Thermal-Activation & Activity Analysis of Neimenggu High Alumina Coal Gangue

In this paper, the Neimenggu high alumina coal gangue was calcined at 400°C~1000°C, its micro-structure in different calcining temperature was studied using XRD and IR, and then the preferred activated condition and the PAI were investigated by testing the strength of cement mortars with activated coal gangue. The result shows that: the optimal calcining temperature of the gangue is 800°C, at this temperature the high activated SiO2 and AI2O3 can be decomposed from the gangue. The activity of the original gangue is very high, the PAI of the cement mortars with 800°C activated coal gangue can achieve to 126%, and thus can be used as high activity cement admixture. The PAI of the high alumina gangue is higher than that of coal gangue from other parts of China.

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Influence of Calcination Temperature on Activity of Hydration Properties of Gangue

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1466 ◽

2011 ◽

Vol 415-417 ◽

pp. 1466-1469

Author(s):

Jian Ping Zhu ◽

Jian Wu Zhang ◽

Song Hai Zhao ◽

Dong Xu Li

Keyword(s):

Compressive Strength ◽

Thermal Activation ◽

Amorphous Material ◽

Coal Gangue ◽

Process Conditions ◽

Gangue Mineral ◽

Activation Process ◽

Activated Coal ◽

Oxygen Bond ◽

Activated Coal Gangue

The mineral structure and hydration activity changes of the Jiyuan gangue calcined at different temperatures were studied in the paper. Differential scanning calorimeter (DSC), X-ray diffraction (XRD) testing, strength testing of cement and Microhardness analysis methods were used to study the thermal activation of coal gangue mineral composition, and macroscopic characterization of the activity of heat-activated coal gangue. The results showed that after heat activation, the destruction of the gangue can be effective in the silicon-oxygen bond, aluminum-oxygen bond, forming amorphous material, and thereby enhanced the activity of coal gangue. Best thermal activation process conditions of Jiyuan gangue is calcined at 800°C for 2h. Adding 40% of the heat-activated coal gangue Activated at this condition to cement, the compressive strength than the same dosage as is the compressive strength of coal gangue increased 106%.

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Experimental Study on the Characteristics of Activated Coal Gangue and Coal Gangue-Based Geopolymer

Energies ◽

10.3390/en13102504 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2504

Author(s):

Weiqing Zhang ◽

Chaowei Dong ◽

Peng Huang ◽

Qiang Sun ◽

Meng Li ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Activation ◽

Amorphous Structure ◽

Coal Gangue ◽

Lower Amount ◽

Activation Temperature ◽

Microstructure Changes ◽

Thermally Activated ◽

Activated Coal ◽

Activated Coal Gangue

Coal gangue-based geopolymer (CGGP) is one of the hot spots existing in the recycling of coal gangue resources due to its good comprehensive mechanical properties. However, the coal gangue structure is stable and reactivity is poor, so the coal gangue needs to be activated before utilization. In this paper, the microstructure changes of activated coal gangue by different mechanical and thermal activation methods, as well as the mechanical properties and microstructure changes of the CGGP specimens were studied by experimental investigation. The results indicated that mechanical activation and thermal activation were two effective methods to change the reactivity of coal gangue, which consisted of destroying the stable kaolinite structure and improving the activity of coal gangue. Conversely, part of the amorphous structure in coal gangue was destroyed when the activation temperature reached 900 °C, which was not conducive to the further enhancement of coal gangue activity. For the CGGP prepared by thermally activated coal gangue and modified sodium silicate alkali solution, the uniaxial compressive strength of the CGGP specimens decreased with thermal activation temperatures of the raw coal gangue materials at 700 °C, 800 °C, and 900 °C. The main reason for this was the lower amount of the active metakaolin structure in coal gangue at 900 °C, which was not conducive to the geopolymerization process.

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Activation & Application Research in Concrete of Neimenggu High Aluminum Coal Gangue

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.450-451.1400 ◽

2012 ◽

Vol 450-451 ◽

pp. 1400-1404

Author(s):

Hai Li Cheng ◽

Fei Hua Yang ◽

Jie Zhang

Keyword(s):

Setting Time ◽

Chloride Ion ◽

Coal Gangue ◽

Application Research ◽

Supplementary Cementitious Material ◽

Chloride Ion Penetration ◽

Activated Coal ◽

Compressive Strength Of Concrete ◽

Activated Coal Gangue ◽

High Aluminum

In this paper, the heat-activated conditions of Neimenggu high aluminum coal gangue were studied, and then, the activated coal gangue as a supplementary cementitious material was used in concrete to investigate the application effect. The result shows that the optimal calcining temperature of high aluminum coal gangue is 800°C, the setting time of concrete was postponed, the slump was reduced and the resistance of concrete to chloride ion penetration was improved for the use of activated coal gangue. The compressive strength of concrete was enhanced when cement was replaced by 20%～30% activated coal gangue powder. Pozzolanic effect of activated coal gangue in the early age (7d) is higher and it can promote the hydration of cement with each other.

