Modified LDHs

Zero-reagent acid control

Layered double hydroxides synthesized from AMD neutralization sludge, capable of in-situ passivation of contaminant metals in waste rocks while raising the pH to neutral levels.

Xu, Qingsheng · Wang, Jin · Xiaodong, Wang · Yanjie, Niu · Ziyi, Li · Deng, Rui · Junyi, Gu · Xiao, He · Wang, Wei · 80269170 · Yue, Zhengbo

Journal of Cleaner Production 2026

Specifications

Metal barrier rate (Cd)

{'zh': '73.08', 'en': '73.08'} %

Metal barrier rate (Cu)

{'zh': '62.77', 'en': '62.77'} %

Metal barrier rate (Fe)

{'zh': '64.59', 'en': '64.59'} %

Metal barrier rate (Mn)

{'zh': '85.56', 'en': '85.56'} %

Metal barrier rate (Zn)

{'zh': '58.48', 'en': '58.48'} %

Acidity barrier efficiency

{'zh': '50', 'en': '50'} %

Initial waste rock pH

{'zh': '4.5', 'en': '4.5'}

Treated waste rock pH

{'zh': '6.88', 'en': '6.88'}

Advantages

Reclassifies waste rock

After treatment, the waste rock pH rises to 6.88, meeting the pH criterion for general industrial solid waste, significantly reducing environmental risk.

50% acidity blocked

LDHs contribute 46.5% of acidity removal and enhance self-neutralization of carbonate minerals, achieving overall 50% acidity barrier efficiency.

Waste treats waste

Raw material is sludge from AMD neutralization, valorized on-site; no additional reagents needed throughout the process.

Applications

• Acid mine drainage treatment：Mixed with waste rocks to suppress acid generation at source, replacing bulk neutralizer addition.
• Environmental remediation materials：Remediation material from sludge immobilizes contaminant metals in waste rocks, reducing AMD risk.
• Heavy metal passivation：Stabilizes Cd, Cu, Fe, Mn, Zn in waste rocks via adsorption, reducing their leaching.
• Soil amendment：Treated waste rock with pH 6.88 and reduced metal lability may be used as a soil amendment.