Innovation and development of Chinese rare earth wet metallurgy and separation of purification technology
One, to start
Before liberation, China had no rare-earth industry and imports of rare earth products. In 1953, jinzhou oil six plants used sulphuric acid method to break down the monolith, which provides the catalyst for the oil industry. In 1957, a large amount of thorium nitrate was needed because of the increase in the use of the lamp. Shanghai yonglian chemical plant began using alkali to handle monolith, but when thorium was produced, rare earths were deposited only as a by-product. In the mid-1950s, comrades like zhong huanbang of the institute of applied chemistry of the Chinese academy of sciences began to study the separation of single rare earths. In 1958, the Beijing institute of nonferrous metals studied the separation of single rare earths from monazite and brownstone, which produced 16 single rare earth oxides in July of that year. And in 1960 set up pilot plant in Beijing nonferrous metal research institute, by ion exchange method and half counter-current extraction craft manufacture single rare earth oxides, for Beijing nonferrous metal research institute in 1962 to complete the preparation of 16 kinds of single rare earth metal created favorable conditions, also provides the design basis for the construction of rare earth smelting plant. In the early 1960s, changsha 602 factory, Shanghai yue long chemical factory, baosteel 8861 was completed and put into production, and the Chinese rare earth industry was industrialized from the laboratory.
Second, the smelting and utilization of rare earth minerals
The comprehensive utilization of the baotou baiyun ebo rare earth resources
Baiyun obo ore is located in baotou city, 150 kilometers north of baiyun obo region is famous in our country, which is mainly composed of iron, rare earth, niobium super-large polymetallic intergrowth ore deposit. There are more than 20 elements in the industry, and the rare earth elements have a reserve of 35 million tons. But since the mine is a hybrid of two types of rare-earth minerals, such as fluorocarbon and solitary rocks, it is difficult to concentrate and smelt. As a result, only 20 to 30 percent of rare earth mines are produced.
1966 Beijing nonferrous metal research institute, Beijing nonferrous metallurgy design institute, baotou, metallurgical research institute, Shanghai yue dragon chemical plant, changchun institute of applied chemistry and baotou rare earth factory of three units of sodium carbonate in the roasting - sulfuric acid leaching - P204 extracting cerium and high temperature chlorination process technology, such as the half industrial test of battle, after the test baotou rare earth three and a half factory use industrial test process of rare earth chloride.
Beijing nonferrous metal research institute in 1972 by rotary kiln sulfuric acid roasting method smelting low grade (REO 20% ~ 20%) of baotou rare earth concentrate production of rare earth chloride (the first generation of acid method), the industrial test in Beijing tong county smelter succeeded, better solve the wet smelting technology of low grade ore concentrate. Baotou rare earth three factory to introduce 1974 Beijing smelting non-ferrous metal research institute rotary kiln sulfuric acid roasting of baotou rare earth concentrate new technology instead of sodium carbonate production of rare earth chloride roasting method, the rare earth recovery increased from 40% to 40%.
From 1973 to 1979, Harbin flint plant, baotou steel rare earth three factory and successively with the Beijing nonferrous metal research institute of gansu province 903 factory production method of the first generation of acid, rare earth chloride, the annual production capacity of up to 10000 tons, to promote the development of the rare earth industry.
Non-ferrous metal research institute in 1975, guangzhou yellow comrade equality research success for flotation reagents with hydroxyl oxime acid concentrate production, for the first time from the baiyun obo resources produced REO - 60% of rare earth concentrate, this is an important breakthrough in baotou ore beneficiation process. In 1976, the flotation industry experiment of producing high grade (REO > 60%) rare earth concentrate in baosteel rare earth plant was successfully carried out. 1981 steel using the process completed two annual output of 5000 tons of high-grade rare earth concentrate ore dressing workshop, make our country high grade ore concentrate production capacity of 10000 tons, marks a rare earth smelting industry in our country has entered a new stage of development.
