As we've documented many times, as in, for just several examples:
West Virginia Coal Association | Coal Ash a Superior Source of High-Tech Metal | Research & Development; concerning: "'Extraction of Germanium and Gallium from Coal Fly Ash'; Technical Report BM-RI-6940; OSTI ID: 7342110; April, 1966; R.F. Waters, et. al.; Bureau of Mines, Rolla, MO. Rolla Metallurgy Research Center"; and:
West Virginia Coal Association | Iowa Mines Metals from Coal Ash for the USDOE | Research & Development; concerning, in part: "'US Patent 4,386,057 - Recovery of Iron Oxide from Coal Fly Ash'; 1983; Assignee: The United States of America; The U.S. Government has rights in this invention pursuant to Contract No. W-7405-ENG-82 between the U.S. Department of Energy and Ames Laboratory; Abstract: A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide"; and:
West Virginia Coal Association | China Extracts Aluminum Ore from Coal Ash | Research & Development; concerning: "'China's Shenua to Produce Alumina from Coal Ash'; December 19, 2011; China's Shenhua Group began construction Sunday of a coal ash-based alumina refinery in the Inner Mongolia autonomous region, the official Xinhua news agency said. Shenhua plans to invest Yuan 135.8 billion ($21.4 billion) in the project, deputy manager Ling Wen is quoted as having said. Located in the Jungar coal mining area in Ordos city, the project will include a 6.6 GW power plant, an alumina plant and a gallium plant. ... All of the plants will use materials recycled from coal burning";
it isn't just possible to consider Coal Ash as an accessible, viable ore of various needed metals, the enlightened people of China are actually treating it that way.
The high-tech metals Gallium and Germanium, with intriguing and essential value especially in the semiconductor industry, might seem like surprising elements which can be profitably extracted, along with the more familiar Aluminum and Iron, from Coal Ash; but, there are elements of value even more rare, so rare they're actually formally called "Rare Earth Elements":
Chemical Elements.com - Rare Earth Elements: "The thirty rare earth elements are composed of the lanthanide and actinide series. One element of the lanthanide series and most of the elements in the actinide series are called trans-uranium, which means synthetic or man-made. All of the rare earth metals are found in group 3 of the periodic table, and the 6th and 7th periods. The Rare Earth Elements are made up of two series of elements, the Lanthanide and Actinide Series".
As noted in the above reference, many of the Rare Earth Elements are man-made, and radioactive. However, most of those in the Lanthanide Series are natural, non-radioactive elements, including Lanthanum and Cerium, and have critically important, and growing, high-tech uses, as explained by the United States Department of Energy's Ames Laboratory:Rare Earth Metals | Ames Laboratory; "Considered a national center for rare earths, the U.S. Department of Energy’s Ames Laboratory is the go-to source for expertise in the synthesis, analysis and engineering of rare-earth metals and their alloys. Rare-earth elements are critical components in modern electronic technologies, ranging from TVs, fluorescent light bulbs, cell phones and computers to "green" magnets in electric motors that power hybrid cars and generators used in wind turbines. Rare earths are essential to medical diagnosis equipment and almost all military systems. Ames Laboratory’s expertise in the field of rare-earths has captured international attention as concern has grown over China’s near-monopoly of the global rare-earth supply".
Note, in the above, emphasis on "China’s near-monopoly of the global rare-earth supply", implying a shortage of Rare Earth Elements, which is further emphasized in:
Rare earth element - Wikipedia, the free encyclopedia; "New demand has recently strained supply, and there is growing concern that the world may soon face a shortage of the rare earths. In several years from 2009 worldwide demand for rare earth elements is expected to exceed supply by 40,000 tonnes annually unless major new sources are developed".
So small is our domestic, United States supply of the strategically important Rare Earth Elements, which "are essential to ... almost all military systems", that, as again explained by our USDOE in:
Rare Earth Metals for Science | Ames Laboratory; "Quantities of high-purity rare earth metals and alloys in single and polycrystalline forms are available to scientists outside of Ames Laboratory. Complete chemical analyses, obtained by laser mass spectrometry, inert gas fusion, and combustion analysis, accompany these materials. Special preparations of high-purity alloys and compounds are also available in small quantities";
our US Government can only make them available to researchers "in small quantities".
Well, King Coal to the rescue.
We can recover all of the strategically critical, China-monopolized yet militarily-essential Rare Earth Elements we might need from good old Coal Ash.
As seen in excerpts from the initial link in this dispatch to the recent:
"US Patent Application 20130287653 - Recovery of Rare Earth Elements and Compounds from Coal Ash
October 31, 2013
Inventors: Prakash B. Joshi, et. al., MA
(As we have often noted, the eventual Assignee of Rights, that is, who the named inventors work for, is usually not named in early versions of US Patent Applications as they are published on the Web. However, the electronic files of the original, formal "US Patent Application 20130287653" documents clearly identify the company, "Physical Sciences, Incorporated", or, interestingly, just "PSI", to be the employer of the named inventors and the eventual Assignee of Rights to any US patent that might issue from Application 20130287653. And, if you have never heard of PSI, that is no doubt because they want it that way. As can be learned via:
Abstract: Rare earth elements are recovered from coal ash. The coal ash with rare earth elements can be treated with a mineral acid to form an aqueous mineral acid solution. The aqueous mineral acid solution can be extracted to form an organic solution that includes the rare earth salts. The organic solution can be mixed with water to form an aqueous solution that includes the rare earth salts. The rare earth elements are separated from the aqueous solution.
