Na2CO3 effect on high-strength lightweight ceramsite prepared from demagnesium boron mud and oil shale semi-coke

High-strength ceramsite was prepared by using demagnesium boron mud and oil shale (OS) semi-coke as the main raw materials, Na(2)CO(3 )as binder, and Na2CO3 as foaming agent. In the ceramsite with a 1:1 ratio of demagnesium boron mud and OS semi-coke, 3% Na2CO3, and 10% Na2CO3 sintered at 1070 degrees C, the porosity, apparent density, and compressive strength reached 22.63%, 1398.33 kg/m(3) and 11.50 MPa, respectively. Na2CO3 played a decisive role in the sintering of high-strength ceramsite. Thermogravimetric analysis and X-ray diffraction results showed that the gas produced by raw meal during the heating process reduced the apparent density of ceramsite, and that new minerals such as albite and forsterite were produced during the firing process. The forsterite formed islands within an albite framework, thereby strengthening the ceramsite.