Calorimetry in the studies of by-pass cement kiln dust as an additive to the calcium aluminate cement

Abstract

The studies focused on the kinetics of early hydration in the high-calcium aluminate cement (CAC 70)-bypass cement kiln dusts (BPCKD)-mixtures. For this purpose, the mixtures of cement with this additive or with some potential constituents of dusts were produced. The microcalorimeter was applied to follow the kinetics of hydration. The investigations with the aim of finding the relationship between the components of initial mixtures and the modification of hydration process were carried out. The rheological properties were characterized, and the chemical shrinkage characteristics were produced. The phase assemblage characterization and microscopic observations were done as well. In case of the high-calcium aluminatebased binders, the modification of setting process was observed; the rheological properties and chemical shrinkage were affected too. The acceleration of heat evolution-the shortening of so-called induction period in the presence of BPCKD additive-was observed. The results were compared to those obtained for the CAC with ordinary Portland cement additive. The results of calorimetric measurements are discussed in terms of the chemical and phase assemblage of this additive as compared to the Portland cement clinker precursors and potassium chloride-the solid and liquid components of the dust.

Properties of a Three-Component Mineral Road Binder for Deep-Cold Recycling Technology

“…To counteract this effect and make the mixture more flexible, an appropriate amount of bituminous binder is added [7]. The stiffness of the layer can also be reduced by replacing cement with supplementary cementing materials (SCMs), such as hydrated lime, and with byproducts of the cement manufacturing process, such as cement kiln dust (CKD) and cement bypass dust (CBPD) [8][9][10][11][12][13][14][15].…”

“…There is a strong body of research exploring alternatives to CBPD utilization [8,11,14,16]. One of important research directions is soil stabilization [13,16,17,25].…”

“…Stiffness reduction with CBPD is associated with strength lowering, as the CBPD provides a weaker skeleton despite its binding properties [9,12,13]. The ability of CBPD to swell while setting is an interesting property [9,11,12] that balances the shrinkage of Portland cement and hydrated lime at the setting stage. By mixing these three binders, setting-related volume changes can be controlled.…”

The influence of cement kiln by-pass dust addition on the properties of Portland and slag cement

“…Skład chemiczny pyłu z bocznikowania gazów z pieca cementowych wykazuje różnice w stosunku do składu chemicznego mączki surowcowej, stanowiącej nadawę surowcową pieca do produkcji klinkieru portlandzkiego (4)(5)(6)(7)(8)(9). Różnice te dotyczą przede wszystkim zawartości jonów chlorowych, która w pyle zmienia się w granicach od 2 do nawet 20 % masowych (6,7,10). W przypadku mączki surowcowej chlor jest składnikiem marginalnym.…”

Pyro processing cement kiln bypass dust: Enhancing clinker phase formation

“…The recycling of CBPD Is interesting due to its the negative effects on human health and ecotoxicity [4,5]. Research on the valorisation of CBPD has focused on using it as an additive to cement [6], for backfilling excavations [7], for sand and soil stabilization [8,9], to activate slags in cement blends [10], for the manufacture of vitrified sewer pipes [11]; or, thermally treated along with other material to produce glass/ceramic for sustainable disposal [12] or pozzolanic cementitious material [13]. The production of cement clinker from CBPD has not been previously studied and will be explored in this work.…”