Low-grade-large-tonnage deposits is a common term to describe unconventional extraction of minerals and element below the economically viable grade to run a mine (at the opposite end “bonanza deposits” which might have a low to moderate tonnage but very high grade so as to extract the ore for a profit).

There are low-grade large tonnage deposits in nuclear fuels, such as some sandstone-hosted U deposits. In Germany and the adjacent Czech Republic (Hamr) it was the Königsstein U deposit near Dresden. It was mined by underground leaching solely for U and pose some problems to the ground water system. You have to flush the aquifer which in parts has been artificially enhanced by what might be-called fracking. The rehabilitation of such a mine after its shutdown takes years to get the site clean or turn it into a restricted area while you have to monitor carefully and steadily the groundwater system.

There are many epithermal and porphyry-type deposits, e. g. in Turkey which are mined by open-pit mining with subsequent heap-leaching either pure acid infiltration or mediated by bacteria.

The “roll-model” of this type of deposits is the black-shale hosted mineral and fuel deposits because these stratigraphic series e.g., Kolm Shales, Graptolite Shales, Lower Jurassic and Cretaceous black shales are attractive for different reasons as some kind of a “protore” for minerals or source rock and reservoir rock all-in-one for hydrocarbons. Uraniferous black shales of the Ranstadt–Alum Shales, Sweden, the Silurian and Lower Devonian Graptolite Shales, Germany and the Devonian Chattanooga Shales, USA, which formed in a marine environment of deposition, are low-grade–large-tonnage deposits for a wide range of elements and uranium, in particular. The Late Paleozoic uraniferous shales at Saint Hippolyte and within the Lodeve Basins, France, evolved in a lacustrine basin, while the uraniferous

lignite deposit at Koldjat, Kazakhstan, Serres, Greece, Stockheim-, Weiden-, Oos-Saale- Basins, Döhlen-Freital, Germany, Central Bohemian Basin (Plzen and Kladno-Rakovnik Basins), Czech Republic, maybe grouped under the comprehensive term U-bearing lignite laid

down in poorly aerated swamps.

Mo sulfide jordisite are accompanied by a wide range of minerals of Zn, As, Ni, Sb, Se, Re, U, PGE (Pt, Pd, and Ir) and native Au. This low-grade–large-tonnage type shale-hosted Mo– Ni–PGE–Zn deposits are of syngenetic deposition with or without hypogene element introduction into the basins. Many black shales are anomalously enriched in these elements but seldom reach ore grade. The most renown representatives are the Early Paleozoic Alum Shales in central and northern Europe, the Zunyi Mo deposits in China and the Nick deposit in Canada.

Polymetallic Sb mineralization in black shales or alum shales falls into the category of low-grade–large tonnage deposits with only a few examples upgraded to a giant deposit such as at Sukhoi Log, Russia under favorable circumstances. Black shales such as the Paleozoic Graptolite Shales, Alum Shales and Chattanooga Shales have been known for a long time to contain a wide range of metals

Another type are LGLT-deposits based on phosphorites which not only contain high amounts of P but also U, V, REE and are concentrate in different phosphate belts around the globe.

These are without any doubt deposits (in the future) which cannot ignore-

There are some problems due to bad ore/waste ratio, the chemical leaching underground or at site by heap leaching and the sensitive issue of water which is always a part of the conflict of interests.

See also the large salinas “harvested” for Li to make our green lifestyle go ahead.

You cannot outwit nature and there does not exist a philosophers´ stone.

Neither politicians nor their electorate have obviously understood this.

HGD