Lepidolite
lepidolite
CAS: 1317-64-2
Molecular Formula: AlFH9KLiO7Si2(-3)
Lepidolite - Names and Identifiers
| Name | lepidolite |
| Synonyms | lepidolite |
| CAS | 1317-64-2 |
Lepidolite - Physico-chemical Properties
| Molecular Formula | AlFH9KLiO7Si2(-3) |
| Molar Mass | 269.25 |
| Physical and Chemical Properties | Contains lithium oxide 1.23% ~ 5.90%. Monoclinic system, a = 5.3, B = 9.2,c = 10.2,β = 100. Symmetrical m or 2/m; usually a fine clover aggregate. Generally light purple, glassy luster, cleandable parallel {001} extremely complete, hardness 2~3, relative density 2.8~2.9. |
Lepidolite - References
| Overview | Lepidolite, also known as "scale Mica", is composed of KLi1.5Al1.5(AlSi3O10), is potassium and lithium-based aluminum silicate, mainly found in the pegmatite, but also found in the quartz and high temperature hydrothermal veins, is the extraction of lithium mineral raw materials, if containing rubidium, cesium can be used comprehensively. Can be used as raw materials for glass. Used in ceramics, can play the role of flux. Lithium extracted from Lepidolite has a wide range of uses, on the one hand, it is an important fuel for hydrogen bomb, rocket, nuclear submarine and new type of jet aircraft; On the other hand, it can be used as a control rod in atomic reactor, as a signal bomb in military, A red emitter of flares and a thick lubricant for aircraft, a light alloy made of lithium in metallurgy, and a purity agent for metallic products. |
| extraction method | 1. Extraction of lithium (1) limestone sintering method limestone sintering method is the most mature method, the advantages of this method are more prominent:(1) short leaching process. There is only one kind of slag, the washing process is simple, and it is relatively easy to select large washing equipment. (2) leaching system is good, alkaline system, equipment corrosion is small. (3) the separation process of lithium hydroxide is simple, and the yield of potassium, rubidium and cesium is high. This system also facilitates the separation of potassium, rubidium and cesium. The disadvantages of this method are:(1) the yield is low, and the yield of lithium is only 62 to 65% by using Lepidolite containing 4.5 or more as the raw material. (2) the amount of slag is large, 1 ton of lithium hydroxide monohydrate dry slag is more than 40 tons. (3) the slag is difficult to use. (4) high energy consumption. The roasting material is large, and the concentration of lithium oxide in the leaching solution is low (4G/l). (5) The investment should be relatively large. (2) sulfate roasting method The advantages of this method are:(1) the amount of slag is less than that of limestone sintering method, which is reported as 1/3 of that of limestone sintering method, from the author's research experience, the amount of slag should be larger than that in the report, which may be about 2/5. (2) the yield is high, and the recovery rate of lithium oxide is 84.1, which is more questionable, and the highest yield is estimated to be no more than 75. (3) low energy consumption, reported on the equivalent of 1/3 of limestone sintering. The deficiencies of this process are also apparent:(1) the use of expensive potassium sulfate, the report said that 1 ton of lithium carbonate products with 1 ton of potassium sulfate. (2) because of the use of 0.1 ~ 0.5M concentration of sulfuric acid to wash the slag, which makes the slag greatly increased, especially this system is a sulfate system, and the composition of Lepidolite complex, resulting in a very long impurity removal process. (3) the expensive potassium, rubidium and cesium in Lepidolite were not obtained. (4) the availability of slag is still unknown. This method the author did not do the confirmatory experiment. (5) ring formation in the process of kiln. (3) salt pressure boiling method The advantages of this method are outstanding:(1) The process is very short. Basically the same as the lime sintering process. (2) the amount of slag is very small, less than 1/3 of the amount of limestone slag. (3) the yield of lithium is high, and it is reported that the yield of lithium is 84.34. (4) the leaching rate of potassium is 80%, and the leaching rate of rubidium may be more than 20%. (5) follow-up lithium precipitation and other processes and Ganfeng existing process can be connected. (6) Ganfeng brine production of lithium carbonate and lithium chloride can produce a certain amount of sodium chloride. The shortcomings of this method are also very obvious:(1) because it involves the chloride system, so the equipment selection is difficult, the report said that the titanium molybdenum nickel equipment is feasible, the author thinks that it should be done some more. (2) leaching requires a temperature of 200 deg C, more than 10kg of pressure, in addition to the chloride system, so the equipment investment will be very large. (3) the slag contains chloride ions. (4) because of the need to remove fluorine roasting, environmental protection pressure. (5) because it is a chloride system, and is a high pressure reaction, there is a potential safety hazard. The author verified this experiment, and found that the leaching rate of lithium is about 90% according to the insoluble lithium. (4) sodium sulfate pressure boiling method The principle is the substitution reaction of lithium, potassium, rubidium and cesium in sodium and defluorinated Lepidolite. But the two systems have a great difference, one is the chloride system, one is the sulfate system. Relatively speaking, the material separation of chloride system is relatively easy, while the material separation of sulfate system is more difficult, and the separation process is longer. And the existence of potassium sulfate and sodium sulfate in the sulfate system will form a double salt