DD159987A1 - METHOD FOR PRODUCING IMPROVED GLASS HYBRID MATERIAL - Google Patents

Abstract

The invention relates to a method for producing a glass raw material mixture using the hydroxides or oxides of the alkali and / or alkaline earth metals, which avoids the problems previously associated with the hydroxide technology. The aim of the invention is the production of a glass raw material mixture, which allows for good technological properties (production, transport, storage, use) an increase in the throughput of glass melting tanks and thus at the same time energy savings. According to the invention, d. Problem solved by d. Alkali in a known manner completely o. Partly used in the form of aqueous sodium hydroxide solution and the introduced and the resulting water in the reaction by a mixture components containing surface and pore rich residue of the acidic extraction of aluminum silicates is absorbed and thus no longer impair the technological handling of the batch can.

Description

231168 4

A process for the preparation of improved glass raw material mixture

Field of application of the invention

The invention relates to a method for producing a glass raw material mixture using the hydroxides or oxides of the alkali and / or alkaline earth metals, which avoids the disadvantages previously associated with the hydroxide technology. ,

O.

Characteristic of the known technical solutions

With the replacement of alkali metal carbonates by aqueous alkali metal hydroxides, preferably sodium hydroxide, possible advantages, eg. B. '

Improved batch homogeneity by using a raw material in liquid form

improved smelting due to increased reactivity improved thermal conductivity of the denser mixture reduced or eliminated dust nuisance elimination of segregation phenomena of the batch

231168

Long ago, efforts were made to develop appropriate technologies.

To date, numerous publications and patent applications have published proposals that address the problems associated with hydroxide technology.

- Creation and handling of pulpy doughy masses

- Baking phenomena of UaOH-CaCO ^ -SiC ^ amounts during mixing, conveying and inserting

- inhomogeneous melting in granules

- Corrosion of harbor material

to eliminate or to circumvent

Raise recommendations on proportionate replacement of soda by aqueous sodium hydroxide, use of highly concentrated sodium hydroxide or use of sodium hydroxide slaked lime to reduce the amount of water supplied in a series of proposals fully or partially pre-reacted mixtures with or without shaping with subsequent drying or sintering, partially in an acidic atmosphere, recommended. Here, for example, the use of alkaline earth oxide and soda and the setting -des. Caustification balance during the mixture is a part of possible Vorr reactions.

In further proposals and pablications for the use of aqueous sodium hydroxide solution in the glass batch, intensive grinding of the glass sand to increase the reactivity and thus u * ä, to improve the homogeneity of the melting and reducing the corrosion of the port material by caustic soda or alkali-rich silicate

231168

recommended to melt. Other proposals include the use of naturally occurring amorphous silica (opal) or cristobalite, tridymite, or alkali or alkaline earth silicates for the same reason. All of these procedural proposals have found no or only limited technical application, since they either

- worked with cumbersome, additional and more expensive process steps and / or

- supplied technologically difficult to handle mixtures and / or

- Contained with additional effort silicosis problems and / or

- use only territorially limited or expensive raw materials.

OBJECT OF THE INVENTION O

The aim of the invention is the production of a glass raw material mixture which, with good technological properties (production, storage, transport, use) (torch combination of the use of reactive glass raw materials, increases the throughput of glass melting tanks and thus at the same time enables energy saving. '

231168 4

Explanation of the essence of the invention

The invention has the object of producing a glass raw material which has the advantages of hydroxide technology when using alkali metal hydroxides and alkaline earth oxides or carbonates and is technologically easy to handle without the use of additional expensive process stages.

According to the invention, the object is achieved in that the alkali is used in a known manner wholly or partly in Porm aqueous alkali solutions and the introduced and the resulting water in the reaction is adsorbed by the addition of a mixture components containing surface and pore-rich substance obtained by treatment of aluminosilicate-containing raw materials is made with mineral acids.

