Saturday, April 15, 2017

Rare Earth Seabed Mining: Renewable Energy Conundrum?

Given that they cost lass energy to refine than their counterparts found on land, should we be mining the seabed for rare earth metals? 

By: Ringo Bones 

The late eccentric billionaire Howard Hughes started an exploratory venture of deep sea seabed mining during the late 1960s and early 1970s but didn’t prove to be economically viable at the time because technology used for such an undertaking were still at its infancy. But given the advances of autonomous undersea craft in the 21st Century, should we be exploring the viability of deep sea seabed mining because minerals used in renewable energy production like rare earth magnets used in wind turbines and tellurium used in advanced photovoltaic solar panels costs less energy to process and extract in comparison to their land-mined counterparts? 

Recently, British scientists exploring an underwater mountain in the Atlantic Ocean have discovered a treasure trove of rare earth minerals in a Tenerife undersea mountain known as the Tropic Seamount located more than 500 kilometers (300 miles) away from the Canary Islands. Samples brought back to the surface contain not only a high concentration of rare earth elements but also a scarce element called tellurium used in newfangled super-efficient photovoltaic solar panels at concentrations 50,000 times higher than in deposits found on land. Given that rare earth metals are used in powerful magnets that made low carbon energy generation a reality, should we be mining the seabed despite of the largely unknown ecological consequences? 

Dr. Bram Murton, the leader of the expedition, told the BBC that he had been expecting to find abundant minerals on the Tropic Seamount but not in such high concentrations. Dr. Murton calculated that the 2,670 metric tons of tellurium on this single seamount represents one-twelfth of the world’s total supply. And Dr. Murton has come up with a hypothetical estimate that if the entire deposit could be extracted and used to make solar panels, it could meet 65-percent of the UK’s electricity demand. One major concern is the effect of plumes of dust stirred up by the excavation of the ocean floor, spreading for long distances and smothering all life whenever it settles. To understand the implications, the expedition to Tropic Seamount conducted an experiment, the first of its kind, to mimic the effects of mining and to measure the resulting plume. The researchers hope that the environmental impact outweighs the resulting carbon dioxide reduction as we intensify the shift to more renewable energy generation.

Monday, May 2, 2016

Neodymium: The Music Producing Rare Earth?

Even though it had stayed a mere scientific curiosity decades after its discovery, but did you know that neodymium had become indispensable in the music producing world near the end of the 20th Century?

By: Ringo Bones  

Ever since it was discovered by the famed Austrian chemist Carl Auer von Welsbach as part of the family of rare earth elements back in 1885, neodymium has stayed a mere scientific and laboratory curiosity decades after its discovery. Its name is a derivation of the Greek neos didymos or new twin. In pure form, neodymium has found use of producing the only bright purple glass known which was used in welder’s goggles before cheaper plastic alternatives were invented. In a cruder state, neodymium is used to take color out of glass and to make special kind of glass that transmits the tanning rays – as in ultraviolet-A spectrum – of the sun but not the unwanted infrared rays. 

Near the end of the 1970s, neodymium was found out to be an important component in ultra compact rare earth magnets that are more powerful than the alnico magnets that were then in use to make high-fidelity loudspeakers and microphones. The new much powerful neodymium magnets used in unbalanced dynamic microphones that are often used as a workhorse in live stage performance applications – like Peavey’s PVM 22 Diamond Mic – manages to generate a much stronger output signal than their alnico magnet equipped predecessors that it has resulted in the proliferation of low-cost dynamic microphones with quite high signal-to-noise ratios that can never be achieved using alnico magnets. 

Small but powerful neodymium magnets also made possible those “active” electric guitar pickups that became popular during the latter half of the Hair Metal revolution of the 1980s. Given that they produce more output signal than their alnico magnet predecessors, noise pickup issues in live onstage electric guitar playing has more or less been solved.

Sunday, March 29, 2015

Samarium: The Audiophile Rare Earth?

