Catalysis of lignite char gasification by exchangeable calcium and magnesium

Fuel ◽  
1984 ◽  
Vol 63 (9) ◽  
pp. 1214-1220 ◽  
Author(s):  
The late Thomas D. Hengel ◽  
Philip L. Walker Jr.
2012 ◽  
Vol 518-523 ◽  
pp. 3150-3154
Author(s):  
Jian She Yang ◽  
Ying Ding

Abstract: Calcium and magnesium contents of sludge composting are measured by using the method of ammonium acetate-EDTA complex metric titration here, through Fermentation accelerant and increased nutrient agent treatments. The results showed as following: 1, exchangeable Ca and Mg contents of sludge single treatment increased more 6.83% and5.12% at the end of composting, than at the beginning of composting. 2, Fermentation accelerant added in sludge from 8% to 40%,,the exchangeable calcium and magnesium are more 4.38% ~ 10.58% and 6.77% ~ 13.78% at the end of composting than at the beginning of composting. The exchangeable Ca increased 19.51% ~ 104.83%, but 6.05% of a decreased trend for exchangeable magnesium, Compared with the sludge single compost. 3, as increasing the amount of nutrient agent from 30% to 50%, the exchangeable calcium and magnesium are more 3.88%~7.75%and 5.24%~9.18% at the end of composting than at the beginning of composting. The exchangeable Ca increased in 11.35%~41.13%,but 49%~-3.96% of a decreased trend for exchangeable magnesium, Compared with the sludge single compost. 4, under the condition added 24% of the Fermentation accelerant agent to the sludge, as the Increased nutrient agents from 8% to 32%, the exchangeable calcium and magnesium measured are increased 2.63%~5.54%and3.6%~4.19% at the end of composting , compared with The beginning of composting. The exchangeable Ca increased in 52.34%~112.04%,but -10.15%~-15.59% for exchangeable magnesium, Compared with the sludge single compost.


2019 ◽  
Vol 147 ◽  
pp. 602-609 ◽  
Author(s):  
Shuai Tong ◽  
Lin Li ◽  
Lunbo Duan ◽  
Changsui Zhao ◽  
Edward John Anthony

2009 ◽  
Vol 44 (8) ◽  
pp. 996-1001 ◽  
Author(s):  
Pedro Rodolfo Siqueira Vendrame ◽  
Robélio Leandro Marchão ◽  
Osmar Rodrigues Brito ◽  
Maria de Fátima Guimarães ◽  
Thierry Becquer

The objective of this work was to assess the relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture. Twelve collection points were chosen in the Distrito Federal and in Formosa municipality, Goiás state, Brazil, representing four soil groups with varied levels of calcium + magnesium and kaolinite/(kaolinite + gibbsite) ratios. Soil macrofauna was collected in triplicate at each collection point, and identified at the level of taxonomic groups. Macrofauna density showed correlation with contents of kaolinite, gibbsite and exchangeable Ca + Mg in the soils. Mineralogy and exchangeable Ca + Mg had significant effects on taxonomic groups and relative density of soil macrofauna. The termites (Isoptera) were more abundant in soils with low exchangeable Ca + Mg; earthworms (Oligochaeta), in soils with high levels of kaolinite; and Hemiptera and Coleoptera larvae were more abundant in gibbsitic soils with higher contents of total carbon.


2019 ◽  
Vol 33 (11) ◽  
pp. 10913-10922 ◽  
Author(s):  
Shusaku Asano ◽  
Cheolyong Choi ◽  
Kentaro Ishiyama ◽  
Shinji Kudo ◽  
Xiangpeng Gao ◽  
...  

CATENA ◽  
2019 ◽  
Vol 181 ◽  
pp. 104054 ◽  
Author(s):  
Nan Li ◽  
Maryem Arshad ◽  
Dongxue Zhao ◽  
Michael Sefton ◽  
John Triantafilis

1969 ◽  
Vol 8 (4) ◽  
pp. 559-567 ◽  
Author(s):  
George P. Curran ◽  
Carl E. Fink ◽  
Everett Gorin

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 255 ◽  
Author(s):  
WW Emerson ◽  
CL Chi

Samples of illites, two extracted from soils, one from a shale, prepared with a range of exchangeable calcium, magnesium, sodium were immersed dry into water. The extent of dispersion with time was estimated visually and also deduced from the O.D. of the suspensions derived from the dispersed clay. The dispersion of wet calcium and magnesium soil illites sheared at a given water content and then immersed in water was also assessed visually. The dispersion of all three illites was enhanced when magnesium was the dominant cation rather than calcium. For the soil clays a lower ESP was required to initiate dispersion of the dry clay when immersed in water. Both calcium and magnesium forms of the shale illite dispersed partially over a period of several days when immersed dry into water, the magnesium to a greater extent than calcium. The magnesium form of the coarser of the two soil illites also dispersed slowly. By comparing the calcium-magnesium and calcium-sodium forms of the last clay, it was deduced that about 10 times the equivalent concentration of exchangeable magnesium as sodium was needed to cause the same degree of dispersion. For the other soil illite the water content for dispersion of the wet, sheared magnesium clay was found to be less than for the calcium clay. The O.D. of suspensions of the clays was found to decrease with increasing ESP and when magnesium was the dominant cation rather than calcium. This is explained in terms of particle aggregation. The ease of dispersion of the illites was correlated with particle size. Possible reasons for this, and the effect of magnesium, as opposed to calcium, on the forces between the clay particles are discussed.


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