— Influence of kaolinite content in coal-series metakaolin and soft metakaolin on the performance of cement blends with and without limestone. ... However, a significant …

It is proposed to develop clinkers from mixtures of limestone and coal gangue. - Limestone from a cement plant denoted L (lime). - The gangue (sterile) of the coal mine of Jerada denoted G. The ...

 — The calorific value of coal gangue refers to the amount of energy that can be released from complete combustion of coal gangue per unit mass under certain conditions, and it usually increases with increasing carbon mass fraction and volatile fraction and decreases with increasing ash fraction [24].The meltability of coal gangue refers to the …

Coal gangue is one of the largest mine solid wastes in China, and its discharge and stockpiling have caused resource waste, environmental pollution and other problems. Starting from the resource characteristics of coal gangue, this paper systematically discusses the ways and research status of coal gangue resource utilization, mainly …

The results state that there is the different optimum temperature for the different coal gangue. For most coal gangues, the optimum activated temperature is 800. The 28days compressive strength of mortar with activated coal gangue can be increased when calcining coal gangue with a certain limestone. The structure of calcining coal gangue and ...

 — The utilization of calcined coal gangue (CCG) and limestone for the preparation of blended cement is an efficient approach to address the issue of coal gangue disposal. However, the compressive strength …

 — Coal gangue (CG) is a rock associated with or symbiotic with coal during the formation process of coal resources and discharged as a byproduct by coal mining or separation, (1) which accounts for …

This study aims to apply microwave-activated coal gangue (MCG) to develop limestone calcined clay cement (LC 3). The impact of microwave activation schemes (microwave temperature and holding time) on the pozzolanic activity of coal gangue were explored.

Keywords: Ordovician limestone karst water; Weathered coal gangue; Water pollution; Filling mining 1. Introduction Coal gangue is harmful solid waste generated during coal production and processing and after the closure of coal mines. According to statistics [1], there are more than 1,500 coal gangue hills in China, which accumulated exceeded

 — Coal gangue is a kind of industrial solid waste with serious ecological and environmental implications. Producing concrete with coal gangue aggregate is one of the green sustainable development requirements. This paper reviews the properties and preparation methods of Chinese gangue aggregate, studies the influence of gangue …

 — The mineral composition of raw coal gangue and calcined coal gangue is shown in Fig. 2. The main components of raw coal gangue were kaolinite and quartz. There was also a small amount of muscovite in it. The XRD curve of calcined coal gangue indicates quartz became the primary mineral, and the kaolinite peak disappeared clearly.

 — Hg exhibited different characteristics in its mean concentrations than Cd. The highest mean concentration (0.1 mg/kg) was found in coal gangue, whereas soil and diorite samples had low mean concentrations (0.02 mg/kg and 0.01 mg/kg, respectively). High Hg concentrations (0.3 mg/kg–6.3 mg/kg) in coal gangue were also found by Niu et al. (2017 ...

 — Results show that the optimum thermal-activation temperature of coal gangue is 800°C: the coal gangues in Yangquan, Huozhou, and Xinzhi, China, had higher activity and the replacement level of ...

transform to suppress the speckles in the gangue images, to enhance edges, because the coal gangue images were always contaminated with speckles of coal dust [8]. Ma and Zang suggested a novel image processing method for separating gangues from coal with wavelet analysis. The Haar wavelet was used to reduce high fre-quent noises of gangue images.

 — Coal gangue (CG) is a rock associated with or symbiotic with coal during the formation process of coal resources and discharged as a byproduct by coal mining or separation, which accounts for 10–15% of …

 — However, coal gangue can still be used for both electricity and heating. As a partial substitute of coal, it also can ease the shortage of coal resources. Due to the huge production of coal gangue, there are large quantities of coal gangue left every year (Long et al., 2019). The disposal of coal gangue causes serious environmental problems.

 — We were interested to elaborate a Portland clinker from mixtures composed of limestone and coal gangue. A preliminary study was focused on the optimization of the composition of the mixture ...

 — The associated gangue minerals from limestone and coal mines were identified using three different approaches. All the methods were based on extensions of the co-occurrence matrix method. In the first method, the color features were extracted from RGB color planes and texture features were extracted using a multispectral extension, in …

 — 1. Introduction. Coal gangue, a waste produced during coal mining, has been regarded as the largest source of industrial waste in China. It is estimated that the production of 1 t coal generates 0.1–0.25 t coal gangue [1], and the total stockpile of coal gangue exceeds 6 billion tons in China [2], [3].The coal gangue not only occupies …

 — Global rise in greenhouse gas emissions (GHG) is triggered mainly due to the consumption of fossil fuels for power generation and domestic usage. Among the fossil fuels, coal is a primary contributor to global GHG with substantial emissions generated during its mining and combustion process. Coal gangue, a residue produced during the …

 — A large amount of coal gangue buildup may be a potential fire hazard associated with the heat released by microorganisms accumulating to the point of spontaneous combustion in the presence of unburned coal, pyrite (FeS 2) and oxygen.Coal gangue is likely to cause large-scale fire and blast disasters, and produce a significant …

 — However, compared to natural aggregate, the strength of coal gangue aggregate (CGA) is much lower, and its interfacial bonding in concrete is weaker. This paper studies the effect of calcination processes at 450 °C and 750 °C on the mineral and chemical compositions, microstructure and suitability of coal gangue as aggregate in …

 — The coal industry is an important pillar industry of economic development in China, with coal mining produced a lot of coal gangue, which is occupied land, and pollution of the environment, and the production and life of coal-producing areas have been seriously affected, coal gangue has become a heavy burden restricting the sustainable …

 — Coal gangue with calorific value of 6270 kJ kg −1 - 12550 kJ kg −1 can be directly used as boiler fuel without sorting, and coal gangue with calorific value of 4180 …

 — 1 Introduction. Coal gangue is a solid waste produced in coal mining and production, due to the lack of effective comprehensive utilization technology coal gangue is mainly disposed of in stockpiles, not only occupying extensive land but also leading to serious environmental pollution [1–5].Coal gangue with kaolinite as the main component, …

 — The reuse of coal gangue for energy recovery is developing rapidly in China, due to its advantage in achieving both economic and environmental benefits. Low-quality coal is often added to elevate the calorific value of the fuel. In this paper, the combustion characteristics as well as pollutant emissions (SO2 and NO) of coal gangue, low-quality …

We investigated the possibility of recycling and recovery of Moroccan coal gangue (coal mine of Jerada). The analysis of the waste showed that it is formed essentially of silica and clays. We were interested to elaborate a Portland clinker from mixtures composed of limestone and coal gangue. A preliminary study was focused on the optimization of the …

 — The acid pollution produced from coal gangue piles is a global environmental problem. Terminal technologies, such as neutralization, precipitation, adsorption, ion exchange, membrane technology, biological treatment, and electrochemistry, have been developed for acid mine drainage (AMD) treatment. These …

 — After calcination, the larger particles of 0–1 mm coal gangue became smaller and there was an increase in smaller particles, the XRD diffraction peak of kaolinite disappeared. Under water-cement ratios of 0.4 and 0.7, the compressive strength of cement mortar with calcined coal gangue was significantly higher than that without calcination at ...

 — To gauge the feasibility of using coal gangue for geotechnical and geoenvironmental applications, comprehensive characterization study was performed …