A series of sodium aluminosilicates (Na_2-xAl_2-xSi_xO₄, x = 0.85, 0.55, 0.45, 0.35, 0.25 and 0.05) can be generated in the soda sintering process, some of which can be dissolved in sodium aluminate solution. This paper focuses on the transformation of aluminum-bearing minerals into Na_2-xAl_2-xSi_xO₄ during the calcination of diasporic bauxite with different proportions of Na₂CO₃ at 400–1100 °C. Based on thermodynamic analysis, the thermal behaviors, phase transformations and bonding changes of the aluminum-bearing minerals are investigated using thermogravimetric analysis and differential scanning calorimetric (TGA-DSC), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) techniques. In addition, the dissolution performances of some Na_2-xAl_2-xSi_xO₄ are verified by water leaching. The results demonstrate that the aluminum-bearing minerals in diasporic bauxite are diaspore and kaolinite, which are converted into Na_2-xAl_2-xSi_xO₄ after calcination with Na₂CO₃ at 700–1100 °C. Increasing the calcination temperature in the range of 700–1000 °C and the proportion of Na₂CO₃ results in Na_2-xAl_2-xSi_xO₄ having lower x value and decomposing into NaAlO₂ and Na₂SiO₃ if Na₂CO₃ is present in excess. As the mass ratio of bauxite to Na₂CO₃ is 1, Na_1.95Al_1.95Si_0.05O₄ is primarily formed at 900–1000 °C, which has excellent dissolution performance, close to that of NaAlO₂. Upon further increasing the calcination temperature to 1100 °C, Na_1.95Al_1.95Si_0.05O₄ transforms into Na_2-xAl_2-xSi_xO₄ with a higher x value, which has worse dissolution performance.

碱烧结过程中可生成一系列硅铝酸钠（Na _2-x Al _2-x Si _x O ₄，x=0.85、0.55、0.45、0.35、0.25和0.05），其中部分可溶于钠中铝酸盐溶液。_{本文重点研究了不同Na 2} CO ₃比例的硬铝石铝土矿在煅烧过程中含铝矿物向Na _2-x Al _2-x Si _x O _{4的转化。}在 400–1100 °C。在热力学分析的基础上，采用热重分析和差示扫描量热法（TGA-DSC）、X射线衍射（XRD）和傅里叶变换红外光谱（FT-红外）技术。此外，通过水浸验证了一些Na _2-x Al _2-x Si _x O _{4的溶解性能。}结果表明，水硬铝石中的含铝矿物为水铝石和高岭石，经Na ₂ CO煅烧后转化为Na _2-x Al _2-x Si _x O _{4 。3}在 700–1100 °C。在700-1000℃范围内提高煅烧温度和Na ₂ CO ₃的比例导致Na _2-x Al _2-x Si _x O ₄具有较低的x值并分解为NaAlO ₂和Na ₂ SiO ₃如果Na ₂ CO ₃过量存在。由于铝土矿与Na ₂ CO ₃的质量比为1，Na _1.95 Al _1.95 Si _0.05 O ₄主要在900-1000℃形成，具有优良的溶解性能，接近于NaAlO ₂。进一步提高煅烧温度至1100℃，Na _1.95 Al _1.95 Si _0.05 O ₄转变为具有更高x值的Na _2-x Al _2-x Si _x O _{4 ，溶解性能更差。}