He is signed as cover for the injured Andy Butler, who is out for up to two months with an ankle injury.
Iron boss Brian Laws said: "We've just got to complete all the paperwork now, but that should all be done in time to include Richard in the squad for Saturday.
"His versatility will be vital to us at a crucial time. He can play at centre-half, right-back and midfield.
"Hull will be able to recall him if they need to, but there's also the possibility, depending on how he performs, that we can make the move permanent.'"