腐植酸形成的生物学机理研究概况

详细论述了腐植酸形成的 7个主要学说 :1 .瓦克斯曼提出的木质素蛋白质复合体学说 ;2 .威廉斯提出的微生物作用学说 ;3.微生物合成假说 ;4 .植物和微生物细胞自溶假说 ;5.科诺诺娃学说 ;6.恩德斯的煤化机制 ;7.厌氧发酵形成腐植酸的

Mechanism study of organic antioxidant and inorganic salt on suppressing coal oxidation

The advantages and disadvantages of organic antioxidant and inorganic salt on suppressing coal oxidation were analyzed on the basis of the theory that coal oxidation mechanisms can be attributed to the free radical chain-type reaction mechanism. The inhibition curves on suppressing coal oxidation of the different type and different concentration of organic antioxidant and inorganic salt were given through experimental study and data processing. Then some conclusions can be gained from the experimental study combining with theoretical analysis. First the inhibition mechanism of the organic antioxidant and inorganic salt is different. The former is that the chemical action is the dominant position. It can be called as the chain termination theory because the free radical is captured during coal oxidation. And the later is that the physical effect is the dominant position. It can be called as the decreasing-temperature theory because the liquid membrane which was formed by the inorganic salt can make coal body be the state of wetness and prevent oxygen from coal surface. Second the inhibition effect of the organic antioxidant is higher than the inorganic salt in the later period. But it is lower in the early period.

Damage and deterioration mechanism and curing technique of concrete structure in main coal cleaning plants

Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Datun Energy Sources Co. Ltd., the first colliery of the Pingdingshan Coal Co. Ltd. and the Sanhejian mine of the Xuzhou Mining Group Co. Ltd. In these projects, the operating environment and reliability of concrete structures in the main plants of the three companies were investigated and the safety of the structures inspected. Qualitative and quantitative analyses were made on the special natural, technological and mechanical environments around the structures. On the basis of these analyses, we discuss the long-term, combined actions of the harsh natural (corrosive gases, liquids and solids) and mechanical environments on concrete structures and further investigated the damage and deteriorating mechanisms and curing techniques of concrete structures in the main coal cleaning plants. Our study can provide a theoretical basis for ensuring the reliability of concrete structures in main coal cleaning plants.

Breakage and separation mechanism of ZGM coal mill based on parameters optimization model

Sampling ports were firstly drilled on a ZGM95 coal mill in the power plant in China, and the coal samples from various points in the pulverizer were collected under the different operation conditions. The prop- erty of the sampling material from the mill was analyzed, applying the float-sink test, size distribution analysis, proximate analysis and so on. It was indicated that the ＋250 I^m fraction in the pulverized fuel accounted for only 0.02%, while it was 83.2% in the new feed. The circulating ratio and coal flow in the separator and the cone zone were calculated using the mass balance of the circulating load. So, the cir- culating ratio in the separator of the pulverizer was between 8 and 13, and the circulating ratio, the feed flow of separator and cone zone all raised with the increase of the air volume. Furthermore, the parameters of the separation functions were obtained based on the fitting method. It was shown that the mean value of the shape factor B was 0.7617, and the parameter D which is the particle size at 50% cumulative yield in the separator almost kept unchanged.

Surface Modification Mechanism of Fine Coal by Electrochemical Methods

In order to reveal the surface modification mechanism of fine coal by electrochemical methods, the structural changes of the coal surface before and after electrochemical modification were investigated by Fourier Transform In- frared Spectra (FTIR) and Raman Spectra. The results show that under certain electrochemical conditions, the oxy- gen-containing functional group in the coal structure and the oxygen content of absorption could be reduced and the floatability of coal improved. At the same time, the sulfur in the coal was reduced to the hydrophilic S2– which could be separated easily from coal. Thus electrochemical modification methods could be used to change the structure and func- tional group on the coal surface and to enhance the floatability of coal.

CO2 Storage Mechanism in Coal and its Effect on Methane Production in Enhanced Coalbed Methane Recovery

In this study, we provided more theoretical method for estimation of dissolution amount and applied this method to enhanced coalbed methane recovery （ECBMR） simulator. Dissolution amount was measured by method of differential heat of adsorption. Akabira coal, a Japanese bituminous coal, was used for the experiment. The results showed that CO2 was stored in coal by both adsorption and dissolution. Using this result the methane production was calculated by ECBMR-simulator, enhanced coalbed methane recovery simulator, the University of Tokyo （ECOMERS-UT）. Total stored CO2 was separated into adsorption component and dissolution component. Only the former component contributes to the competitive adsorption. Coalbed methane （CBM） production simulation considering the dissolution showed later and smaller peak production and prolonged methane production before the breakthrough than the conventional competitive adsorption.

