you can still use a HDD with "marked" bad sectors, for a while, could be for one day could be 5 years !
In my experience however once you get bad sectors it won't be long till it's dead. They seem to spread, the bad sectors are faults on the surface of the platters.
Scan it again in a couple of days you will prob. have more.
About 10 years ago this was common and accepted but now I would return it and demand an exchange.
This comes under the "not fit for the purpose for which it is intended"