<link href="//maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet">

#page-loading {
    width: 100%;
    height: 100%;   
    left: 0px;
    position: fixed;
    display: table;
    background-color: rgba(0, 0, 0, 0.2);
    z-index: 9999;
    text-align: center;
    cursor: wait;
}
 
#page-loading i{     
    vertical-align: middle;
    text-align: center;
    display: inline-block;
    font-size: 225px;
    color:#fff;
}
#page-loading h2{
    color: #fff;
}

<div id="page-loading">
    <p style="margin-top: 15%;">&nbsp;</p>
    <i class="fa fa-spinner fa-5x fa-spin fa-fw"></i>
    <h2>처리 중입니다.</h2>   
</div>

https://coding-factory.tistory.com/192