These may be dried in an atmosphere of dried air or other inert gas, such as nitrogen, and if desired, under sub-atmospheric pressure. [0046] In one embodiment, there is provided a concentrate composition comprising silicon carbide in an amount of at least 0.05 wt. %, preferably at least 2 wt. %, and up to about 35 wt. %, preferably up to 20 wt. % and a thermoplastic polymer normally solid at 25??