the solubilized lignin and hemicellulose the softwoods that can be used in the pulping process are any of the coniferous species and can include fir douglas fir pine spruce hemlock and larch the present invention provides a method which converts commercial softwood alkali lignin into a form which can be melted and extruded into lignin fibers this method renders the kraft softwood lignin to a form which can not only be melted and thermally extruded but also allows the lignin fiber to be thermally stabilized the thermally stabilized lignin fibers can be carbonized into carbon fibers using conventional techniques the method is characterized by acetylating the kraft softwood lignin such that the acetyl content of the lignin is at least 16 by weight and at the same time the lignin is not cross linked sufficiently to prevent melting in the process the softwood kraft black liquor is filtered to remove extraneous material the ph of the softwood kraft black liquor is approximately 13 treatment with acid lowers the ph and precipitates the lignin the acid can be co 2 or a mineral acid such as hydrochloric acid sulfuric acid or nitric acid the acid treatment can be at ambient or at elevated temperature in one embodiment the lignin precipitation is done at 80 u00b0 c the ph of the black liquor can be lowered to any ph in one embodiment the ph of the black liquor is lowered to ph 8 to precipitate the lignin the precipitate from the acid treatment is separated after coagulation.