Yuzhuang Sun

Geochemical evidences of natural gas migration and releasing in the Ordos Basin, China

Natural gas, in its migration from source rocks to release zones may travel a long distance and change the geochemical characteristics of the rocks which it flowed through. In order to study the geochemical evidence of the natural gas migration, 24 samples were taken from different natural gas migration zones in the Ordos Basin, China. Five samples of them are from natural gas release zones (dark sandstone samples), 17 samples are from bleaching zones (bleaching sandstone samples), and two samples are from non-release zones (background samples). These samples were analyzed by organic and inorganic geochemical methods. The results of GC traces and ICP-MASS indicate that three zones show different organic and inorganic geochemical characteristics. Natural gas migration and releasing may be recognized by the geochemical evidences.

Tectonic background of Ordos Basin and its controlling role for basin evolution and energy mineral deposits

In order to study the relationship of energy mineral deposits and tectonic movements in Ordos basin, more than 82 samples were taken for determination of apatite and zircon fission tracks. Furthermore, 93 apatite and zircon fission tracks have been selected from other publications. According to these data and other geological background, the evolution of Ordos basin can be divided into 4 stages, and the reformation of the basin can be divided into 5 stages. The basin formation and development were controlled by regional geodynamics. Oil, coal, nature gas and uranium deposits were formed in deferent stages. In the same time, 140 samples were taken and analyzed by organic and inorganic geochemical methods. The results indicate that coal and source rocks generate oil and natural gas, which migrate through reservoir rocks. Oil and natural gas changed the redox conditions of sediments and let uranium accumulate in the sandstones.

Early Hydrocarbon Generation of Algae and Influences of Inorganic Environments During Low Temperature Simulation

Algae were simulated for 5 years at low temperature (80°C) in order to study their early hydrocarbon generation processes. The samples were analyzed by gas chromatography-mass spectrometry. The results show that the range of carbon numbers and relative concentrations of alkanes are different under different simulated conditions. Hypersaline condition favors the formation and maturity of saturates. Iron ion probably delays the evolutionary pathways from phytol to phytene to phyane, while may catalyse the release of high concentrations of squalene and bicyclic terpanes. Meanwhile, common aromatic compounds have been formed during this low temperature simulation, and high abundant methyldibenzothiophenes were found in the hypersaline sample. The formation pathways of methylnaphthalenes in the early evolution of algae were proposed tentatively. By mathematical cluster and factor analyses on some classical thermal maturity parameters, the converted relations between phenanthrene and methylphenanthrenes and their inorganic environmental effects were discussed.

Production and Analysis of Biodiesel from Non-Edible Seed Oil of Pistacia Chinensis

Pistacia Chinensis is a potential and suitable non-edible feedstock for biodiesel production in China. In the present paper, three extraction methods to obtain seed oil of Pistacia Chinensis were compared and the Soxhlet extraction was found as the most effective one. Two kinds of biodiesels were produced catalyzed homogeneously by sodium hydroxide from crude oil of Pistacia Chinensis in Hebei province and Jiangsu province. Fourier transform infrared spectroscopy was used to compare the alterations of the functional groups in the crude oils and their biodiesel products after transesterification, and gas chromatography-mass spectrometry and gas chromatography were used to compare the composition of the biodiesels qualitatively and quantitatively. The results show that the C18 fatty acid methyl esters are the main components in both the biodiesels, and the seed oil of Pistacia Chinensis from Hebei province is more suitable for biodiesel production than that from Jiangsu province in terms of their chemical structure.

Gold enrichment mechanism in crude oils and source rocks in Jiyang Depression

Gold enrichment in crude oils and source rock samples has been reported in Jiyang Depression, Shengli Oilfield. In order to study the mechanism of gold enrichment, 18 samples collected around deep faults were analyzed by geochemical methods. The results indicate that the gold accumulation in Jiyang Depression is closely related to the mantle fluids and sulfur polycyclic aromatic hydrocarbon (S-PAH) in oil and source rocks. Gold elements could be from the mantle fluids and accumulated when they were carried into source rocks, especially when they encountered S-PAH. Rare earth element (REE) contents are high when gold contents are high. This phenomenon may indicate that a part of REE is also from the mantle fluids.

Comparison of the Geochemical Characteristics of "Barkinite" and Other Macerals From the Dahe Mine, South China

Late Permian coal samples from the Dale Mine, South China, were separated into macerai groups in order to compare the characteristics of “barkinite” with vitrinite, inertinite, and sporinite. The maceral groups were extracted and analysed by GC-MS. The extract residues (kerogen) were analysed by open-system pyrolysis. The results indicate that “barkinite” has geochemical characteristics different from those of vitrinite, inertinite, and sporinite. The significant differences lie in the compound contents obtained by open-system pyrolysis method. The contents of saturated and aromatic compounds from the “barkinite” sample are also different from the vitrinite, inertinite, and sporinite samples, but these differences are observed only in their compound quantities.

Minimum mining grade of associated Li deposits in coal seams

High Li concentration in coal seams has been reported by several papers in recent years. However, there is no minimum mining grade (or minimum economic grade; or ore border grade; or cut off grade) for lithium in coal seams because associated Li ore deposits in coal seams have not been found until now. In this paper, the minimum mining grade is suggested by compared the Li enrichment in coal with the Geology and Ore Deposit Standard Specifications in rocks for Rare Metal Mineral Exploration of the Peoples Republic of China (DZ/T 0203–2002), and also compared with the minimum mining grade for Ga and Ge in coals.

Characteristics of trace elements of the No. 6 Coal in the Guanbanwusu Mine, Junger Coalfield, Inner Mongolia

Forty-four samples of the No. 6 Coal were taken from the Guanbanwusu Mine, Junger Coalfield, Inner Mongolia, in 2009 in order to study trace elements. Twenty-two trace elements of the samples were analysed by ICP-MASS method. The results show that Li, Se and Ag are significantly enriched in the No. 6 coal. Most trace elements are enriched near the roof and floor. The content ratios of Sr and Ba, V and Ni, V and Zn might indicate that the peat swamp of this area during this period is influenced by sea water or in a sea-land transition environment. The enrichment of Li, Se, Ag shows that it formed in a relatively oxidated environment, and ancient water salinity is slightly high. In harmful elements, only Se is significantly enriched. The contents of the other harmful element are low, and do not pose many hazards to the environment. They can be partially removed by physical coal washing.

Coal petrological characteristics and coal facies of No. 11 seam from the Antaibao mine, Ningwu coalfield, China

Twenty-one coal samples of Seam 11 from the Antaibao Mine, Ningwu Coalfield, Shanxi Province, were analyzed by microscopic method. The macerals were identified and their ratios were calculated. The vitrinite contents decrease and the inertinite contents increase from bottom to top of the seam section. The data were used as indicators in the definition of different types of coal facies and hydrodynamic condition diagrams. The results indicate that the peat moor of Seam 11 might be formed in a regression environment, and it can be divided into 7 secondary regression processes. The peats evolved from low-open moor to dry-forest moor. The water depth of the moor decreased, and activity of water flowing decreased.

Mechanism of Uranium Accumulation in the Kupferschiefer from Poland and Germany

In order to investigate the mechanism of uranium accumulation in the Kupferschiefer, 88 samples from 10 sections were analysed by geochemical method. The results indicate that the higher uranium contents originated from and are transported from the underlying Rotliegendes into the Kupferschiefer by oxidized brines, and then precipitated when they encountered the organic matter, which occurred as reductant, in the Kupferschiefer.