ʻO ka mōʻaukala o nā mea magnet mau loa no nā kaʻa

ʻO nā mea ʻano honua laʻa (nā mākēneki mau loa honua) are 17 metallic elements in the middle of the periodic table (atomic numbers 21, 39, and 57-71) that have unusual fluorescent, conductive, and magnetic properties that make them incompatible with more common metals such as Iron) is very useful when alloyed or mixed in small amounts. Geologically speaking, rare earth elements are not particularly rare. Deposits of these metals are found in many parts of the world, and some elements are present in roughly the same amount as copper or tin. However, rare earth elements have never been found in very high concentrations and are often mixed with each other or with radioactive elements such as uranium. The chemical properties of rare earth elements make it difficult to separate from surrounding materials, and these properties also make They are difficult to purify. Current production methods require large amounts of ore and generate large amounts of hazardous waste to extract only small amounts of rare earth metals, with waste from processing methods including radioactive water, toxic fluorine and acids.

ʻO nā mākēneki mau loa i ʻike ʻia, ʻo ia nā minelala i hāʻawi i kahi kahua magnetic paʻa. A hiki i ka hoʻomaka ʻana o ke kenekulia 19, ua palupalu nā magnet, paʻa ʻole, a hana ʻia me ke kila kalapona. I ka makahiki 1917, ua ʻike ʻo Iapana i ke kila kobalt magnet, kahi i hoʻomaikaʻi ai. Ke hoʻomau nei ka hoʻokō ʻana o nā magnet mau loa mai ko lākou ʻike ʻana. No nā Alnicos (Al/Ni/Co alloys) i nā makahiki 1930, ua hōʻike ʻia kēia hoʻololi ʻana i ka helu kiʻekiʻe o ka hoʻonui ʻana i ka ikehu huahana (BH) max, i hoʻomaikaʻi maikaʻi loa i ke kumu maikaʻi o nā magnet mau loa, a no ka nui o nā magnet, hiki ke hoʻololi ʻia i ka mana hiki ke hoʻohana ʻia i nā mīkini e hoʻohana ana i nā magnet.

Ua ʻike ʻole ʻia ka magnet ferrite mua i ka makahiki 1950 i loko o ke keʻena ʻoihana physics o Philips Industrial Research ma Netherlands. Ua kuhi hewa kekahi mea kōkua - ua manaʻo ʻia ʻo ia e hoʻomākaukau i kahi laʻana e aʻo ai ma ke ʻano he semiconductor. Ua ʻike ʻia he magnetic maoli, no laila ua hāʻawi ʻia i ka hui noiʻi magnetic. Ma muli o kāna hana maikaʻi ma ke ʻano he magnet a haʻahaʻa i ke kumukūʻai hana. No laila, he huahana Philips i hoʻomohala ʻia i hōʻailona i ka hoʻomaka ʻana o ka hoʻonui wikiwiki ʻana i ka hoʻohana ʻana i nā magnet mau loa.

I ka makahiki 1960, ʻo nā mea hoʻokalakupua mua loa(nā mākēneki mau loa honua)ua hana ʻia mai nā huila o ka mea lanthanide, yttrium. ʻO lākou ka ikaika ikaika loa me ka saturation magnetization kiʻekiʻe a me ke kūpaʻa maikaʻi i ka demagnetization. ʻOiai ke kumukūʻai, palupalu a maikaʻi ʻole i nā wela kiʻekiʻe, ke hoʻomaka nei lākou e hoʻomalu i ka mākeke no ka lilo ʻana o kā lākou noi. Ua laha ka mana o nā lolouila pilikino i nā makahiki 1980, ʻo ia hoʻi ke koi nui ʻana i nā magnet mau loa no nā kīkī paʻakikī.

Ua hoʻomohala ʻia nā hui like me ka samarium-cobalt i ka waena o 1960s me ka hanauna mua o nā metala hoʻololi a me nā honua laha, a i ka hopena o nā makahiki 1970, ua piʻi nui ke kumukūʻai o ka cobalt ma muli o nā lako paʻa ʻole ma Congo. I kēlā manawa, ʻoi aku ka kiʻekiʻe loa o ka samarium-cobalt permanent magnets (BH) max ka mea kiʻekiʻe loa a pono ke kaiāulu noiʻi e pani i kēia mau magnet. I kekahi mau makahiki ma hope mai, i ka makahiki 1984, ua hoʻokumu mua ʻia ka hoʻomohala ʻana o nā magnet mau loa e pili ana iā Nd-Fe-B e Sagawa et al. Ke hoʻohana nei i ka ʻenehana ʻenehana pauka ma Sumitomo Special Metals, me ka hoʻohana ʻana i ke kaʻina wili hoʻoheheʻe mai General Motors. E like me ka mea i hōʻike ʻia ma ke kiʻi ma lalo nei, (BH) max ua hoʻomaikaʻi ʻia ma kahi kokoke i hoʻokahi haneli, e hoʻomaka ana ma ≈1 MGOe no ke kila a hiki i kahi o 56 MGOe no nā magnet NdFeB i nā makahiki he 20 i hala.

ʻO ka hoʻomau ʻana i nā kaʻina hana ʻoihana i lilo i mea nui, a ua ʻike ʻia e nā ʻāina he kumu waiwai nui ma muli o ko lākou kiʻekiʻe kiʻekiʻe a me ka waiwai waiwai, ua wehe i nā wahi no ka noiʻi ʻana i nā magnet mau loa ʻole honua. ʻO kahi kuhikuhi noiʻi hiki ke nānā i hope i nā mea hoʻokele mau loa i kūkulu ʻia, nā magnet ferrite, a e aʻo hou iā lākou me ka hoʻohana ʻana i nā mea hana a me nā ala hou i loaʻa i nā makahiki i hala iho nei. Ke hana nei kekahi mau hui i nā papahana noiʻi hou e manaʻo nei e hoʻololi i nā magnets rare-earth me nā ʻōmaʻomaʻo a ʻoi aku ka maikaʻi.