查询词典 anglesite

Meanwhile, the concentration of Pb,Zn and other heavy metals is rather high in the oxidation zone and decreasesdownward to levels that are unbelievably low for Pb-Zn mine tailings. Theseobservations suggest that heavy metals should be re-immobilized by secondaryminerals, rather than primary minerals, in the oxidation zone, and could be leachedout from suboxic environment due to low rate oxidative dissolution which preventsthe precipitation of secondary minerals in significant amount. Thus, cover scenarioswhich establish a suboxic environment beneath the cover layer might not always beeffective in preventing heavy metal release from mine tailings.Sequential extraction studies indicate that, in addition to heavy metal leaching,oxidation of the mine tailings increased the mobility of residual Zn, and Cu, while Pb remains immobile due to the formation of anglesite (PbSO4). Using the seven-step extraction technique developed by Dold (J. Geochem. Explor., 2003, 80: 55-68), galena dissolves in significant amount at step 2 most probably due to the strong complexing of Pb2+ by acetate, while other metal sulfides dissolve at step 6, which suggest that this extraction technique could not be used to evaluate the mobility of lead in natural environment

重金属含量均低于新鲜尾矿，但以硬化层中的含量最高(Pb、Zn含量分别为0.47%和0.93%)，往下大幅度降低，表明尾矿风化过程中形成的次生矿物对Pb、Zn等重金属元素有较强的固定作用，而次氧化带的淋溶作用造成了金属元素的大量流失；(4)与新鲜尾矿相比，硬化层中铅的可迁移性大大降低，硬化层之下尾矿样品中铅的可迁移性也不同程度降低，这是由于硫化物氧化产生的硫酸根与尾矿中的铅反应形成铅矾(PbSO_4)的缘故；(5)氧化作用使尾矿中的zn、Cu等重金属的可迁移性不同程度地增大，其中对锌的可迁移性影响最大，铜的可迁移性与铁比较相似，铅则容易与硫化物氧化形成的SO_4~(2-)反应形成铅矾(PbSO_4)；(6)为了减少尾矿污染和修复矿山环境，人们提出了各种不同的尾矿覆盖方案，本文的研究结果表明，这些方法不一定能够有效地阻滞污染元素的迁移。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失