An oxy-fuel burner including a central burner element having a central conduit terminating in a central nozzle and an annular conduit terminating in an annular nozzle surrounding the central conduit, the central conduit flowing a first reactant and the annular conduit flowing a second reactant; a first staging conduit spaced apart from a side of the central burner element and terminating in a first staging nozzle; a second staging conduit spaced apart from an opposite side the central burner element and terminating in a second staging nozzle; a first mechanism to apportion a flow of the second reactant into a non-zero primary flow of the second reactant directed to the annular conduit and a non-zero secondary flow of the second reactant; and a second mechanism to selectively apportion the secondary flow of the second reactant between the staging conduits; wherein one reactant is fuel and the other reactant is oxygen.