JPS58190900A - Production of quartz crystal - Google Patents

Abstract

PURPOSE:To produce a quartz crystal easily by making use of a concn. phenomenon at an ordinary temp., by mixing a soln. contg. iron and a soln. contg. silicon dioxide, adding a seed crystal to the mixed solns. and allowing the solns. to stand. CONSTITUTION:A soln. prepd. by dissolving iron to 4-12 normal nitric acid and an aq. soln. of silicate or silica gel are mixed and a seed crystal of quartz crystal is put in the mixed soln. If the soln. is allowed to stand thereafter, the quartz crystal crystallizes in the gellike material contg. SiO2 produced in the soln. The inexpensive quartz crystal is thus obtained without using any intricate and costly device and installation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing quartz, which is a refractory oxide, by utilizing a room temperature concentration phenomenon.

Quartz has a wide range of uses, including abrasive materials, watch bearings, jewelry, and record needles. Conventionally known methods for obtaining single crystals of refractory oxides include (1) pulling method, (2) EFG method, (2) heat exchange method, (2) Bakdazarov method, (2) Bernoulli method, and (2) flux method.

Methods (1) to (2) are all methods in which raw materials are placed in a crucible or container, heated to high temperatures, melted, and grown under seed crystals. ■
It is the same as ① to ③ in that it does not use a melting pot or container, but the raw materials are melted at high temperatures.

■The raw materials are flux agent PBO and crystal stone (Naμ/7
6) is melted at a temperature lower than its melting point, and crystals are crystallized. Either way, at least 10
It is necessary to raise the temperature to a temperature of 00° C. or higher, and therefore a high melting point metal material such as platinum, iridium, or molybdenum must be used for the crucible or container. Special materials and equipment are also required for the high-temperature melting needle and heating element.

The present invention provides a method for easily producing crystal using a room-temperature concentration phenomenon without using complicated and expensive equipment.

The method of this invention is to mix a solution containing iron (Fe) and a solution containing silicon dioxide (8102), add seed crystals to this mixed solution, and leave it to grow crystals by concentration at room temperature. It is a feature.

For example, if you mix a solution of Fe in 4-12 nitric acid and an aqueous solution of silicate or silica dal and leave it to stand, crystals will form in the shell-like substance containing 5to2'i produced in the solution. Crystallizes. This crystal growth requires Fe in solution.
It is thought that (OH)3 or 5i02 Dal acts as a catalyst.

The basic advantage of the method of this invention is that it does not require high temperatures unlike conventional methods and can be easily carried out at around room temperature. The size and growth rate of the resulting crystals are controlled by controlling the concentration of the solution, temperature, degree of supersaturation, etc., and by introducing seed crystals.

This invention will be described in detail below. Prepare two 100CC beakers, and add about 50% of 8-regulation nitric acid to one beaker.
CC is inserted, and an iron rod containing trivalent Fe (2 groups φX
30+mn) was added. Furthermore, N was added to adjust the pH concentration.
Approximately 5 cc of aOH was added. In the other beaker, add 50C water.
Add C and dissolve silica gel to make 5IO2 concentration 5
A 0 ppm silica solution was made. It is also possible to mix these solutions little by little alternately to finally achieve 3-hole growth.

Put everything into one beaker, add quartz seed crystals to it, and leave it for 5 days. As a result, quartz crystals were formed on the seed crystals.

Although the embodiments have been described above, the method of the present invention is not limited to simple concentration from a solution, but may also be hydrothermal synthesis at about 200° C. under pressure. Further, in the above embodiment, nitric acid was used to dissolve Fe, but a mixture of nitric acid and other acids may also be used. Furthermore, for solutions containing 5i02, N
An aqueous solution containing a silicate such as a 2 Si O 3 or 2 SiO 3 which produces 5I02r when mixed with a solution containing Fe can be used.

The effects of this invention can be listed as follows. (1)
Quartz crystal, which conventionally could only be grown at a high temperature of at least 1000° C., can be produced extremely easily at room temperature. (2) Heat-resistant container.

Complex and expensive devices and equipment such as high-temperature melting equipment are not required, and therefore inexpensive crystal can be provided. (3) Crystal growth can be performed on seed crystals by controlling the pH of the solution to 8 degrees, etc.

Claims (2)

[Claims] (1) Mix a solution containing iron and a solution containing silicon dioxide,
A method for producing crystals, which comprises adding seed crystals to this mixed solution and leaving it to stand. (2) The solution containing iron is a solution in which iron is dissolved in 4-12 nitric acid, and the solution containing silicon dioxide is a solution in which silicate or silica glu is dissolved in water.Claim 1
2. Method for producing crystals described in Section 1.