HU211455B - Method for producing heat resisting material systems, incorporating rhyolite-tuff and micro-silicate additives - Google Patents

Abstract

The present invention relates to a process for the production of refractory systems of riolite tuff and microsilicate. The process consists of replacing some of the refractory lining materials built into the monolithic boundaries of fire and workpieces with different temperatures, and replacing them with a relatively inexpensive blend of mineral or waste materials, rhyolite tuff and microsilicate, which - due to their very high specific surface area - by providing a solid phase reaction, they provide a masonry with higher thermochemical and thermophysical resistance and a longer service life at a given technological temperature. The additive pre-homogenized with the binder at the expense of the weight ratio of the feedstock is always a mixture of rhyolite tuff and microsilicate in a ratio of 3: 1, which may be 2 to 10% by weight depending on the maximum technological temperature of the application. EN 211 455 B Description: 4 pages

Description

The present invention relates to a process for the preparation of refractory material systems for the addition of rhyolite tuff and microsilicate. Dry, monolithic, chemical, chemical-ceramic and hydraulically bonded, fire-resistant masonry units, consisting solely of refractory oxides (A1 ₂ O ₃ , SiO ₂ , Cr ₂ O ₃ MgO, CaO), containing no clay minerals refractory or non-refractory consisting of a mixture of raw materials and chemical or hydraulic binders. The process is intended to improve the thermochemical and thermophysical properties of thermal insulating ramming compounds. The corrosion resistance is increased by increasing the compactness and lowering the formation temperature of the ceramic bond, and the strength is increased by the addition of rhyolite tuff and microsilicate by forming a larger and more effective bonding phase.

In accordance with the present invention, chemical, chemical, and hydraulically bonded, refractory ramming compounds are suitable for delimiting high temperature, fire and work areas, both for the monolithic and homogeneous construction of the thermo-chemical and thermophysical working liner, biker-ceramic wood elements, burning stones, ovens platform etc. the preparation.

Cost reduction factors for widespread refractory masonry include the use of monolithic masonry that does not require pre-firing, or the design of a working space made from non-fired "heat only" (up to 600-800 ° C) prefabricated elements.

This saves considerable energy for refractory manufacturers and can give their products a slightly cheaper price.

The user buys products made from expensive raw materials which, when installed, especially in monolithic lining, save time and labor compared to traditional masonry.

However, you need to invest in the energy required for the "on-site firing" of the masonry, even if it is usually done at the same time as the first heating of the heating installation and continuously, rather than during a separate heat treatment. This is where the problems come from.

For example, if a furnace with a working temperature of 1200-1800 ° C is formed with a high lining content over 90-95% of A1 ₂ O ₃ due to the expected frequent heat shock effects, the technological temperature is not sufficient In a refractory structure that reaches a refractory temperature up to ° C, a ceramic bond is formed. so the masonry is quickly destroyed.

In a number of practical cases, such as the example, research and development practitioners have come up with, among other things, a solution for reducing the starting temperature of a solid phase reaction with a glass additive.

Such a solution is described in German Patent Specification No. 2,117,283, according to which glass powder is introduced into the mass, which, during heat treatment, melts the refractory particles and connects them by means of a glassy phase.

However, due to its relatively high (12-16%) alkaline oxide content and low (4-6%) Al ₂ O ₃ content, the glass additive may suddenly melt in certain temperature ranges. This can cause the high refractory particles to slip on one another, which ultimately reduces the strength of the refractory material to an unacceptable extent.

To improve thermal insulation and reduce shrinkage, U.S. Patent Nos. 916,502 and 985,010 suggest several additives containing organic matter and alkalis. The disadvantage of the method is that with the addition of alkalis, the fire resistance deteriorates, as here too low melting point phases are formed, and the burnt organic materials deteriorate the thermophysical properties of the masonry.

Mixture of the aforementioned and similar materials, as raw materials, can be used to improve the dimensional stability and strength properties of prefabricated building materials which, when used in the manufacturing process, obtain their final application properties and do not significantly exceed the combustion temperature or melt corrosion. also significant circumstances.

Such solutions are also described in patent HU 200 434 A, which discloses that coarse ceramic or During the production of refractory materials, transition metal compounds, red sludge, peat are added to the clay mass to reduce drying and firing cracking and to increase thermal insulation.

This concept may be useful for burnt coarse-grained ceramics, but it would be extremely detrimental to the unacceptable reduction in the strength and corrosion resistance of masonry "burnt out" monolithic masonry, and to the toxic effects of toxic materials formed during the combustion or transformation of hazardous wastes.

