Method for extracting rare earth metals
OwnerPeter F. Santinainventor
Life of this patent
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Abstract
Overburden from surface coal mining in many regions can produce a rain runoff laden with selenium, in the selenate form, as well as rare earth elements (REEs). This occurs from rainwater leaching through exposed selenium/mineral-containing rocks in the overburden. The mineral-containing runoff water is caught in ponds, or deep mine water is collected from pools. Alternatively, leachate can be collected from coal gob or refuse piles. Extraction of REEs, as well as remediation of deleterious substances such as selenium, is performed by treatment with sulfur-modified iron (SMI) in a contact bed of an upflow reactor vessel. After a period of use of the SMI, the spent SMI is subjected to a recovery process for REEs.
Claims20
A method for recovering rare earth elements (REEs) from a water source containing rare earth elements, comprising:
- collecting acidic raw water from a mine or other water source containing REEs,
- assuring pH of the raw water is within a preselected range, and adjusting pH of the raw water as needed to bring the raw water into the preselected range,
- directing the raw water through a reactor column, in a vessel containing a contact bed of SMI which is contacted by the raw water, thereby removing from the raw water and attaching to the SMI REEs from the raw water, along with additional substances that may be present in the raw water,
- after a period of time in which the raw water passes through the reactor column and the SMI becomes less effective in removing REEs from the raw water, discontinuing directing of the raw water through the contact bed, and
- applying an REE recovery process to the SMI to recover at least some of the REEs.
A method for recovering rare earth elements (REEs) from a water source containing rare earth elements, comprising:
- collecting acidic raw water from a mine or other water source containing REEs,
- assuring pH of the raw water is within a preselected range, and adjusting pH of the raw water as necessary,
- directing the raw water through a reactor column, in a vessel containing a contact bed of zero-valent iron (ZVI) which is contacted by the raw water, thereby removing from the water and attaching to the ZVI REEs from the water, along with additional substances that may be present in the raw water,
- after a period of time in which the raw water passes through the reactor column and the ZVI becomes less effective in removing REEs from the water, discontinuing directing of the raw water through the contact bed, and
- applying an REE recovery process to the ZVI to recover at least some of the REEs.
Dependencies are inferred from the claim text.