Preparation method of high-purity and high-density lithium tetraborate

Abstract

The invention relates to the technical field of preparation of lithium tetraborate, and particularly discloses a preparation method of high-purity and high-density lithium tetraborate. The preparation method comprises the following steps of: carrying out purification on industrial-grade lithium hydroxide by the steps of low-temperature dissolving, filtering, evaporative concentration, cooling crystallization, centrifugal separation and the like; dissolving the purified lithium hydroxide in boiled pure water according to the mass ratio 1:2 of solid and liquid; and according to the content of the lithium hydroxide in the solution, adding the lithium hydroxide into industrial-grade boric acid for neutral reaction according to the rate 105%-120% of stoichiometric numbers in reaction, and then preparing the high-purity and high-density lithium tetraborate by the processes of evaporative concentration, primary drying, crushing, secondary drying, high-temperature melting, water-quenching and cooling and the like. The prepared lithium tetraborate is about 1.4g / cm<3> in crystal density, and is more suitable for the current market demand.

Description

technical field [0001] The invention relates to the technical field of preparation of lithium tetraborate, in particular to a preparation method of high-purity and high-density lithium tetraborate. Background technique [0002] Lithium tetraborate, also known as lithium pyroborate, has a molecular formula of Li 2 B 4 o 7 , the molecular weight is 169.12. High-purity, high-density lithium tetraborate is a new type of temperature-compensated surface wave substrate chip and piezoelectric single crystal substrate material. , satellite communications, national defense technology and many other fields have extensive and important applications. Lithium tetraborate was produced as early as the beginning of the 20th century. However, due to the weak application of chemical technology at that time, lithium tetraborate was not widely used in various industries. It was not until the 1980s that it was gradually applied to the glaze of the enamel industry. In the later period, with t...

AI Technical Summary

Problems solved by technology

Lithium tetraborate was produced as early as the beginning of the 20th century. However, due to the weak application of chemical technology at that time, lithium tetraborate was not widely used in various industries. It was not until the 1980s that it was gradually applied to the glaze of the enamel industry. In the later period, with the promotion of material chemistry, lithium tetraborate was gradually applied to buffers and preservatives, and was also used in the development of new materials. Until the 21st century, with the innovation of iron and steel smelting technology, four Lithium borate is used in wavelength dispersive XRF fluorescence spectrometer, AA atomic absorption and ICP to detect steel components, which officially announces the arrival of lithium tetraborate in the new year, but with the continuous advancement of technology, the high Pure lithium tetraborate (density about 0.7g / ㎝ 3 ) can no longer satisfy the use of the detection industry, and various high-purity and high-density lithium tetraborates are becoming more and more popular

[0003] At present, as far as the production process of lithium tetraborate is concerned, the production of such products in developed countries mainly adopts "reduction, electrolysis, regional melting, vacuum distillation, vacuum sublimation" and other process technologies. Although it has certain application value, the technology is cumbersome and complicated. The process is long, the equipment is expensive, the process conditions are very demanding, the production cost is high, the environment is polluted and difficult to control, and it is not suitable for the current domestic technical conditions