Is it possible to create a, I dunno, grenade that makes a small blackhole?

Not a grenade; It was thought the LHC may create 'micro black holes' - which would only last a tiny fraction of time before they evaporated; to my knowledge, none have been detected... And, the LHC is miles in diameter - not exactly an object you can carry into battle.

There is no such thing as a small black hole. Black holes have to begin as a massive object with tremendous gravity. A small black hole would never come into existence because of the lack of mass and the gravity associated with the mass. As far as any exploding device, grenade or any other device that explodes rapidly, the answer is no.

Only in Borderlands.

Several H bombs exploding at exactly the same time perhaps, but small black holes evaporate in much less than a second.

No - a black hole of any size would be billion of tonnes in mass, so not a very effective weapon.

If it is possible to lobby a small hand held thermonuclear device across the hotel lobby and live then it makes sense.

No. Not only is there no known technology that could accomplish that, a black hole of so little mass would evaporate almost instantaneously. You would get something like a very large nuclear explosion instead.

no.

The LHC at CERN Switzerland tries to do that, and has failed, and IT is secverl MILES wide.

Simply no.

Black holes are produced by implosions (viz. the compression of matter).concurrent with the explosion of a star.

No, sorry. Not possible.

do YOU know how to do that? - NEVER EVEN SAW THAT IN SCIENCE FICTION STORY

Whe I was in the Army, I threw one in a cave n made one!!!