Duangporn Rodphaya, director-general of the Foreign Trade Department, said the department would call for bids on 1.63 million tonnes, 730,000 tonnes of which would be slated for general uses, including a mix of Grade C, which is categorised as substandard quality for industrial use; Grade P, which has received ministry certification; and Grades A and B, meaning in slightly poor condition and in need of sorting for improvement.