阅读说明：本技术 一种用氢氧化锂制备高纯碳酸锂的方法 (Method for preparing high-purity lithium carbonate by using lithium hydroxide ) 是由 唐刚昌 钟元兴 于 2021-01-04 设计创作，主要内容包括：本发明涉及一种用氢氧化锂制备高纯碳酸锂的方法,本发明以工业级碳酸锂为原料,在工业级碳酸锂溶液种通入高纯二氧化碳气体,使溶液碳酸氢化,向碳酸氢化的溶液种加入氢氧化锂固体粉末,溶液种碳酸氢锂与氢氧化锂反应生成碳酸锂,过滤洗涤得到高纯碳酸锂,滤液返回工业级碳酸锂调浆,经碳酸氢化后经过离子交换除杂得到纯碳酸氢锂溶液。此方法与传统的制备高纯碳酸锂方法流程更短,反应条件更为温和,简化了生产工艺和降低了生产成本,值得推广。(The invention relates to a method for preparing high-purity lithium carbonate by using lithium hydroxide, which takes industrial-grade lithium carbonate as a raw material, high-purity carbon dioxide gas is introduced into an industrial-grade lithium carbonate solution to carbonate and hydrogenate the solution, lithium hydroxide solid powder is added into the solution subjected to carbonate hydrogenation, lithium bicarbonate in the solution reacts with lithium hydroxide to generate lithium carbonate, the lithium carbonate is filtered and washed to obtain high-purity lithium carbonate, filtrate is returned to the industrial-grade lithium carbonate for size mixing, and after the carbonate hydrogenation, the pure lithium bicarbonate solution is obtained through ion exchange and impurity removal. Compared with the traditional method for preparing high-purity lithium carbonate, the method has the advantages of shorter flow, milder reaction conditions, simplified production process, reduced production cost and worth of popularization.)

1. A method for preparing high-purity lithium carbonate by using lithium hydroxide is characterized by comprising the following steps: the method comprises the following steps:

(1) slurrying lithium carbonate with pure water, feeding the slurry into a carbonic acid hydrogenation tower, introducing carbon dioxide for carbonic acid hydrogenation, and filtering after the carbonic acid hydrogenation is finished to obtain a lithium bicarbonate solution, wherein the chemical reaction equation is as follows:

the reaction is carried out for 120min at the temperature of 20-30 ℃, and the solution is filtered to obtain a lithium bicarbonate solution after the reaction is finished;

adding lithium hydroxide into the solution, directly precipitating lithium carbonate, filtering, washing and drying to obtain high-purity lithium carbonate, wherein the chemical reaction equation is as follows:

(3) and (3) sending the filtrate obtained after filtering in the step (2) to industrial-grade lithium carbonate for size mixing, hydrogenating by carbonic acid, then removing impurities by ion exchange to obtain a pure lithium bicarbonate solution, and repeating the step (2) on the pure lithium bicarbonate solution to prepare the high-purity lithium carbonate.

2. The method for preparing high purity lithium carbonate from lithium hydroxide as claimed in claim 1, wherein: the lithium hydroxide added in the step (2) is fixed powder, the addition amount is 1.05 times of the theoretical reaction amount, and the solution is stirred in the adding process.

3. The method for preparing high purity lithium carbonate from lithium hydroxide as claimed in claim 1, wherein: the reaction conditions of the step (1) and the step (2) are normal temperature and normal pressure.

4. The method for preparing high purity lithium carbonate from lithium hydroxide as claimed in claim 1, wherein: and (3) if the sodium content of the lithium bicarbonate solution subjected to ion exchange impurity removal in the step (3) exceeds 160mg/L, recovering lithium in the filtrate without entering the step (2) for reaction.

Technical Field

The invention relates to the technical field of chemical industry, in particular to a method for preparing high-purity lithium carbonate by using lithium hydroxide.

