Will permanent-magnet motors be replaced by induced motors without rare earth elements in the future?

The alternative motor without rare-earth minerals was developed by Toyota Motor, If this motor can be produced in large amount, Toyota Motor doesn’t need at risk of supply disruptions in the future. The alternative motor was called induction motor which is lighter and more efficient than the magnet-type motor. It has been used in Toyota Prius and Tesla Model S.1

Induction motors, except not requiring rare-earth materials, induction motors also can offer higher efficiency and durability than permanent-magnet motors in some applications. Induction motors operate by inducing electrical currents in conductors in the motor’s rotor. these currents in turn give rise to a magnetic field in the rotor and thus produce torque. As a result, when switched off, these motors are inert, producing no electrical voltage or current, no losses and no cogging torque. These machines can produce high levels of performance using modern and well understood vector control techniques.2

References

1. Toyota Reading Motors That don’t use rare earths. http://www.bloomberg.com/news/articles/2011-01-14/toyota-readying-electric-motors-that-don-t-use-rare-earths

2. J. D. Widmer, R. Martin, M. Kimiabeigi. Electric vehicle traction motors without rare earth magnets. Sustainable Materials and Tecnologies. Volume 3, April 2015, Pages 7–13

Safe nuclear and rare earth minerals

Recently I read a article about ‘why nuclear will rely on rare earth minerals’1 which briefly introduced the important relationship between safe nuclear and rare earth minerals. Actually, as for safe nuclear, it means to make nuclear power safer.  In short, it is better to replace uranium fuel with a different element.

Fortunately, Scientists found thorium is one of the best succedaneums for nuclear power, which is also introduced in our previous blog by Mark Foreman 2. Because thorium produces little dangerous, weapons-grade waste. Especially thorium‘s waste survives for only a few hundred years, not the 10s of thousands or even millions of years for uranium. So it will reduces the weapons-proliferation threat associated with nuclear power in the future.

Thorium is a basic element of nature, like Iron and Uranium. Like Uranium, its properties allow it to be used to fuel a nuclear chain reaction that can run a power plant and make electricity (among other things). Thorium itself will not split and release energy. Rather, when it is exposed to neutrons, it will undergo a series of nuclear reactions until it eventually emerges as an isotope of uranium called U-233, which will readily split and release energy next time it absorbs a neutron. Thorium is therefore called fertile, whereas U-233 is called fissile.3

1

Photo of Monazite-(Ce) : (Ce, La, Nd,Th)(PO4), Taken from: http://www.mindat.org/photo-48025.html

Nowadays, scientists have been  working on using thorium as nuclear fuel as opposed to uranium because of some of the possible benefits, one of which is that estimated to be about three to four times more abundant than uranium, easy to mine, and refined from monazite sands as a by-product of extracting rare earth metals.4  Monazite is a phosphate mineral which is a lanthanide phosphate (LnPO4), it often contains plenty of thorium. 2

1 why nuclear will rely on rare earth minerals.  http://www.smartplanet.com/blog/intelligent-energy/why-safe-nuclear-will-rely-on-rare-earth-minerals/

2 Thorium radioactivity. I http://erean.eu/wordpress/thorium-radioactivity-i/

3 Thorium as nuclear fuel. http://www.whatisnuclear.com/articles/thorium.html

4 Thorium. http://en.wikipedia.org/wiki/Thorium

Current situation and problems of rare earth industry in China

China produces more than 90 percent of the world’s rare earth. Meanwhile, overcapacity, a low proportion of high-end products, smuggling and pollution still hamper the development of the rare earth industry. Hence, in order to try to curtail pollution and prevent over-mining, China has been cracking down on the industry for years to curb illegal mining, smuggling and environmental devastation. Subsequently, China imposed strict rare earth export quotas in 2010.

After many years of development, China has established a relatively complete R&D system, pioneered numerous technologies of international advanced levels in rare earth mining and dressing, smelting, separating, etc., and its unique mining and dressing processes and advanced separating techniques have laid a solid foundation for efficient exploitation and utilization of rare earth resources. The rare earth new materials industry has experienced steady development, and industrialization has been achieved in using rare earths to produce permanent-magnet, luminescent, hydrogen-storage, and catalytic materials, and other new materials, providing support for the restructuring and upgrading of traditional industries, and the development of emerging industries of strategic importance.

With a relatively complete industrial system armed with mining, dressing, smelting and separating technologies and incorporating equipment manufacturing, material processing and end-product utilization, China can produce over 400 kinds of rare earth products in more than 1,000 specifications. In 2011, China produced 96,900 tons of rare earth smelting separation products. Currently, China supplies over 90 percent of the global rare earth demand with 23 percent of the world’s total reserves.

After more than 50 years of excessive mining, China’s rare earth reserves have kept declining and the years of guaranteed rare earth supply have been reducing. The decline of rare earth resources in major mining areas is accelerating, as most of the original resources are depleted. In Baotou, only one-third of the original volume of rare earth resources is available in the main mining areas, and the reserve-extraction ratio of ion-absorption rare earth mines in China’s southern provinces has declined from 50 two decades ago to the present 15.

Outdated production processes and techniques in the mining, dressing, smelting and separating of rare earth ores have severely damaged surface vegetation, caused soil erosion, pollution, and acidification, and reduced or even eliminated food crop output.

Due to multiple factors, including domestic and international demand, the smuggling of rare earth products to overseas markets continues to be a problem in spite of the efforts made by China’s customs listing it as a key criminal act to crack down on.

References

1. China’s rare earth industry expands but problems persists, http://www.mining.com/chinas-rare-earth-profits-fall-98385/

2. China’s rare earth industry sees progress, challenges, http://www.globaltimes.cn/content/80252

3. Situation and policies of China’s rare earth industry. Foreign Languages Press, 2012.

4. ZHANG Shujing. Problems and countermeasures of rare earth industry in China, Canadian Social Science, Vol. 9, No. 3, 2013, 9-14.

5. REE – Rare Earth Elements and their Uses. http://geology.com/articles/rare-earth-elements/