problem, resulting in the difficulty of sodium sulfate and potassium sulfate separation. Because it is also to defluorination of Lepidolite roasting, environmental protection is the same pressure. At first, the author thinks that the equipment of the sulfate system has no corrosion problem. Later, it is found that because of the certain content of chlorine in the national standard of sodium sulfate and the additive effect, the corrosion of chloride ion must be considered in this method, investment in equipment remains significant. This kind of slag because the chloride ion content is relatively small, so the availability will be better. (5) lime pressing method lime pressing method is a method for treating lepidolite in Yichun studied by Central South University of Technology. The advantages of this method are as follows:(1) the system is an alkaline system, and lithium hydroxide is directly obtained. (2) raw materials are cheap, mainly milk of lime. (3) pressure boiling pressure is not high, about 4kg of pressure. (4) the amount of slag is only about half of the limestone method. The disadvantages of this method are:(1) the filtration performance of the slag is not very good because of the residual milk of lime. (2) the availability of slag is not clear. (3) Lepidolite must first defluorination roasting, environmental protection pressure. (6) sulfuric acid roasting method The advantages of this method are also obvious:(1) the equipment used in this method can be connected with spodumene sulfuric acid method. This is the greatest advantage of this approach. (2) the amount of slag in this method is relatively small, but since the residual acid of the acidification roasting is subjected to a wet reaction during water immersion, the amount of slag is actually larger than expected. (3) the energy consumption is not too high. Disadvantages: the yield is relatively low, because the author uses lithium oxide content of less than 4% of the lithium mica, the leaching rate of lithium is only about 75%, of course, the author is the static defluorination roasting and static sulfuric acid roasting, the results may be better in dynamic situations. In addition, the two processes of defluorination roasting and acidification roasting will bring environmental pressure. (7) sulfuric acid method The advantage of this method is (1) The leaching rates of lithium, potassium, rubidium and cesium are very high. (2) because the roasting process is saved, this piece of great investment is saved. (3) This method has no high-temperature calcination process, and the concentration of lithium is high, so the energy consumption of this method may be the lowest of all these methods. However, this method also has obvious disadvantages:(1) The process is very long, which brings great difficulties to engineering and equipment selection. (2) the amount of sulfuric acid is large, the amount of residual acid is large, and the price of sulfuric acid fluctuates greatly. (3) the corrosion resistance of the equipment is a problem because of a strong acidic environment. (4) in addition to aluminum this step is very difficult, with calcium carbonate in addition to the amount of aluminum slag, with sodium carbonate in addition to the amount of aluminum slag is 1/4 of the amount of calcium carbonate in addition to aluminum slag, however, the use of sodium carbonate to remove aluminum is due to the formation of lithium-containing fluoroaluminate. In general, the loss of lithium in this step is large (more than 10%), and the slag in this step is difficult to use. (5) the treatment of mixed alum is also not a good way. (6) If pressure boiling is used, safety is a problem. (7) if it is to be ground, there is a big problem that the Lepidolite is difficult to be ground. (8) chlorination roasting method The advantages of this method are:(1) the safety is better than that of sodium chloride pressure leaching method. (2) from the report see rubidium and cesium leaching rate reached 50% ~ 60%. (3) the amount of slag is not mentioned in the report, but because of the small amount of limestone input, the amount of slag should be much less than that of limestone sintering method. Disadvantages:(1) to use calcium chloride. (2) there may be a ring phenomenon in the kiln mentioned in the report, and there are some difficulties in operation. (3) because it is a chloride system, corrosion problems must be considered. Figure 1 is the process flow chart of Lepidolite sodium chloride leaching method and comprehensive utilization of resources Figure 2 is the process flow chart of extraction technology of rubidium carnallite |
| Application | can be used as glass raw material. Used in ceramics, can play the role of flux. Lithium is the lightest metal, with a specific gravity of 0.534. It can produce the lithium -6 needed for hot nuclei. It is an important fuel for hydrogen missiles, missiles, nuclear submariners and new jet planes. Lithium is capable of absorbing neutrons and is used as a control rod in atomic reactors and in military applications as a signal bomb, as a red emitter of flares and as a thick lubricant for aircraft. Light alloys made of lithium in metallurgy and pure agents used in metal products. The above information about the physical and chemical properties and extraction methods of Lepidolite was compiled by D. |
| Main references | [1] Ma Shichang, ed. A Dictionary of chemical substances. Xi'an: Shaanxi Science and Technology Press. 1999. Page 764. [2] Deng Xiaolin, editor-in-chief. A Dictionary of Geosciences. SHIJIAZHUANG: Hebei Education Publishing House. 1992. Page 519. [3] Li Liangbin et al. The process of extracting lithium from Lepidolite and the problems should be paid attention to in industrialization. Nonferrous metals in the world. 2014.8. |
Last Update：2024-04-10 22:29:15
