Investigation on ash fusion temperature and slagging characteristic of Zhundong coal blends, Part 1: The effect of two solid wastes from calcium carbide production
Abstract
The potential of purified dust (PD) and removed dust (RD) from calcium carbide production as additive to improve the slagging characteristic of Zhundong (ZD) coal blends was studied. Ash fusion tests with varying proportion of two additives (2.5, 5.0 and 7.5 wt%), and ash sample preparation at 1150/1250 °C were conducted. The deposits at different temperatures (1200/1000/800/600 °C) were collected by using an un-cooled probe which was inserted into a drop-tube furnace. The detail characterizations of ash or slag samples were used for analyzing the transformation of mineral phases, and evaluating the effectiveness of additives. The results show that PD and RD have a feature of Ca and C enrichment. The former has a higher Ca content, while the later owns more abundant C element. The addition of PD or RD improves ash fusion temperatures of coal blends, but the effectiveness of 5.0% PD is the best. The addition of 5.0% PD could convert the glassy slags collected at 1200 °C into deposits with low melting fraction, due to the formation of calcium-rich crystal minerals. Controlling the CaO/SiO2 molar ratio at the range of 2.2– 3 would significantly relieve the high temperature melting behavior of ZD coal blends featured by high Ca and low Si.
- Publication:
-
Fuel Processing Technology
- Pub Date:
- April 2022
- DOI:
- 10.1016/j.fuproc.2021.107138
- Bibcode:
- 2022FuPrT.22807138W
- Keywords:
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- Ash;
- Slagging;
- Mineral phases;
- Solid wastes