Acid mine drainage treatment through a two-step neutralization ferrite-formation process in northern Japan: Physical and chemical characterization of the sludge
Acid mine drainage treatment through a two-step neutralization ferrite-formation process in northern Japan: Physical and chemical characterization of the sludge
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DOI：
10.1016/j.mineng.2007.08.002
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发表时间：
2007-11-01
影响因子：
4.8
通讯作者：
Kawada, Satoshi
中科院分区：
文献类型：
--
作者：
Herrera S, Pepe;Uchiyama, Hiroyuki;Kawada, Satoshi
采用连续流实验装置对日本北部某封闭式硫化铁矿山酸性废水进行了现场处理。在两步中和铁氧体生成工艺的实验规模装置中，在第一步中和时使用氧化镁或碳酸钙将pH值提高到4.8左右，产生氢氧化铝污泥。在第二个中和步骤中，使用氢氧化钠达到pH为8.5，产生铁氧体污泥。产生的铝和铁氧体污泥的初始沉降速率比目前在该矿运行的处理厂产生的污泥的初始沉降速率高1.2至4.8倍。污泥中的悬浮固体（SS）浓度比现有设施产生的污泥中的悬浮固体浓度高1.0至11.8倍。用氧化镁和碳酸钙制备铝污泥时，污泥体积指数（SVI）分别为I I和36 mL/g。无论第一次中和使用何种中和剂，铁氧体污泥的SVI均为4 mL/g，而当前装置产生的污泥在相同参数下（SVI）为70 mL/g，这表明两步中和铁氧体形成工艺产生的污泥密度要高得多。此外，该工艺有效地将砷、铜和锌的有毒重金属浓度分别从800 ppb、13 ppm和15 ppm以上降低到1.4 ppb、0.02 pprn和0.2 ppm。(c) 2007 Elsevier Ltd.版权所有。
The acid mine drainage of a closed iron sulphide mine in northern Japan was treated on-site using a continuous flow bench scale plant. In the bench scale plant of the two-step neutralization ferrite-formation process, magnesium oxide or calcium carbonate was used during the first neutralization step to raise the pH to around 4.8 to produce aluminiurn hydroxide sludge. In the second neutralization step sodium hydroxide was applied to reach a pH of 8.5 to produce ferrite sludge. Initial settling rates of the produced aluminium and ferrite sludge were from 1.2 to 4.8 times higher than the initial settling rates of the sludge produced by the treatment plant currently operated at the mine. The suspended solids (SS) concentration in the sludge ranged from 1.0 to 11.8 times higher than the SS concentration in the sludge produced by the current facility. The sludge volume index (SVI) of aluminium sludge was I I and 36 mL/g when produced with magnesium oxide or calcium carbonate, respectively. The SVI of ferrite sludge was 4 mL/g regardless of the type of neutralizer used in the first neutralization, while the same parameter (SVI) of the sludge produced by the current facility is 70 mL/g, which indicates that the two-step neutralization ferrite-formation process generates sludge with much higher density. In addition, the process effectively reduced the concentration of toxic heavy metals from above 800 ppb, 13 ppm, and 15 ppm to as low as 1.4 ppb, 0.02 pprn and 0.2 ppm for arsenic, copper, and zinc, respectively. (c) 2007 Elsevier Ltd. All rights reserved.