The foregoing references, which also state of the art, resemble the premixing of all ingredients (dry matter), which in very rare cases will result in a homogeneous mixture after long periods of mixing and may compromise the effect of high refractory components due to its high alkali content.

It is an object of the present invention to use such additives as chemical (e.g., phosphoric acid) or hydraulic (e.g., phosphoric acid) involved in bonding expensive and refractory oxide particles having sufficient thermochemical and thermophysical properties to eliminate said defects, i.e. to increase the corrosion and erosion resistance of refractory masonry. refractory cement) binders which do not impair the other properties of the system and, on the other hand, improve the bond strength of the binder and the workability of the mass.

The present invention is based on the discovery that the 3: 1 mixture of rhyolite tuff powder and microsilicate (3: 1 by weight mixture of iron alloy and melting refractory material) contains no contaminants which are hazardous to the refractory material and does not low melting point eutectics. A mixture of rhyolite tuff and microsilicate can be finely divided into a refractory blend which is an additive.

Due to its lower melting point compared to the system and its high reactivity due to its very high specific surface area, it significantly reduces the starting temperature of the solid phase reaction, thereby improving the ceramic bonding in the refractory material by technological heat, increasing operational safety and durability of masonry.

Thus, the present invention provides a process for supplementing the formulation of masses and concretes known in the art and currently being developed for the production of refractory ramming materials, which are well known in the art, from dry blend (refractory oxide particle blend) and chemical or hydraulic binder. Depending on the expected application temperature, a total of 210% by weight of the refractory system is added to a 3: 1 weight ratio of rhyolite tuff and microsilicate, which improves the cost, quality and durability of masonry at the same time. When determining the new mixing ratio according to the invention, care must be taken that the replacement of the refractory components of the base material mixture in the order of their fire resistance is the component with the lowest fire resistance. by reducing the weight of their creators. (For example, if the base material mixture contains alumina, mullite and silica, mixing should be done at the expense of silica.)

It is an essential element of the process of the invention that the fine-grained (less than 0.1 mm) additives are first mixed homogeneously with the binder and then added to the base mixture in a conventional manner.

The use of additives according to the invention, which are naturally occurring or technological wastes, is supplemented by pre-mixing a 3: 1 weight ratio of magnesium oxide-based rhyolite tuff and microsilicate of the oxide composition (fly-powder) to the chemical binder and cement only. then we apply it to the dry refractory stock.

Example 1

For confining work areas with temperatures up to 1000 ° C, eg. Formulation of refractory materials, modified in accordance with the present invention, for the lining of smoke ducts, heat recovery units, drying ovens, and heat insulating layers of equipment having a higher fire or technological space temperature:

At the expense of the weight or weight ratio of the dry refractory base mixture, a homogeneous mixture of 10% by weight of rolyolite tufficosilicate (3: 1 by weight) is added to the refractory system by first mixing the additive with a binder in a suitable apparatus. for dry ingredients.

Example 2

For refractory masonry units with a maximum process temperature of 1000-1400 ° C - eg. brick and tunnel heat treatment furnace masonry, carriage platform, etc. - formulation of refractories to be used, modified according to the invention:

At the expense of the weight / weight ratio of the dry refractory feedstock mixture, a homogeneous mixture of 6% w / w rhyolite tuff microsilicate (3: 1 w / w) is added to the refractory system by first mixing the additive with the binder.

Example 3

Equipment with a maximum process temperature of 1400-1800 ° C - eg. masonry installations for the transport of ferrous and metallurgical melting and liquid metals, masonry units for oxide ceramics, steel furnaces, burners, etc. - Formulation of refractories for refractory masonry, modified according to the invention:

At the expense of the weight / weight ratio of the dry refractory base mix, in an effort to ensure that the highest refractory component content of the single oxide is not reduced when other multi-oxide components are present in the base blend, 2% w / w rolite tuff microsilicate (3: 1) ), it is first mixed with the binder and then added to the dry base mixture.

Refractory systems can be manufactured either at the manufacturing plant or at the place of use. All requirements for storage, incorporation and heat treatment are identical to those of the pre-modification technology.

Claims (3)

PATIENT INDIVIDUAL POINTS A process for the preparation of riolithufa and microsilicate additive refractory systems comprising the addition of from 2 to 10% by weight of a mixture of riolithuf and microsilicate based on the total weight of the mixture, wherein the weight ratio of riolithuf to microsilicate is 3: 1. Method according to claim 1, characterized in that the added additive is added at the expense of the smallest refractory component or components of the refractory material mixture. 3. The method of claim 1, wherein the additive to be added is first mixed with the binder homogeneously and is then applied to the dry refractory material mixture.