It has now been examined in experiments on Glasrohstoffgemengen according to a target glass composition SiO ₂ 68 %; Ia ₂ O 15 % ', CaO 11 %>, Al ₂ O ₃ 3 %; TiO ₂ 3 %

when using the total amount of Na ₂ 0 as 50% KaOH of the SiOrj content gradually replaced by sour highly extracted aluminum silicates (hereinafter referred to as extraction residue) and tested the behavior during the batch mixture and storage. , , It is well known that glassand hardly reacts with caustic soda and the causticization equilibrium

CaCO ₃ + 2UaOH z = ± Na ₂ CO _3. + Ca (OH) ₂

largely on the side of the calcium carbonate and is slow to adjust.

231168

In contrast, it was found that sodium hydroxide solution with sufficient supply with the chemically highly active, surface and pore-rich and X-ray amorphous extraction residue with strong Y / poor development. Furthermore, it has been found that, with gradual replacement of the glass sand by extraction residue, initially liquid pulpy mixtures are formed which are not suitable as feed material due to / thixotropic properties. These unfavorable mixed states are causally due to the fact that in the formation of sodium silicates water is formed in addition to the amount of water of the sodium hydroxide and thus changes the state of mixing in the direction of low-viscosity consistency.

If the amount of extraction residue added increases in order of magnitude in excess of that required for a quantitative reaction of the added caustic soda solution, then the proportions of water present in the batch are physically adsorbed on the large surface of the extraction residue.

The adsorption of Y / ater of unreacted Extraktiohs- '' - .. J residue affects the batch consistency of such glass raw material mixture of the more, the higher the proportion of adsorptionsfähigem material.

The extraction residue can, due to its pore structure and its high surface area, the

2 3oo. m · / g, with good technological

^: ';''. habitat up to 60 % of its own weight on Wa'öser '.

According to the invention, the problem of unsatisfactory. Consistency of the mixture achieved in that at least 30 % of the SiOp content by extraction residue instead of .. Glassand are introduced to granulated or krümlige

231168 4

Glass raw material mixture based on the use of aqueous sodium hydroxide solution to produce. Such mixtures are · storable and transportable, do not dust and allow by improved smelting and lautering behavior, a substantial increase in the throughput of glass melting tanks.

The invention will be explained in more detail by way of examples.

Example 1:

To a sodium hydroxide mixture for container glass 62.5 parts of extraction residue with 21.6 parts of glass sand and

20.4 Parts of limestone intimately mixed. To this mixture, 38.7 parts of a 50% sodium hydroxide solution were added in a forced mixer and mixed thoroughly, with heat development occurred. The resulting mixture had a good chemical homogeneity from a good homogeneity, was crumbly, Granalienhafter nature and gave at a melting temperature of 1300 ⁰ G in 4 hours a green glass of very good quality.

Example 2_;

89.5 parts of extraction residue were intimately mixed with 20.4 parts of limestone and then admixed with 38.8 parts of 50% sodium hydroxide solution and subjected to compulsory mixing. "A pulverulent, homogeneous amount of Ge is formed, which is interspersed with small granules. , :. At 1350 ⁰ ^ a green, bubble-free glass was melted from this mixture without Lautermittelzu- * set in 2 hours.

Example 3? , · ''

In a raw material batch according to Example 2, the entire limestone was completely replaced by 10.8 parts Rübeländer burnt lime, It also resulted in a homogeneous,

231168 k

Crumbly Geraenge, which was melted at 1300 ⁰ C without Läutermittelzusatz in 2 hours to bubble-free glass.

Claims (3)

231168 4 invention claim 1. A process for preparing a glass raw material mixture in granular or bulk material form with improved technological handling characterized in that the alkali used in a known manner wholly or partly in the form of aqueous alkali solutions and the introduced and the water formed in the reaction by adding a mixture containing surface components and porosity-rich substance produced by treating aluminosilica thaitigen raw materials with mineral acids. 2. Method according to item 1 characterized that with the addition of the surface and pore-rich substance 30 - 100%, preferably 75 - 100% of
SiOo of the target glass composition can be introduced » 3. The method according to item 1 and 2 characterized marked characterized in that the alkaline earth component is used in carbonatic, oxidic or hydroxide form ·