RE:RE:AISC ;Smelting and Refining Charges in Q1 AISC on page 21 of MDA are not based on TCs of $300 per ton. They are based on TCs of $159 per ton.
Apart from TCs, Smelting and Refining Charges include freight from the loading port to the receiving smelter. This freight component in Smelting and Refining Charges varies from mine to mine and is very substantial. For example, in case of Perkoa, based on the following analysis, 0.17/lb are the treatment charges and 0.13/lb are the Freight Charges from the loading port to the receiving smelter.
| Perkoa - Q1 2021 | |
| Zn Head Grade | 12.90% |
| Zn Recovery | 87.50% |
| Zinc Concentrate Grade | 50.50% |
| | |
| Tons of ore milled to produce one tonne of zinc concentrate: | 4.47 |
| Zinc Concentrate Grade/(Zinc Head Grade X Zinc Recovery) | |
| | |
| Tons of ore Milled | 206,069 |
| Tons of zinc concentrate produced: (4.47 X 206,069) | 46,059.48 |
| | |
| Tons of Payable Zinc Produced | 19,575.28 |
| 50.5% (Zinc Concentrate Grade) - 8% (Std. Deduction) = 42.8% | |
| Mlbs of Payable Zinc Produced | 43.12 |
| | |
| TCs/Ton of Concentrate | $ 159 |
| TCs for 46,059.48 Ton of Zinc Concentrate Produced | $ 7,323,458 |
| TCs for 38 Mlbs of Payable Zinc Sold | $ 6,454,278 |
| | |
| TCs/lb of Payable Zinc | 0.17 |