Effect of phosphor on the formation of alite-rich Portland clinker

The anions HPO4(3-), F-, SO4(2-) and their composition were mixed with some industrial waste into the raw meals of alite -rich рortland clinkers(ARPC). The effects of the anions and the waste on the burnabilities of the raw meals, properties of the clinkers and polymorphisms of the alite were studied. And volatilities of the anions in sintering progress were also investigated. The burnability could be improved whether HPO4(3-) was added solely or with F-, F-/SO4(2-) synchronously into raw meals of ARPC. The burnability could be improved remarkably when HPO4(3-), F(-) and the industrial waste were added synchronously in the raw meals. The strengths were heightened when the clinkers were doped with HPO4(3-) or HPO4(3-)/ F(-). And the strengths of the clinkers were further heightened if the raw meals were added HPO4(3-), F(-) and the industrial waste together. The reasons are that the content of alite was increased in the ARPC and the symmetries of the alites changed. The symmetries were heightened when the alites in the ARPC doped HPO4(3-), F(-). The polymorph of the alite extracted from normal clinker was monoclinic (M3) form. The alite extracted from ARPC doped phosphorus and fluorine was rhombohedral(R) form. In ARPC phosphor was mainly dissolved into alite. The concentration of phosphor was about twice more in the alite than in the matrix. The volatilities of the anions can be expressed in the following decreasing order: SO3> F->P2O5.

Author: Zongfu Guan, Yimin Chen, Shouwan Qin, Suihua Guo

Section: Science and production

Keywords: alite-rich Portland clinker (ARPC); phosphates; industrial waste; properties