Ce qui se déplace réellement
Heavy rare earths do not come from a conventional orebody. They come from weathered granite where the metal ions cling loosely to clay, and they are recovered by washing a salt solution through the hillside. The grade is tiny; the strategic weight is enormous.
- Le matériau
- Dysprosium
- La variété
- Ion-adsorption clay, very low grade, unusually rich in heavy rare earths
- Où cela commence
- China — Weathered granite hills in Jiangxi, Guangdong and Fujian
Étape par étape, et frontière par frontière
China · Jiangxi and Guangdong détenu par State-consolidated producers (Producteur d'État)
Leaching the hill in place
Ammonium sulfate solution is injected into the weathered granite and collected downslope. The rare-earth ions swap places with ammonium on the clay and come out in solution. Nothing is blasted and, in modern practice, little is dug.
Ce qu'il est advenu du reste: Older, uncontrolled in-situ leaching left serious groundwater and slope-stability damage, which is much of why the industry was consolidated under state control.
Pourquoi ici: This deposit type needs a specific granite, a specific climate and millions of years. It is not a matter of looking harder elsewhere.
China · On site détenu par Producers (Chimique)
Precipitating a mixed carbonate
The pregnant solution is precipitated into a mixed rare-earth carbonate — the intermediate everything downstream starts from.
Pourquoi ici: Concentrating before transport, as always.
China · Ganzhou, Jiangxi détenu par China Rare Earth Group and affiliates (Affineur)
Separating the heavies
Solvent extraction, but far harder than for the light rare earths: dysprosium, terbium, holmium and erbium are even more alike than neodymium and praseodymium, so it takes more stages and more patience.
Ce qu'il est advenu du reste: Terbium, yttrium, gadolinium and the rest come out alongside. Yttrium is by far the largest fraction; dysprosium and terbium are the ones everyone actually wants.
Pourquoi ici: Heavy separation capacity is concentrated here to a degree unmatched by any other material in this atlas.
China · Magnet plants détenu par Magnet manufacturers (Fabricant)
Diffused into a magnet's grain boundaries
Rather than alloying dysprosium throughout the magnet, it is painted on and diffused into the grain boundaries where it does the most good. The technique cut dysprosium use per magnet several-fold.
Ce qu'il est advenu du reste: This is substitution by engineering rather than by chemistry — same performance, a fraction of the scarce element.
Pourquoi ici: Grain-boundary diffusion is a process advantage held by a small number of manufacturers.
Germany · Traction motors and turbines détenu par Motor manufacturers (Fabricant)
A motor that can get hot
Without dysprosium a neodymium magnet begins losing strength around 80 °C. A traction motor or a turbine nacelle routinely runs hotter than that. 15 kg is enough for several thousand car motors.
Pourquoi ici: A few kilograms of a metal from a Chinese hillside is what lets an electric motor survive a summer traffic jam.
Il s'agit d'un exemple traité. Il suit une quantité de départ déclarée à travers des rendements et des taux de récupération typiques publiés, de sorte que les proportions sont vérifiables ; ce n'est pas le relevé d'un envoi spécifique. Les données d'itinéraire — quels pays, quels procédés, et pourquoi le matériau ne peut simplement pas être traité ailleurs — sont compilées à partir de sources publiques.