Horizontally centered column in flex block

[dmitriy-8gears]

Hello! I'm having trouble making a horizontally centered icon column. When I set both classes (uk-flex-center and uk-flex-column), alignment stops working, but when I remove column class, alignment takes effect. I set icons with method from documentation and also tried to use Font Awesome icons - result the same. I don't know is it bug or something, so I start discussion. Any ideas?