2.2.1. X-Ray Diffraction Analysis

X-ray diffraction (XRD) analysis was performed with the Rigaku SmartLab X-ray diffractometer (Rigaku, Tokyo, Japan) in the Korea Institute of Geoscience and Material Resources. Cu-Kα radiation was used with a tube voltage of 40 kV and a current of 30 mA. The scan range was 3–90◦ (2θ) with an interval of 0.02◦.

## 2.2.2. BET (Brunauer-Emmett-Teller) Specific Surface Area Analysis

The specific surface area of the talc sample was measured using the specific surface area analyzer (Micromeritics ASAP-2420, Norcross, GA, USA) in the Jeonju Center of Korea Basic Science Institute. Before the experiment, the adsorbed water on the talc particle surface was removed at 300 ◦C for 2 h, and then the BET method involving nitrogen adsorption method at 77 K was used.
