Can a DC load be used with Solid-state Relays for AC loads?

No, it cannot be used. The element characteristics of Solid-state Relays will not allow it to reset if a DC load is used.

Explanation

Solid-state Relays for AC load switching use thyristors and triacs as output elements. By turning Solid-state Relays input ON, the output can be turned ON, but simply turning the input OFF doesn't mean that the output will be turned OFF. This is because Solid-state Relays have a characteristic that it stays turned ON until the load current becomes zero regardless of the absence of input signals into Solid-state Relays.
The DC current will never become zero, therefore it will not be reset.