JPS59141491A - Spodumene mineral - Google Patents

Abstract

PURPOSE:The titled inexpensive mineral free from inclusion, using a flux comprising a proper amount of mixed powder having a composition of Li2O.V2O5, equal to that of spodumene crystal, synthesizing a crystal from it by an F.Z furnace. CONSTITUTION:LiOH, Al2O3, SiO2, and Cr2O3 are weighed to prepare mixed powder having a composition of Li2O.Al2O3.4SiO2.0.005Cr2O3, blendd, and sintered to give a raw material rod. LiOH and V2O5 are weighed to prepare a composition of Li2O.V2O5, which is blended with about 20wt% of the mixed powder to give blended powder, which is molded and sintered to give a sintered pellet of flux. A beryl crystal synthesized by flux process as a seed crystal is cut in such a way that it is longer in the direction of C-axis, and it is processed to given size. The pellet of flux is placed on the seed crystal 2, the tip of the raw material rod 1 is brought into contact with the top of the pellet, the flux is melted under heating by the halogen lamp 5 in the rotary elliptic mirror 4 of F.Z furnace, to grow a spodumene crystal.

Description

Detailed Description of the Invention Subodiumene crystal has a composition of Li20w “2”314
E3i02 is made of a monoclinic system, decomposition-melting type material, and has a melting temperature of 1500 to 2000°C.

Conventionally, the flux synthesis method is considered to be the main method for artificial synthesis. However, the flux method requires a platinum crucible for the following reasons.

■ Strict control of synthesis temperature.

■ A large amount of molten salt (7 wo/ku) is used.

■ It is difficult to prevent the occurrence of crystal defects (feezy inclusions).

■ Crystal growth rate is low.

Moreover, it is extremely expensive to manufacture.

The present invention provides an inexpensive synthesis method as an alternative to the above methods. The basic idea is an improved modification of the well-known F.2 method. That is, the synthesis conditions were newly devised using a well-known infrared concentrated heating single crystal manufacturing apparatus (abbreviated as F, Z furnace). This method: ■ Does not require a platinum crucible ■ The amount of flux used is extremely small.

■ In the conventional ρ7-works method, crystal defects can be controlled using a non-inclusive control parameter.

■ The crystal growth rate can be increased compared to the flux method.

■ Crystal growth direction can be controlled arbitrarily.

As a result, the process has higher throughput and is cheaper than the previous flux method.

Examples will be described below.

Example 1 First, raw material powder is prepared. Reagent grade lithium hydroxide (L70I(), aluminum oxide (AjhO3)
, rL cation'y ii ("zO2), chromium oxide (C
r203], weigh L4. o, hp2o3.4
A mixed powder having a composition of szo2°0.005Cr203 is prepared. Next, the mixed powder is mixed and pulverized for 50 hours or more using a ball mill. At this time, the material of the pot and pole is a high-purity sintered material of TERMINA. Next, a sintered rod is produced from the mixed powder by the well-known F, Z method for producing raw material rods. This becomes the raw material rod for the F and Z furnaces. On this occasion,
LioH undergoes a decomposition reaction and becomes an Lj2o composition.

Next, as a flux, reagent grade lithium hydroxide (LjOH) was used as a flux, so that the composition was Li2O#V2O3.
and vanadium pentoxide (vzOs).

The above Li2 o, h, g2 o3°4si○2 is added to the powder.
．． Powder with the composition of Sail 005Cr203 in a weight ratio of 20
Add the equivalent of %.

The mixed powder is then molded and sintered to produce disk-shaped sintered pellets. Next, as a seed crystal, a beryl crystal synthesized by a flux method is cut long in the C-axis direction and processed into a predetermined size.

Next, the items f and F prepared in advance through the above process
, ZfVr are set, and crystal synthesis is performed.

The F and Z furnaces generally have the structure shown in FIG. 1, and may be, for example, the 5C-2 type manufactured by Nichiden Kikai Co., Ltd. That is, ■ is the raw material rod, ■ is the seed crystal, and ■ is the raw material rod.
There are two focal points for the spheroidal mirror; one is a heat source with a nozzle pump, and the other is a molten flux. ■ is a transparent quartz tube, ■ is a lens, and ■ is a screen to monitor the synthesis situation.

■ and ■ are upper and lower rotation axes, and control the rotation and vertical movement of ■ and ■.

