Custom smelters are offering a service to the mining companies by converting copper concentrates with a copper content of typically 20-25% to copper cathodes.
TCs are charged in US$ per tonne of concentrate smelted. RCs are charged for refining copper anodes to produce copper cathodes by electrolysis. This charge is expressed in ct/lb and refers to the amount of copper in the concentrate.
TCs and RCs are very volatile and can change from year to year as well as within a year. Díaz-Borrego provides a table of historic TC/RCs for the period of 2004 - 2017:
Year | TC (US$/ton) | RC (ct/lb) | Year | TC (US$/ton) | RC (ct/lb) |
2004 | 45 | 4,5 | 2011 | 56 | 5,6 |
2005 | 85 | 8,5 | 2012 | 63,5 | 6,4 |
2006 | 95 | 9,5 | 2013 | 70 | 7,0 |
2007 | 60 | 6,0 | 2014 | 92 | 9,2 |
2008 | 45 | 4,5 | 2015 | 107 | 10,7 |
2009 | 75 | 7,5 | 2016 | 97,35 | 9,7 |
2010 | 46,5 | 4,7 | 2017 | 92,5 | 9,3 |
TC/RCs provide part of the revenue of a smelter. E.g. the table below gives an indicative calculation for revenue per tonne of copper for various TC/RC levels and levels of concentration:
Level of concentration | ||||
TC ($/tonne) | RC (c$/lb) |
20% | 25% | 30% |
45 | 4,5 | 324 | 279 | 249 |
55 | 5,5 | 396 | 341 | 305 |
65 | 6,5 | 468 | 403 | 360 |
75 | 7,5 | 540 | 465 | 415 |
85 | 8,5 | 612 | 527 | 471 |
95 | 9,5 | 684 | 589 | 526 |
105 | 10,5 | 756 | 651 | 581 |
Smelters can have other sources of revenue besides TC/RCs:
- Sulfuric acid, although normally, the costs for sulfur fixation in sulfuric acid are higher than the credit for sulfuric acid.
- Free metal, such as additional copper, gold and silver extracted from the concentrate above the amounts estimated.
- Penalties related to the amount of deleterious elements in the concentrate (mercury, arsenic, bismuth, lead tellurium, selenium, antimony, fluoride) above a certain accepted level.
- Innovative revenue streams include the valorisation of residual heat from operations [3] or the use of iron-silicate slags in civil engineering and construction projects.
Langner provides an example of a revenue distribution for a particular smelter. This breakdown is based on assumptions related to concentrate composition, TC/RC, commodity prices and process efficiencies. Such breakdown will vary significantly per smelter as well as with time. In particular, the proportion of TC/RCs in total revenue may be much higher in some cases, as TC/RCs may vary from year to year as well as within a year.
Other breakdowns of smelter revenues are given by Boliden in references, showing TC/RC revenue representing 33 - 54% ot total revenue.
Considering this volatility of revenues and rising energy and climate costs, running a smelter/refiner operation requires skill, prudence and a long-term vision.
References
- Díaz-Borrego, Francisco J., María del Mar Miras-Rodríguez, and Bernabé Escobar-Pérez. 2019. “Looking for Accurate Forecasting of Copper TC/RC Benchmark Levels.” Complexity 2019 (April). https://doi.org/10.1155/2019/8523748. Accessed July 27, 2021
- Langner, Bernd E. 2011. Understanding Copper: Technologies, Markets, Business. Page 168. Accessed July 27, 2021.
- Industrial Heat - A Climate Alliance of Aurubis and enercity. Accessed August 18, 2023.
- See page 46 of Boliden 2021. Accessed August 26, 2024.
-----
Last update: August 26, 2024.
-----
Comments
0 comments
Article is closed for comments.