At-source control of acid mine drainage

AbstractAcid mine drainage (AMD) has caused serious and long-lasting damage to the environment in many countries. Preventing AMD formation at the source is considered the most direct and effective method of remediation. Carbide slag, an industrial waste, is a potential AMD treatment material due to its strong alkalinity. However, applying carbide slag at the source carries difficulties due to its rapid release of alkalinity. This is the first attempt to mix carbide slag with bentonite to prepare sustained-alkalinity-release particles for source control of AMD. The size of Ca(OH)2 crystallites is decreased from 267 to 211 nm, and the reduced part forms calcium silicate hydrate gel (C–S–H) between the carbide slag and bentonite. C–S–H encapsulated on the surface of the carbide slag, increasing the mechanical strength of the particles, and achieving slow release of alkalinity. The suggested optimum preparation conditions for the particles are as follows: bentonite-to-carbide slag mass ratio of 3:7, Na2CO3 dose of 10 wt%, and calcination temperature of 500 °C for 1 h. The particles can remove 105 mg/g Cu2+ within 12 h, and the loss rate is only 7.4%. The alkalinity release time of the particles is 4 times greater than that of carbide slag.

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Research Progress of Acid Mine Drainage Treatment Technology in China

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.409-410.214 ◽

2013 ◽

Vol 409-410 ◽

pp. 214-220 ◽

Cited By ~ 4

Author(s):

Ting Ting Wei ◽

Yang Yu ◽

Zhen Qi Hu ◽

Yuan Bo Cao ◽

Yang Gao ◽

...

Keyword(s):

Acid Mine Drainage ◽

Mine Drainage ◽

Mining Industry ◽

Research Progress ◽

Source Control ◽

Treatment Technology ◽

Acid Mine ◽

Control Technologies ◽

Development Tendency ◽

Acid Mine Drainage Treatment

Acid mine drainages treatment technology is a hot issue in the mining industry. It summarizes the causes, the reaction mechanism and impact on the environment of acid mine drainage, and introduces the monitoring indicators of acid mine drainage. Further it focuses on the acid mine drainages terminal treatment technologies that including neutralization, sulfide precipitation, microbiological method, constructed wetlands, membrane method and the iron-carbon micro electrolysis, with the analysis of its theories, advantages, disadvantages and practical application. Meanwhile it introduces the major source control technologies, and further proposes the development tendency that is from terminal treatment technology to the combination of source control and terminal treatment technology. And its a focus and hotspot in the research of the acid mine drainage in China's future.

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Formation Mechanism of "Encapsulated" Carbide Slag Composite Alkalinity Sustained-release Particles for the Source Control of Acid Mine Drainage

10.21203/rs.3.rs-764148/v1 ◽

2021 ◽

Author(s):

Jichi Bai ◽

Haiqin Zhang ◽

Liping Xiao

Keyword(s):

Acid Mine Drainage ◽

Sustained Release ◽

Loss Rate ◽

Mine Drainage ◽

Source Control ◽

Release Time ◽

Acid Mine ◽

Preparation Conditions ◽

Carbide Slag ◽

Gel Phase

Abstract Acid mine drainage (AMD) has caused serious and long-lasting damage to the environment in many countries. The source control of AMD is considered to be the most direct and effective method of remediation. Carbide slag is an industrial waste which is considered as a potential treatment material for AMD treatment due to the strong alkalinity. However, the application of carbide slag in the source control of AMD encounters difficulties due to its fast alkalinity release rate. This is a first attempt to mix carbide slag with bentonite to prepare alkalinity sustained-release particles for the source control of AMD. Results showed that the gel phase(C-S-H) formed between the interface of carbide slag and bentonite encapsulated the surface of the Ca(OH)2 which grain decreases from 267nm to 211nm. The optimum preparation conditions are suggested as follows: a mass ratio of bentonite to carbide slag of 3:7, a Na2CO3 dose of 10 wt%, and a calcination temperature of 500°C for 1 h. The particles can remove 105 mg/g Cu2 + within 12 h, and the loss rate is only 7.8%. Compared with carbide slag, the alkalinity release time of the particles is prolonged by 4 times.

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