Effect of water‐soluble magnesium lactate on the volume stability of refractory castables containing calcium aluminate cement

Abstract

A kind of organic magnesium salt, water-soluble magnesium lactate, was used as the MgO-precursor in new forms to identify the particular impact of additive dispersity on properties of calcium aluminate cement (CAC)-bonded castables, especially the volume stability. Magnesium lactate could dissolve in water in the mixing process, distribute uniformly, and decompose during heating, providing space for counterbalancing the expansion from in-situ calcium aluminates and MgAl 2 O 4 spinel generation. Hence, in this study, CAC-bonded castables containing 0-1.2 wt% magnesium lactate were prepared. The volume stability and thermo-mechanical strength of castables were tested. Results show that the dissolution of magnesium lactate in water distinctly enhances the volume stability of castables. To understand the underlying mechanism of water-soluble magnesium lactate on the samples, phase compositions and microstructure development of castable matrices were examined.

Particle grading effect on properties of reactive MgO‐bonded castables

“…Refractory castables encompass a broad range of materials that have undergone significant advancements, [1][2][3][4] leading to intricate and technically advanced formulations aimed at fulfilling highly demanding and rigorous industrial applications at elevated temperatures. [5][6][7][8][9][10] The primary features of castables consist of a well-chosen combination of raw materials, including aggregates, fillers, binders, and admixtures, [11][12][13][14][15][16][17][18] which leads to a deliberately designed particle gradation affecting the flowability and density of the mixture, [19][20][21][22][23][24][25] alongside the binder that influences both the green mechanical strength and the high-temperature properties, including phase evolutions. 6,[26][27][28] More recently, reactive MgO (RM) is considered as hydraulic binder to prepare castables with superior properties and performance.…”