Neutralization/prevention of acid rock drainage using mixtures of alkaline by-products and sulfidic mine wastes
Neutralization/prevention of acid rock drainage using mixtures of alkaline by-products and sulfidic mine wastes
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DOI：
10.1007/s11356-013-1838-z
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发表时间：
2013-11-01
影响因子：
5.8
通讯作者：
Mueller, Seth
中科院分区：
文献类型：
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作者：
Alakangas, Lena;Andersson, Elin;Mueller, Seth
用含硫废石回填露天矿并进行淹没是矿山关闭后减少硫化物氧化的常用方法。这种方法可以通过将废石与来自纸浆厂和钢厂米尔斯的碱性材料混合来补充，以增加系统的中和潜力。从1米（3）坦克含有硫化物丰富的（约30重量%）废石在干燥和水饱和条件下形成的实验室条件下的渗滤液进行了表征，并从混合物形成的那些相比。258 d后，废石浸出液产生酸性浸出液（pH < 2），其中As（65 mg/L）、Cu（6 mg/L）和Zn（150 mg/L）浓度较高。水饱和废石浸出液中As和Cu浓度较低（< 2 μ g/L），Pb和Zn浓度较低（20 μ g/L和5 mg/L），pH值在6左右。将与不同部分（1-5重量%）的绿色液体渣、粉煤灰、梅萨石灰和氩氧脱碳（AOD）渣混合的破碎（< 6 mm）废石以小规模浸出65天，并且显示出接近中性的pH值，除了废石与AOD渣和粉煤灰（5%w/w）的混合物更碱性（pH > 9）。渗滤液中元素浓度的下降最明显的是铅和锌，而铝和S相对较高。总体而言，所获得的结果是有希望的，并表明碱性副产物可以是用于最小化ARD形成的有用添加剂。
Backfilling of open pit with sulfidic waste rock followed by inundation is a common method for reducing sulfide oxidation after mine closure. This approach can be complemented by mixing the waste rock with alkaline materials from pulp and steel mills to increase the system's neutralization potential. Leachates from 1 m(3) tanks containing sulfide-rich (ca.30 wt %) waste rock formed under dry and water saturated conditions under laboratory conditions were characterized and compared to those formed from mixtures. The waste rock leachate produced an acidic leachate (pH < 2) with high concentrations of As (65 mg/L), Cu (6 mg/L), and Zn (150 mg/L) after 258 days. The leachate from water-saturated waste rock had lower concentrations of As and Cu (< 2 mu g/L), Pb and Zn (20 mu g/L and 5 mg/L), respectively, and its pH was around 6. Crushed (< 6 mm) waste rock mixed with different fractions (1-5 wt %) of green liquid dregs, fly ash, mesa lime, and argon oxygen decarburization (AOD) slag was leached on a small scale for 65 day, and showed near-neutral pH values, except for mixtures of waste rock with AOD slag and fly ash (5 % w/w) which were more basic (pH > 9). The decrease of elemental concentration in the leachate was most pronounced for Pb and Zn, while Al and S were relatively high. Overall, the results obtained were promising and suggest that alkaline by-products could be useful additives for minimizing ARD formation.