Abstract Mixtures of spodumene + Na2SO4 with a mass ratio of 1:0.5 were prepared and milled using either zirconia or metallic media in a planetary ball mill for 5 h. The milled samples were heated in a furnace at temperatures ranging from 800 °C to 1000 °C for one hour under an air atmosphere. X-ray diffraction (XRD) results showed the traces of new phases such as LiNaSO4 and β-spodumene in the produced calcine after isothermal roasting. Increasing temperature resulted in increasing formation of LiNaSO4 and the XRD results were consistent with a thermodynamic assessment of the spodumene-Na2SO4 mixture. The results showed that changing the milling media did not have a significant role in formation of phase(s) during isothermal heating regime. The XRD results revealed that LiNaSO4 was the major phase after heating a 5 h milled mixture of spodumene-Na2SO4 in both metallic and zirconia media at 1000 °C. There were signs of β-spodumene observed in the sample heated at 800 °C however the peaks of this phase were overlapped with LiNaSO4 phase. The dissolution of lithium during leaching in water reached ~92% for the 5 h milled samples after heating at 1000 °C irrespective of milling media used.

中文翻译：

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等温加热后机械活化锂辉石-Na2SO4混合物的相变

摘要 制备质量比为 1:0.5 的锂辉石 + Na2SO4 混合物，并在行星式球磨机中使用氧化锆或金属介质研磨 5 小时。将研磨过的样品在空气气氛下在炉子中在 800°C 至 1000°C 的温度范围内加热一小时。X 射线衍射 (XRD) 结果表明，等温焙烧后生成的煅烧物中存在 LiNaSO4 和 β-锂辉石等新相的痕迹。温度升高导致 LiNaSO4 的形成增加，XRD 结果与锂辉石-Na2SO4 混合物的热力学评估一致。结果表明，在等温加热状态下，改变研磨介质对相的形成没有显着作用。XRD 结果表明，锂辉石-Na2SO4 在金属和氧化锆介质中的研磨混合物在 1000 °C 下加热 5 小时后，LiNaSO4 是主要相。在 800 °C 加热的样品中观察到 β-锂辉石的迹象，但是该相的峰与 LiNaSO4 相重叠。无论使用何种研磨介质，在 1000 °C 下加热 5 小时后，锂在水中浸出过程中的溶解度均达到约 92%。