Y prif ddull cynhyrchu diwydiannol ar gyfer cynhyrchu metelau daear prin trwy electrolysis halen tawdd. Yn y 1970au, roedd graddfa celloedd electrolysis clorid daear prin wedi cyrraedd 50000 amperes, gyda chynhyrchiad blynyddol o filoedd o dunelli o fetelau daear prin, yn bennaf metelau daear prin cymysg cerium, ac yna metelau cerium, lanthanum, praseodymium, a neodymium. Yn ôl y system electrolysis halen tawdd daear prin, gellir ei rannu'n ddau gategori: y system RCl3-KCl (NaCl), sy'n electrolyzes cloridau daear prin; Yr ail yw system RF3 LiF BaF2 (CaF2), sy'n electrolyzes ocsidau daear prin. Mae'r electrolyt ar gyfer electrolysis system clorid yn cael ei baratoi o 35-50% anhydrus RCl3 a KCl. Mae'r cynnwys amhuredd (%) yn y deunyddiau crai wedi'i nodi fel Fe2O3<0.07, Ca<3, Th<0.03. The electrolysis temperature is higher than the melting point of the metal, and the temperature for producing mixed rare earth metals and cerium by electrolysis is 850-900 ℃; The temperature for electrolytic production of lanthanum is 900-930 ℃; The temperature for electrolytic production of praseodymium neodymium alloy is about 950 ℃. Using a molybdenum rod as the cathode, the current density is 3-5 A/cm2. Using graphite as the anode, the current density is less than 1 ampere/cm2. The slot voltage is 8-9 volts, and the pole spacing is adjustable. The metal yield is 80-90%, and the purity is 98-99.5%. The electrolysis method can also be used to produce alloys of rare earths, aluminum, magnesium, and even transition metals. There are two methods based on their working principles: ① using liquid metals such as aluminum or magnesium as cathodes, electrolyzing Y2O3 or YCl3 in YF3 LiF or YCl3 KCl systems to reduce and precipitate Y3+on the liquid aluminum or magnesium cathode, generating Y-Al or Y-Mg alloys with yttrium content of up to 20% and 48%, respectively; ② Co precipitation of electrolytic alloy components to produce Y-Al and Y-Mg alloys. When producing Y-Al alloy by electrolysis, an electrolyte with a molar ratio of LiF: YF3=1:4 is used. Under the process conditions of electrolysis temperature of 1025 ℃ and cathode current density of 0.6 A/cm2, a mixture of Al2O3 and Y2O3 with an electrolysis content of 14-17% is electrolyzed. Y3+and Al3+are reduced and precipitated together on the cathode to form Y-Al alloy. When producing Y-Mg alloy by electrolysis, the electrolyte of YCl3-MgCl2-KCl system is used for electrolysis at 900 ℃, and Y3+and Mg2+ions are jointly reduced and precipitated on the cathode to form Y-Mg alloy.