Coal gangue is an industrial solid waste produced by coal mining and processing [1–3]. The average production of gangue accounts for 10–15% of raw coal production [4,5], making coal gangue one of the biggest solid wastes in China. At present, utilization ratio of coal gangue …
Analytical data of coal samples were referred to study the great difference of the F content between coals and gangue. The results show that the average value of the F in the coal samples collected in different coalfields of China is 304×10−6, while that of gangue samples is surprisingly 1 319×10−6, especially the F content of coal ash from Bangmai in Yunnan Province reaches 4 800×10−6.
the coal gangue is that minerals are layered structure silicates except for quartz and feldspar. Chemical compositions are mainly SiO2, Al2O3 and C, followed by Fe2O3, CaO, MgO, Na2O, K2O, SO3, P2O5, N and H, as well as such metal elements as Ti, V, Co and Ga in some cases[12]. Proportions of chemical compositions are not fixed and vary in ...
The pyrolysis characteristics of low quality mixing coal are investigated by thermal analyses,in which the coal is mixed by coal gangue and washed middling coal. The sample is five kinds of mixing materials which their proportion is 1:4, 2:3, 1:1, 3:2, 4:1. The experiment showed that 2:3 coal sample is to achieve best result to the pyrolysis; The pyrolytic characteristic temperatures and the ...
Coal gangue-based cemented backfill material (CGCBM) is developed for backfilling the goaf in coal mines. As fresh CGCBM slurry is generally transported into underground openings through a pipeline, and after hardening, it plays the role of supporting the overlying strata. The fluidity, stability, and mechanical (compressive strength) of CGCBM become the most important properties.
Fluoride pollution in groundwater and soil occurred in the air depositing areas of coal spoils. The average content of fluorine in coal spoils was 525mg/kg with the highest value of 1885mg/kg.
Fluorine is a noxious trace element in coal. While coal is burning, most of the fluorine in it is emitted as gases such as HF, SiF4, CF4, etc, resulting in contamination of the atmosphere. The endemic fluorosis caused by coal burning was reported mainly from Yunnan, Guizhou and south of Shaanxi province in China, where coal with high fluorine content was used for cooking and warmth with open ...
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions.As the most electronegative element, it is extremely reactive, as it reacts with all other elements, except for argon, neon, and helium.. Among the elements, fluorine ranks 24th in universal abundance and 13th in ...
Fluorine content and distribution pattern in Chinese coals Kunli Luoa,*, Deyi Renb, Lirong Xua, Shifeng Daib, Daiyong Caob, Fujian Fenga, Jian'an Tana aInstitute of Geographical Sciences and Natural Resource Research, CAS, Building 917, 3 Datun Road, Beijing 100101, China bChina University of Mining and Technology, Beijing 100083, China Received 13 April 2003; received in revised form 29 ...
1. Introduction. Coal gangue is an industrial solid waste produced by coal mining and processing [1–3].The average production of gangue accounts for 10–15% of raw coal production [4,5], making coal gangue one of the biggest solid wastes in China.At present, utilization ratio of coal gangue can reach about 60% in some countries.
coal-mixed combustion pollutants. Coal gangue (CG) is an undesired but inevitable byproduct of coal mining and wash-ing. In addition, this material has become one of the largest industrial wastes [14], which con-tain a high ash content, a low volatile content, and a low calorific value [15]. The massive
01-09-2011· The trace element levels in the coal gangue and the soil are shown in Table 1. It can be seen that fluorine and arsenic in the soil are 385.12 and 9.5 mg/kg, respectively. The same elements in the coal gangue are varied from 318.43 to 331.53 mg/kg and from 8.2 to 8.8 mg/kg, respectively. These values are a little lower than those in the soil.
Fluorine, a hazard that is associated with coal, has resulted in serious environmental issues during the production and utilization of coal. In this paper, we provide a detailed review of fluorine ...
from coal gangue was related to the pH of leachate and the element concentrations in coal gangues [34]. ... coal gangue from sampling sites located at Yongshun Coal Mine (located at 39.864657, 110.031856), ... The natural CG gradation was poor due to the proportion of large grain particles, ...
0.00318, which was 1.11 and 1.35 times greater than that of 50% and 80% proportions, respectively. Co-combustion can reduce the activation energy of coal gangue during the ini-tial and end stages. Therefore, co-combustion is helpful to improve the problems of low calo-rific value and refractory burnout of coal gangue. Introduction
The impact and collision behavior between the coal gangue and the hydraulic support widely exists in the top coal caving. However, due to the complex interactions between the large number of coal gangue particles in the mining surface and the limitations of the coal mining technology and other factors, it becomes a difficult problem to study the collision behavior and the contact response ...
13-07-2008· Analytical data of coal samples were referred to study the great difference of the F content between coals and gangue. The results show that the average value of the F in the coal samples collected in different coalfields of China is 304×10−6, while that of gangue samples is surprisingly 1 319×10−6, especially the F content of coal ash from Bangmai in Yunnan Province reaches 4 800×10−6.
Fluorine occurs naturally in the crust of the earth where it is present in rocks, coal, and clay. Through wind-blown soil, fluorides are released into the air. Fluorine is the 13th most abundant element in the crust of the Earth: The Earth's crust contains 950 parts per million of fluorine.
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions.As the most electronegative element, it is extremely reactive, as it reacts with all other elements, except for argon, neon, and helium.. Among the elements, fluorine ranks 24th in universal abundance and 13th in ...
Fluorides, hydrogen fluoride, and fluorine are chemically related. Fluorine is a naturally-occurring, pale yellow-green gas with a sharp odor. It combines with metals to make fluorides such as sodium fluoride and calcium fluoride, both white solids. Sodium fluoride dissolves easily in water, but calcium fluoride does not. Fluorine also combines with hydrogen to make hydrogen fluoride, a ...
