XING M F, WU X F, LIU Y J, et al.Removing heavy metal lead from waste leaded glass by phase separation in glass and mechanochemical method[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(4):96-102.

doi:10.16186/j.cnki.1673-9787.2022040047

Received:2022/04/19

Revised:2022/06/01

Published:2024/07/05

Removing heavy metal lead from waste leaded glass by phase separation in glass and mechanochemical method

XING Mingfei, WU Xiaofang, LIU Yuanjie, ZHAO Li

School of Resources and Environment，Henan Polytechnic University，Jiaozuo 454000，Henan，China

Abstract:The traditional phase separation used hot acid leaching process to remove heavy metal lead from phase separation product of cathode ray tube（CRT） funnel glass.However，the acid leaching process consumed a large amount of strong acid，the waste acid cannot be reused and may cause acid pollution.  Objectives  In order to achieve green and efficient recovery of heavy metal lead from the phase separation product of CRT funnel glass， Methods  ethylene diamine tetraacetic acid（EDTA） was selected as the extractant  through mechanochemical method.By studying the migration and transformation laws of heavy metals in funnel glass during the rapid phase separation process and mechanical activation leaching process，the main factors and action mechanism affecting the removal rate of heavy metals were revealed.  Results The results showed that during the phase separation process，Pb，K，Ca and other elements contained in the funnel glass were mainly enriched in the B₂O₃-rich phase with interconnected structure.During the subsequent wet ball milling extraction process，the B₂O₃-rich phase was rapidly dissolved into water under mechanical activation，meanwhile，metal cations contained in the B₂O₃-rich phase formed soluble complex with EDTA，and which can be removed from the phase separation product.The extraction rate of Pb，K，Ca and other metals increased with the increase of EDTA addition，ball milling speed and ball milling time，but it shows a trend of first increasing and then decreasing with the increase of water/solid ratio.When the EDTA addition amount was 80%，milling speed was 500 rpm，liquid-solid ratio was 0.8 and ball milling time was 30 min，and，the extraction rates of Pb，K，Ca，Al were 98.79%，94.92%，95.17% and 65.71%，respectively，and high silica glass powder with silica purity exceeding 92% was obtained.  Conclusions  This study provided reference and guidance for the green and high value-added utilization of heavy metal containing glass.

Key words:CRT funnel glass;glass phase separation;mechanochemical method;lead recovery;EDTA