Abstract:

This study is the first to employ lithium slag to partially replace mineral aggregates in inorganic artificial stone and carry out the design of compact packing grading based on the compressible packing model (CPM model) to investigate its effects on the compressive strength, flexural strength, density, water absorption and shrinkage properties of inorganic artificial stone. The results show that compared with the whole quartz sand group without aggregate grading and the lithium slag partially replacing quartz sand group, the compressive strength at 28 d increased by 13.7% and 24.1%, and the flexural strength in 28 d increased by 27.3% and 36.2%, respectively, mainly because the aggregate gradation improved the compactness of the artificial stone structure. The pore structure test of the mercury intrusion method showed that the porosity of the former decreased by 40.88% and 47.19%, respectively, and the pore structure test of BSE image statistical analysis showed that the mesoscopic porosity of the former was reduced by 58.1% and 60.9%, respectively, so that the density of the former increased by 4.8% and 5.3%, and the water absorption decreased by 62.9% and 64.5%, respectively. Since lithium slag contains the expansion component CaSO₄, which can reduce the shrinkage and deformation of artificial stone, the 28 d drying shrinkage value of the lithium slag partially substituting quartz sand group is 5.0% lower than that of the whole quartz sand group, and the 28 d drying shrinkage of the lithium slag partially replacing quartz sand group after aggregate gradation is further reduced by 8.5%. The use of lithium slag in artificial stone aggregates expands its resource utilization methods, and provides a new method for the design of artificial stone mix ratio based on the CPM model aggregate gradation design.

Key words: lithium slag, inorganic artificial stone, Compressible Packing Model, aggregate grading