Utilization of waste glycerin, industry lignin and cane molasses as grinding aids in blended cement

• Waste glycerin (WG), industry lignin (IL) and cane molasses (CM) are used as grinding aids.
• Grinding efficiency of WG, IL and CM on the blended cement are different.
• Performance of blended cement with composite grinding aids are evaluated.

This paper investigates the viability of using waste glycerin (WG), industry lignin (IL) and cane molasses (CM) used as grinding aids in blended cement, performance of the blended cement with single and composite grinding aids were researched. The structure characterization of the grinding aids was carried out by Fourier transform infrared spectroscopy (FT-IR); the particle size distribution, Blaine specific surface area, setting times, water requirement of normal consistency, flexural and compressive strengths at 3 and 28 days of the blended cement were researched, the experiments results indicate that the addition of grinding aids results in an improvement of the fineness and strength of the blended cement. Compared with the cement mixture without grinding aids, waste glycerin has a better optimization effect on the particle size distribution, industry lignin and cane molasses perform a better retarding effect, and enhancement effect of cane molasses on the strength of blended cement is more significant. For the blended cement with composite grinding aids (0.0065% WG, 0.0095% IL, 0.024% CM), the compressive strength at 3 days and 28 days are 2.6 MPa and 10 MPa higher than those of the control cement respectively. The hydration products and microstructure of blended cement with composite grinding aids were analyzed by X-ray diffraction (XRD), thermo-gravimetric and differential scanning calorimetry (TG-DSC) analysis and scanning electron microscopy (SEM), the research shows that for the blended cement, the addition of grinding aids can accelerate the hydration reaction degree and improve the compactness and uniformity of the products structure.