Ore Decomposition and Treatment
on rare earth ore decomposition and treatment has
been standing at leading status in the world. Professor
Zhang Guocheng, the member of Chinese Academy of
Engineering, and his colleagues have been engaged
in Rare earth ore decomposition and treatment for
all kinds of rare earth ores and concentrate since 1957.
The excellent results have been achieved and transferred
to productive force. Some of the achievements are
Calcination-Solvent Extraction Process Treating
Baotou Mixed-type Rare Earth Concentrate
|The process realized
the idea of direct production of rare earth chloride by solvent
extraction. The rare earth recovery rate reaches to 80%, while
the cost is reduced by 30%. The process realized the conversion
from monazite to bastnasite at rare earth raw material in China.
In 1982, a production line adopting the process was built
up in Gansu rare earth Company. Its annual output was up to 6000
tons of rare earth chloride product. Due to advantage of the process,
CREM won the State Invention Award (3rd class), the Ministerial
Science & Technology Advance Award (1st class) and
the Ministerial Science & Technology Application Award
Sulphatizing Calcination-Solvent Extraction with HDEHP
Process Preparing Individual rare earth Compound
The process, which is called as "The Third Generation
Acid Method", realized successful joint of "Ore
Decomposition -Leaching -Solvent Extraction". The
element Nd can be extracted and Nd-Sm can be grouped directly
from leaching solution with the cheap extractant DEHPA.
The original process is shortened and the product cost
is reduced greatly. The process has been spread to large
rare earth plants, including Baotou Rare Erath Metallurgical Plant, Gansu
Rare Earth Company, Baotou Hefa Rare Earth Company, Xinguang Rare Earth plant,
Rare Earth Hi-Te Group and so on. Especially in 1997, the process
was applied to build up the largest product line of Rare EarthCl3
in Gansu Rare Earth Company. Its productive capacity is up to
18,000 tons of RECl3 annually. Now, About 10000 tons of
Baotou rare earth concentrate is treated annually with this process
in China. Due to the advantage of the process, CREM won
the State Science & Technology Advance Award (3rd
class), the Ministerial Science & Technology Advance
Award (1st class) and the Excellent Patent Award.
Oxidizing Calcination-H2SO4 Leaching Method Processing
In 1960's, CREM developed Oxidizing Calcination -H2SO4
Leaching method to treat bastinasite. This method simplifies
the process of decomposition of bastinasite. This method
has been adopted widely to decompose bastinasite.
CREM has studied the method of treatment of bastnaesite
in America and monazite ore in Mt. Weld in Australia.
So far, good progress have been made.