新鲜电解锰渣和长期堆存渣的矿物成分和毒性特征的差异分析

Differences analysis of minerals compositions and toxicity characteristics between the fresh electrolytic manganese residue and the stockpiling residue

以电解锰渣为研究对象,对比分析了新鲜电解锰渣和长期堆存渣的重金属含量、矿物成分、浸出毒性等的特征和差异。结果表明:新鲜渣中Mn的含量高于堆存渣。两种渣的矿物成分主要包括SiO_2、含不同结晶水的硫酸钙以及铵盐、锰盐等。堆存渣与新鲜渣的矿物成分相比,不含FeS_2、MnSO_4·H_2O、(NH_4)_2SO_4等矿物;电解锰渣浸出液中毒性污染物主要是Mn和NH_4^+-N。堆存渣中Mn和NH_4^+-N的含量、浸出量均低于新鲜渣,说明在电解锰渣堆存过程中,Mn、NH_4^+-N不断从渣中溶出。电解锰渣渗滤液中Mn和NH_4^+-N的含量分别为1 776.8mg/L、1 225.8mg/L,分别是污水排放标准GB8978-2002的355倍、49倍。该研究为电解锰渣无害化处置提供参考。

The objective of this work was to analyze and compare the contents of heavy metals,minerals compositions and leached toxic substances from the fresh electrolytic manganese residue and the stockpiling residue. The results indicated that the content of Mn from the fresh residue was greater than from the stockpiling residue. The both residues mainly contained SiO_2,calcium sulfates embodying different crystal waters,ammonium salts and manganese salts,etc. The minerals forFeS_2,MnSO_4·H_2O,（ NH_4）_2SO_4 disappeared in the stockpiling residue. The toxic pollutants were Mn and NH_4^＋- N in the leaching solutions of the both residues. The contents and leaching amounts of Mn and NH_4^＋- N in the stockpiling residue were lesser than in the fresh residue,which revealed that the dissolutions of Mn and NH_- N occurred at the stockpiling process of the electrolytic manganese residue（ EMR）. The contents of Mn and NH_4^＋- N in the EMR percolating water were 1 776. 8mg / L,1 225. 8mg / L,respectively,and 355 times,49 times as many as the requirement values of the GB8978- 2002 standard. This study could provide a reference for the harmless treatment of EMR.