scholarly journals Chemical Composition Variations of Altered and Unaffected Coals from the Huaibei Coalfield, China: Implications for Maturity

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3028
Author(s):  
Songbao Feng ◽  
Qiang Wei ◽  
Xianqing Li
Keyword(s):  
Weight Loss ◽  
Chemical Composition ◽  
Coal Mine ◽  
Vitrinite Reflectance ◽  
Coal Mines ◽  
Matter Content ◽  
Aliphatic Hydrocarbon ◽  
Aliphatic Chain ◽  
Heating Rates ◽  
Huaibei Coalfield

The composition characteristics of altered coals in the Huaibei Coalfield, China, was investigated through a comparative analysis between altered and unaffected coals from the Wolonghu, Taoyuan and Renlou coal mines. Results indicated that the altered coals in Wolonghu coal mine are mostly anthracite coals, with a maximum vitrinite reflectance of 1.6–3.9% (average of 2.9%). Coals from Wolonghu coal mine were mainly consisted of vitrinite (66.2–97.0%), followed by inertinite (2.0–4.0%) and exinite (0.4–6.9%). Differences in volatile matter content were observed between the altered coals in Wolonghu coal mine and unaffected coals from neighboring coal mines, implying that the chemical composition and maturity of coals were changed after magmatic alteration. In addition, differences in hydrogen element were noted among the coals from Wolonghu, Renlou and Taoyuan coal mines, and the phenomenon of “deficient in hydrogen element” was observed in Wolonghu coals. The aliphatic hydrocarbon structure parameters suggested that the aliphatic chain lengths of Wolonghu coals are shorter than those of coal samples from the Renlou and Taoyuan coal mines. In addition, maturity is positively correlated with hydrogen enrichment degree, but negatively related with aliphatic hydrocarbon structure. Coals from Renlou and Taoyuan coal mines showed great weight loss with various heating rates at temperatures of 0–1000 °C, whereas those from Wolonghu coal mine had less weight loss.

Study on the Relationship Between Suspended Solids Concentration and Tur-bidity in Coal Mine Water

2021 ◽  
Author(s):  
Song Du ◽  
Wenbiao Jin ◽  
Guichuan Qiao ◽  
Huiming Fang
Keyword(s):  
Error Analysis ◽  
Coal Mine ◽  
Suspended Matter ◽  
Mine Water ◽  
Suspended Solids ◽  
Coal Mines ◽  
Matter Content ◽  
Solids Concentration ◽  
Coal Mine Water ◽  
The Relationship

Abstract Coal mine water in China is mainly mine water containing suspended solids（SS）. The relationship between suspended solids and turbidity in mine water with different SS content gradients was studied and a model formula was established. Finally, the accuracy of the model formula is verified by the actual detection values of five kinds of mine water. Two conversion formulas for turbidity and suspended matter have been obtained in the study. When the suspended matter content is 0-200mg/L, the relationship curve between turbidity and SS is y=0.9336x-3.1393, R2=0.9986; When the suspended matter content is 200-600 mg/L, the relationship curve between turbidity and SS is y=0.5314x+94.421, R2=0.9905. Finally, the study has used the measured values of SS in other coal mines and the calculated values obtained from the formula to carry out error analysis. It is found that the error of the relationship between turbidity and SS with a suspended matter content of 0~200mg/L is controlled within 4%; the error of the relationship between turbidity and SS of mine water with a suspended matter content of 200~600mg/L is controlled within 5%. Considering the unavoidable error factors, it is considered that the model formula can be applied to the detection of suspended solids in actual mine water.

scholarly journals Prediction of metabolizable energy values in poultry offal meal for broiler chickens

2010 ◽  
Vol 39 (10) ◽  
pp. 2237-2245 ◽  
Author(s):  
Edney Pereira da Silva ◽  
Carlos Bôa-Viagem Rabello ◽  
Luiz Fernando Teixeira Albino ◽  
Jorge Victor Ludke ◽  
Michele Bernardino de Lima ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Broiler Chickens ◽  
Crude Protein ◽  
Matter Content ◽  
Metabolizable Energy ◽  
Mineral Matter ◽  
Ether Extract ◽  
High Fat ◽  
Collection Method ◽  
Gross Energy

