LIGNITE COMBUSTION BYPRODUCTS-FLY ASH USE POSIBILITIES IN KOSOVA AND THEIR IMPACT IN ENVIRONMENTAL PROTECTION

, although in certain cases, in our research, reactions and phenomena have shown quite some originality. Water Demand and setting times of self-compacting materials-Experiments in the VICAT Aparat The method used to determine the water demand and start and end times of solidification, is widely known as the Vicat Method. This is one of the oldest methods, which is still used widely today. This is a relatively simple devicery, in which fresh samples and depertimiTime min I (mm) II (mm)

200 40 0 diagrami2

600 120 150 170180 190 210 240 245 -5 0 5 10 15 20 25 30 35 40 45

50 100 150 200 250 300 timep e n e t r a t i o n -5 0 5 10 15 20 25 30 35 40 45 serie 1 serie 2 (C/H2O=1/ 01/)0,4 determination of parameters required is made through penetration of the Vicat needle in the sample. The sample prepared is placed in Vicat circles, which are placed in a glass plate and four minutes from the time of mixing the sample, the test which determines water demand is done. In these experiments, the water demand has been determined accurately in these mixtures as were the times of initial and final solidification prepared for the sample. It may be seen that the fly ash addition has resulted in a longer time of initial and final solidification, while indirectly this has reflected in volume changes and processes of hydratization developed. According to Literature and different authors there are allegations that there is a difference between measurement of volume changes from one device to the other, since according to them, in Schwind kegel the measurement is three dimensional because of the form of the device. Still there is a prevailing conviction that both devices have the same measurement, but in the device in figure eight, the measurement is done in a laser manner, while on the a figure nine this measurement is mechanical.. Depertimi Nr time (min) I (mm) II (mm)

220 40 0 diadrami 3

17 47 162 172 182 195 210 220225 -5 0 5 10 15 20 25 30 35 40 45

50 100 150 200 250 timep e n e t r a t i o n -5 0 5 10 15 20 25 30 35 40 45 Series2 Series1 -5 0 0 -4 5 0 -4 0 0 -3 5 0 -3 0 0 -2 5 0 -2 0 0 -1 5 0 -1 0 0 -5 0 0

,0 0 4 ,0 0 8 ,0 0 1 2 ,0 0 1 6 ,0 0 2 0 ,0 0 2 4 ,0 0 2 8 ,0 0 0

0 p a s te -rin n e -co v p a s te -rin n e -u n c o v p a s te -k e g -u n c o p a s te -k e g -c o v te m p -m a t-k e g -u n co v m a t-te m p -k e g -c o v C :W -1 :0 ,3 V e rs u c h 1 -re in e p a s te (C/H2O=1/ 0.3) Conclusions Researches made, have shown that in analysis made in different samples and mixtures, different conditions and devices, results gathered are rather diverse, and in general it can be concluded that the utilization of Kosovo lignite fly ash in self-compact materials and building industries is possible, and may turn useful in many aspects. In this direction, it may be concluded also that this type of ashes may be used as a connecting material, and as a substitute of cement, and also as an additive. The use of lignite fly ash in materials of construction industry has a positive impact not only in improving hydraulic attributes, but also in improving rheological attributes, as a consequence of its regular particle shape. Based on the increased demand for construction and other materials in general, the importance of using lignite ash additives in production of these materials increases. This is specifically important in the aspect of energy saving, since the production of each cement ton spends a certain energy amount, and substitution of any amount of cement with fly ash directly saves the amount of that energy which would be spend. Hence, the greater the utilization of lignite ash as a substitute, the greater the energy saving is. In principle, many authors (Malhotra, Mehta etc) think that in the 21st century, none of the connecting construction materials and other fields should not be produced without including ashes and other secondary materials in their structure. This is best described with the statement of a known technologist of these materials from the USA, Abdun-Nur, who says that “In a real modern construction material world, the fly ash is an essential component of mixtures, the same with cement, water and other chemical components, hence concrete without ashes would only find a place in museums and exhibitions “. Referencies

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