Una mena es un mineral del que se puede extraer un elemento, un metal generalmente, por contenerlo en cantidad suficiente para ser aprovechado. Así, se dice que un mineral es mena de un metal cuando mediante minería es posible extraer ese mineral de un yacimiento y luego mediante metalurgia obtener el metal de ese mineral.

Asociado al concepto de mena, está el de ganga. Es el conjunto de minerales que, en un yacimiento, se encuentra en la roca explotada junto a la mena. La ganga hace que la ley del metal disminuya, por lo que es necesario separarla de la mena, como primera etapa en la concentración

Las menas suelen ser óxidos, sulfuros o silicatos.
Menas importantes

Argentita: Ag2S para la obtención de plata
Barita: BaSO4
Bauxita Al2O3 para la obtención de aluminio
Berilo: Be3Al2(SiO3)6
https://www.quimica.es/enciclopedia/Mena_(minería).html
https://es.wikipedia.org/wiki/Mena_(minería)
https://es.wikipedia.org/wiki/Ganga_(minería)



--------------------------------------------------
Note added at 34 mins (2021-05-05 15:34:25 GMT)
--------------------------------------------------

Ore, gangue, ore minerals, gangue minerals
In most cases, an ore does not consist entirely of a single ore mineral but it is mixed with other valuable minerals and with unwanted or valueless rocks and minerals. The part of an ore that is not economically desirable and that can not be avoided in mining is known as gangue.[1][2] The valuable ore minerals are separated from the gangue minerals by froth flotation, gravity concentration, and other operations known collectively as mineral processing, or ore dressing.
https://en.wikipedia.org/wiki/Ore



--------------------------------------------------
Note added at 6 hrs (2021-05-05 21:35:08 GMT)
--------------------------------------------------

https://www.proz.com/kudoz/english-to-spanish/tech-engineeri...

https://www.proz.com/kudoz/spanish-to-english/engineering-ge...

https://www.proz.com/kudoz/english-to-spanish/geography/2035...

Ore, a natural aggregation of one or more minerals that can be mined, processed, and sold at a profit. An older definition restricted usage of the word ore to metallic mineral deposits, but the term has expanded in some instances to include nonmetallics
Although more than 2,800 mineral species have been identified, only about 100 are considered ore minerals. Among these are hematite, magnetite, limonite, and siderite, which are the principal sources of iron; chalcopyrite, bornite, and chalcocite, the principal sources of copper; and sphalerite and galena, the principal sources, respectively, of zinc and lead. Copper,
molybdenum, and gold are commonly found in disseminated deposits—i.e., scattered more or less uniformly through a large volume of rock……

The ore is always mixed with unwanted or valueless rocks and minerals that are collectively known as gangue. Generally, the ore and the gangue are mined together—i.e., taken out of the host rock in a mass by either mechanical or manual means. Then the ore is separated from the gangue by various operations known collectively as mineral processing, or ore dressing. The desired metallic element is then extracted from the ore by various smelting, roasting, or leaching processes.
https://www.britannica.com/science/ore-mining