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Modelowanie powierzchni odpowiedzi i optymalizacja parametrów procesu ługowania rudy tlenku cynku roztworami amoniaku i wodorowęglanu amonu z następczą flotacją

Mao Y., Wen S., Deng J., Fang F.

Przemysł Chemiczny

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2015

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T. 94, nr 7

1086-1094

PL

Tlenkową rudę cynku (zawartość cynku 12,22%), zawierającą głównie smitsonit i hemimorfit oraz sfaleryt i skałę płonną, poddano ługowaniu wodnymi roztworami amoniaku i wodorowęglanu amonu i przeprowadzono badania optymalizacyjne, stosując metodę powierzchni odpowiedzi na 3 zmienne niezależne (stężenia amoniaku i wodorowęglanu amonu oraz czas ługowania). Wyznaczono wielomianowy model procesu (współczynnik wielokrotnej korelacji R2 = 0,9926) i obliczono optymalne wartości zmiennych niezależnych (stężenie amoniaku 2,23 mol/L, stężenie wodorowęglanu amonu 2,90 mol/L, czas ługowania 1,65 h). W tych warunkach wydajność procesu ługowania cynku wyniosła 59,04% i była w przybliżeniu równa wydajności prognozowanej 59,75%. Do odzyskania siarczku cynku z pozostałości po ługowaniu zastosowano proces flotacji. Hybrydowy „metalurgiczno-flotacyjny” proces obejmujący amoniakalne ługowanie rudy i flotację pozostałości po ługowaniu tlenkowej rudy cynku umożliwił wydobycie 94,29% cynku zawartego w rudzie.

EN

A highly alk. refractory ZnO ore (Zn content 12.22%) was leached with aq. NH₃ and NH₄HCO₃ solns. (concns. up to 3 and up to 4.50 mol/L, resp.) for 2 h using the response surface method. The optimum leaching conditions were detd. (NH₃ concn. 2.23 mol/L, NH₄HCO₃ concn. 2.90 mol/L, leaching time 1.65 h). Under the optimum conditions, the Zn recovery degree was 59.04% (model-predicted value 59.75%). The leaching residues were processed by a closed-circuit flotation to recover ZnS contained. Total Zn recovery degree was 94.29%.

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Soil organic carbon of different decomposition rate and its relation to microbial activity in saline-alkali desert ecosystem

Fang F., Hu Y.-K., Gong Y.-M., Tang H.-P.

Polish Journal of Ecology

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2015

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Vol. 63, nr 1

102--109

EN

Soil microbes’ activity is very important for forming of the nutrient stock and , soil structure, as well as the carbon cycle simulation. This is particularly crucial for deep soil layers. Effect of soil microbes on the rate of accumulation and decomposition of the soil organic carbon (SOC) has been found for different regions. However, it is known still a little on the SOC performance for different decomposition rates and its relation to the microbial activity in the saline-alkali desert ecosystem. Therefore, the main task of our research was investigation of interrelation between the soil organic carbon and microbial carbon (SMC) at different depths in the original saline-alkali Gurbantünggüt Desert. Our results showed in the soil vertical profile, (i) SMC and SOC presented a very significant positive linear correlation (R2 = 0.63, P = 0.0003); (ii) SMC exhibited two obvious changed-interfaces - 20 cm and 80 cm, the SMC at depth of 0–20 cm, 20–80 cm and 80–500 cm was 2.24–3.06, 0.19–0.72, and 0.0017–0.0097 mg kg-1, respectively; (iii) in the depth of 0–20 cm and 20–80 cm, the SMC had highly significant difference (P < 0.0001) and at 20–80 cm and 80–500 cm, significant difference (P = 0.013); (iv) according to the soil division based on the SMC, SOC also had some certain stratification; (v) organic carbon layers can be respectively defined according to different microbial activities as active, inert, and stable organic carbon pool. Therefore, these three kinds of organic carbon pools can be quantitatively measured by analyzing their location at different depths of the soil profile.

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ESR dating of the Donggutuo Palaeolithic site in the Nihewan Basin, northern China

Liu C.-R., Yin G.-M., Fang F., Voinchet P., Deng C.-L., Han F., Li J.-P., Song W.-J., Wang D., Bahain J.-J.

Geochronometria

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2013

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Vol. 40, no. 4

348--354

EN

The fluvio-lacustrine sequences in the Nihewan Basin, northern China, provide important terrestrial archives about Palaeolithic settlements and, therefore, about early human occupation in high northern latitude in East Asia. Here we present detailed ESR dating of the Donggutuo Palaeo-lithic site, located in this basin. Four levels A, B, C and E of the Donggutuo archaeological layer yield ESR ages ranging from 1060±129 ka to 1171±132 ka with a mean of 1119±132 ka. The ages are con-sistent with the paleomagnetic data, which show that the Donggutuo Palaeolithic site lies just below the onset of the Jaramillo normal subchron (0.99-1.07 Ma). Furthermore, our results indicate that the reliable ESR dating range of bleached quartz using Ti-Li centre can be effectively extended to 1100 ka and the Ti-Li centre was zeroed before the last deposition, which requires improvement of the understanding of the bleaching mechanism conditions.

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An adaptive Slotted ALOHA Algorithm

Fang F., Mao Y., Leng S.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 5b

17-21

EN

Slotted ALOHA channels are inherent instability and must be equipped with proper control. In this paper, we analyze the principle of ppersistent control algorithm (pPCA) at first, we propose a novel auto-control algorithm which combines the multiple factor into p-persistent autocontrol algorithm (MF-pPCA). The simulation demonstrates that the novel algorithm can accelerate the adjusting speed and can acquire stable throughput on the conditions that there is large fluctuation of system load.

PL

W artykule analizuje sie nowy algorytm pPCA umożliwiający poprawę szczelinowego algorytmu ALOHA w zastosowaniu do przesyłu danych.