A separation apparatus for removing particulate material from a flash zone gas oil stream produced in a delayed coking unit. The apparatus of the invention employs cyclonic separation to remove particulate material from the flash zone gas oil stream. The stream can then be further processed, for example by passing the stream to a fixed bed catalytic hydroprocessing unit and then to a fluidized bed catalytic cracking unit, or to other processing units, thereby enhancing the value of the flash zone gas oil stream.