First, a flux pellet is placed on top of the seed crystal (2), and the raw material rod is brought into contact with and set directly above the pellet. In this state, the electric power of the logen one is increased to melt 75 txf, and the state in which the flux is held between the yuzu crystal (1) and the raw material rod (2) by surface tension is maintained. After that, the molten flux part was held at 1100°C, and the vertical axis was turned in the opposite direction, 50 r, p,
Rotate at η2 and hold for 10 hours. Thereafter, the electricity and oxygen are moved downward while maintaining the vertical distance of the melting zone. In this case, the movement speed immediately corresponds to the crystal growth rate, degree. The crystal growth rate must be controlled, as inclusions will occur if it is too large;
, /DAY. At a growth rate lower than this, a crystal without inclusions can be produced, and at a low rate, there is a greater margin of control over other growth conditions, and growth can be made easily.

Crystal growth proceeds at the interface between the melt and the crystal, so when the synthesis is completed, the lower crystal can be used immediately as a spodiume crystal by cutting off the upper flux solid, and post-processing is especially necessary. I don't. With the above method, 0
．． Subojiu and men without inclusions were synthesized at a speed of 1 to 1 Q, , /[)AY.

The diameter of the crystal is approximately 5 to 15π1.

Example 2 Synthesis was carried out under the same preconditions as in Example, with the arrangement of the raw material rod (2) and the seed crystal (2) reversed upside down. moreover,
While holding at 1100°C in the first stage, the upper seed crystal and the melt were not brought into contact with each other, and the melt was maintained at the upper end of the lower raw material rod by surface tension, and after 10 hours, It was brought into contact with seed crystals and allowed to grow crystals thereafter.

In this case, it is easy to control the saturation solubility of the melt, and crystal growth can proceed immediately after contact with the seed crystal. The quality of the crystals was determined by observation using a gemstone microscope at 80x magnification, as in the examples, and no inclusions were observed.

Example 3 Under the same conditions as in Example 1, the molar ratio of v205/Li2O was changed as the composition of the flux pellet, and as a result of the experiment, subodiumene with rarely observed inclusions was synthesized in the range of 1 to 5. It was done.

Example 4 An experiment was conducted under the same conditions as in Example 1 while changing the crystal growth temperature, that is, the melt temperature. The temperature is calculated by converting the fluctuation in the power of the No. This result is 5/DA
At the growth rate of Y, growth without inclusion runs is possible between 950 and 1200°C.

Example-5 As a flux pellet under the same conditions as Example 1,
We experimented with Li20-MoO3 system. As a result, growth rate: Q. ] ~10+++@”DAY growth temperature = 750~
950°C Composition molar ratio: A range of 2 to 5 (M003//IJi20) is appropriate.

Example 6 Under the same conditions as Example 1, L was
The i2O-WO3 system was tested. As a result, growth rate: 0
．． 1 to J, f1m-AY growth temperature 2800 to 1000° C. Composition molar ratio: Suitable range is 2 to '6 (W03/Giant 20).

Example 7 An experiment was conducted under the same conditions as in Example 1, but with different raw material rod compositions. That is, lithium hydroxide (LiOH), aluminum oxide (#z03), p silicon oxide (5ho2
), manganese oxide (Mn3o4), weigh Li
20゜A7hO3,48j○2.0.003M? L30
4. Prepare a mixed powder having the composition. Hereinafter, a raw material rod is produced using the sintering method of Example 1. Furthermore, crystals are synthesized as in the previous Example 1. As a result, in Example 1, crystals colored emerald and green were produced, whereas in this example, crystals colored fiwok were produced. Moreover, the shading of the color tone could be created by changing the amount of manganese oxide added.

As the amount of addition increases, the color can be increased or decreased from a visually perceptible pale color to a very dark color within the range of 0.001 mol to 0.1 mol.

As explained above in the Examples, the present invention provides F,
The new modification of the Z method is extremely useful.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing an F, Z furnace according to the present invention. ■ is the raw material rod, ■ is the seed crystal, ■ is the two focal points of the spheroidal mirror, ■ is the spheroidal mirror, ■ is the halogen lamp, ■ is the transparent quartz tube, ■ is the lens, and ■ is the screen.
The image of the synthesis situation is observed by (2) and (2). Applicant: Suwa Seikosha Co., Ltd. No. 1

Claims (1)

[Claims] A method for synthesizing crystals using an F, Z furnace, characterized by the use of flux.
Sei-kisubojiumen mineral.