This research aimed at generating and evaluating prediction equations to estimate metabolizable energy values in poultry offal meal. The used information refers to values of apparent and true metabolizable energy corrected for nitrogen balance (AMEn and TMEn) and for chemical composition of poultry offal meal. The literature review only included published papers on poultry offal meal developed in Brazil, and that had AMEn and TMEn values obtained by the total excreta collection method from growing broiler chickens and the chemical composition in crude protein (CP), ether extract (EE), mineral matter (MM), gross energy (GE), calcium (Ca) and phosphorus (P). The general equation obtained to estimate AMEn values of poultry offal meal was: AMEn = -2315.69 + 31.4439(CP) + 29.7697(MM) + 0.7689(GE) - 49.3611(Ca), R² = 72%. For meals with high fat contents (higher than 15%) and low mineral matter contents (lower than 10%), it is suggest the use of the equation AMEn = + 3245.07 + 46.8428(EE), R² = 76%, and for meals with high mineral matter content (higher than 10%), it is suggest the equations AMEn = 4059.15 - 440.397(P), R² = 82%. To estimate values of TMEn, it is suggested for meals with high mineral matter content the equation: TMEn = 5092.57 - 115.647(MM), R² = 78%, and for those with low contents of this component, the option is the equation: TMEn = 3617.83 - 15.7988(CP) - 18.2323(EE) - 96.3884(MM) + 0.4874(GE), R² = 76%.

Analysis of Wear-Resistant Materials of Mixer - Pneumosuperchargers Blades Operating under Conditions of Abrasive Wear

2021 ◽  
Vol 316 ◽  
pp. 893-898
Author(s):  
Natalya Gabelchenko ◽  
Artem Belov ◽  
Artem Kravchenko ◽  
Oleg Kryuchkov
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Wear Resistance ◽  
Chemical Composition ◽  
Abrasive Wear ◽  
Abrasive Medium ◽  
Wear Resistant ◽  
Comparative Tests ◽  
Before And After ◽  
110G13l Steel

We conducted comparative tests of the wear resistance of metals operating under abrasive conditions. Samples were cut from the working parts of mixer-pneumosuperchargers. The chemical composition and mechanical properties were determined. To compare samples under abrasive wear conditions, we designed and assembled a carousel installation. The principle of its operation is based on mixing the abrasive medium by the samples being studied with a given speed. Wear resistance was evaluated by weight loss by samples after several test cycles. To determine changes in the structure of the metal during abrasive wear, metallographic studies of the samples were carried out before and after the tests. It is shown that the best complex of service and mechanical properties is possessed by 110G13L steel.

scholarly journals Chemical composition of leaves of a mangrove tree (Sonneratia apetala Buch.-Ham.) and their correlation with some soil variables

1970 ◽  
Vol 39 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Ashafaque Ahmed ◽  
Mikael Ohlson ◽  
Sirajul Hoque ◽  
Md Golam Moula
Keyword(s):  
Heavy Metals ◽  
Chemical Composition ◽  
Coastal Zone ◽  
Organic Matter Content ◽  
Matter Content ◽  
Sonneratia Apetala ◽  
Mangrove Tree ◽  
Soil Variables ◽  
Wide Range ◽  
High Concentrations

Chemical composition of leaves of Sonneratia apetala Buch.-Ham. collected from three islands (chars) representing three hydrological regimes in a segment of the coastal zone of Bangladesh was studied. Their relations to some soil chemical and physical variables have also been investigated. The results showed that concentrations of B, C, Fe, Ga, Li, Mg, Mn, N, Na, P, Zn and Sr in leaves of S. apetala grown in different islands differed significantly. It was also revealed that some heavy metals, viz. Mn, Fe, Al, Sr and Ti showed wide range of concentrations. The leaves from one of the locations in Motherbunia island were characterized by exceptional high concentrations of heavy metals such as Al, As, Cu, Fe, Li, Ni, Pb that may be due to local contamination. Leaves sampled in the most seaward locations of the same island had highest concentrations of Ba, Ca, Cu, Mn and Na. High Mn concentration was found in the leaves of S. apetala of Motherbunia island. Correlations among soil and plant samples were generally very weak and organic matter content of soil did not appear to play a significant role in the nutrient supply of S. apetala. Key words: Coastal zone; tidal inundation; elemental concentration; Sonneratia apetala DOI: 10.3329/bjb.v39i1.5528Bangladesh J. Bot. 39(1): 61-69, 2010 (June)

scholarly journals Methane Content Estimation in DuongHuy Coal Mine

2018 ◽  
Vol 35 ◽  
pp. 01005 ◽  
Author(s):  
Van Thinh Nguyen ◽  
Waldemar Mijał ◽  
Vu Chi Dang ◽  
Thi Tuyet Mai Nguyen
Keyword(s):  
Experimental Data ◽  
Coal Mining ◽  
Coal Mine ◽  
Coal Mines ◽  
Methane Content ◽  
Underground Coal Mining ◽  
Coal Seams ◽  
Underground Coal Mine ◽  
Different Depths ◽  
Quang Ninh

