Bi-crystal silicon ingots separated by near coincident site lattice (near-CSL) grain boundaries (GBs), namely Sigma 9 and Sigma 27a, have been grown in a small scale Bridgman-type furnace at 3 mu m/s. Surface observations show different microstructure developments, depending on the nature of the seed GB and initial deviation from the low energy configuration. Grain boundary structure evolution and dislocation emission sources have been assessed for both types of GBs. Topological imperfections forming at the near - Sigma 9 and Sigma 27 GBs during the growth have been found to be the major source of defect generation. These imperfections are the result of the re-arrangement of the GBs during the growth due to the seed GBs deviation from low energy configurations - i.e. Sigma 9{221}(1)/{221}(2) and Sigma 27a{511}(1)/{511}(2). (C) 2014 Elsevier B.V. All rights reserved.