Яшил иқтисодиёт ва тараққиёт 4-tom 9-san (2026) · 1-7-betler
MECHANICAL ACTIVATION OF SUGAR-BEET DEFECATE: EFFECTS ON PARTICLE SIZE, SPECIFIC SURFACE AREA AND SORPTION CAPACITY
K.M. Umarkulov
Annotaciya
This work quantifies how dry ball-milling parameters govern the dispersity, BET specific surface area and single-point sorption uptake of defecate (sugar-beet carbonation lime residue), and identifies the preferred activation regime under an explicit energy-efficiency criterion. Ten samples were examined: an unmilled dried control (D0) and nine activation regimes covering milling time 5–60 min, ball-to-material ratio 5:1–20:1, mill speed 200–500 rpm and initial moisture 0.9 and 5.0 %. Median particle size d₅₀ and BET surface area were recorded for every sample, and sorption activity was assessed in a single-point static test (C₀ = 100 mg/L, dose 2 g/L, 25 °C, 60 min, pH₀ = 7.0) towards phosphate, methylene blue, Congo red and Pb(II). After 30 min of milling d₅₀ fell from 73.7 to 7.9 µm (9.3-fold), BET area rose from 6.4 to 28.4 m²/g (4.4-fold) and phosphate uptake increased from 8.4 to 26.3 mg/g (3.1-fold); at 60 min d₅₀ rebounded to 9.8 µm and BET dropped to 24.1 m²/g, indicating the onset of agglomeration. Across all ten samples, phosphate uptake correlated almost perfectly with specific surface area (r = 0.993; q = 0.814·BET + 3.42; R² = 0.987), and surface-normalised phosphate uptake stayed within a narrow band (0.91–1.31 mg/m² over all ten samples; 0.91–1.08 mg/m² over the nine activated samples). For phosphate, therefore, the gain in sorption activity within the present dataset is explained almost entirely by the gain in specific surface area; an independent contribution of a “mechanically activated defect state” was not resolved by these experiments and can only be proved against an unmilled control brought to the same dispersity by classification. For methylene blue and Pb(II) the surface-normalised uptake was not constant, so the same conclusion does not extend to them without further evidence. The best regime by absolute uptake is D30-500 (27.6 mg/g phosphate), whereas by energy efficiency it is D5 (14.1 (mg/g)/(kW·s/kg)); the two criteria point to different regimes.
DefecateCarbonation Lime ResidueMechanical ActivationBall MillingSpecific Surface AreaPhosphate SorptionHeavy MetalsEnergy ConsumptionAgglomeration
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