Background

Lithium carbonate is the most important lithium product and the most basic product in the lithium industry, and accounts for about 40% of the total consumption of lithium salts in the world. The lithium carbonate has wide application, and has wide application in the fields of new energy sources and new materials such as aluminum industry, lubricant, medicine, refrigerant, nuclear industry, ceramics, glass and the like. The battery-grade lithium carbonate is a key raw material for synthesizing lithium cobaltate, lithium manganate, lithium iron phosphate and other lithium battery positive electrode materials; the lithium carbonate can improve the affective disorder of schizophrenia in medicine and has obvious effect of inhibiting mania. Today of new energy popularization, the application range of lithium ion batteries is wider and wider, and the demand of high-purity lithium carbonate is larger and larger.

Disclosure of Invention

In view of the above, a method for preparing high-purity lithium carbonate by using lithium hydroxide is provided, which has the advantages of shorter flow, milder reaction conditions, simplified production process and reduced production cost. Which comprises the following steps of; the method comprises the following steps:

(1) slurrying lithium carbonate with pure water, feeding the slurry into a carbonic acid hydrogenation tower, introducing carbon dioxide for carbonic acid hydrogenation, and filtering after the carbonic acid hydrogenation is finished to obtain a lithium bicarbonate solution, wherein the chemical reaction equation is as follows:

the reaction is carried out for 120min at the temperature of 20-30 ℃, and the solution is filtered to obtain a lithium bicarbonate solution after the reaction is finished;

(2) adding lithium hydroxide into the solution, directly precipitating lithium carbonate, filtering, washing and drying to obtain high-purity lithium carbonate, wherein the chemical reaction equation is as follows:

(3) and (3) sending the filtrate obtained after filtering in the step (2) to industrial-grade lithium carbonate for size mixing, hydrogenating by carbonic acid, then removing impurities by ion exchange to obtain a pure lithium bicarbonate solution, and repeating the step (2) on the pure lithium bicarbonate solution to prepare the high-purity lithium carbonate.

Further, the lithium hydroxide added in the step (2) is fixed powder, the addition amount is 1.05 times of the theoretical reaction amount, and the solution is stirred in the adding process.

Further, the reaction conditions of the step (1) and the step (2) are normal temperature and normal pressure.

Further, if the sodium content of the lithium bicarbonate solution subjected to ion exchange impurity removal in the step (3) exceeds 160mg/L, lithium in the filtrate is recovered and does not enter the step (2) for reaction.

Compared with the prior art, the method has the advantages of mild reaction conditions, guaranteed safety, no waste gas, short process flow and equivalent production cost to that of the traditional method.

Detailed Description

The present invention will be described in detail with reference to specific examples.

A method for preparing high-purity lithium carbonate by using lithium hydroxide comprises the following steps:

(1) slurrying lithium carbonate with pure water, feeding the slurry into a carbonic acid hydrogenation tower, introducing carbon dioxide for carbonic acid hydrogenation, and filtering after the carbonic acid hydrogenation is finished to obtain a lithium bicarbonate solution, wherein the chemical reaction equation is as follows:

the reaction is carried out for 120min at the temperature of 20-30 ℃, and the solution is filtered to obtain a lithium bicarbonate solution after the reaction is finished;

(2) adding lithium hydroxide into the solution, directly precipitating lithium carbonate, filtering, washing and drying to obtain high-purity lithium carbonate, wherein the chemical reaction equation is as follows:

(3) and (3) sending the filtrate obtained after filtering in the step (2) to industrial-grade lithium carbonate for size mixing, hydrogenating by carbonic acid, then removing impurities by ion exchange to obtain a pure lithium bicarbonate solution, and repeating the step (2) on the pure lithium bicarbonate solution to prepare the high-purity lithium carbonate.

Further, as a preferable example of this embodiment, the lithium hydroxide added in the step (2) is a fixed powder, the addition amount is 1.05 times of the theoretical reaction amount, and the solution is stirred during the addition.

Further, in this embodiment, it is preferable that the reaction conditions in the step (1) and the step (2) are normal temperature and normal pressure.

Further, in this embodiment, it is preferable that the reaction environment in the step (3) is normal temperature and normal pressure.

Further, as a preferable example of this embodiment, if the sodium content of the lithium bicarbonate solution after ion exchange impurity removal in the step (3) exceeds 160mg/L, lithium in the filtrate is recovered and does not enter the reaction in the step (2).

The above disclosure is only one preferred embodiment of the present invention, and certainly should not be construed as limiting the scope of the invention, which is defined by the claims and their equivalents.