Burner apparatus and methods for making inorganic fibers

Inorganic fiber production burner apparatus and methods of use are disclosed. One burner includes a refractory block adapted to be in fluid connection with sources of primary oxidant and fuel, the refractory block having a fuel and primary oxidant entrance end and a flame exit end, the flame exit end having a substantially rectangular flame exit having a width greater than its height, the refractory block defining a combustion chamber and a second chamber fluidly connecting the combustion chamber and the flame exit end; and an oxygen manifold fluidly connected to the combustion chamber and adapted to route oxygen to the combustion chamber through a plurality of passages through the refractory block.