In 1979, the research institute of nonferrous metals in Beijing successfully developed the new process for the production of chlorinated rare earth (second-generation acid), which produces chlorinated rare earth in sulfuric acid. The Shanghai leaping dragon chemical plant and the baotou metallurgical research institute and other units collaborate to study the successful caustic soda method; Coupled with high temperature and carbon chlorination process, sulfuric acid and sodium carbonate roasting method always referred to as the "five golden flowers", to form the flowers of smelting process, smelting in baotou rare earth concentrate compete with each other, the light of the gratifying situation.
During the third plenary session of the 10th central committee, China's rare earth industry entered a period of vigorous development, and the market for rare earth products was developed domestically. From 1978 to 1986, comrade fang yi was in baotou seven times and presided over the comprehensive utilization meeting of baiyun resources. The national economic and social commission has set up the national leadership group on rare earth rare earth promotion, and established the national rare earth application office in 1978. The China rare earth society was established in 1980. This series of powerful measures has promoted the development of China's rare-earth industry.
Gansu rare earth company with 300000 yuan to buy 1980 Beijing nonferrous metal research institute strengthen sulfate roasting - extraction new technology for producing rare earth chloride (the second generation of acid method), update the old process, improve the economic benefit. Led by the Beijing nonferrous metals research institute, zhang guocheng and other comrades, the design team is responsible for the design of the design. And the main equipment in the Beijing nonferrous metallurgical design & research institute is responsible for the design, a new annual output of six thousand tons of rare earth chloride production line, put into production in 1982, rare earth chloride recovery above 85%. This means that the smelting industry technology of baotou rare earth mining is advanced in the world.
In 1985, Beijing nonferrous metal research institute and successful method for dealing with the third generation of baotou rare earth concentrate acid process, namely sulfate roasting - P204 extraction separation of rare earth elements from sulfuric acid system technology, the technological process is simple, the rare earth recovery rate is high, the product cost is low, from 1985 to 1993, successively transferred to Harbin rare earth materials plant, baotou steel rare earth three factory (rare earth high-tech), 202 factory, gansu rare earth company factory in baotou, become the mainstream technology of baotou rare earth ore processing. At present, more than 90% of baotou rare earth ore is processed by acid process, and the extraction process of the extraction process has some changes and improvement based on the different structure of the product.
Development of ion-adsorption rare earth minerals
In 1968, jiangxi province, 908 geological team and 13 team for the first time in longnan area of jiangxi metallurgical exploration company found the world's rare heavy rare earth ion adsorption type rare earth mine, it's rare earth minerals in the past has never been reported at home and abroad. Undressed ore of rare earth in the form of ion occurrence on the clay minerals such as kaolin, sand weathered ore body cover is very shallow, some exposed on the surface, and this kind of mineral with normal concentration methods can not get. In October 1970, jiangxi nonferrous metallurgy research institute of rare earth mineral composition and trial run in longnan research, found that 90% of the rare earths can use the electrolyte solution by ion exchange elution mode to make it into solution, and for the first time named "ion adsorption type rare earths."
1970 ~ 1973, jiangxi nonferrous metallurgy research institute as the group leader, 908 geological team of jiangxi province, nanchang 603 factory, jiujiang 806 to participate in the joint group, the success of leaching of ionic type rare-earth ore sodium chloride - oxalic acid precipitation mixed rare earth extraction process (i.e., the first generation of pool leaching), solved from extracting rare earth ion adsorption type mineral process problems. And in longnan county industry USES the process at the foot of the jiangxi metallurgical institute set up for making hole area production mines, began to ionic mineral mining extraction using.
From march to December 1975, the jiangxi institute of nonferrous metallurgy cooperated with the 909 geological team of jiangxi province to complete the semi-industrial experiment of 50 tons of rare earth oxides per year in the search of UI river ridge. This is the first time at home with (NH4) 2 so4 leaching ore is successful, and leaching liquid directly with P204 extraction of rare earth and grouping, which is given priority to with light rare earth the found of rare earth in the open market at home and abroad.