Claims: A method of recovering rare earth elements from coal ash, the method comprising: treating coal ash that includes rare earth elements with a mineral acid to form an aqueous mineral acid solution; extracting the aqueous mineral acid solution to form an organic solution that includes the rare earth salts; mixing the organic solution with water to form an aqueous solution that includes the rare earth salts; and separating the rare earth elements from the aqueous solution (and) wherein the mineral acid is nitric acid.
The method ... wherein treating the coal ash further comprises: heating the mineral acid to approximately 90 C; and exposing the coal ash to the mineral acid for at least one hour (and)wherein exposing the coal ash further comprises additional heating of a resulting solution formed when exposing the coal ash to the mineral acid to generate a more concentrated mixture.
The method ... wherein the extracting the aqueous mineral acid solution further comprises: mixing the aqueous mineral acid solution with tributyl phosphate and kerosene; and removing the organic solution from the aqueous mineral acid solution such that the rare earth salts are substantially removed along with the organic solution (and) wherein extracting the aqueous mineral acid solution further comprises performing a dry extraction, a liquid extraction, or any combination thereof.
The method ... wherein the dry extraction comprises performing continuous extraction of rare earth salts with tributyl phosphate (and) further comprises diluting the organic solution with kerosene.
The method ... further comprising exposing the coal ash to a magnetic treatment such that the coal ash separates into a substantially magnetic portion and a substantially non-magnetic portion of the coal ash.
(As in our above-cited report concerning: "'United States Patent 4,386,057 - Recovery of Iron Oxide from Coal Fly Ash'; 1983; Assignee: The United States of America; The U.S. Government has rights in this invention pursuant to Contract No. W-7405-ENG-82 between the U.S. Department of Energy and Ames Laboratory; Abstract: A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide". See, as well, our report of:
West Virginia Coal Association | China Recovers Iron Ore from Coal Ash | Research & Development; concerning: "United States Patent 8,505,735 - Vertical Ring Magnetic Separator for De-Ironing of Pulverized Coal Ash; August 13, 2013; Assignee: China Shenhua Energy Company Limited, Beijing".)
The method ... wherein separating the rare earth elements comprises ion exchange of either anion or cation exchange (and) wherein ion exchange separation leads to rare earth element mixtures suitable to be converted to mixtures of rare earth oxides and rare metals for various applications such as catalyst, magnets, and phosphor applications.
Background: Rare earth elements can be fundamental to emerging green energy technologies in the United States (e.g., permanent magnet motors for wind turbines and disk drives, hybrid car batteries, compact fluorescent lighting, and/or displays in all types of consumer/defense electronics), as well as other usages such as industrial catalysts for refining heavier crude oil, automobile catalytic converters, and/or as alloying elements.Coals from certain regions of the world can be particularly rich in rare earth elements, approaching a total concentration of about 1000 parts-per-million ("ppm").
A method to extract rare earth elements from coal is desired. The United States alone produces on the order of 100 million metric tons of fly ash annually. Accounting for process yield and variability in rare earth element content, if rare earth elements are extracted from coal ash, a reasonable fraction of currently available fly ash (e.g., about 10-15%) can be adequate to meet rare earth elements demand in the United States.
Summary: Advantages of the invention include recovering rare earth elements from coal ash. Another advantage of the invention includes economical production of rare earth elements and/or compounds from alternative, non-mineral raw materials. Another advantage of the invention is the ability to build reliable production capabilities and/or supply chain for rare earth elements and/or byproducts. Another advantage of the invention is processing fly ash to recover rare earth materials, particularly heavier rare earths, more economically and energy-efficiently per kilogram of rare earth elements than from processing and extracting mineral resources. Another advantage includes the beneficiation of coal ash, which is an abundant waste material, for recovering economically useful and marketable industrial materials that include rare earth elements as a significant component. Another advantage includes energy efficient extraction of rare earth elements, which can save energy use by about 75% relative to conventional mining per unit weight of rare earth elements produced. Yet another advantage is the accompanying carbon dioxide (CO2) emission can be lower than mining by about 75%. Still another advantage includes production of environmentally beneficiated ash cake, which can be free of hazardous elements.
In one aspect, the invention involves a method of recovering rare earth elements from coal ash.
The method involves treating coal ash that contains rare earth elements with a mineral acid to form an aqueous mineral acid solution. The aqueous mineral acid solution is extracted to form an organic solution that includes the rare earth salts. The organic solution is mixed with water to form an aqueous solution that includes the rare earth salts. The rare earth elements are recovered by separating the rare earth elements from the aqueous solution.
Thus, only "10 - 15%" of our Coal Ash can supply all of our domestic United States needs for strategically critical Rare Earth Elements, "which are essential to ... military systems"; and most of which Rare Earth Elements we might now import from China, who have a "near monopoly on the global rare earth supply".