SU1204588A1 - Charge for producing fluorinated glass - Google Patents

Description

one

The invention relates to the technology of glasses, in particular fluoride glasses, and can be used to create optical materials intended for the IR region of the spectrum.

The purpose of the invention is the visualization of optical characteristics.

The proposed method is carried out as follows.

The mixture of raw materials is placed in a platinum crucible, which is loaded into the chamber from platinum, and begin to pass helium. The temperature in the furnace is constantly raised to 780-800 s and the melt is held at these temperatures for 0 h, after which the glass is cast into a brass mold and annealed.

The advantage of the invention is that fir based on complex fluoride compounds does not contain metal oxides. The temperature range of glass formation in the fluoride charge and the thermal decomposition of the fluorine-ammonium salts of zirconium or hafnium and other salts are close (400-700 s). This helps preserve the fluorinating medium in the melt at high temperatures, thereby reducing the presence of oxygen and hydroxyl groups in fluoride glass. In addition to TorOj, the thermal decomposition of fluorine-ammonium co, proceeds as follows:

(KHjjZrF, -bxNH). t.

NH ZrF

. ZrF,

and is not associated with the release of water and hydroxyl groups. Complexing fluorides, unlike fluorides of zirconium, hafnium, aluminum and lanthanum, do not form crystalline hydrates and are more stable with respect to water vapor. These compounds are significantly less aggressive, in contrast to individual fluorides of zirconium or hafnium, lanthanum, barium, etc. With the introduction of fluorozirconates, fluoro-naphthenes, fluoro-alucate salts, etc. into the mixture. the duration of the process of synthesis of fluoride glasses is reduced due to the fact that no additional time is required for their formation when the charge is heated, as observed 5: during the synthesis of glasses based on individual O / 5 8 82

fluorides, in the melt, the groups characteristic of fluorocirconates or fluorogunnates, fluoroaluminates, etc. are retained. As a result of this, the homogeneity of the synthesized fluoride glasses significantly increases. In addition, the homogeneity of fluoride glasses is also enhanced due to the lower volatility of complex fluorides in comparison with individual fluorides. An additional advantage of using highly soluble fluorine-ammonium salts in water is the possibility of their deep cleaning with simple: and technological hydrometallurgical methods, which is practically impossible for heavy metal fluorides due to their insolubility.

Moreover, additional purification of alkali and alkaline earth metal fluorocirconates or fluorine fluids is easily achieved due to their preliminary vacuum melting.

25 A decrease in the content of oxygen and hydroxyl groups dissolved in a melt leads to a broadening of the transmission limits in the synthesized glasses due to the increase in the optical density

Hde homogeneity. Fluorozirconate. Or

Ammonium fluoride fluxes are a semi-product in technological schemes for producing metallic zirconium IIIHf, which significantly reduces the cost of fluoride glass. Example 1. For the production of fluoride glass in the gGHz-BaF-LaF-j-NaF system, the components presented are taken as starting materials.

in tab. one . 40

The crucible with the mixture of initial components is placed in a platinum chamber, closed with platinum and helium is passed through the system. The temperature in the furnace is raised to and the melt is held for 1.0 h, after which it is cast into a preheated brass form and annealed at a temperature close to

50 transformation temperature, glass (THAT). The result was 30 g of fluoride glass, the properties of which are given in table. 1. Uniformity with: tech.p. is estimated by the change in the index

55 pr | breakage by sample volume. When measuring the optical characteristics of glasses, the sample's crowd was 5.

35

Example 2. To obtain fluoride glass in the BaFj-LaFj-NaF-AlF system, the components shown in Table 2 are taken as starting materials. 2. A crucible with a mixture of initial components is placed in a platinum chamber, closed with a platinum crack and helium is passed through the system. The temperature in the furnace is raised to 800 ° C and the melt is held for 1.0 h, after which it is cast into a preheated brass mold and annealed. The glass output is 30 g.

The properties of the glass obtained are given in Table. 2

Example 3. To obtain a fluoride glass in the HfE / -BaFj-LaFj-NaF system, the components represented by the

NaLaF ,.

2, 79 7.31

270 340

BaZrF,

9.77 25.59, 4.89 12.81 (NH) 3ZrF6 20.73 54.29

NaLaFj (BaZrFg

2.73 6.96

7.43 18.94 300

,, 4.28 10.91 (23.14 58.99 BajAlgF 1.65 4.20

in tab. 3. The process of obtaining fluorine-garnate glass is similar to the process of obtaining fluoride glasses, shown in examples 1 and 2. The cooking temperature of this glass. Received 30 g of fluorine glass.

The properties of the synthesized glass are given in table. 3

The use of the proposed blend for obtaining fluoride glasses provides for increased optical homogeneity of fluoride glasses by reducing the content of oxygen and hydroxyl groups, which leads to an increase in the boundaries of spectral transmission and a decrease in optical loss.

In addition, the invention makes it possible to reduce the cost of fluoride glasses.

Table 1

90 0.2-7.3 Missing .. .. ± 0.001

.Table 2

90

0.2-7.3

Missing

tO, 001

NaLsF /, 2.025.62

BaHfF 9.1525.46

, 5.1414.30

(NH) jHfFr19,6354,62

288 380 95 0.23-8.0 Missing ± 0.001

Compiled by 0. Samokhina Editor N.Kishtulinets Tehred Z.Kastelevich Corrector M. Demchik

Order 8488/23 Circulation 456 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-358 Raushsk nab. 4/5

Branch 1ShG1 Patent, Uzhgorod, st. Project, 4

Table 3

Claims (2)

1. BATTERY FOR PRODUCING FLUORIDE GLASSES of the BaF _z -LaF ₃ -NaF-ZrF <, or HfFj system, comprising a compound of zirconium or hafnium and alkali, alkaline-earth and rare-earth fluorides, characterized in that, in order to increase the optical characteristics glass, it contains as compounds of zirconium for -gafnium and fluorides of alkaline, alkaline-earth and rare-earth elements. (NH4) ₃ ZrF ₆ or (NH _{1 (} ) ₃ HfF _? , NaLaF ₄ , BaZrF ₆ or BaHfF ₆ , Na ₇ Zr ₆ Fj., Or Na ₇ Hf ₆ F _3f in the following ratio, May.%: (NH “) ₃ Zr F ₆ or (NH _ll ) ₃ HfF ₇ 54.29-58.99 NaLaFj, 5.62-7.31 BaZrF ₆ or Bahff ₆ 18.94-25.46 Na ₇ Zr ₆ F _3t wni Na ₇ Hf ₆ F ₃₁ 10.91-14.30 e 9 2. The mixture of pop. 1, characterized in that it further contains Ba ₃ Al ₂ F _n in the amount of May 4.2.