Novel method for removing fluorine by lithium carbonate prepared by utilizing tantalum-niobium tailing lepidolite

Abstract

The invention discloses a novel method for removing fluorine by lithium carbonate prepared by utilizing tantalum-niobium tailing lepidolite, wherein a method for acid leaching and neutralization fluorine removal by adding dilute sulfuric acid solution in lithium carbonate raw material is adopted. The method is characterized by comprising the steps of: crushing lithium mica powder to about 200 meshes; inputting the lithium mica powder and sulfuric acid solution with concentration of 30-70% into a reaction device according to solid-liquid mass ratio of 1: 2-8 so as to carry out acid leaching and fluorine removal reaction for 3-10h at a temperature of 60-200DEG C; vacuumizing to separate generated hydrofluoric acid after the reaction so as to obtain solid-liquid mixed solution; and filtering and removing the slag to obtain mother solution I, wherein the neutralization fluorine removal comprises the step of adding calcium hydroxide after adding water equal to the separated hydrofluoric acid solution in the solid-liquid mixed solution and the pH in the solution is controlled within 9-12.

Description

technical field [0001] The invention belongs to the field of chemistry and chemical engineering, and relates to a method for preparing lithium carbonate by using lepidolite from tantalum-niobium tailings to remove fluorine. Background technique [0002] The tantalum-niobium-lithium mine in Yichun, Jiangxi is currently the largest tantalum-niobium-lithium mine in Asia, and it contains rich rare metal materials. Lepidolite is a by-product obtained by flotation of tantalum and niobium mining tailings. Lepidolite is not only Li 2 The content of O is as high as 4.5%, and the content of potassium, sodium, rubidium, cesium, etc. is also very rich, and its comprehensive development and utilization has very important economic and strategic value. [0003] As the world's energy sources that use petroleum as raw materials become increasingly tense, the development and utilization of new energy sources is a common issue for the world. Lithium battery new energy, as one of the importan...

AI Technical Summary

Problems solved by technology

Using high-temperature sintering method to remove fluorine, the energy consumption is extremely high, and it is easy to cause the loss of some metal elements, such as rubidium, cesium and other metal raw materials, the recovery rate is low, thus greatly reducing the comprehensive development and utilization value of lepidolite ore, and also Increased its production cost, may cause the loss of the economic value advantages of extracting lithium and lithium carbonate from lepidolite raw materials, resulting in waste of resources, such as Chinese patent "a method for extracting lithium from lepidolite" (application number 201010001287.1) and The Chinese patent "Processing Method of Potassium Sulfate Process to Prepare Lithium Carbonate from Lepidolite" (Application No. 85101989) is a method of high-temperature roasting to remove fluorine