Method for extracting lithium from lepidolite

Abstract

The invention relates to a method for extracting lithium from lepidolite, which comprises the steps of removing fluorine, pressing and soaking, separating, removing impurity, separating out natrium, analyzing kalium, separating, depositing lithium, separating, and separating crude wet lithium carbonate and lithium depositing mother liquid after depositing lithium. The invention is characterized in that the concentration of Rb+ contained by the lithium depositing mother liquid is detected, the circulation trend of the lithium depositing mother liquid is decided by the consistency, when the consistency is low, the product quality is not influenced, the lithium depositing mother liquid which is acidulated returns to the step of removing impurity before analyzing natrium, and when the concentration of the Rb+ is high and influences the product quality, the lithium depositing mother liquid is separated in an Rb and Cs product manufacturing procedure. The invention can avoid increasing the load of a pressing and soaking kettle when the lithium depositing mother liquid returns to the pressing and soaking step, and the content of natrium and kalium in the lithium depositing mother liquid which is finally educed is reduced to enable the subsequent separation of Rb and Cs to be easier, thereby the cost of whole technique comprising the processing cost of lithium carbonate, rubidium and cesium is greatly reduced.

Description

technical field [0001] The invention belongs to a method for extracting lithium, in particular to a method for extracting potassium from lepidolite. Background technique [0002] In the early days, lithium was mainly extracted from ores. Later, due to the low cost of extracting lithium from brine, lithium was mostly extracted from salt lake brine. Now, due to the increasing demand for lithium, the price of its raw materials has risen sharply, and many companies have begun to extract lithium. Lithium is extracted from ores, such as Li in lepidolite concentrate in Yichun, my country 2 The O content can reach about 4.5%, and it also contains valuable precious metals such as potassium, rubidium, and cesium. Therefore, if these resources can be comprehensively utilized, it is possible to compete with the extraction of lithium from brine. [0003] One of the methods for extracting lithium from lepidolite mainly includes the following processes: [0004] Press immersion-separation...

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Problems solved by technology

[0005] One part is to directly return to the pressure immersion kettle for pressure immersion. At this time, the contents of potassium, rubidium, cesium, and lithium in the mother liquor are relatively high, which will increase the cycle load of the pressure immersion kettle (because high pressure and chloride ion corrosion resistance should be considered. problem, the investment in the pressure leaching kettle is very large), because according to the principle of the same ion effect, potassium, rubidium, cesium, and lithium are harmful to the leaching of lithium, potassium, rubidium, and cesium in lepidolite

[0006] Another part is to directly separate a part of the mother liquor after acidifying the mother liquor after lithium precipitation to recover rubidium and cesium. At this time, the content of potassium and sodium in the mother liquor is relatively high compared to rubidium and cesium, which will lead to the removal of rubidium and cesium. If the amount is too large, the greater the content ratio of potassium and sodium relative to rubidium and cesium, the more problems will be brought to the subsequent separation, so one will make the process very complicated, and the other will greatly increase the separation cost of rubidium and cesium

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