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Shrinkage-reducing measures and mechanisms analysis for alkali-activated coal gangue-slag mortar at room temperature

Construction and Building Materials ◽

10.1016/j.conbuildmat.2020.119001 ◽

2020 ◽

Vol 252 ◽

pp. 119001 ◽

Cited By ~ 2

Author(s):

Hongqiang Ma ◽

Hongguang Zhu ◽

Hongyu Chen ◽

Yadong Ni ◽

Xiaonan Xu ◽

...

Keyword(s):

Room Temperature ◽

Coal Gangue ◽

Activated Coal ◽

Activated Coal Gangue ◽

Alkali Activated

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Effects of Kiln Dust-Activated Coal Gangue on the Properties of High-Content Slag Cement

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.753-755.525 ◽

2013 ◽

Vol 753-755 ◽

pp. 525-528

Author(s):

Chun Mei Wang ◽

Jing Wang ◽

Li Rong Yang ◽

Guang Dong Cao ◽

Dan Yang Dong

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Setting Time ◽

Coal Gangue ◽

Slag Cement ◽

Activated Coal ◽

Kiln Dust ◽

Activated Coal Gangue

The effects of amounts of the kiln dust-activated coal gangue on the setting time and compressive strength of high-content slag cement were investigated. The performance of sulphate resistance of cement with 30 wt.% kiln dust-activated coal gangue was evaluated. The results reveal that the setting time of high-content slag cement is prolonged. Appropriate kiln dust-activated coal gangue amounts can increase the compressive strength, while too much activated coal gangue (>30 wt.%) leads to the decrease in compressive strength. Cement with 10 wt.% kiln dust-activated coal gangue exhibits a good compressive strength. The performance of sulphate resistance of Portland cement with 30 wt.% kiln dust-activated coal gangue is distinctly enhanced, while that of high-content slag cement is improved to some extent.

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Effect of Added-Calcium Thermal Activated Coal Gangue on Cement Hydration

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.71-78.833 ◽

2011 ◽

Vol 71-78 ◽

pp. 833-836

Author(s):

Xu Yan Song ◽

Jing Yun Han ◽

Zhi Hai Gao

Keyword(s):

Water Content ◽

Hydration Product ◽

Coal Gangue ◽

Hydration Reaction ◽

X Ray Diffraction ◽

Specific Strength ◽

Activated Coal ◽

Pozzolanic Properties ◽

Activated Coal Gangue ◽

Xrd Method

Through determining Ca(OH)2 content and chemically combined water content, hydration degree of cement with added-calcium thermal activated coal gangue may be analyzed. Variation of mineral composition during hydration process of system was analyzed by X-ray diffraction(XRD) method. Simultaneously, specific strength index was applied to study pozzolanic effect of activated coal gangue. The results can show high contribution of added-calcium coal gangue calcined at 1050°C for pozzolanic properties and high hydration reaction degree in this kind of activared coal gangue cement system, with fewer Ca(OH)2 content, more chemically combined water content and obviously reduced hydration product Ca(OH)2 at each age.

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Simulation of Microwave Activation Effect of Coal Gangue by ANSYS

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.838-841.1898 ◽

2013 ◽

Vol 838-841 ◽

pp. 1898-1902 ◽

Cited By ~ 1

Author(s):

Xiao Mei Zhang ◽

Zhi Man Zhao ◽

Chun Jie Wang

Keyword(s):

Irradiation Time ◽

Microwave Energy ◽

Coal Gangue ◽

Activation Process ◽

Computer Simulation Model ◽

Microwave Activation ◽

Activation Effect ◽

Complex Process ◽

Activated Coal ◽

Activated Coal Gangue

Microwave activated coal gangue is a complex process, which is bound up with irradiation time, fineness, composition and other factors.Coal gangue is not easily absorbed substances,so it could be get microwave energy for activation from strong wave absorbing materials. In this paper,as influence of the activation process of coal gangue by microwave irradiation time, establish the computer simulation model by ANSYS.As a reference to modify the activation process,improve and perfect the model of microwave activated coal gangue.

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Study of Complex Chemical Activator on Activation Effect of Calcined Coal Gangue

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.450-451.832 ◽

2012 ◽

Vol 450-451 ◽

pp. 832-835 ◽

Cited By ~ 1

Author(s):

Xu Yan Song ◽

Jing Yun Han ◽

Zhi Hai Gao

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Coal Gangue ◽

Activation Effect ◽

Complex Chemical ◽

Mortar Strength ◽

Activated Coal ◽

Cement System ◽

Activated Coal Gangue ◽

Chemical Activator

Three kinds of complex chemical activators were prepared and then introduced into calcined coal gangue cement. Physical and mechanical properties such as mortar fluidity and mortar strength and shrinkage were tested. The results can show that: excitation effects of multiple complex chemical activators may obvious, where with 8% of J1, 50% of cement replaced with activated coal gangue, compressive strength of the system at ages of 28 days can reach 40.7MPa. Compared with coal gangue cement system without exciting agent, in calcined coal gangue cement system with complex activators early shrinkage increased obviously and later shrinkage may be equivalent to that of pure cement.

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