Vývoj a výzkum briket karbidu křemíku nové generace s cílem zvýšení jejich užitných vlastností

Ing. Radka Navrátilová, Ph.D.

The main aim of this paper is possibility of using recycled raw materials in form of new cementitious recipes. Paper is focused on relationship between compounds in matrix, making knowledge about structure and function on microscopic level and create limit its technical properties. Artificial corundum and silicon carbide are increasing especially mechanical parameters of mixture because these materials have number 9 on Mohs hardness scale. Set of measurements about primary characteristics of this materials were done as well as the basic physical, mechanical and material properties of cement mixtures.

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Ing. Radka Navrátilová, Ph.D.

The main aim of this paper is influence of composition samples partially made from recycled silicon carbide on integrity of .products. Since the products are used in the foundry industry, it is necessary to achieve high wholeness and strength of the samples in order to avoid their disintegration during handling. Further restrictions are the requirements of the foundry on the limits of quantity of individual raw materials. Purpose of this research is using silicon carbide waste material and therefore minimalizes of its production and reduces ecological effect on environment by its recycling. A set of measurements simulating the impact of briquettes, with different composition, on concrete from 3 meters was performed, representing the most common way of sample damage in real operation. This series of experiments has been successfully demonstrated that it is possible to accelerate briquette hardening and thus also to increase its workability and primary strength. This change in the physical properties of briquettes was caused especially by replacing part of the cement by other binders on a different chemical base. Minor influence also had shape of size distribution curve of aggregate. On the other hand, various amounts of silicon carbide in the mixture, in the percentages allowed by foundry limit, did not affect the integrity of the sample.

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Ing. Radka Navrátilová, Ph.D.

This document explains and demonstrates the influence of plasticizing additives on concrete – wet cured concrete with aggregate based on silicon carbide specifically. These special products have been designed for the foundry industry and have specific requirements for treatment in their early curing stage. The paper deals with the optimization of the currently used formula in order to increase their mechanical and surface properties by adding several different types of plasticizing additives and/or combinations thereof. Indicators of the measured characteristics have been mechanical tests, surface properties, and bulk density, which represented the SiC indicator of the mixture. With regard to the measured data, it can be stated that the effect of the plasticizing additive on special concrete with SiC aggregate have been considerable and depended very much on the type of additive used and its dosage, as the resulting mechanical properties differed by up to 40%.

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Ing. Radka Navrátilová, Ph.D.

Navržené brikety zlepšují materiálové vlastnosti vyrobku používaných ve slévárenském průmyslu při výrobě litiny. Cílem je také zvýšit úspornost a efektivitu provozu s využitím odpadního materiálu a snížit tak ekologickou zátěž použitím druhotného materiálu.

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Ing. Radka Navrátilová, Ph.D.

Užitný vzor je zaměřen na vytvoření nových produktů briket karbidu křemíku určených pro slévárenský průmysl. Předkládané řešení se týká nové receptury suché směsi pro brikety na bázi karbidu křemíku pojeného cementem, kdy je dosaženo lepší vlastnosti ve srovnání s referenčními recepturami, které prezentuje současná produkce na trhu. Plnivo na bázi karbidu křemíku může být z části recyklovaného nebo druhotného původu.

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