In 1981, jiangxi nonferrous metallurgical research was carried out in ganxian large port rare earth mine (NH4) 2SO4 mining industry experiment was successful. In 1985, completed by ganzhou non-ferrous metallurgy research institute of jiangxi province and the university of the "new technology of ion adsorption type rare earth ore extraction" (i.e., ammonium sulfate leaching - producyion precipitation process), the rare earth extraction cost greatly reduced, is widely used in industrial extraction of ion adsorption type rare earths.
In order to protect the ecological vegetation, ganzhou institute of non-ferrous metallurgical research, in 1983, put forward the "in-situ" extraction of ion-type rare earth mining technology. In December 1988, the research on the in-situ immersion process of ionic mines was completed. In December 1995, the national "eighty-five" national "eight five" attack task of "the new process research on ion-type rare earth deposit" was completed. The results are widely promoted in the longnan type rare earth mine. The new technology should meet 15% of the surface.
Now the south of jiangxi rare earth high technology co., LTD. Took the in-situ leaching of ionic type rare-earth ore and direct extraction separation technology "national key projects, are implemented, found in 2003 will be completed for the domestic first-class in-situ leaching mining and directly from leach liquor extraction enrichment and separation of rare earth demonstration project.
Smelting of CFC in sichuan
DeKanJu 109 geological team of sichuan province in the mid - 1980 - s found that the sichuan crown rather rare earth mine, it belongs to the bastnaesite single ore body, less phosphorus impurities such as titanium, is China's second largest rare earths. Beginning in 1989, the construction of rare earth smelters began in 1993, and after nearly a decade of development, a set of smelting and separation technology has been developed for the characteristics of sichuan mining.
(1) the deposition of the roasting and dilute sulfuric acid (1) - recompound salt precipitation
In the 1960 s, Beijing nonferrous metal research institute to study the oxidation roasting - dilute sulphuric acid leaching process of baotou rare earth concentrate, found that almost all the cerium to four valence state into the leach liquor, after double salt precipitation can extract pure cerium. But due to the fact that the baotou mine contains a solitary stone, the rare earth can not be fully decomposed, and the rare earth yield is low, so the process is not suitable for processing the mixed type of baotou. Compared to the rare earth mine in sichuan, the mineral is made of a single stone, which makes it easier to smelt. In 1990, baotou rare earth research institute in sichuan province mian ning bastnaesite concentrate oxidizing roasting, dilute sulphuric acid leaching, and study of double salt precipitation extracting cerium, the purity of cerium oxide is more than 99%, the yield of 78%. The process was transferred to sichuan rare earth materials factory in 1992. Later, after many years of production practice, many improvements were made on the process, the purity of cerium oxide and rare earth yield has increased greatly, at present about seventy percent of rare earth in sichuan smelter production by the technology. This process is characterized by simple equipment, less investment, low requirements for chemical raw materials, but the process is long, chemical raw materials used up big, "three wastes" emissions, rare earth recovery rate is low, poor product purity.
(2) oxidation roasting - hydrochloric acid leaching process
This process is the development of molybdenum companies in the United States in the 1960 s, when leaching tetravalent cerium in slag get enrichment of cerium content (cerium content greater than 90%), can be used as a raw material, polishing powder can also be used as raw materials for the purification of high purity cerium, the other three price of rare earth in hydrochloric acid solution, and then after extraction separation. The process lost two double salt separation process, greatly shortened process, reduced the consumption of chemical raw materials, "three wastes" emissions and the production cost, cerium yield can be improved by more than 5%. It is difficult to stabilize the production of cerium, which produces 2N, and contain certain radioactive thorium.
