is there much limestone from coal gangue in Mexico

Influence of Curing Temperature on the Performance of …

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 development of blended cement is slow, …

Study on the macro–micro evolution of compaction …

In summary, this paper studies the stress and strain of coal gangue in the compression process through the confined compression test of coal gangue with different particle sizes in the...

Article Properties and Hydration Mechanism of Cementitious …

First, this part investigated the effect of mixing only calcined coal gangue on the strength of cementitious materials. The changes in compressive strength of the gelling material at 3, 7, and 28 days with different amounts of calcined coal gangue are shown in Fig. 3.The addition of calcined coal gangue led to a significant decrease in the 3-day compressive …

The Sustainable Utilization of Coal Gangue in Geotechnical …

Abstract Among coal mining-related wastes, coal gangue (CG) is the heterogeneous waste generated during the mineral processing or coal washing phase of coal mining. A thorough understanding of environmental concerns associated with the current model of ...

Geochemical effects of different types of mine water on …

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

Kinetics of alumina extraction from coal gangue by …

The leaching kinetics of alumina extraction from coal gangue with hydrochloric acid was investigated. ... at a calcination temperature of 700 Â°C [24]. The dissolution rate of alumina can be greatly improved by adding limestone during calcination; furthermore, sodium carbonate can react with coal gangue to form nepheline during …

Recycling of Moroccan coal gangue in the elaboration …

The comparison of this coal gangue to the usual clays shows that it is richer in silica and alumina, but poorer in calcium and iron oxides. 3.1. Optimization of the mixture limestone-gangue For each mixture, we studied the changes in the three criteria values when changing the percentage of gangue in the mixture limestone-gangue.

Representative coal gangue in China: Physical and chemical …

1.2. Source and distribution of CG in China. CG is a kind of black gray shale rock produced in the process of coal production. China is the world's largest coal producer (Munir et al., 2020) and also the largest coal consumer.Coal provides about 62% of China's energy demand (Mita et al., 2015).In the process of sorting and processing, the production of …

The properties and hydration of a calcined coal series …

To enhance the application of coal series kaolinite clay in the cement industry, the properties and hydration of ternary system based on calcined coal series metakaolin (CMK), limestone (LS), and Portland cement were investigated in this work. The results showed that the kaolinite phase transformed into an amorphous phase for …

Novel Methods for Separation of Gangue from Limestone and Coal …

Ore sorting is a useful tool to remove gangue material from the ore and increase the quality of the ore. The vast developments in the area of artificial intelligence allow fast processing of full-color digital images for the preferred investigations. The associated gangue minerals from limestone and coal mines were identified using three different approaches.

Optimizing the formulation of coal gangue planting …

To investigate the optimal ratio of all components of the coal gangue planting substrate, we designed and implemented four-factor orthogonal experiments, each at three- levels (Table 2).These orthogonal experiments produced nine different component ratios, as shown in Table 3 (Yin et al., 2016; Li et al., 2017); sandy loam soil was used …

Heavy Metal Concentrations of Soil, Rock, and Coal Gangue …

Here, to compare the variety of heavy metal concentrations in the geological profile, 39 samples (including soil, rock, and coal gangue) were collected and analyzed from hundreds of meters ...

Valorization of calcined coal gangue as coarse aggregate in …

CG used in this paper was obtained in Huaibei mining area, Anhui Province, China. NA was selected as an experimental comparison. The particle sizes of both raw coal gangue aggregate (CGA raw) and NA were in range of 4.75–9.50 mm. Type P.II 52.5 Portland cement was provided by Onoda Co. Ltd., Nanjing. Table 1 reveals that the …

Hydration mechanism of limestone calcined clay cement …

The beneficial improvement of LC 3 cement on mechanical properties can be ascribed to the synergistic effect of limestone with the OPC and calcined coal gangue forms CO 3-Afm, inhibiting the decomposition of ettringite and reducing porosity.

Catalytic reduction of nitric oxide by carbon monoxide over coal gangue …

In the experiment, coal gangue hollow ball with open pores is used as catalyst for NO reduction by CO in fluidized bed reactor. The preparation process of coal gangue hollow ball with open pores includes the following steps: coal gangue is smashed into 0.1–10 μm; the powders are mixed with water, Y 2 O 3 sintering additive and …

Excess sulfur and Fe elements drive changes in soil and

Coal mining is indispensable due to the widespread use of coal, and gangue is the accumulated solid waste byproduct that persists in mined lands, even after the mines have been abandoned 1.In the ...

Co-combustion and emission characteristics of coal gangue …

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 …

Synergic performance of low-kaolinite calcined coal gangue blended …

Liu et al. [26] studied the effect of coal gangue with low kaolinite content on the mechanical properties of cement, and the results showed that for binders with Calcined coal gangue and limestone ...

Precise detection of coal and gangue based on natural …

coal‑gangue detection technology in complex structure thick coal seam with multiple gangue. Field tests were conducted in Lilou, Xiaoyu and Tashan Coal Mine.

Exploring calcined coal gangue fines as the total substitute …

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 …

Minerals | Free Full-Text | Leaching Behavior and Potential

In order to better understand the role of coal gangue in potential environmental and ecological risks, the leaching behavior of trace elements from coal gangue has been investigated in an open-cast coal mine, Inner Mongolia, China. Four comparative column leaching experiments were conducted to investigate the impacts of …

Application of Coal Gangue as a Coarse Aggregate in Green …

Along with the excavation and washing of coal in the production process, large amounts of rock-like coal gangue (CG) accompanying the carboniferous beds are discharged as industrial residues, accounting for around 10–20% of the coal production [2,3,4].In the largest coal production country, namely China, more than 700 million tons …

Hydration mechanism of limestone calcined clay cement …

2.2. Experiment procedures2.2.1. Thermal treatment. The treatment process for the original coal gangue involves three sequential steps: (1) the raw coal gangues were crushed to achieve a size of no more than 20 mm; (2) the crushed coal gangue powder underwent a 24-hour high-temperature drying phase at 80°C until it reached a constant …

Study on the macro–micro evolution of compaction …

With the long-term sustained development of coal resources, the continuous underground coal mining activities have caused surface subsidence and accumulation of coal gangue waste, which has ...

[PDF] Recycling of Moroccan coal gangue in the elaboration …

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 …

Novel Methods for Separation of Gangue from Limestone and Coal …

The analysis of coal and gangue characteristics throughout the development of separation systems leads to different work implementation directions, some separation systems perform image geometric ...

Experimental Study on Nonuniform Compaction and Re

The crushed coal gangue particles are widely used in solid backfilling. However, the non-uniform compaction and internal re-crushing behavior of crushed coal gangue under bearing-stress have not ...

Novel Methods for Separation of Gangue from Limestone and Coal …

Identification and Activation of Coal Gangue and …

Gangue, a typical waste associated with the coal mining process in northern China, was characterized before and after thermal treatment by XRF, XRD, TGA-DSC, and SEM. The pozzolanic reactivity of calcined gangue with different calcined temperature was tested by standard mortar strength and R3 calorimetry test. The performance of blended cement …