The influence factors on pozzolanic activity index（PAI） of thermal activated coal gangue which include geographic distribution geological age chemical composition mineral composition content and crystallinity of kaolin in coal gangue thermal activated scheme of coal gangue have been discussed comprehensively The results show that the pozzolanic activity of
The pozzolanic activity of the burned coal gangue and the hydration products were examined the compressive strengths of the pastes of the mixtures were tested and the mechanism of the reaction is discussed The results show that the burning temperature of the coal gangue affects the pozzolanic activity of the resulting products and the optimum burning temperature used
The invention aims to provide a production method of a light weight aggregate used for industrial and civil buildings and in particular relates to the light weight aggregate produced by using coal gangue The light weight aggregate is characterized in that a production raw material of the coal gangue light weight aggregate is unburned coal gangue the coal gangue is selected from
· Coal gangue which has a similar composition to clay [5] is a solid waste produced during coal mining and processing [6 10] and its annual production accounts for about 10% to 15% of the coal output in that year [6 7 11] Fresh undisturbed coal gangue does not have pozzolanic activity [9] More
Coal gangue CG and coal gasification slag CGS contain a large amount of siliceous and aluminous minerals and have certain pozzolanic reactivity In recent years the use of CG and CGS as SCMs in concrete attracted more researcher s attention Wang et al studied the effects of CG with different fineness 200 325 500 1250 and 2022 mesh on the mechanical
Journal ofMining andJournal of Mining and Metallurgy 50 A 1 2022 19 25MetallurgyIMPROVEMENT OF COAL FLY ASH POZZOLANIC ACTIVITY BY DIFFERENTPHYSICAL METHODSI Jovanović1 # Lj Andrić2 M Bugarin1 D Urošević1 S Bugarinović112Mining and Metallurgy Institute Bor Zeleni bulevar 35 Bor SerbiaInstitute for
The pozzolanic activity of the coal gangue burned at 500℃ to 1000℃ was investigated The pozzolanic activity and compressive strength at different firing temperatures were tested according to GB2847 81 and cement glue sand 28 day method respectinely In order to judge the pozzolanic activity of burned coal gangue the hydration process of the burned gangue
The pozzolanic activity of coal gangue powder was enhanced Finally after the coal gangue powder activated by mechanical microwave was added with 8% Ca OH 2 as the activator the film outside the coal gangue particles was rapidly hydrolyzed in alkaline environment to form Ca Si Al amorphous film The internal active material was also rapidly released which reacted
8 hours ago· coal gangue pozzolanic activity mainly depended on the degree of non crystallization kaolinite Cao [30] resulted show that heating temperature directly affects the mineralogy and crystallinity of calcined coal gangue kaolinite in coal gangue transforms into metakaolin which is an irregular and amorphous phase as calcined at 600 °C 800 °C
Results indicated that microwave activation changed the mineral composition of coal gangue powder CGP separated its active substances and made its particles more round and finer that those prior to the activation thereby forming a CGP with pozzolanic activity The strongest activity was recorded within the microwave temperature of 600 °C 700 °C The activated
[J] 1996 3 56 35 Zhang C Pozzolanic activity of burned coal gangue and its effects on structure of cement mortar[J] Journal of Wuhan University of Technology Materials Science Edition 2022 21 4 150 36 Cao Z Cao Y Dong H et al Effect of calcination condition on the microstructure and pozzolanic activity of calcined
The experimental results indicate that the lattice structure of metakaolin in coal gangue samples calcined at 700 ℃ disorganizes gradually and becomes disordered and the lattice structure of α quartz is distorted slightly The pozzolanic activity of the coal gangue increases obviously with its structural disorganization
In order to study the correlations between different pozzolanic activity evaluation methods of calcined coal gangue NMR XPS ICP XRD techniques are pozzolanic activity of coal gangue calcined at different temperatures is evaluated by strength method polymerization degree method chemical method and XPS correlations of these results obtained
The ordinary method to improve the pozzolanic reactivity of coal gangue is direct calcination known as the thermal activation method Some studies [15 17 18] suggested that the generated amorphous reactive SiO 2 and Al 2 O 3 from kaolinite contribute to improving the Eects of coal gangue on the sulfate attack resistance of cement based materials Ceramics Silikáty 65 2
The influence factors on pozzolanic activity index（PAI） of thermal activated coal gangue which include geographic distribution geological age chemical composition mineral composition content and crystallinity of kaolin in coal gangue thermal activated scheme of coal gangue have been discussed comprehensively The results show that the pozzolanic activity of