Given that we common folk usually encounter it in our consumer electronic gear – especially hi-fi, does samarium represent the audiophile side of the rare earth elements? 

By: Ringo Bones 

More famously known in those ultra-small yet very powerful samarium-cobalt permanent magnets, the rare earth element samarium’s “global strategic importance” seems to be just way greater to be left to geopolitical tensions give that if Beijing blocks supplies destined to the rest of the planet, it would be us civilians – especially the audiophile community – that would be left high and dry. Given its importance in our modern way of life, it would only be proper to know a bit more about this largely obscure member of the rare earth kingdom. 

Discovered by Lecoq de Boisbaudran in 1879 and further chemically refined to be identified to be a member of the rare earth family by Carl Auer von Welsbach back in 1885, the rare earth element samarium’s contribution to human civilization would not be fully realized until almost 90 years after its discovery. The primary source of the rare earth element samarium is the mineral samarskite – which is named after a 19th Century Russian mining officer, Colonel V.E. Samarsky. 

During the American science boom of the 1960s, samarium was often experimented in laser applications. Calcium chloride crystals doped with samarium have been employed in laser devices for producing beams of light intense enough to burn metal or bounce off the moon. Its more widespread applications in the civilian consumer electronics market now includes those small but powerful samarium-cobalt magnets used in hi-fi headphone units and the small electric motors used in almost everything from disc drives in CD and DVD players and the memory drives and cooling fans in personal computers and laptops. Samarium-cobalt magnets are also extensively used in the actuators of unmanned drones. As a scientific curiosity, the isotope samarium-152 is the only alpha particle emitting radioactive element known to occur naturally among the elements lighter than bismuth. Samarium-152 has a half-life of 1-trillion years. 

Monday, May 26, 2014

Cerium: The Most Abundant Rare Earth Element?

Though considered “rare” in name only but does cerium qualify as the most abundant rare earth element?

By: Ringo Bones

It is considered rare in name only given that cerium occurs in the Earth’s crust at a concentration of 44 parts per million. On a percentage basis of abundance in the Earth’s crust – cerium is more plentiful than either tin or lead. And cerium is also found dissolved in seawater at a concentration of 1.8 tons per cubic mile of seawater. By comparison, the rare earth element thulium – the scarcest of the family on a percentage basis in the Earth’s crust – is only slightly rarer than iodine.

Chemical symbol Ce, atomic number 58 and named after the asteroid Ceres, cerium was discovered in 1803 by Jöns Jakob Berzelius and Wilhelm Hisinger of Sweden. It is the chief ingredient – at just under 50 percent – of misch-metal alloy often used in the manufacture of lighter flints. Cerium is used in alloys to make heat-resistant jet engine parts; its oxide has been used as a de rigueur petroleum cracking catalyst since the 1960sand as a volumetric oxidizing agent in most important industrial chemical processes. 

Tuesday, September 3, 2013

Rare Earth Hexaborides For Cathode Poisoning Resistant CRTs?

Even though they are a fairly dated discovery, are rare earth based hexaboride cathode coatings made possible ultra-long-life cathode ray tubes in color television sets and even hi-fi thermionic vacuum tubes?  

By: Ringo Bones 

Though now virtually forgotten when virtually every consumer electronic devices we have are solid state based – including the now “affordable” organic light emitting diode (OLED) video display monitors, there was a time when cathode poisoning was of grave concern – like back in the days when the first programmable digital computers still use thermionic vacuum tubes. But as thermionic vacuum tubes returned in the high end audiophile scene, and given there are certain cathode ray tube based color television sets manufactured in the mid 1990s that are still running, could the concept of cathode poisoning – in a strange twist of fate – inspire consumer electronic companies to design longer lasting thermionic vacuum tubes, even ones rivaling the longevity of solid state transistors and integrated circuits? 

