阅读说明：本技术 一种纳米碳酸锂的制备方法 (Preparation method of nano lithium carbonate ) 是由 卢伟红 孙俊彬 陈满生 于 2020-12-15 设计创作，主要内容包括：本发明公开了一种纳米碳酸锂的制备方法。该方法是将碳酸锂溶液冷冻成冰块后,冷冻干燥,即得纳米级碳酸锂。该方法操作简单,成本低,其制备的碳酸锂为纳米级别,且粒径均匀,粒径大小可控,具有更高的反应活性,相对粉碎、球磨等方法制备碳酸锂具有明显的优势。(The invention discloses a preparation method of nano lithium carbonate. The method comprises the steps of freezing a lithium carbonate solution into ice blocks, and then carrying out freeze drying to obtain the nano-scale lithium carbonate. The method is simple to operate and low in cost, and the prepared lithium carbonate is in a nanometer level, uniform in particle size, controllable in particle size and higher in reaction activity, and has obvious advantages compared with the lithium carbonate prepared by crushing, ball milling and other methods.)

1. A preparation method of nano lithium carbonate is characterized by comprising the following steps: and freezing the lithium carbonate solution into ice blocks, and then freezing and drying to obtain the lithium carbonate ice block.

2. The preparation method of nano lithium carbonate according to claim 1, characterized in that: the lithium carbonate solution is a lithium carbonate saturated solution or a diluent of the saturated solution.

3. The preparation method of nano lithium carbonate according to claim 1, characterized in that: the freezing temperature is-80 to-20 ℃.

4. The preparation method of nano lithium carbonate according to claim 1, characterized in that: the freeze drying time is 3-48 hours.

5. The preparation method of nano lithium carbonate according to claim 1, characterized in that: and adding ethanol into the lithium carbonate solution to promote the generation of lithium carbonate crystal nuclei.

Technical Field

The invention relates to a preparation method of lithium carbonate, in particular to a method for preparing nano lithium carbonate by freezing and freeze-drying technologies, and belongs to the technical field of lithium carbonate preparation.

Background

Lithium carbonate is a very important lithium compound and is widely used in enamel, glass manufacturing, semiconductors, synthetic rubbers, medicine, defense industry and the like.

In the ceramic industry, lithium carbonate is used as an additive for preparing low-melting-point ceramics and glass, and plays a role in obviously improving the thermal shock resistance of the ceramics.

Lithium carbonate is also an important raw material for preparing lithium ion batteries, for example, lithium cobaltate, lithium manganate and ternary cathode materials are all prepared by lithium carbonate, and the size of lithium carbonate particles directly influences the activity of the reaction.

Lithium carbonate is used as a sedative in the pharmaceutical industry for treating manic psychosis, and the size of lithium carbonate particles directly influences the speed of the drug in the delivery process.

Lithium carbonate plays an important role in many fields, and particularly, the nano-scale lithium carbonate can play a role in quick administration in the treatment of manic psychosis, and has potential application value in other fields. The method for preparing the nano lithium carbonate in the prior art mainly adopts ball milling, crushing, membrane filtration and the like, but other impurities are often brought in the processes of crushing, ball milling and the like, and the membrane filtration efficiency is low.

Disclosure of Invention

Compared with the defects in the prior art, the invention aims to provide the preparation method of the nano lithium carbonate, the method is simple to operate and low in cost, the prepared nano lithium carbonate particles are uniform and controllable in size and have higher reaction activity, and the method has obvious advantages compared with the method for preparing the nano lithium carbonate by crushing, ball milling, membrane filtration and the like.

In order to achieve the technical purpose, the invention provides a preparation method of nano lithium carbonate, which comprises the steps of freezing a lithium carbonate solution into ice blocks, and then carrying out freeze drying to obtain the nano lithium carbonate.

As a preferable mode, the lithium carbonate solution may be a saturated lithium carbonate solution or a diluted solution of the saturated lithium carbonate solution. The lithium carbonate saturated solution or the saturated solution diluent can ensure that the lithium carbonate is uniformly dispersed, so that lithium carbonate particles with uniform particle size can be further obtained. The lithium carbonate particles can be effectively adjusted by adjusting lithium carbonate solutions with different concentrations, the particle size is controllable, the thinner the solution is, the smaller the particle size of lithium carbonate correspondingly obtained is, and lithium carbonate crystals with the particle size within the range of 20-200 nm can be obtained by adopting a lithium carbonate saturated solution or a diluent of the saturated solution. In addition, the saturated lithium carbonate solution is used for preparing the nano lithium carbonate with the highest yield, so the saturated lithium carbonate solution is preferably used industrially.

