Hi there,

No there is no option for removing the menu icon on mobile view.
Try the following CSS:

@media only screen and (min-width: 1px) and (max-width: 999px){
.slide-out-widget-area-toggle {
    display: none !important;
}
}

add it to salient \ general settings - css script related - custom css code.
If it does not work then give us a link to the actual site we see what we can do.

Thanks.