CN112320844A

CN112320844A - Preparation method of lithium fluorozirconate

Info

Publication number: CN112320844A
Application number: CN202011397126.9A
Authority: CN
Inventors: 严永生
Original assignee: Nantong Keyong Technology Equipment Co ltd
Current assignee: Nantong Keyong Technology Equipment Co ltd
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-02-05

Abstract

The invention discloses a preparation method of lithium fluorozirconate, wherein metal zirconium or zirconium compound is dissolved in hydrofluoric acid or fluorine-containing solution, and excessive metal lithium or lithium compound is added to form lithium fluorozirconate solution. Desorbing metal ion impurities by using lithium fluozirconate solution ion resin, concentrating by electrodialysis, drying at low temperature in vacuum, drying by using a high-temperature oven, and crushing into a finished product.

Description

Preparation method of lithium fluorozirconate

Technical Field

The invention relates to a preparation method of lithium fluorozirconate, belonging to the field of fine chemicals.

Background

Metallic beryllium also has special nuclear properties, such as a low neutron absorption cross section and a high neutron scattering cross section, and therefore another important application thereof is as a material for a reactor reflecting layer. It can make scattered and leaked neutrons return to the reactor core. Especially, it can be used as neutron reflecting layer and neutron speed regulator under the condition of light weight, small volume and high neutron flux.

A Molten Salt nuclear Reactor (MSR) is a Reactor using Molten Salt in a Molten state, in which a fissile material is dissolved, as nuclear fuel, and is a Reactor of a nuclear power generation technology commonly used at present. The molten salt nuclear reactor is a liquid nuclear fuel prepared by directly dissolving nuclear fuel into molten salt in a molten state. Molten salt nuclear reactors are determined as one of the fourth-generation nuclear reactor design proposals that are preferentially developed in the international seminar of the fourth-generation nuclear reactors held by tokyo in 2002 because of their advantages such as extremely high neutron economy, high power density, controllable inherent load, large negative temperature coefficient, high conversion ratio, high reliability, low fuel combination consumption, and high breedability. And the molten salt has higher requirements on the content of anions and metal ions. Wherein the metal ion content is less than 100ppm and the anion content is less than 100 ppm. Wherein the content of metal ions such as Fe ions, Co ions, Ni ions, Mn ions, Cr ions, Ti ions, Mo ions, Al ions and W ions in the molten salt is controlled, and the content cannot be too high.

Disclosure of Invention

The invention aims to solve the technical problem that the ion content is high by adopting a plurality of purification means aiming at the current method for preparing high-purity beryllium fluoride.

In order to solve the technical problems, the invention adopts the following technical scheme:

a preparation method of lithium fluorozirconate comprises the following steps:

dissolving, namely dissolving metal zirconium or a zirconium compound in hydrofluoric acid or a fluorine-containing solution, and adding a metal lithium or a lithium compound to form a lithium fluorozirconate solution;

secondly, removing impurities: passing lithium fluorozirconate through a resin tower for ion exchange adsorption;

thirdly, concentrating: introducing the purified lithium fluozirconate solution into electrodialysis for concentration;

fourthly, freeze drying: primarily drying the concentrated fluorine-containing lithium zirconate solution by freeze drying;

fifthly, high-temperature drying: after freeze drying, crushing and granulating after high-temperature drying;

sixthly, wherein the content of alkali metal ion single ions is lower than 500ppm, and the content of other metal ion single ions is not more than 150 ppm.

The lithium-containing material can be metallic beryllium, or lithium fluoride, lithium hydroxide, lithium oxide, lithium carbonate or lithium-containing ore raw material.

The hydrofluoric acid is electronic grade hydrofluoric acid or electronic grade hydrogen fluoride gas.

Detailed Description

Example 1:

firstly, dissolving: dissolving metal zirconium by 49% electronic grade hydrofluoric acid, and adding pure water 3 to obtain a zirconium-containing solution 4 with the mass content of more than 100 g/L; adding metal lithium, and removing impurities: introducing the beryllium-containing solution 4 into a 5-resin tower for ion exchange adsorption; the ion exchange resin adopts cation exchange resin, anion exchange resin and mixed resin which are connected in series to treat the beryllium-containing solution. Thirdly, concentrating: introducing the purified beryllium-containing solution 5 into an electrodialysis 6 for concentration;

fourthly, freeze drying: the concentrated beryllium-containing solution is subjected to primary drying by freeze drying 7; fifthly, high-temperature drying: drying the freeze-dried mixture at high temperature for 8 hours, and then drying the freeze-dried mixture in a sectional manner, wherein the drying is carried out by heating the freeze-dried mixture at 120 ℃ for two hours, heating the freeze-dried mixture at 180 ℃ for eight hours, heating the freeze-dried mixture at 360 ℃ for 12 hours and heating the freeze-dried mixture at 400 ℃ for 12 hours. Sixthly, wherein the content of alkali metal ion single ions is lower than 500ppm, and the content of other metal ion single ions is not more than 150 ppm.

Claims

1. A preparation method of lithium fluorozirconate is characterized by comprising the following steps:

dissolving, namely dissolving metal zirconium or zirconium compound in hydrofluoric acid or fluorine-containing solution, and adding metal lithium or lithium compound to form lithium fluorozirconate solution;

impurity removal: passing lithium fluorozirconate through a resin tower for ion exchange adsorption;

③, concentrating: introducing the purified lithium fluozirconate solution into electrodialysis for concentration;

and fourthly, freeze drying: primarily drying the concentrated fluorine-containing lithium zirconate solution by freeze drying;

drying at high temperature: after freeze drying, crushing and granulating after high-temperature drying;

wherein, the content of single ion of alkali metal ion is lower than 500ppm, and the content of single ion of other metal ion is not more than 150 ppm.

2. The method for preparing lithium fluorozirconate according to claim 1, wherein: the lithium-containing material may be metallic beryllium, or lithium fluoride, lithium hydroxide, lithium oxide, lithium carbonate or a lithium-containing ore material.

3. The method for preparing lithium fluorozirconate according to claim 1, wherein the method comprises the following steps: the hydrofluoric acid is electronic grade hydrofluoric acid or electronic grade hydrogen fluoride gas.