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.
Coal mine paste filling technology can effectively solve the problems caused by coal mining and is a key technology to realize green mining and is widely used in coal mining (Qi et al. 2019;;Qi2020). In coal mine paste filling technology, the performance of filling materials directly determines the filling effect of a coal mine ...
Further, it is unsafe to store as it is a potential explosive. To address these issues, coalwater mix is a wiser alternative. Coal liquefaction and gasification is economical compared to its pulverized counterpart. It behaves like a liquid fuel in combustion as a fuel [11]. Another advantage of it is that it could be transported in pipeline ...
Besides, an optimum mix with considerable water resistance was obtained by equal proportions of coal waste and limestone powders, while the CWP and particularly its ash resulted in a more sensitive mix to water [39]. A study by Xu et al. (2019) examined the effects of coal waste as filler on the functional characteristics of asphalt mastics and ...
Download Citation | Study on the effect of mixing water on coal mine filling cemented paste backfill performance under pHT coupling conditions | This research is aimed at the influence of...
When the coal powder is mixed in, hydrophilic minerals on the coal surface interact with the water in the water cores, causing some of the coal particles to enter the reverse micelles. As a result of this, the hydrophobic chain of Tween 80 reaches into the oil phase and the water core becomes a hydrated film on the surface of the coal particles ...
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
Abstract. The preparation of coal water slurry (CWS) as a new substitute for oil and the factors affecting the stability of CWS were studied in this paper. Dry method was used to prepare CWS. Dry coal water slurry refers to the preparation of CWS by grinding coal into powder, then adding water and additives, mixing and stirring.
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.
Based on the analysis of the stress intensity factor, the drilling fluid with coal powders exceeding 100 mesh can reduce the capillary force in microfractures, and in combination with other factors (such as reduced filtration loss and sealing and supporting of the microfractures), improves wellbore stability.
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 ...
Utilization of iron coke hot briquette (ICHB), prepared by carbonizing coaliron ore composite agglomerate, is considered as an effective countermeasure to achieve low carbon emission blast furnace (BF) ironmaking. ICHB shows high reactivity and thereby presents low postreaction strength, which could have serious impact on the permeability of this paper, the effects of coal and iron ore ...
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 ...
A concrete mixer as shown in Fig. 2 (also commonly called a cement mixer) is a device that homogeneously combines cement with aggregates such as sand or gravel and water. A typical concrete mixer uses a revolving drum to mix the components. Internal blades are arranged in such a manner to lift and tumble the ingredients and direct the concrete into the circulatory path.
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.
This chapter contains the findings of the Subcommittee on Adsorption of the National Research Council's Safe Drinking Water Committee, which studied the efficacy of granular activated carbon (GAC) and related adsorbents in the treatment of drinking water. Some attention is given to an examination of the potential health effects related to the use of these adsorbents, but detailed toxicological ...
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 ...
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.
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.
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.
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 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.
As illustrated in Fig. 1, the whole briquettes production process involves mixing coal ash with pellet powder, blending water with the mixed powder, briquetting the final blended material, drying the green briquettes, preheating the dry briquettes and carbonizing the preheat briquettes. Bonding strength of different powder briquettes
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...
After mixing different explosion suppressants with coal dust and testing the ignition temperature, it is found that when Al(OH) 3 is mixed with coal dust and the mass percentage is 60%, the coal ...
This research is aimed at the influence of the hydration environment on the performance of cemented paste backfill (CPB). In this experiment, the CPB was prepared by mixing water at three temperatures (5°C, 15°C, 30°C) and three pH (4, 7, 10). Testing the setting time of CPB and uniaxial compressive strength (UCS) of different ages, a scanning electron microscope (SEM) was used to explore ...
The effect of addition sequence for mixed collectors comprising of dodecane(D) and nvaleric acid(A) on lowrank coal flotation was explored by the following three sequences: D first and then A(D + A), A first and then D(A + D), D and A were added simultaneously(M). The total organic carbon, contact angle, zeta potential, and Xray photoelectron spectroscopy results revealed that the coal had ...
The results show that some parameters of the drilling fluid, including viscosity, lubrication coefficient, adhesion coefficient, contact angle, and surface tension, increase after adding coal...
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 ...
Several mechanisms were responsible for the NO x reduction, including lower flame temperature from the addition of the water, staged combustion from cofiring in lowNO x burners, and the CWM acting as a reburn fuel when injected in upper level burners.
Coal is a nonpolar hydrocarbon whose surface contains a lot of aliphatic hydrocarbons, aromatic hydrocarbons and other hydrophobic groups, which enhance the hydrophobicity of coal powder. Fig. 2 shows that the contact angle of sample c (dried CWS) is °, which is slightly lower than that of sample a (coal dried after soaking in deionized ...
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