The Study On The Reduction Clinkeruv Absorption Characteristicsin Portland Cement

Thispapermainly study on the reduced clinker of cement production enterprise. This object is mainly to study the differences between the reduced clinker and the normal clinker, and put forward the reduction degree of H to characterize cement clinker reduction degree.By means of use the theory of transition metal "ion-ligand" structure under the excitation of light, electron transition to generate ultraviolet absorption characteristics to analysis of cement clinker of Ferrite,we discovered that, because of trivalent iron salts with ultraviolet absorption properties and make the clinker absorption peak produced in λ=1437nm, due to the existence of the reducing atmosphere make theFe3+reduce in the clinker system, thus the deoxidize clinker of UV absorbance below oxide clinker. This is the main difference of ultraviolet spectrum between the normal clinker and reduced clinker.Synthetic clinker mineral through analytical reagent (Silicate, Aluminate and Ferrite), To measure its ultraviolet absorption spectrum,we find that:Only the Ferrite qualified ultraviolet absorption characteristics and produce absorption peak. This suggests that cement clinker caused by ultraviolet absorption is mainly due to the Ferrite. At the same time, different cooling systems of Ferrite generate ultraviolet absorption,and their ultraviolet absorption is not obvious distinct.In cement clinker system, clinker UV absorbance increases with Fe3+content. Both accords with power function relationship. Their correlation coefficient is0.96. At the same time, Mn4+which havethe similar phase iron salt structure can also result in ultraviolet absorption characteristics, make cement clinker to produce absorption peak. Consequently shows a base "metal-ligand" structure is the main cause of cement clinker to produce ultraviolet absorption.Through burning reduced clinkerat different temperature,we find that:the clinker UV absorbance increase with the oxidation temperature, but in1200-1300℃range, the UV absorbance almost no change. And in1300extended the burning time60min also does not increase the clinker absorbance. Mean while, when clinker is burnedat1300℃, UV absorbance has no obvious increase in5min,but UV absorbance is still increased in11min when the temperature just is1200℃.By using the ultraviolet spectrum to quantitatively analysis the cement clinker of Ferrite shows that:The correlation between the two is better,their related absorption R2=0.970.It’s provides us a direct basis to use the UV absorption spectra of iron phase in cement clinker salt research.Through study of clinker ultraviolet absorption characteristics and the reduced clinker after oxidation treatment, We proposed the evaluation criteria and definition of the reduction degree. Criteria is:by grinding the raw material which burned30min at1300℃,then going through the80μm square hole sieve, taking sample1.0g,compression molding under20MPa, determination of clinker UV absorbance. Define the reduction degree of clinker H as the absorbance difference of reduction material before and after oxidation ΔA dividing after oxidation A.