CS258623B1 - Preparation of a glass batch - Google Patents

Abstract

The essence of the solution for the preparation of the stock is that the glass sand is preferably brought into contact and mixed with boric acid, or components that improve melting, and then with other components such as limestone, dolomite, etc. The prepared stock is suitable for the production of glass fibers. It is possible to adjust the humidity with water with the addition of surfactants and various adhesives, preferably with waste from lubricating compositions.

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)

The preparation of the glass batch was carried out in such a way that about 30% of the glass batch weight was mixed with 50% by weight of boric acid and the entire batch of sodium bicarbonate and 15% for 15-20 seconds. Finally, the components of the glass batch were mixed together. The strain thus prepared was used for the production of glass. In the fiber pulling technology tests, it has been found that, compared to the commonly used method, the pulling power increased by 3 to 4%. Example 2 In an electric oven at 1500 ° C, 80 g of a glass batch of the composition shown in Example 1 were melted. Dry glass sand 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 strain was mixed by a system of pre-mixing the total amount of sand, boric acid, fluorspar and sodium sulphate, and the components of the strain were then mixed. The parallel fused strain was mixed in a conventional manner. Enamel samples were assessed visually and microscopically. In the case of the samples prepared according to the process of the invention, the enamel was clearer in all cases, whereas in the classical sposobubol the ring in the flotated sand was observed. EXAMPLE 3 The tests were carried out as in Example 2 except that the moisture was adjusted with a 0.5% polyvinyl alcohol solution and in a second series with a lubricant composition waste! with a dry weight of 2% by weight. The results obtained confirm that this principle of simple production of the strain significantly affects the melting process, which at the same time allows to control the amount of fluxes and the fluxes. According to the present invention, the inventive strain can be directly metered into the melting aggregate, possibly even preheated or even briquetted to reduce dustiness, depending on the technology used. OBJECT CLAIMS 1. A method for preparing a glass batch, particularly suitable for preparing glass for the production of glass fibers, by mixing raw materials containing, among other ingredients, silica sand and boric acid and / or melting agents such as e.g. boron trioxide, tartrate, calcium fluoride, sodium sulfate, characterized in that the glass sand is preferably contacted and mixed with "boric acid / or melting agents, thus agglomerating the sand with other components of the glass batch. 2. A process for preparing a glass batch by the step of claim 1, wherein in the case where the moisture of the raw material or of the glass mill is less than 1% by weight, it is adjusted by adding water at a maximum of 20% by weight. ynAlezu 3. A process for preparing a glass batch as claimed in claim 2, wherein the moisture is treated with water containing 0.001 to 0.5% by weight of water suppressants, for example surfactants, whether ionic or nonionic, such as acyl polyglycol ethers, alkyl polyglycol ether sulfates, soaps and nitrogen quaternary compounds. 4. A process for preparing a glass batch by the steps of 2 and 3, wherein the moisture is treated with water containing 0.001 to 20% by weight of the mechanical stability agents of the agglomerated sand, for example, polyacrylates, polyvinyl acetate, polyvinyl alcohol. 5. A method of preparing a glass batch by the point of point 4, characterized in that the moisture is treated with the waste of the lubricating composition! from the treatment and processing of glass fibers.