[14] coal bottom ash [15] glass powders [16] crushed bricks [4] silica fume [13 17] and sewage sludge ash [18 19] Results from an indirect pozzolanic activity test are often corroborated using direct tests to confirm that pozzolanic reactions are occurring [14 20] The objective of this research was to assess if different test methods for pozzolanic activity correlate with each
Vor 22 Stunden · Effect of calcination condition on the microstructure and pozzolanic activity of calcined coal gangue International Journal of Mineral Processing 146 2022 pp 23 28 Article Download PDF View Record in Scopus Google Scholar D Liu L Fang Y Guo K Yan C Yao F Cheng Effects of calcium oxide and ferric oxide on the process of alumina extraction of
improving the pozzolanic activity of coal gangue is a critical process in its utilization as building materials Many studies have been carried out on the activation of coal gangue containing clay minerals and thermal treatment is the most common method used by these researchers Buchwald et al 2022 Seiffarth et al 2022 The main reaction that happened in the
The metakaolin is the main source of calcined coal gangue CCG activity [19 21] In the process above β quartz formation the original α quartz transition of CG most of the illite and montmorillo nite dehydroxylated and the remaining part of the siderite at 490 590 °C generated a small amount of magnetite and hematite through endo thermic decomposition [22] Then the
· Gangue is one of the most important components of CGB for coal mining this is because crushed gangue exhibits a pozzolanic activity and a certain degree of strength [8 10] However considering the slurry transportation restriction and the compressive properties of the CGB the maximum particle size of coal gangue is normally 15 mm at maximum Previous
The pozzolanic activity of coal gangue burned and the hydration products were examined the compressive strengths of the pastes of the mixtures were tested and the mechanism of the reaction was discussed The experimental results show that the coal gangue burned at 750 ℃ has the optimum pozzolanic activity and the burned coal gangue with SiO 2 and Al 2O 3
· The Department of Energy s Office of Scientific and Technical Information
Coal gangue is a typical waste produced during coal mining and washing Synthesis of zeolites via coal gangue can contribute to resource recycling and environmental protection In this study high silica SSZ 13 was synthesized by one step hydrothermal synthesis from coal gangue without the traditional pretreatment methods of high temperature roasting and alkali melting
· CFBCA has pozzolanic activity and cementitious hydration coal gangue sub bitumen petroleum coke and other poor quality fuels can be burned in CFBC boilers If pure petroleum coke is the fuel in the boiler it has a slight impact on the performance of the boiler In contrast if petroleum coke is co fired with limestone it accelerates the capture of
· Due to the poor pozzolanic activity of shale rock it is necessary to subject it to the thermal processing of calcination [11 12 13 14 15] During the calcination process of waste coal shale dehydroxylation of clay minerals such as kaolin occurs This leads to the formation of metakaolin which is an amorphous phase with high reactivity pozzolanic activity
Structure and Pozzolanic Activity of Calcined Coal Gangue during the Process of Mechanical Activation 【】： On the basis of analyzing coal gangue s chemical and mineral compositions the structure change of coal gangue during the mechanical activation was investigated by XRD FTIR NMR and the mechanical strength of the cement doped coal
The coal gangues were dissolved in NaOH solution with various concentration at different temperatures and reacting time It is found that the content of Si^4＋and Al^3＋of coal gangue is linear with its pozzolanic reactive activity under the proper experimental conditions A new rapid evaluation method for pozzolanic reactive activity of coal gangue is provided The
Research on cementitious behavior and mechanism of pozzolanic cement with coal gangue Dongxu Li a Xuyan Song b Chenchen Gong a Zhihua Pan a a College of Material Science and Engineering Nanjing University of Technology New Mofan Road Nanjing 210009 People s Republic of China b Department of Civil Engineering University of Science and Technology of
· Spontaneous or artificially burned coal gangue has certain activity and can be used as an active mixing material for cement to produce ordinary Portland cement with a content of less than 20% pozzolanic cement with a content of 20 50% and less clinker Cement mixing amount greater than 50% It can also be ground directly with lime and gypsum in an
· The prepared coal gangue based blended cement containing 52% of activated coal gangue C by CMHTA technology has a better mechanical property than activated coal gangue T by TMTA technology and raw coal gangue The results show that both of the TMTA and CMHTA technologies can improve the cementitious activity of raw gangue greatly