Mullite with puncheon like grains was synthesized by sintering the mixtures of coal gangue and γ Al2O3 at 1400 °C 1550 °C for 4 h The phase and microstructure evolution of the mullitization behavior were investigated by XRD SEM and EDS Phases of the sintered specimens were mullite corundum and cristobalite at 1400 °C to 1450 °C Arise of temperature would enhance
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
On this basis combined with fractionalstripping method for extraction of alumina and silica gel from coal gangue by acid water themain process parameters on leaching rate of alumina （including roasting activation leaching separation of silica and alumina and auxiliary recovery etc ） are analyzed and as thefollowing conclusions 1chemical composition of coal gangue is
The odd axes resist pressure intensity with large quantity coal gangue was discussed and experimented on fly ash and coal gangue gel filling body between different concentration proportion and
Calcined coal gangue has better activity when it reaches 700 C [5 6] and then the alkali activated coal gangue slag can be employed as a cement Therefore this test sets the temperature for calcined coal gangue at 700 C and the ratio of replacing gangue calcined and uncalcined with gravel
The invention relates to a method for extracting alumina and amorphous silica from fly ash or coal gangue The fly ash or coal gangue is calcined and then crushed the amount of the required alkali metal sulfate is calculated based on the content of alumina in the fly ash and mixing and roasting are carried out according to the molar ratio of sulfur trioxide in the alkali metal sulfate
Improving strength of calcinated coal gangue geopolymer Mar 30 2022 When the geopolymer was prepared by low calcium raw materials for example low calcium fly ash coal gangue etc the increase of active calcium content in geopolymer was helpful for the generation of C S H and C A S H gel and improved the internal structure of geopolymer as well as obviously enhanced
· Coal gangue concrete CGC with 30% fly ash FA content has the best workability and FA content enhances the effect of average gel pore size on the properties Abstract Fly ash FA and gangue are common solid wastes In this study coarse aggregates were replaced with coal gangue at a constant substitution rate of 40% to promote
· For comprehensive utilization of coal gangue and iron ore tailingsXRDFE SEM and EDX were used to analyze hydration products and microstructure of autoclaved aerated concrete AAC mainly from coal gangue and iron ore was studied that the influence of raw materials and the optimal thermal activation temperature of coal gangue to
· PDF In order to solve the problem of the spontaneous combustion of coal gangue a coal gangue fire extinguishing material of gel foam was developed
· Besides the 28d compressive strength of coal gangue geopolymers is greater than pure cement specimens when the slag content is 20% The geopolymer products of slag containing coal gangue geopolymers are C A S H and N A S H gels The two kinds of gels which are highly compatible jointly constitute the network like disordered structure of
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 There are still huge amounts of coal gangue being
The invention discloses a method for extracting aluminum oxide from coal gangue which comprises the following steps of mixing and grinding the broken coal gangue and sodium carbonate in a certain ratio roasting performing circular extraction precipitating filtering decomposing carbon recycling carbon dioxide and an auxiliary agent washing calcining and
The coal gangue used in this study was obtained from the Jinyang Coal Mine in Ordos China The main chemical composition presented in Table 1 of coal gangue was determined by an X‐ray fluorescence spectrometer Axios Pw4400 PANalytical Almelo Netherlands according to ASTM E 1621‐05 [34]
gel foam was tested in a spontaneous combustion coal gangue hill in a certain area and no reburning sign was found within one month Keywords gel foam
The hydrophobic SiO2 aerogel was prepared by using coal gangue as the starting material—which is viewed as waste in most coal mining and preparation plant—via ambient pressure drying through sol gel method The effects of different temperature time to keep the temperature vary in mass ratio of coal gangue to sodium hydroxide on the leaching ratio of
The results show that the red mud coal gangue based cementitious materials mainly form fibrous C A S H gel needle shaped/rod like AFt in the early hydration period With increasing of the hydration period densification of the pastes were promoted resulting in the development of strength EDS analysis shows that with the Ca/Si of red mud coal gangue based cementitious
· Coal gangue geopolymers in this paper show high initial strength which is consistent with existing researches on geopolymers N A S H gels are main gel phases of coal gangue geopolymers It can be assumed that all Al 2 O 3 comes from coal gangue while all Na 2 O comes from alkali activators
> The odd axes resist pressure intensity with large quantity coal gangue was dis cussed and experimented on fly ash and coal gangue gel filling body between different concentration proportion and additive results show that forepart intensity of new gangue filling body is very low and anaphase intensity have some increase which still go up
In this paper slag is used as a calcium source to make alkali activated coal gangue slag AACGS based material The reaction mechanism of AACGS materials was discussed in depth by means of XRD FT IR 29 Si MAS NMR nuclear magnetic resonance and SEM EDS energy dispersive spectrometer The experimental results show that coal gangue can be used as a
· Fire extinguishing with the superior performance of fly ash composite colloid material is a cost effective colloid fire prevention technology In this paper a new powder additive suspending agent XK XJ and gelling agent was developed for the existing fire extinguishing technology of fly ash compound colloid Tests show that the best additions to the fly ash slurry
coal gangue fuel boiler for power generation Details Production capacity ： 35 75 t/h Work pressure： MPA Applicable fuel： Bituminous coal anthracite meagre coal lignite gangue waste sludge Applicable industry： Chemical food tobacco textile printing and dyeing feed medicine building material wine rubber hospital Product introduction As a new mature
Coal gangue is mainly composed of SiO2 Al2O3 and other components It is a huge reserve of aluminum and silicon resources The coal gangue stockpiles in China is more than 5 billion tons at present of which contain Al2O3 more than 1 billion tons SiO2 more than billion tons It will make supplement for the lack of bauxite resources in China to some extent by extracting
· Using coal gangue CG as supplementary cementitious materials SCMs is believed to be one of the effective strategies for CG disposal While the low reactivity of CG restricts its large scale applications To increase the reactivity of CG wet grinding treatment was conducted in this work X Ray diffraction XRD Fourier transform infrared spectroscopy
· The odd axes resist pressure intensity with large quantity coal gangue was discussed and experimented on fly ash and coal gangue gel filling body between different concentration proportion and additive dosage The results show that forepart intensity of new gangue filling body is very low and anaphase intensity have some increase which still go up
Previous research shows [4] the bonding of gel role of fresh coal gangue is very weak because this kind of coal gangue have steady crystal structure whose atom ion and member etc are put according to certain law by order even if its chemical composition is proper and lowly active however coal gangue has certain activity after burning After calcined at a certain
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
Moreover the gel foam was used in a spontaneous combustion of coal gangue mountain field practice The results showed that when the mass fraction of sodium dodecyl sulfonate and coconut oil amide propyl betaine was % and 4 6 the foaming amount was as high as 1500 mL When the mass ratio of chitosan to acrylic acid was 1 6 the neutralization degree was 80%