When water is adopted as the coal slag discharge medium in the process of drilling in soft coal seams, coal slurry with great agglomerated and viscous is formed after the water invades the coal powders. As the dry coal powders gradually mix with the wet coal slurry, the strength and consistency of the coal slurry will continue to be promoted.
Fly ash is a fine powder recovered from gases created by the burning of coal. It is the largest component of coal combustion waste, totaling around 70 million tons annually in the United States ...
In a coal preparation plant, typical contaminants in the reused water are pyrite oxidation products (Fe 2+, Fe 3+ and SO 4 2−), soluble inorganic ions released from the inorganic matters in the coal (Ca 2+, Al 3+ and Mg 2+), humic acids and residual flotation reagents. These chemical species can have a profound effect on coal processing [[25 ...
Coal gasification slag (GS) is a potential pozzolanic industrial waste discharged during coal gasification. The study aimed to investigate the effect of finely ground GS powder on the fluidity, rheology and viscoelasticity properties of cement paste, which is essential for utilizing GS as a supplementary cementitious material for building materials.
Based on the obtained results in comparison to the reference mix ( a mix containing limestone powder) the coal waste and its ash resulted in higher stability and resilient modulus. Furthermore, the combination of coal waste and limestone powders in equal proportion resulted in a desirable mix with high water resistance.
Abstract. The main objective of this research was to investigate the effect of coal waste powder as filler material in hot mix asphalt. After sampling the coal waste material from a coal washing plant, it was processed to achieve natural coal waste filler. Furthermore, after incinerating the natural coal waste powder at 750 °C, the coal waste ...
This invention relates to a mixed fuel comprising a coal powder or the like and heavy oil obtained by adding and mixing a dilute aqueous solution of a watersoluble highmolecular compound and a carbonaceous solid fuel powder such as coal powder or the like (hereinafter referred to as "coal powder and the like") to heavy oil so as to disperse the coal powder and the like and water (in very ...
The numerical simulation results showed that as the water supply pressure increased, the internal pressure and water flow velocity in the mixing chamber of the nozzle increased while the air flow rate decreased sharply, resulting the continuous decrease in the relative velocity between gas and liquid.
Coal mining. Mining operations can negatively impact water supplies, often with longlasting effects. The fundamental issue involves contamination of nearby rivers, lakes, and aquifers by what comes out of a coal mine—usually highly acidic water containing heavy metals like arsenic, copper, and lead. The process is known as acid mine happens when certain substances (typically ...
The objective of this study was to investigate the influence of mixture composition and water content of the powders on mixing and mixture quality of three binary spice powder mixtures with significant differences in mixing behaviour. Furthermore, powder flowability of the mixture's constituents at various moisture contents were measured, as ...
In the "Sample configuration" stage the sample was prepared by mixing coal powder and mineral powder in six different ratios ( 100:0, 96:4, 92:8, 88:12, 84:16, 80:20). ... a pile of coal powder with infinitesimal grain size can be considered as a large size coal core. This means that the effect of grain size on temperature rising rate ...
Numerical simulation has become a useful approach to explore the complex physical and chemical process inside the supercritical water (SCW) fluidized bed reactor. Due to the drastic and nonlinear variation of water properties near pseudocritical point, the flow field and drag coefficient of SCW flow past a cold particle are considerably different from that of conventional flow. Therefore, in ...
To accurately verify the effect of coal cuttings on waterbased polymer dril ling fluids, we add coal powders to the drilling fluid, and measure their performance after mixing the coal powders.
The effects of the mix proportion and curing temperature on the pozzolanic reaction of fly ash in cement paste were investigated by examining the productions of calcium hydroxide and the pozzolanic reaction ratio of fly ash. It is possible to accurately determine the reaction ratio of fly ash in cement paste from the insoluble residue and the quantity of dissolved Al 2 O 3.
For the casting of iron, powdered coal additions or coal substitutes are usually added to greensands to improve surface finish in this way, providing a carbon layer to both the sand grains and the liquid surface. The reactions in the pyrolysis of coal were originally described by Kolorz and Lohborg (1963):. 1. The volatiles are driven out of the coal to form a reducing atmosphere.
The effects of the fineness of coal gangue powder, microwave temperature, and type and amount of chemical activator on the activity and cementitious properties of coal gangue were explored. ... After all the water is added, mixing was continued for 2 min. ③ The mixture was placed into a mold of mm × mm × mm for molding. After ...
Inert powders played an important role in the explosion inhibition of dust removal equipment and coal gasification this paper, SiO 2, dry water, carrageenan dry water, and NaHCO 3 were adopted to explore the influences of inert powders on the deflagration flame propagation characteristics of mixed pulverized coal by a vertical pipeline. The results showed that the flame brightness ...
Coal companies generally mix fine coal slime into commercial coal for sale, and some coal companies mix highash fine slime into coal gangue dumps. ... if each reagent has enough time to adsorb at the coalwater interface, a good flotation effect can be obtained. The addition sequence does not seem to be as important as it is considered in ...
Wastederived slurries can be burned both in a fluidized bed and when injected into a boiler furnace. This paper is the first to analyze the dynamic characteristics of ignition and combustion of a group of three slurry droplets based on coal slime, water, and waste industrial oil in a lowtemperature air flow with a temperature of 500600 °C and velocity of m/s.
Preparation of slurry. The slurrying experiments were performed by mixing the coal sample with 5%, 10%, 15%, and 20% (mass ratio of dry sludge to dry coal) modified sludge and sludge. The SCWS and modified sludge coal water slurry (MSCWS) were prepared using a dry slurrying process as follows.
Effect of coal waste powder in hot mix asphalt compared to conventional fillers: mix mechanical properties and environmental impacts ScienceDirect Journal of Cleaner Production Volume 91, 15 March 2015, Pages 262268
Activated charcoal is thought to offer several other benefits, including less gas and flatulence, lower cholesterol levels, and improved kidney function. Some people claim that it helps whiten ...
Later it also affects the hardened properties of concrete. The associated effect of prolonged mixing exhibits insufficient water for mixing, higher rate of evaporation and higher rate of hydration than expected. Johanson [16] varied mixing time and measured the homogeneity of concrete by fresh and hardened properties.
In addition, coal may be made into a coaloil mixture or coalwater mixture to replace petroleum. This type of technology is developing rapidly, with General Motors in the United States currently conducting research and experiments using 3 μm coal powder as automotive fuel. b Developing nuclear energy
Chlorides, sulfates, alkalis and solids in mixing water play a substantial role on quality and behavior of fresh and hardened fill from the cementtowater ratio and cement hydration points of view. Table 3 tabulates the chemistry of mixing water. To mix both coal fly ash and OPC, tap water as mixing water was only utilized in this study.
The effects of several parameters in terms of the fuel category, the heating rate, the coal/coke mass flow ratio, the CO2 partial pressure, and the Ca/S molar ratio on the ignition and burnout ...
Introduction In 2020, coal accounted for % of China's total energy consumption. Due to abundant resource reserves and technological advances, coal will still occupy a dominant position in the Chinese energy structure in the longterm.
This paper determines the optimal surfactant concentration for enhancing coal's wettability and explores the wetting mechanism at surfactant concentrations above the critical micelle concentration (CMC) during coal seam water injection. In this study, laboratory experiments and field tests were used to investigate the influence of monomeric surfactants and compound surfactants at various ...
Based on the problems of high carbon emission and high cost of traditional mining methods and filling materials, the tailings powder modified Coal Ganguebased Cementitious Backfill Material (CGCBM) was used for paste filling mining. In this study, the samples were prepared with different tailings powder content and different curing ages.
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