Error in the original post, CAPS produced 15.4 million tons, NOT...

Error in the original post, CAPS produced 15.4 million tons, NOT 154 million. They put Romeral on care & maintenance in early 2016 for a couple of months due to low prices.

The CAPS mine at Romeral produced 1.1 million ton in 2015 and 1,5 million in 2014, it is difficult to imagine them "begging for material", especially from an operation that can only deliver 5000/ton a month and failed to meet that on previous orders.
YB was required to supply a total of 10,000 tonnes of iron ore product to CAPS within a prescribed period of 2 months between 23 October 2015 and 23 December 2015. The Company has been advised by the Freehill Investments that as at the date of this Prospectus, CAPS’ order of 10,000 tonnes of iron ore has only been partially fulfilled.
The Romeral cost of production is supposedly $44 /ton so they would presumably only buy outside at less than that price.
In 2015 CAPS bought only 6000 tons externally against a production of 15.4 million tons.
http://www.capmineria.cl/operacione/produccion/
Interestingly Romeral only uses the same amount mining equipment as YB, two front end loaders and a backhoe, but 6 trucks instead of 3. If they can produce 1.5 million tons/year with that, compared, to 28,500 tons at YB, there must be quite some scope for efficiency improvements.
Carguío
La operación de carguío se realiza con dos cargadores frontales y una retroexcavadora. Estos equipos están ubicados en distintos sectores de los acopios y/o Cerro Principal, según sean los requerimientos del plan minero.T
Transporte de Mineral y Estéril
El material es transportado a la Planta de Beneficio y botaderos de estéril, según corresponda, por una flota de 6 camiones.