stanje i perspektive u rudarstvu i odrţivi razvoj mining present state ...

Rudarstvo 2011 / Mining 2011ash and control of its dispersion in the plant surroundings, the problem of environmental protectionwould be solved as well (Jovanović et al. 2000.-2002).2. PHYSICAL AND CHEMICAL CHARACTERISATION OF INITIAL SAMPLESFor this experiment, the gypsum samples from the cement plant Beocin (origin from Zorka - Subotica)were used and ash was from thermal plant Vreoci. The Table 1 shows the chemical composition of theused waste gypsum sample, while Table 2 gives the chemical composition of ash sample. The resultsof the chemical analysis of these samples showed that those were the raw materials most frequentlyused in cement production. The Tables 3 and 4 present the grain-size composition of the used ash andgypsum samples; they show that the used raw materials were of much finer composition than theportland cement klinker with which they are milled during cement production.2.1. Chemical composition of gypsum and ash samples:Table 1. Chemical composition of waste gypsum.Komponents SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 P 2 O 5 I.L. N.O.Content % 2,71 0,10 0,12 33,36 0,034 46,62 0,0218 16,78 2,89Table 2. Chemical composition of ash.Komponents SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO Na 2 O K 2 O I.L. N.O.Content % 57,83 17,01 9,44 9,79 1,41 0,24 0,58 3,41 60,482.2. Grain-size composition of gypsum and ash samples:Table 3. Grain-size composition of gypsum.Class of coarseness, M, % SM, % SM, % mm+ 0,074 7,95 7,95 100,00- 0,074 + 0,050 7,85 15,80 92,05- 0,050 + 0,037 1,40 17,20 84,20- 0,037 + 0,000 54,30 71,50 82,80Dissolved 28,50 100,00 28,50Input 100,00Table 4. Complete grain-size composition of ash from “Vreoci”.Class of coarseness, mm M, g M, %+ 0,500 2,50 1,30- 0,500 + 0,400 0,70 0,36- 0,400 + 0,300 1,00 0,52- 0,300 + 0,200 4,20 2,19- 0,200 + 0,100 29,80 15,50- 0,100 + 0,075 7,20 3,75- 0,075 + 0,053 23,20 12,07- 0,053 + 0,037 3,40 1,77- 0,037 + 0 000 120,20 62,54Input 192,20 100,00671