Requesting used rail iron materials (R50/R65) 50,000 MT

My company deals with scrap metal and we do export to many countries across the world. Currently we have one client with the following requirements.
COMMODITY: Used Rail Iron Materials (R50/R65)
*QUANTITY: 50,000MT as trial, 200,000MT/monthly x 12months or more
*ORIGIN: No limited
*DESTINATION: Any port in China
*SHIPPING: CIF
*PAYMENT: LC at sight
*OTHERS: To be negotiated
Kindly let me know what quantities you can supply and at what price CIF China. 

Thank you