Font icon as background-image text-replacement.

icon-bg-text-replacement.scss

.icon-bg {
  width: 32px; /* required for layout, adjust as needed */
  a {
    margin-top: -60%; /* adjust as needed */
    overflow: hidden; /* required for replacement */
    padding-left: 0;
    padding-right: 0;
    position: relative;
    text-indent: 100%;
    &:after {
      content: '\f099'; /* change as necessary */
      position: absolute;
      text-align: center;
      text-indent: 0; /* part of the magic */
      color: inherit;
      line-height: 1;
      font-family: 'FontAwesome';
    }
  }
}