Influence of Calcination Temperature on Activity of Hydration Properties of Gangue

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%.

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

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.

Simulation of Microwave Activation Effect of Coal Gangue by ANSYS

2013 ◽  
Vol 838-841 ◽  
pp. 1898-1902 ◽  
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.

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

2012 ◽  
Vol 198-199 ◽  
pp. 9-13
Author(s):  
Hai Li Cheng ◽  
Fei Hua Yang ◽  
Jie Zhang ◽  
Yi Wang
Keyword(s):  
High Activity ◽  
Thermal Activation ◽  
Activity Analysis ◽  
Coal Gangue ◽  
High Alumina ◽  
Micro Structure ◽  
Cement Mortars ◽  
Activated Coal ◽  
Activated Coal Gangue ◽  
Very High

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.

Study on compressive strength and durability of alkali-activated coal gangue-slag concrete and its mechanism

2020 ◽  
Vol 368 ◽  
pp. 112-124 ◽  
Author(s):  
Hongqiang Ma ◽  
Hongguang Zhu ◽  
Chao Wu ◽  
Hongyu Chen ◽  
Jianwei Sun ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Coal Gangue ◽  
Activated Coal ◽  
Strength And Durability ◽  
Activated Coal Gangue ◽  
Alkali Activated

Effect of Activated Coal Gangue in North China on the Compressive Strength and Hydration Process of Cement

2019 ◽  
Vol 31 (4) ◽  
pp. 04019022
Author(s):  
Shuangxi Zhou ◽  
Jingliang Dong ◽  
Lehua Yu ◽  
Changjie Xu ◽  
Xiangke Jiao ◽  
...  
Keyword(s):  
Compressive Strength ◽  
North China ◽  
Coal Gangue ◽  
Hydration Process ◽  
Activated Coal ◽  
Activated Coal Gangue

Laboratory Investigation of the High Temperature Rheological Property of Activated Coal Gangue Modified Asphalt Binder

2015 ◽  
Vol 744-746 ◽  
pp. 1261-1265 ◽  
Author(s):  
Xiao Kai Yang ◽  
Rui Xiong ◽  
Fa Yang ◽  
Hui Qing Yin ◽  
Tao Yang
Keyword(s):  
High Temperature ◽  
Asphalt Binder ◽  
Coal Gangue ◽  
Gangue Mineral ◽  
Modified Asphalt ◽  
Industrial Solid Waste ◽  
Activated Coal ◽  
Modified Asphalt Binder ◽  
Mineral Powder ◽  
Activated Coal Gangue

The coal gangue is one of the largest industrial solid waste emissions in our country at present, the research about making coal gangue as the filler to modify the properties of asphalt is still blank both at home and abroad. Using rotational viscosity test and dynamic shear rheological test (DSR) to study the high temperature rheological properties of the activated coal gangue modified asphalt binder when under the condition of different filler-bitumen ratio, and compared with mineral powder modified asphalt binder; Based on this, explores the mechanism of coal gangue modified asphalt binder. The results show that the activated coal gangue instead of mineral powder can make the high temperature performance of asphalt binder increases sharply. Research results provide feasible basis of activated coal gangue mineral powder can instead of mineral powder improving the high temperature rheological performance of asphalt binder.

scholarly journals Study of Mechanical Properties and Durability of Alkali-Activated Coal Gangue-Slag Concrete

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5576
Author(s):  
Hongguang Zhu ◽  
Sen Yang ◽  
Weijian Li ◽  
Zonghui Li ◽  
Jingchong Fan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Damage Mechanics ◽  
Ordinary Portland Cement ◽  
Coal Gangue ◽  
Function Model ◽  
Freeze Thaw ◽  
Activated Coal ◽  
Activated Coal Gangue ◽  
Alkali Activated

Herein, a new geopolymer is recognized as a potential alternative cementing material of ordinary Portland cement (OPC), which is used for reducing carbon emissions and efficiently recycling the waste. Therefore this paper mainly studied the alkali-activated coal gangue-slag concrete (ACSC) was prepared by using the coal gangue-slag and Na2SiO3 and NaOH complex activator. The ratio of coal gangue (calcined and uncalcined) coarse aggregate replacing the gravel was 0%, 30%, 50%, 70%, and 100%. The water and salt freeze-thaw resistance, compressive strength, chloride permeation, microstructure, performance mechanism, inner freeze-thaw damage distribution, and mechanics models of ACSC were investigated. Results show that ACSC displayed excellent early age compressive strength, and the compact degree and uniformity of structure were better compared with the ordinary Portland cement (OPC) when the coal gangue replacement rate was less than 50%. The ACSC demonstrated the best chloride penetration resistance under 30% uncalcined coal gangue content, which was less than 27.75% lower than that of using OPC. At the same number cycles, especially in the salt freezing, the calcined coal gangue had lowered advantages of improving resistance freeze-thaw damage resistance. Water and salt accumulative freeze-thaw damage mechanics models of ACSC were established by using the relative dynamic elasticity modulus. The exponential function model was superior to the power function model with better precision and relativity, and the models accurately reflected the freeze-thaw damage effect.

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

Energies ◽  
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.

scholarly journals Experimental Study of the Mechanical and Microstructure Characteristics of Coal Gangue Road Stabilization Materials Based on Alkali Slag Cementation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3601
Author(s):  
Changbai Wang ◽  
Junxin Yang ◽  
Shuzhan Xu
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Coal Gangue ◽  
Hydration Time ◽  
Alkali Activated Slag ◽  
Microstructure Characteristics ◽  
Activated Coal ◽  
Activated Slag ◽  
Activated Coal Gangue ◽  
Alkali Activated

To accelerate the resource utilization of coal gangue and meet the strategic requirements of carbon neutralization, alkali-activated, slag-cemented coal gangue is applied in the preparation of solid waste-based road stabilization materials. Here, the cementation characteristics and microstructure characteristics of alkali-activated, slag-cemented coal gangue road stabilization materials are studied using the alkali equivalent and coal gangue aggregate ratio as experimental variables. The results show that with the increase in alkali equivalent from 1% to 7%, the unconfined compressive strength of the alkali-activated coal gangue road stabilization material initially increases and then decreases, with 3% being the optimal group in terms of stabilization, the aggregate ratio of coal gangue increases from 70% to 85%, and the 7-day unconfined compressive strength of the stabilized material decreases approximately linearly from 8.16 to 1.68 MPa. At the same time, the porosity gradually increases but still meets the requirements of the specification. With the increase in hydration time, a large number of hydration products are formed in the alkali slag cementation system, and they are closely attached to the surface of and interweave with the coal gangue to fill the pores, resulting in the alkali slag slurry and coal gangue being brought closer together.

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

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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