Methane hazard has always been considered for underground coal mining as it can lead to methane explosion. In Quang Ninh province, several coal mines such as Mạo Khe coal mine, Khe Cham coal mine, especially Duong Huy mine that have high methane content. Experimental data to examine contents of methane bearing coal seams at different depths are not similar in Duong coal mine. In order to ensure safety, this report has been undertaken to determine a pattern of changing methane contents of coal seams at different exploitation depths in Duong Huy underground coal mine.

scholarly journals Structural characteristics and chemical composition of andropogon grass pasture managed under different defoliation intensities and rest periods

2017 ◽  
Vol 18 (4) ◽  
pp. 492-504
Author(s):  
Clésio dos Santos Costa ◽  
Rosane Cláudia Rodrigues ◽  
Francisco Naysson de Sousa Santos ◽  
Ricardo Alves Araújo ◽  
Giovanne Oliveira Costa Sousa ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Linear Trend ◽  
Structural Characteristics ◽  
Rest Period ◽  
Matter Content ◽  
Neutral Detergent Fiber ◽  
Dry Matter Content ◽  
Linear Effect ◽  
Rest Periods ◽  
Dry Biomass

SUMMARY This study aimed to evaluate the agronomic, structural traits and chemical composition of andropogon grass subjected to different defoliation intensities and rest periods. Two defoliation intensities (15 and 30 cm) and four rest periods (25; 35, 45 and 55 days) were evaluated in a factorial completely randomized design, with four replications. The rest period promoted a linear decreasing effect (P <0.05) on the dry biomass of leaf blades in the two defoliation intensities. The dry biomass of stems showed an increasing linear effect (P <0.05) according to the rest periods in the two defoliation intensities. Production was recorded at 2427.71; 2907.39; 3325.72 and 3749.45 kg ha−1 for the periods of 25; 35; 45 and 55 days, respectively. The dry matter content showed an increasing linear effect (P <0.05) as a function of the rest periods evaluated in the two defoliation intensities. The rest period indicated a decreasing linear trend (P <0.05) for the crude protein content in the two defoliation intensities. A decrease of 0.9 and 0.7 g kg−1 was verified for each day of the rest period. For each additional day in the rest period, there was an increase of 1.2 and 1.5 g kg−1 DM in the neutral detergent fiber content at intensities of 15 and 30 cm. The andropogon grass pasture managed with a 25-day rest period and defoliation intensity of 30 cm showed high leaf/stem ratio and good nutritional value.

scholarly journals Applications of Vitrinite Anisotropy in the Tectonics: A Case Study of Huaibei Coalfield, Southern North China

2012 ◽  
Vol 2012 ◽  
pp. 1-16
Author(s):  
Yudong Wu ◽  
Quanlin Hou ◽  
Yiwen Ju ◽  
Daiyong Cao ◽  
Junjia Fan ◽  
...  
Keyword(s):  
North China ◽  
Vitrinite Reflectance ◽  
Eastern China ◽  
Tectonic Stress ◽  
Deformation Mechanisms ◽  
Thermal Metamorphism ◽  
Regional Tectonic ◽  
Projection Analysis ◽  
Huaibei Coalfield

29 oriented and 10 nonoriented coal samples are collected in the study from three different regions of the Huaibei coalfield, eastern China, and their vitrinite reflectance indicating surface (RIS) parameters are systematically calculated and analyzed. Using the available methods, Kilby’s transformations and RIS triaxial orientations are obtained. The magnitudes and orientations of the RIS axes of the three regions were respectively projected on the horizontal planes and vertical sections. The results show that the samples in high deformed region have significant anisotropy magnitudes (higher Bw/Rmax and Ram values) with a biaxial negative style, whereas the samples in the slightly deformed area have unimpressive anisotropy magnitudes with a biaxial negative style. Thermal metamorphism superposed might enhance the complication and variation of RIS style. RIS projection analysis deduced that the RIS orientation is mainly controlled by regional tectonic stress, and likely influenced by deformation mechanisms of coal.

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