Actually, the Large Hadron Collider near Geneva (at CERN, the last of the super accelerators), plans on delivering a regular stream of micro black holes if current models are true.

According to Stephen Hawking's findings on the thermodynamics of black hole, they are not black at all. They radiate, and the smaller they are, the hotter and more intense the radiation. So if they are small enough and not fed fast enough, black holes actually explode.

At some point, the "Gamma Ray Bursts" from deep space where shown as evidence that primitive black holes (born from density variations at the big bang), would blast back their mass-energy from time to time. It turned out that super-super-novae are an easier explanation.

Back to the LHC black holes: they cannot explode with more power than what you put in creating them (not much by macroscopic standards), and their lifetime is so short that they have no time to exit the detector at beam collision point.

Even if one were to move a bit further on, its diameter is so small (and its absolute weight to) that its efficient collision diameter with matter would be nil: it would fly through matter, between electron and nucleus, with a gravity pull far below the electromagnetic force that binds them into atoms. So it couldn't eat any, and would not be able to compensate for mass lost in radiation. Eventually, it will still explode after a shord dash.

Pierre