New technology of rare earth extraction - Process to cut 5 / no radioactive waste/no ammonia nitrogen wastewater
at present the rare earth industry in China has dominated the world, but with the expansion of the rare earth industry, rare earth resources recycling process of 'three wastes' pollution problems become increasingly serious, need to develop effective practical green mining mineral smelting and processing, solve the problem of three wastes pollution to the environment, and to further reduce product consumption and improve the comprehensive utilization of resources.
a, rare earth resources classification and all kinds of rare earth smelting separation of mainstream technology analysis
the development and utilization of rare earth industry in China's rare earth minerals mainly have three kinds: baotou mixed rare earth mine, sichuan bastnaesite, south ion adsorption type rare earths. Due to the different mineral species, composition and structure, adopted by the process is different also. For different rare earth resources in our country to develop a series of original rare earth smelting separation technology:
1, the baotou mixed rare earth mine: - sulfuric acid decomposition Water - P204 or carbon - ammonia transformation Saponification P507 - HCL system extraction separation;
the process for easy control, suitable for mass production, low running cost, rare earth recovery rate is high. But in the process of baotou ore smelting separation, baotou rare earth minerals (per processing 1 ton REO) , about 1 tons of slag, belongs to the Ⅰ low level radioactive waste, to dam stacked; Produce about 60000 m after roasting gas, which contain fluoride, SO2 and acid fog, generally adopt the method of three-level lye spray absorption, produced by the acidic wastewater, using lime neutralization treatment; Produce 80 - 1 100 m3 wastewater containing ammonia nitrogen. 3 tons.
2, sichuan bastnaesite: oxidizing roasting - Hydrochloric acid leaching - Optimal solution - alkali Saponification P507 - HCL system extraction separation;
the process is characterized by small investment, cerium product production cost is low, but the technology gap, hydrochloric acid leaching process of 4 valence cerium, thorium, fluorine insoluble in slag, slag after alkali conversion, fluorine into the wastewater discharge in the form of sodium fluoride, thorium, fluorine scattered in the residue and waste water are difficult to recycle, damage to the environment, and only 97% purity cerium products - 98%, low value.
3, south of ionic type rare-earth ore: ammonium sulfate leaching - Carbon precipitation - ammonia Hydrochloric acid leaching - Saponification P507 extraction separation, naphthenic acid system.
the process due to the organic phase in the process of extraction separation of the liquid ammonia or alkali saponification, extraction separation of 1 ton of rare earth oxides to 1 m tonnes of liquid ammonia consumption, causing high costs, and generate a large amount of ammonia nitrogen wastewater, and high ammonia nitrogen recycling cost, processing incomplete, causing serious pollution of water resources.
the above three kinds of technology of annual production capacity of more than 300000 tons, about 85% of the world, more than 90% using solvent extraction separation, the product purity is 2 n - 5N。
2, new technology of leaching extraction integration of ionic type rare-earth ore extraction 'green revolution'
in view of the three kinds of rare earth industry resources and environmental problems, developed a series of research institutions and enterprises smelting separation technology of high efficiency, clean environmental protection. Beijing nonferrous metal research institute and professor YouYan rare earth new materials co. , LTD. Xiao-wei huang, lead the team system was carried out by rare earth separation green chemistry basic theoretical research, proposed to the ionic rare earth mine instead of alkali metal or alkaline earth metal calcium magnesium ammonium, unbalanced centrifugal extraction instead of precipitation recycling and purification of enrichment of rare earth and other new ideas, invented the new technology of extraction and separation of ionic type rare-earth ore efficient green, from the source to reduce ammonia nitrogen, radionuclide pollution, water and material efficient recycling, is a new kind of clean production technology.
diagram: a new technology of leaching of ionic type rare-earth ore extraction integration process
process to cut 5
does not produce radioactive waste
no ammonia nitrogen wastewater
the rare earth recovery increased by more than 8%
3, new technology of integration of immersion extraction production line of industrial demonstration projects to introduce
in 2016, the integration of immersion extraction technology in chinalco chung left rare earth mine in guangxi built first immersion extraction model line, the project by Beijing nonferrous metal research institute, zhengzhou collaboration such as extractive technology co. , LTD. , has realized the ionic rare earth leaching liquid direct extraction enrichment of industrial application, solved perplex of ionic type rare-earth ore containing radioactive solid wastes pollution problem.
in the production line of the demonstration projects, require extraction in 20 - flow ratio 50, but the huge volume of conventional extraction equipment, production efficiency is low, unable to realize the flow ratio and high flux. Zhengzhou extraction for rare earth metals extraction process, launched with independent intellectual patent products ( The patent number: ZL2014205865573) Product - — New centrifugal extraction machine, the realization of the flow than the industry of rare earth ore extraction, extraction rate > 98. 5%, won industry recognition.
8 single CWL650 - zhengzhou extraction are adopted in this project M type centrifugal extraction machine ( Fluorine material) Late, running stability. Zhengzhou new. cwl - M series centrifugal extraction machine also has the following advantages:
1, the equipment enclosure with steel lining fluoride materials, drum made of fluorine material resistant to strong acid corrosion;
2, device, cover an area of an area small, low power consumption, in the capacity of 50 m after/h, under the condition of the actual power consumption is only 2. 8 kw;
3, at the bottom of the bearing and mechanical seal, no leakage risk, greatly reduce the maintenance cost of equipment and labor intensity;
4, high degree of automation, good operating environment;
5, which can realize continuous operation and intermittent operation, high extraction efficiency.