Browsing by Publisher "Grup Matbaacilik"

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    Enrichment of a low grade chromite ore
    (Grup Matbaacilik, 2009) Çiçek T.; Cöcen I.; Cengizler H.
    The applicability of Mozley centrifugal force gravity separator (MGS) to fine fractions (-0.1 mm) of a low grade chromite ore (9.3 % Cr2O3) was investigated. The metal-screen analysis revealed that 83.9 % of the material ground under 1 mm for tests was in the +0.106 mm fraction containing 8 % Cr2O3. On the other hand, 16.1 % was in the-0.106 mm size fraction containing 16.12 % Cr2O3. The +0.1 and -0.1 mm fractions were used as feed for shaking table and MGS tests respectively. A saleable shaking table concentrate with low chromite recovery was obtained by shaking table tests. However, after some of the shaking table products were ground under-100 μm and concentrated with MGS, a chromite concentrate with 46.22 % Cr2O3 grade and 66.1 % Cr2O3 wt. recovery was obtained by the combination of shaking table and MGS. It was seen that MGS was an applicable beneficiation method at fine fractions for concentration of a low grade chromite ore. A principal flowsheet for the concentration plant was proposed.
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    Variation in coal surface wettability with carbonization temperature and effect of pitch on coal fluidity
    (Grup Matbaacilik, 2009) Cengizler H.; Kemal M.
    The effect of pitch (Z) ratio on the fluidity of coal and of carbonization temperature on the wetting behaviour of coal surface in the binary mixtures have been investigated with the experimental runs performed by the constant-torque Gieseler plastometer. The binary mixtures consisted of Tunçbilek brown coal (TK) or its semicokes and Z in different ratios. TK200, TK400, TK600, TK800 and TK1000 semicokes were obtained at 200°, 400 °, 600 °, 800 ° and 1000 °C carbonization temperatures respectively. It was found that the maximum fluidity values of the binary mixtures increases with increasing Z ratios. The lowest maximum fluidity values were obtained in TK400+Z binary mixture and it was shown that TK400 is the semicoke which has the optimum surface wetting behaviour. It was determined that the maximum fluidity values increase in the order of TK400, TK200, TK, TK600, TK800 and TK1000. The surface wettability also decreases in the same order.
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    Evaluation of leachability of potentially toxic elements from fly ash bricks
    (Grup Matbaacilik, 2009) Cengizler H.
    Batch leach tests were carried out to investigate the leachability of some toxic elements from fly ash bricks. The tests simulating the acid rain environment and natural rain water were conducted to gain insight regarding the behavior of the elements during weathering and to determine their toxicity characteristics. In the tests using TCLP method, the solubility levels of Fe, Zn and Mn detected in the leachate of the whole brick pieces were in agreement with the drinking water standards. In the tests using ASTM method, no detectable level of any element was found in the leachates of the whole brick pieces and of ground brick. In the tests using TCLP method, the solubility concentrations of the elements such as Fe, Zn, Cu, Cr, Ni, and Mn from the leachate of the ground brick were higher than those of the whole brick pieces. However, only Fe, Ni and Mn concentrations were determined to be higher than those allowed in the drinking water standards.