补连塔和保德煤矿矸石中无机氮和重金属的溶出特征对比研究

Dissolution characteristics of inorganic nitrogen and heavy metals in coal gangue from Bulianta and Baode mines

文中以神东矿区补连塔矿和保德矿煤矸石为研究对象,通过浸泡实验来对比研究不同地质年代煤田煤矸石中Fe3+、Cu2+、Cr6+及无机氮的溶出特征,以此来探讨煤矿地下水库中矸石对矿井水质的影响。研究结果表明:两种煤矸石浸泡液中无机氮均以氨氮含量最高,其变化趋势与硝酸盐氮一致,亚硝酸盐氮含量最低,但各无机氮含量均以补连塔矿较高。补连塔矿的单位质量煤矸石中重金属的最大溶出量分别为:Fe3+,2.904mg/kg;Cu2+,0.314mg/kg;Cr6+,0.248mg/kg,且均呈现先增加后降低的变化规律;浸泡液电导率整体上呈增加趋势,最大值为438.7μS/cm。保德矿煤矸石浸泡液中Fe3+、Cu2+、Cr6+含量大部分低于检出限,电导率呈对数增长至最大值131.2μS/cm。两种煤矸石浸泡液均呈弱碱性,由于煤矸石组成及结构的不同,造成其pH在96h后的变化规律恰好相反。

The coal gangues from Bulianta and Baode Coal mines in the Shendong Mining Area were taken as the research object in this paper.The leaching experiments were used to compare the dissolution characteristics of Fe3+,Cu2+,Cr6+and inorganic nitrogen in coal gangues in different geological ages.In this way,the influence of gangue in the underground water reservoir of coal mines on mine water quality was discussed.The result shows that for the ammonia nitrogen is the highest in the two types of coal gangue soaking liquids,and the change trend is consistent with nitrate nitrogen,and nitrite nitrogen content is the lowest.However,the content of each inorganic nitrogen is higher in the Bulianta Mine.The maximum dissolved amounts of heavy metal ions per kilogram coal gangue in Bulianta mine are:Fe3+、2.904 mg/kg,Cu2+、0.314 mg/kg,Cr6+、0.248 mg/kg;all show increase firstly and then decrease,and the conductivity shows an increasing trend integrally,and the maximum value is 438.7μS/cm.The contents of Fe3+,Cu2+,and Cr6+in the water samples obtained from the coal gangue in Baode mine are mostly lower than the detection limit,and the conductivity increases logarithmically to the maximum 131.2μS/cm.Both coal gangue soaking liquids are weakly alkaline.Due to the different composition and structure of coal gangue,the change of pH is just the opposite after 96 h.