Study On Clean Production Process Of Combined Separation Of Light Rare Earth And Medium Yttrium Ion Rare Earth

Rare earth,as an important strategic resource in China,plays an important role in the fields of science and technology,military affairs,materials and so on.Solvent extraction is the most widely used method in rare earth separation industry,but the three wastes,especially a large amount of acid and alkali waste water,caused great harm to the surrounding ecological environment.In the face of increasingly serious environmental conflicts,rare earth industry also needs to seek and study clean production process.In this study,we used P507-HCl system to extract light rare earth and medium yttrium europium-rich rare earth ore by pre-separation extraction method,namely the organic phase loaded at the outlet of the pre-separation extraction section of light rare earth ore,used as the extraction organic phase for medium yttrium europium-rich rare earth ore,so as to realize the combined separation of two rare earth ores in the same process flow,combine the two original independent production lines,reduce acid and alkali consumption at the source.Through the experiment,we draw the following conclusions:1.La-Nd rare earth with a purity of more than 99.995 % can be obtained from the outlet water phase of the 8-stage pre-extraction section of the combined separation process,and the content of Sm2O3 is less than 0.005 %,and the medium and heavy rare earth elements after Sm and Sm are separated very cleanly.2.The organic phase loaded at the outlet of the 8-stage pre-separation extraction section of the light rare earth ore is used for pre-separation extraction of the organic phase relative to the medium yttrium europium-rich rare earth ore,the heavy rare earth elements of the outlet water phase are separated very cleanly,and the light medium rare earth elements of the outlet organic phase are separated cleanly.The raw materials respectively enter the LaNd/SmEuGd/GdTbDy/Ho-Lu,Y four-outlet separation process,so that the processing capacity of the La-Nd/SmEuGd/GdTbDy/Ho-Lu,Y four-outlet separation process can be improved,the flow rate and washing amount of organic phases can be reduced,and the discharge amount of acid and alkali wastewater can be reduced at the same time.3.The application of the combined separation process in rare earth industrial production is feasible,the treatment capacity is greatly improved,and the discharge amount of acidbase wastewater is obviously reduced.The consumption of saponification ammonia wat can be reduced by 30.2 %,that consumption of HCl can be reduce by 58.8 %,the discharge of waste water can be reduced by 42.6 %,the volume of the extraction tank can be reduced by 18.1 %,and the economic benefit can be obviously improve.