If the SD Card on your Android device can be removed without turning off your phone, it is better to unmount it for a safely remove. To safely remove SD card from Android devices, do as follows
1. Open "Settings" and go to "Storage"
2. Tap "Unmount SD Card"
3. Some apps may stop functioning properly. Tap "Mount SD Card" to use the SD Card again
Note that, we used a Samsung Galaxy device to write this tip, and on other Android devices the path may vary a little