Spectra response from macromolecular structure evolution of tectonically deformed coal of different deformation mechanisms

Coals with different deformation mechanisms(brittle deformation,brittle-ductile deformation,and ductile deformation) repre-sent different ways in macromolecular structure evolution based on the metamorphism.The evolution of coal structure could affect the occurrence condition of coalbed methane(CBM) because the nanopore structure affected by macromolecular struc-ture is the most important reservoir for CBM.This paper analyzes the evolutions and mechanisms of structure and functional group of tectonically deformed coals(TDCs) collected from Huainan-Huaibei coalfield using X-ray diffraction(XRD),Raman spectroscopy,and Fourier Transform Infrared(FTIR) spectroscopy methods.The results show that the macromolecular struc-ture evolutions of TDC are different from the primary structure coal as a result of the different metamorphic grade and defor-mation mechanisms.The different deformation mechanisms variously affect the process of functional group and polyconden-sation of macromolecular structure.Furthermore,the tectonic deformation leads to secondary structural defects and reduces the structure stability of TDC.The coupled evolution on stacking and extension caused by the changes of secondary structural de-fects results from different deformation mechanisms.We consider that the changes of chemical structure and secondary struc-tural defects are the primary reasons for the various structure evolutions of TDC compared with primary structure coal.

Structure and coalbed methane occurrence in tectonically deformed coals

Research on structure of tectonically deformed coals(TDC) is a key issue in coal and gas outburst prevention and coalbed methane(CBM) exploitation.This paper presents a summary on the research progress in TDC's structural-genetic classification,tectonic strain influence on coal microstructure,coal porosity system,coal chemical structure and constituents,and their relationship with the excess coalbed methane.Previous studies suggested that tectonic deformation had significant influence on coal microstructure,coal super microstructure,and even chemical macromolecular structure.The main mechanisms of coal deformation are the tectonic stress degradation and polycondensation metamorphism(dynamical metamorphism).Besides,under different deformation mechanisms,the ultra-and micro-structure and chemical constituents of TDC presented distinct characteristics.Based on these achievements,we propose one possible evolutionary trend of TDC with different deformation mechanisms,and suggest that the coal and gas outburst in the TDC,especially in the mylonitic coals,may be not only controlled by geological structure,but also influenced by the tectonic stress degradation of ductile deformation.Therefore,further study on TDC should be focused on the controlling mechanism of deformation on structure and composition of coal,generation conditions and occurrence state of excess coalbed methane from deformation mechanism of coal.

The effect of different deformation mechanisms on the chemical structure of anthracite coals

To study the effect of different deformation mechanisms on the chemical structure of anthracite coals and further understand the correlation between changed chemical structures and coal and gas outburst, ten groups of sub-high-temperature and sub-high-pressure deformation experiments were performed. All samples maintained primary structure, which were collected from the Qudi Mine in the southern Qinshui Basin of China. The samples were analyzed by ultimate analysis, Vitrinite Reflection(VR), Fourier Transform Infrared spectroscopy(FTIR), and Raman spectroscopy both before and after deformation experiments for contrasting. The results showed that the VR values of all samples after experiments were significantly higher than before experiments, which suggested that the metamorphism degree of anthracite coals was increased by deformation. The results also indicated that both temperature and strain rate had significant effects on the chemical structure of anthracite coals. At a high strain rate of 4×10?5 s?1, the deformation of the samples was mainly brittle in which the mechanical energy was transformed mainly into frictional energy. In this situation, all samples developed several distinct fractured surfaces and the change of chemical structures was not obvious. On the contrary, with the decrease of the strain rates, the ductile deformation was dominated and the mechanical energy was mainly transformed into strain energy, resulting in the accumulation of deformation energy confessed by increasing quantity of dislocation and creep in the coal's interior nucleus. The absorption in the aromatic ring groups increased; otherwise the absorption in the aliphatic structures and ether oxygen groups decreased rapidly. During these experiments, CO was collected from two experimental samples. The number of aromatic rings and the structure defects within the two generated gas samples increased and the degree of molecular structure orders decreased.