Application of calcium fluoride to preparation of transparent soil, transparent soil prepared from calcium fluoride and production method of calcium fluoride

Abstract

The invention discloses application of calcium fluoride as a transparent solid material in a process of preparing transparent soil. Calcium fluoride is a particle with the size of 0.25mm-2.0mm (or not more than 0.074mm), and the particle is in an irregular shape and has the refractive index of 1.434 and the density of 3.18g/cm<3>. A preparation method of the transparent soil comprises the following steps: preparing calcium fluoride particles and colorless porous liquid with the same refractive index, mixing, vacuumizing (and solidifying). The prepared transparent soil has the physical and mechanical properties capable of meeting simulated saturated sand (or clay), is high in transparency, low in price, nontoxic, harmless, good in similarity to the properties of a natural soil body, can widely replace natural oil, is used for simulating complicated geological conditions, and is effectively used for a model test in geotechnical engineering.

Description

technical field [0001] The present invention relates to a kind of transparent soil and its production method, in particular to a transparent solid material with low refractive index and a water-soluble solution of the same refractive index to prepare transparent soil and its production method, in particular to a kind of calcium fluoride in the preparation of Application in transparent soil, prepared transparent soil and production method. Background technique [0002] In the model test of geotechnical engineering, it is of great significance to explore the nature of geotechnical engineering problems by studying the law and mechanism of soil internal deformation. The traditional soil deformation measurement method is to bury a series of sensors inside the soil to obtain the displacement of some discrete points, but the sensors are easily affected by the disturbance of the external environment, and the measurement results are often not accurate enough, and at the same time, th...

AI Technical Summary

Problems solved by technology

There are disadvantages: first, the edges and corners of broken glass are easy to cause incident light reflection; second, the basic characteristics of broken glass materials are quite different from the basic characteristics of soil; third, the transparent soil made is a translucent material, and non-transparent materials

Disadvantages: First, because the amorphous silica powder or gel is a porous medium, there are many internal micro-pores, the artificial synthetic transparent soil made of it is relatively compressible, and there is still a relatively large difference from the natural soil; second, its vacuum It is difficult to saturate, which affects the transparency effect; the third is the transparent thickness, about 12cm, which limits the further application of artificially synthesized transparent soil in geotechnical engineering model tests

There are disadvantages: first, the calcium bromide solution is highly corrosive and has poor operability; second, the purity of fused silica sand is low, and the price is relatively high, which also limits its wide application in model tests; third, Because the refractive index of fused silica sand is relatively high, the calcium bromide solution with the corresponding refractive index is prepared with a high concentration; as the temperature changes, calcium bromide crystals are easy to precipitate, thus affecting the refractive index of the calcium bromide solution

When using a water-soluble solution to prepare transparent soil (the refractive index of water is between 1.309 and 1.333), the concentration of the solution is required to be relatively high, and at this time crystals are easy to precipitate (for example, the refractive index of the calcium bromide solution should be adjusted to 1.458, At 20°C, the concentration of the solution needs to reach about 65%, and at this concentration, the calcium bromide solution is prone to crystal precipitation due to temperature changes, etc.), thus changing the concentration and affecting its refractive index