a method comprising the following steps:
a) providing a starting material that has a molar Ca/(Si+Al+Fe) ratio from 1.0 to 3.5 and a molar Al/Si ratio from 100 to 0.1,
b) mixing the raw materials,
c) hydrothermal treating of the starting material mixture produced in step b) in an autoclave at a temperature from 100 to 300° C. and a residence time from 0.1 to 24 h, wherein the water/solids ratio is 0.1 to 100,
d) tempering the intermediate product obtained in step c) at 350 to...
(22) 07.05.2014
(43) 21.04.2016
(57) The present invention relates to the use of a belite calcium aluminate obtainable in a method comprising the following steps:
a) providing a starting material that has a molar Ca/(Si+Al+Fe) ratio from 1.0 to 3.5 and a molar Al/Si ratio from 100 to 0.1,
b) mixing the raw materials,
c) hydrothermal treating of the starting material mixture produced in step b) in an autoclave at a temperature from 100 to 300° C. and a residence time from 0.1 to 24 h, wherein the water/solids ratio is 0.1 to 100,
d) tempering the intermediate product obtained in step c) at 350 to 600° C., wherein the heating rate is 10-6000° C./min and the residence time is 0.01-600 min
as an accelerator for Portland cement.
(71) HeidelbergCement AG, Heidelberg (DE)
(73) HeidelbergCement AG, Heidelberg (DE)