As a preferred scheme, the freezing temperature is-80 to-20 ℃. The lithium carbonate solution is rapidly frozen and instantly frozen by controlling the temperature, so that the lithium carbonate particles with uniform particle size can be obtained.

Preferably, the freeze-drying time is 3 to 48 hours. The growth of lithium carbonate particles in the water sublimation process can be effectively prevented through freeze drying.

As a preferable mode, ethanol is added to the lithium carbonate solution to promote the generation of lithium carbonate crystal nuclei. Because lithium carbonate is insoluble in ethanol, ethanol is a poor solvent of lithium carbonate, the poor solvent can ensure that lithium carbonate particles in a lithium carbonate solution are instantaneously and massively nucleated to form a large number of nano particles, and the particles almost keep original appearance through freeze drying. The preferable addition amount of the ethanol is 1/5-1/25 of the volume of the lithium carbonate solution, and the size of lithium carbonate crystal grains can be regulated and controlled by adding the ethanol and controlling the use amount of the ethanol.

Compared with the prior art, the technical scheme of the invention has the following beneficial technical effects:

the method for preparing the nano lithium carbonate can realize the regulation and control of the size of lithium carbonate particles within a certain range.

Compared with micron-sized lithium carbonate, the nano lithium carbonate prepared by the invention has higher reaction activity, no impurity is introduced in the process of preparing the nano lithium carbonate by adopting low-temperature freezing and drying, and the nano lithium carbonate has higher purity, has obvious advantages compared with nano lithium carbonate particles prepared by methods such as ball milling, crushing, membrane filtration and the like, can meet the requirement of Good Manufacturing Practice (GMP) of medicine, and is more feasible in preparing medicine-grade lithium carbonate.

The method for preparing the nano lithium carbonate has the advantages of simple steps, controllable conditions, low cost and easy industrial production.

Drawings

Fig. 1 is an XRD pattern of nano lithium carbonate prepared in example 1 and example 2.

Fig. 2 is a scanning electron microscope image of the nano lithium carbonate prepared in example 1.

Fig. 3 is a scanning electron microscope image of the nano lithium carbonate prepared in example 2.

Fig. 4 is a scanning electron microscope image of the nano lithium carbonate prepared in example 3.

Detailed Description

The following specific examples are intended to illustrate the invention in further detail, but not to limit the scope of the claims.

Example 1

Dissolving high-purity lithium carbonate in 25ml of water at room temperature until the lithium carbonate is saturated, filtering the undissolved lithium carbonate, reserving the undissolved lithium carbonate as a lithium carbonate solution for the next process for preparing, placing the filtrate in a cold trap at the temperature of between 50 ℃ below zero and 40 ℃ below zero for pre-freezing to prepare small-particle ice blocks, and vacuumizing and drying for 12 hours under the condition of keeping freezing to obtain high-activity and superfine lithium carbonate white powder. The XRD pattern of the nano lithium carbonate product is shown as 1 in figure 1, and the morphology is shown as figure 2. It can be seen from 1 in fig. 1 that only one pure phase of lithium carbonate is present, and from 2 it can be seen that the particle size is about 100 nm and is in a dispersed state and not dense.

Example 2

Dissolving high-purity lithium carbonate in 25mL of water at room temperature until the lithium carbonate is saturated, filtering the undissolved lithium carbonate, reserving the undissolved lithium carbonate for preparing a lithium carbonate solution for later use in the next process, adding 20mL of water into 5mL of the saturated solution, placing the liquid in a cold trap at the temperature of between 50 ℃ below zero and 40 ℃ below zero for pre-freezing to prepare small-particle ice blocks, and vacuumizing and drying for 12 hours under the condition of keeping freezing to obtain high-activity and superfine lithium carbonate white powder. The morphology is shown in fig. 3, and it can be seen that the particles are about-30 nm, dispersed, and not dense.

Example 3

Dissolving high-purity lithium carbonate in 25ml of water at room temperature until the lithium carbonate is saturated, filtering the undissolved lithium carbonate, reserving the undissolved lithium carbonate for preparing a lithium carbonate solution for later use in the next process, adding 2-5 ml of ethanol into the filtrate to instantly generate a large amount of white emulsion, placing the white emulsion in a cold trap at the temperature of-50 to-40 ℃, and vacuumizing the prepared ice blocks with small particles for 12 hours under the condition of keeping refrigeration to obtain high-activity and superfine lithium carbonate white powder. The XRD pattern of the nano lithium carbonate product is shown as 2 in fig. 1, and it can be seen from 2 in fig. 1 that only one pure phase of lithium carbonate exists, and the morphology is shown in fig. 4, and it can be seen that most of the particles are less than 100 nm, and are in a dispersed state and are not dense.