Rare earth extraction
Rare earth extraction (solvent extraction method) is the core industrial process for separating and purifying rare earth elements from mixed minerals. It utilizes the difference in distribution coefficients of different rare earth ions in organic solvents and inorganic aqueous phases to achieve the separation of high-purity single rare earth elements. This technology has established China’s dominant position in the global rare earth smelting and separation field.
The following is the core structure of rare earth extraction process:
1. Core principles and processes
Basic principle: Mix an acidic solution (aqueous phase) containing multiple rare earths with a specific organic extractant (organic phase) vigorously in an extraction box. Due to the differences in chemical properties of different rare earth elements, they will transfer to the organic phase with different affinities.
Multi stage cross flow/countercurrent extraction: Due to the extremely similar properties between rare earth elements (especially adjacent lanthanide elements), continuous extraction, washing, and back extraction at hundreds or even thousands of levels are necessary to separate a single rare earth element to a purity of up to 99.999%.
2. Common extractants
According to different types of rare earth minerals and extraction requirements, the following types of phosphorus or amine organic extractants are commonly used in industry:
P204 (HDEHP): Acidic extractant, mainly used for the separation of heavy rare earths and the extraction of elements such as yttrium, samarium, europium, gadolinium, etc.
P507 (EHEHPA): Acidic extractant with high separation coefficient, is currently the mainstream reagent for separating light rare earths (such as lanthanum, cerium, praseodymium, neodymium).
N235 (N1923): Alkaline/neutral extractant, commonly used for separating light rare earths or extracting associated elements from hydrochloric acid systems.
3. Technological breakthroughs and industrial impacts
Cascade extraction theory: proposed by the team of renowned Chinese chemist Academician Xu Guangxian, it solves the world-class problem of traditional processes being difficult to achieve industrial mass production of single high-purity rare earths, and enables China’s rare earth separation technology to reach a global leading level.
Green extraction process: Modern extraction technology is developing towards non saponification and low ammonia nitrogen wastewater discharge to solve the environmental pain points in traditional extraction processes.
Our metal extractants as below, if you need any kind, please ask us:
- P204 (D2EHPA or HDEHP) This is used for first step to remove impurity for laterite nickel ore.
- P507 non-ferrous metal extractant for copper, zinc, cobalt-nickel, cadmium, gold-silver, platinum group metals, rare earths and so on.
- DY272 Nickel cobalt separation extractant, it can take cobalt out from nickel cobalt solution, then leave pure nickel.
- DY984N copper solvent extraction reagent.
- DY319 high efficiency nickel cobalt co-extraction extractant for battery recycling, can take out nickel and cobalt together from Lithium battery electrolyte.
- QL256-2 Nickel Cobalt Manganese co extraction Extractant.
- DY377 efficient nickel and diamond separation extractant.
- DY366 Scandium extractant.
- DY316 Lithium extractant.
