CS258623B1 - Method of glass cement preparation - Google Patents

Abstract

The essence of the stem preparation solution lies in that the glass sand is preferred contacting and mixing with boric acid, or melt-improving components and subsequent with other ingredients such as limestone, dolomite and the like glass fiber production. Humidity is possible treat water with surfactant and various additives adhesives, preferably lubricating wastes composition.

Description

Vynalezeš * refers L | $ P and ^the H, the glass batch, ideal ^ ép £ ^ lave glass for the glass fibers, by mixing raw materials comprising addition of other constituents of the glass sand based on silica, and boric acid and / or agents which improve the melting, such as. boron oxide, aroundanite, borax, calcium fluoride, sodium sulfate.

The ever-increasing demands on the quality of the melted glass, which significantly affects the drawing process in the production of glass fibers, are due to the search for various ways of increasing the performance in the production of fibers. It is known to prepare a glass batch containing boric acid (U.S. Pat. Nos. 4,074,989 and 4,074,991), according to which the quality of glass production is ensured by pelletizing and drying the agglomerates of the batch. This method is demanding in terms of technology and energy. The method of preparation of the strain by conventional mixing, whereby the individual raw materials are transported to the mixer irrespective of their character and function, i.e. unsystematically and usually at the same time, has the disadvantage that the individual components are wrapped in a non-transparent manner. Their mutual contact is inefficient in terms of strain inhomogenization and other effects in the melting process. These disadvantages are substantially eliminated using the method of the invention.

The invention discloses a process for preparing a glass batch, particularly suitable for the preparation of glass for the production of glass fibers, by mixing raw materials containing, among other components, glass sand based on silica and boric acid and / or melting enhancers such as e.g. boron trioxide, aroundanite, calcium fluoride, sodium sulfate. The principle of the invention is that the glass sand is preferably contacted and mixed with boric acid and / or melting agents, and the agglomerated sand thus mixed with other components of the glass batch. The improvement of the mechanical stability of such agglomerated sand can be achieved by using wet sand or the raw materials of the batch, if necessary, in particular depending on the nature of the mixers and stackers. In the case where the moisture is less than 1% by weight, it is preferred to treat it with water by adding at most 20% by weight. Improvement of water wetting can be achieved by adding 0.001 to 5% by weight of the surface tension reducing agents. A wide variety of known surfactants, whether ionic or nonionic, such as various acyl polyglycol esters, alkyl polyglycol ether sulfates, soaps and nitrogenous quaternary compounds can be used for this purpose. Improvement of the mechanical stability can also be achieved by adding 0.001 to 20% by weight of substances with adhesive properties, e.g. polyacrylates, polyvinyl acetate, size, gelatin and polyvinyl alcohol. One of the possibilities for this purpose is also used waste from lubricating compositions! from the treatment and processing of glass fibers, which also contains various surfactants and polymer compounds.

The method of the invention achieves a more even surrounding of solid sand parts with a primary melt made of boric acid, which most effectively affects the diffusion processes used to dissolve the sand. Good and early contact of the primary boric melt occurs in the first phase at low temperatures, i. j. 500 [deg.] C., with silicon dioxide, by its formation and by its low surface tension, the components are more intensively wetted, and in the next phase of higher temperatures, this effect is exacerbated by the fact that boric oxide significantly reduces viscosity. This effect also affects flotation agitation, acceleration of blackening and homogenization rate. As a result, a glass with better fiber production properties is obtained, i.e.. j. production performance will be improved.

In the preparation of the glass batch, a part or all of the weight of the sand, part or all of the boric acid and / or a melting aid is discharged into the mixer. After mixing, the components of the glass batch are added. Wetting may be carried out before mixing the raw materials, during mixing and / or the already mixed strain is wetted.

The invention is further elucidated by way of examples.

Example 1

The raw materials listed in the table were used to prepare glass for the production of glass fibers.

raw material weight (% w / w) moisture (% w / w) glass sand kaolin boric acid dolomite limestone fluorspar sodium sulphate

24.38 5.17 32.98 0.31 11.55 0.00 14.38 15,15 4.72 0.00 1.78 0.00 0.39 0.00

The glass batch preparation was carried out by mixing about 30% by weight of the glass sand with 50% by weight of boric acid and a whole portion of fluorspar and sodium sulfate for 15 to 20 seconds. Finally, the ingredients of the glass batch were mixed. The strain thus prepared was used to make glass. Technological pulling tests have revealed that the pulling performance has been increased by 3 to 4% compared to the conventional method.

Example 1 and d 2

80 g of a glass batch having the composition given in Example 1 were melted in an electric oven at 1500 ° C. The glass sand after drying was treated with water containing 0.05% by weight of oxyethylated nonylphenol to a moisture content of 1.5%, 3.0%, 8.0% and 16.0% by weight. The batch was mixed with a system of premixing the total amount of sand, boric acid, fluorspar and sodium sulphate before the batch components were mixed. In parallel, the fused batch was mixed in a classical manner. Enamel samples were evaluated visually and microscopically. In the case of samples prepared according to the process of the invention, the enamel was in all cases clearer, whereas in the classical manner a ring in the flooded sand was observed.

Example 3

The tests were carried out as in Example 2 with the difference that the moisture was treated with 0.5% polyvinyl alcohol solution and in the second series by the waste of the lubricating compositions! With a dry matter content of 2% by weight. The results obtained confirm that this melting process is significantly influenced by this essentially simple method of batch preparation, which at the same time makes it possible to control the amount of fluxes and the type of fluxes. The strain prepared according to the invention can be directly dosed into the heating unit, optionally pre-heated, or even briquetted in order to reduce dustiness during handling, depending on the technology and machinery used.

Claims (5)

A process for preparing a glass batch, particularly suitable for preparing glass for the production of glass fibers, by mixing raw materials comprising, among other components, glass sand based on silica and boric acid and / or melting agents such as e.g. boron oxide, aroundanite, calcium fluoride, sodium sulfate, characterized in that the glass sand is preferably contacted and mixed with boric acid and / or melting agents and the agglomerated sand is mixed with other components of the glass batch. 2. The method according to claim 1, characterized in that in the case where the moisture content of the raw material or of the glass batch is less than 1% by weight, it is treated by adding water in an amount of at most 20% by weight. INVENTION It 3. A process according to claim 2, characterized in that the moisture is treated with water containing from 0.001 to 0.5% by weight of a surfactant, for example surfactants, whether ionic or non-ionic, such as acyl polyglycol ethers, alkyl polyglycol ether sulfates, soaps and nitrogenous quaternary compound. 4. Process according to claim 2, characterized in that the moisture is treated with water containing from 0.001 to 20% by weight of substances improving the mechanical stability of agiomerized sand, for example polyacrylates, polyvinyl acetate, polyvinyl alcohol. 5. A process according to claim 4, characterized in that the moisture is treated by the waste of the lubricating compositions from the treatment and processing of the glass fibers.