Mineral Resources and their subsequent conversion to Ore Reserves are of key importance to mining companies. Their reliable estimation is critical to both the confidence in a feasibility study, and also to the day-to-day operation of a mine. Together with sampling, assaying, geological and other errors introduced during interpretation and estimation, additional errors are likely to be introduced during the application of technical and economic parameters used for conversion of resources to reserves. There is thus a requirement for high-quality interpretation and estimation to be supported by high-quality data.

Petrology, from the Greek words petra , meaning rock, and logos, meaning knowledge, is the study of rocks and the conditions in which they form. It includes igneous, metamorphic, and sedimentary petrology.

To produce materials from mine to market it is necessary to overcome obstacles that include the force of gravity, the strength of molecular bonds, and technological inefficiencies. These challenges are met by the application of energy to accomplish the work that includes the direct use of electricity, fossil fuel, and manual labor. The tables and analyses presented in this study contain estimates of electricity consumption for the mining and processing of ores, concentrates, intermediate products, and industrial and refined metallic commodities on a kilowatt-hour (kWh) per unit basis, primarily the metric ton (ton) or troy ounce. Data contained in tables pertaining to specific currently operating facilities are static, as the amount of electricity consumed to process or produce a unit of material changes over time for a great number of reasons. Estimates were developed from diverse sources that included feasibility studies, company-produced annual and sustainability reports, conference proceedings, discussions with government and industry experts, journal articles, reference texts, and studies by nongovernmental organizations (NGOs). Suggestions for additions and corrections are welcome by the author. <...>

Con la aparición de] Tomo VII de fas /leías de la Academia Nacional de Ciencias empezamos una nueva serie de esta publicación, interrumpida durante varios años por razones age ñas a la voluntad del Instituto y debido principalmente a los reducidos recursos de su presupuesto, que no permitía la confección de obras ilustradas y de mayor extensión.