Chinese company buys copper ore, concentrate

Our company is very interested in the copper cargo.
Name of the Product : copper 
（1）copper concentrate ≥ 15%，sulfur≥ 25%
（2）copper ore ≥ 10 %
（3）copper compound≥ 10 %
 Sulfide or oxide both ok 
As<0.5%,Cl<0.5%,Cd<0.05%, Hg<0.01%,Pb+Zn<6%
For the trial order,we only can do TT payment terms as follws：70%  payable against Telex release Bill of Lading（or Original Bill of Lading） and all shipping documents and the payment will base on the result of CCIC/SGS testing report at loading port,and the balance will be paid after testing the goods up to standard at the destination.（this need the product size within 5mm)