Tatyana Nazarova

STRATEGY OF ECONOMIC DEVELOPMENT OF MARIUPOL PLANT "CERAMIC" BY BRICK TECHNOLOGY IMPROVEMENT.

Report of the XVth scientific students’ conference “Economic and Business. Visions of Future Specialists in Donetsk State University of Management” on 18 April, 2007

Brick is the most ancient building material. The raw materials, which are needed to make bricks, are found everywhere, and methods of its production are very simple.

The Sumerians used plano-convex bricks, flat on one side and curved on the other, as early as 4000 B. C.. Ancient Egyptians and the citizens of Babylon decorated their facades with ceramic bricks. The Great Chinese Wall was also lined with bricks, and the symbol of Russian statehood became an architectural composition of the Kremlin with its toothed walls and towers of red bricks. The ceramic brick was always treated as the work of art, it used to be stamped with its producer’s brands.

In spite of the fact, that brick is one of the oldest building materials ever known, it is commonly used in civil and housing-building today. In Ukraine the most of bricks are produced by method of plastic forming. This method has some disadvantages. One of them is that formed bricks need to be dried. But for getting qualitative brick surface the process of drying must go slowly. As a result, drying takes long time: from 3 days to several weeks. Although some plants add the complex of components into the clay for reducing bursting, pops and wall saltpeter on surface, only few manage to achieve success and get brick surface without any defects.

Today every director of the plant, which uses the method of plastic forming, faces the choice: either to produce high-qualitative but more expensive bricks or cheap but less qualitative brick. To produce more or less qualitative bricks, it is necessary to prolong the term of brick drying and increase the number of improvers in mixture, or to use more qualitative and effective but more expensive raw materials. Long drying rises usage of energy carriers by 1,5 - 2 times. Expensive raw materials result in rise of brick prime-price, because any improvers cost much more expensive than clay. Manufacturing of cheaper but less qualitative bricks has also some disadvantages. It is greatly power-consuming, because clay needs to be thoroughly processed.

Nowadays for many manufacturers of ceramic brick it is strategically very important to improve the technological process in order to get bricks with high aesthetic-decorative properties and increase the product range.

All these facts explain necessity of using effective methods of ceramic brick surface elevation.

At present front bricks and ceramic stones made from artificial building materials are used in housing-building. These front bricks and ceramic stones, as a rule, are manufactured from natural clay with or without face-covering by the method of two-ply-forming, glazing, angobe coating, sputtering with mineral crumb, application of relief stippling on faced surface of brick and heat treatment.

Choosing the methods of brick surface elevation we must, firstly, take into account the fact that each kind of raw materials needs its own specific method of elevation in order to reach necessary aesthetic-decorative effect. It means that when we use specific raw materials for front brick manufacturing, we need to select the most effective methods of brick surface elevation for this kind of raw material.

The main purpose of this work is to create and select elevation methods in order to improve visual characteristics of ceramic bricks, which are manufactured at Mariupol brick plant "Ceramic". The plant uses clay obtained from the quarry, which is near the plant. But this clay is of low quality because of considerable number of lime impurities and salts. As a result such defects as pops and wall saltpeter appear on the brick surface and spoil exterior look of buildings.

We have attempted the method of sputtering man-caused grained materials on a surface of brick - granulose slag and stained crumb. The method of sputtering with granulose slag has appeared to be very effective. Such bricks have the same properties as ordinary bricks have, though they have very good visual characteristics and can be used in brick lying of houses and buildings.

The sputtering with stained glass has resulted in desired decorative effect of brick surface; its aesthetic characteristics were not so satisfactory.

Very unexpected result was obtained when we used slurry, made from milled yellow glass with the addition of only 5% of red glass to it, as covering. After covering the baked brick surface with the clay of slurry and baking it again at the temperature of 1050 oC, we got bright glassy red-vinous covering with the leopard pattern. But after the using slurry of the same composition at the stage of forming we got the covering with dominative dark-vinous colour in its colour spectrum. And if we add definite quantity of clay into the same slurry the colour of the covering is getting dark, almost black. Next interesting composition was obtained by adding yellow and red milled glass into matt white glaze and mixed in such way, that this composition let us get marble effect on the surface. The mixture of colourless frit, clay and milled stained glass lets us get covering with colour and texture like natural stone.

Using of pearlite appeared to be very effective for bricks' decorative elevation. We have devised different compositions of covering, which contain pearlite, stained glass, clay, yellow pigment and other components. As a result we have obtained the covering with good decorative properties, much better than can be obtained with an ordinary brick. Pearlite has been used in different compositions and it has become clear, that the best results can be received from pearlite containing high concentration of muscovite.

It is very important to ensure tough connection of a covering layer with ceramic brick surface after baking. That is why we need to select composition of covering in such a way that the value of linear coefficient of thermal expansion of covering is close to one of brick itself.

All covering compositions devised for ceramic brick elevation provide necessary strength properties, nontoxic and add high aesthetic-decorative properties to brick. The important fact is also that the cheaper and more accessory raw materials are, the more interested in their application a producer is.