Back in the 1950s, when vacuum tube technicians were still concerned with their tubes developing “sleeping sickness” whenever it was kept in soft-start mode for a prolonged period of time in radar and digital computer applications, cathode poisoning was of a grave concern on how to prolong the life of their banks upon banks of vacuum tubes when they are mostly switched to low current mode in switching applications. In short, cathode poisoning is the failure mode of a thermionic vacuum tube where the emissive layers degrade slowly with time and much more quickly when the cathode is overloaded with too high a current – which usually results in weakened emission and diminished power of the vacuum tubes or brightness of the cathode ray tubes – i.e. CRTs. Given what every “thermionic vacuum tube experts” had learned through such first hand events, were there any progress made in prolonging vacuum tube life and making cathode poisoning less of a concern? 

Various rare earth borides had been used to prolong the life of thermionic vacuum tubes but there’s no news yet on how they affect sound quality of vacuum tubes when used in audio applications. Like boride cathode vacuum tubes that use lanthanum hexaboride and cerium hexaboride as coating of some high-current cathodes. Hexaborides show low work function around 2.5 eV. They are also resistant to cathode poisoning. Cerium hexaboride cathodes show low evaporation rate at 1,700 Kelvin than lanthanum hexaboride, but becomes equal at 8,800 Kelvin and higher. Cerium hexaboride cathodes have one and one half times the lifetime of lanthanum hexaboride cathodes due to its higher resistance to carbon contamination. Hexaboride cathodes are about 10 times as bright as the tungsten ones and have lifetimes up to 10 to 15 times longer. They are used in electron microscopes, microwave vacuum tubes, electron lithography, electron beam welding, X-Ray vacuum tubes and free electron lasers. However, these materials tend to be expensive. Other useful rare earth based hexabordes with long lives are yttrium hexaboride, gadolinium hexaboride and samarium hexaboride. 

Even though rare earth based hexaboride cathode coatings for thermionic vacuum tube devices may not yet be a hit in the hi-fi audio world sound quality wise, but I think these might have contributed in making extra long life CRTs or cathode ray tubes in television sets. Back in 1995, I’ve bought a 14-inch Goldstar color TV manufactured by LG Collins Electronics Manila, Inc. It’s a model CN-14A146 with serial number 60524212 which I bought for around 150 US dollars and it is still running until this very day. I wonder if this particular Goldstar 14-inch color TV uses a rare earth based hexaboride cathode coated CRT? 

Monday, August 19, 2013

The James Webb Space Telescope: A Rare Earth Telescope?

Slated to replace the now aging Hubble Space Telescope, is the James Webb Telescope deserve the moniker “Rare Earth Telescope” due to the amount of rare earth elements needed to make it do its cosmic exploration?

By: Ringo Bones 

Insiders from Lockheed Martin often joked that its rare earth element content equals that of three Predator drones, but why does the James Webb Space Telescope need such prodigious amounts of rare earth elements to do its intended function in exploring the cosmos? Well, maybe it has to do on where the new space telescope will be finally situated. 

Unlike the Hubble Space Telescope, which is situated in low Earth orbit 250 miles or 400 kilometers above us, the James Webb Space Telescope will be situated 1-million miles from the Earth so any fixing by NASA astronauts in case of a post launch in-space field repairs will be much, much harder than the Hubble fix in low Earth orbit by EVAing astronauts back in the early 1990s. The unfurling of the James Webb Space Telescope’s over-sized mirrors and heat shield 1 million miles in space must go as planned or it will become a sad multi-billion US dollar astronomical blunder. 

In order for the James Webb Space Telescope to achieve reliability in the hostile vacuum and near absolute zero cold of outer space, its servo motors are especially made with advanced proprietary samarium rare earth magnets that can still reliably function at 2.7 Kelvin – the average temperature of the hard vacuum of outer space. These servo motors not only unfurl the over-sized mirrors once the space telescopes arrive in a point in space 1-million miles away from Earth but also the aluminized gold plated mylar heat shield that would protect the James Webb Space Telescope’s main mirror from the relentless unfiltered glare of the Sun.