Though above two kinds of technology is currently widely used in sichuan ore smelting, but also has many shortcomings, is not very satisfied, so many researchers have been trying to develop new technology, want to use simple continuous extraction process instead of chemical process, because the tetravalent cerium and trivalent rare earth separation coefficient is very large, so the direct extraction separation is easy to get high purity cerium, extraction residue after other trivalent rare earth extraction separation, but the solution containing large amount of impurities, such as fluorine, thorium emulsion in the extraction process, influence the extraction process smoothly. Direct extraction separation process has been developed in China, but it has not yet been used in industrial production.
The separation and purification of rare earths
China's rare earth science and technology workers starting in the 1950 s to a large number of solvent extraction separation of rare earth elements of the research and development, has made many scientific research achievements, and is widely used in industrial production of rare earths. Such as the 1970 successfully in industry USES the N263 extraction separation purity is 99.99% of yttrium oxide, replaced the yttrium ion exchange separation of oxidation process, the cost is less than one over ten of the ion exchange method; In 1970, the classic recrystallization was replaced by P204 extraction. Using methyl dimethylene (P350) extract, the classical classification of crystallization was replaced by lanthanum oxide. In the 1970s, the process of extracting and separating rare earth from ammonia and extracting yttrium from naphthenic acid was used in the metallurgical industry of China. Extraction technology in the rapid development of rare earth industry in our country is with the Chinese academy of sciences, Shanghai institute of organic chemistry, such as yuan comrade of hard work, they study the success of various extraction solvent (e.g., P204, P350, P507 etc.) are widely used in industry; In the 1970s, xu guangxian, a professor at Peking University, proposed and promoted the theory of cascade extraction, which helped guide the extraction and separation of our country. At the same time, the separation process of design optimization of series extraction theory is put forward, and it is widely used in the rare earth extraction and separation industry.
Over the past 40 years, China has achieved many achievements in the field of rare earth separation and purification.
In the 1960 s, Beijing nonferrous metal research institute research successfully production of high purity europium oxide by zinc powder reduction basicity process, is the first secondary output is more than 99.99% of the products, the method is still used by rare earth factories all over the country; And Shanghai yue dragon chemical plant, Beijing nonferrous metal research institute of fudan university cooperation using, extraction, ion exchange process first enrichment N263 extraction with P204 get 99.95% purity preparation for the purification of yttrium oxide, 1970 using P204 enrichment N263 secondary extraction is more than 99.99% purity was obtained for the purification of yttrium oxide.
In 1967 ~ 1968, 801 factory in jiangxi province demonstration plant and Beijing nonferrous metal research institute cooperation study group - N263 extraction with P204 extraction successful extraction process of yttrium oxide, and was completed in December 1968, 3 tons/year of yttrium oxide production workshop, yttrium oxide purity of 99%.
In 1972 by Beijing nonferrous metal research institute, 806 factory in jiangxi, jiangxi nonferrous metallurgy research institute of non-ferrous metallurgy, changsha design institute of four team, such as non-ferrous metal research institute in Beijing after two years of joint research experiments, research success using naphthenic acid as extraction agent, mixed alcohol as a diluent extraction process of yttrium oxide.
Changchun institute of applied chemistry in 1974 for the first time found that when using naphthenic acid extraction separation of rare earth, position of yttrium in front of lanthanum, is the most difficult to be extracted in the rare earth elements, then puts forward from nitric acid system using naphthenic acid yttrium oxide extraction separation technology. At the same time, Beijing nonferrous metal research institute conducted from separation of yttrium oxide in hydrochloric acid system using naphthenic acid, and in 1975 respectively in nanchang and jiujiang 806 603 expanded experiment, raw materials for longnan mixed rare earth oxides. Jump dragon chemical plant, 1974 Shanghai fudan university and Beijing nonferrous metal research institute work together, and studied from monazite, brown ytterbium niobium ore after using P204 extraction group in the mixed rare earth of heavy rare earth as a raw material, yttrium oxide by naphthenic acid extraction separation. Three fronts