bit of rare earth chemistry

Just thought I'd post something relevant. FYI I'm a 5th year Chemical Engineering/Economics Student. Decided to get my hands on: Extractive Metallurgy of Rare Earths, Gupta.

Thought i could add a bit of detail to the quarterly Reports: Lamp Process review-Illustrated PFD (p4).

Cracking and Leaching Process:
The bastnasite concentrates are processed in China by heating with 98% sulfuric acid at 500°C in a rotary kiln. By this, the fluorocarbonate matrix is destroyed, carbon dioxide and hydrofluoric acid gases are released, and the rare earths are converted to their sulfates.

Water leach and filter used to remove all insolubles/solids such as Thorium, Rutile etc to be further processed into roadbase.

Subsequently, the soluble rare earth sulfates are fed forward and converted to hydroxides by digestion in a strong caustic solution(Ammonia)to form soluble metal hydroxides.

MGOH2, is used to precipitate out Ca, etc which form insoluble metal hydroxides.These maybe further processed to get RE's. Possibly with a second train--see attached flow diagram, using Nitric Acid?

Rare Earth Separation:
The soluble hydroxides are then dissolved in hydrochloric acid. Separation of non RE, RE and TH occurs
Separation and purification of the rare earths is done using solvent extraction (Hart and Levins 1988, Koch 1987).
The solvent extraction separation of each rare earth element is carried out in multistage batteries of mixer settlers. At least 50 mixture settler stages per stream are needed to obtain a product with four to 99.9999% purity.

I have attached a flowsheet from the book, hope it gives you all a little perspective on the true technical difficulties involved in RE processing. Haha makes iron ore mining, crushing , grinding, smelting seem a hell of a lot easier. To investors: So do you think updates will be relaeased for every little commissioning mishap that occurs, since 99% of investors will fail to understand? This is an extremely advanced plant. So please investors have some patience...I havnt even scratched the surface of the Chem involved. BTW i am long if you havnt guessed, it would be truly amazing to see this succeed!

Not sure if entirely correct, please tell me if you find mistakes. Btw... "The Rhône-Poulenc solvent extraction
flowsheet has been regarded as the standard for all industrial producers (Bautista 1995)".