Effect of Ore Mineralogy and Bedrock Lithology on Metal Loading Rates and Acid-Mine Drainage: Bayhorse Creek,Idaho and the North Fork of the American Fork River,Utah

Metal contamination of the water in two streams was investigated at the Ramshorn Mine along Bayhorse Creek in Idaho, and the Pacific Mine along the North Fork of the American Fork River in Utah. The studies were conducted to determine what remediation measures should be implemented at each site to reduce metal loads in the streams. Discharge measurements and chemical analyses of filtered and unfiltered water samples allowed dissolved and total metal loads to be calculated. Copper, Fe, Mn, Pb, Zn, and As were found at both sites, and Cd also was present at the Utah site. Of these, Fe had the highest dissolved and total loading rates at the Ramshorn Mine, with Mn and Zn having intermediate rates; Fe and Zn had the highest loading rates at the Pacific Mine. Hydrous ferric oxides, particularly ferrihydrite, are abundant at both sites. Pyrite is the iron source at the Pacific Mine, while it is siderite at the Ramshorn Mine. The lack of sulfide at the latter site inhibits acid mine drainage (AMD) formation, and the presence of dolomite provides abundant alkalinity to neutralize any AMD that might be generated. PHREEQC was used to gain insight into the metal phases and oxidation states, to calculate saturation indices, and to perform surface sorption modeling. The results suggest that most of the metals at both sites are transported in the suspended rather than dissolved state, As occurs exclusively in the less toxic As⁵⁺ form, and several metals are likely sorbed to ferrihydrite. Based in part on the results of these studies, the US Forest Service removed the tailings at the Pacific Mine site, but only capped and regraded the tailings pile at the Ramshorn Mine.

     

喷射混凝土在北美地下矿山的过去、现在和将来

介绍了北美地下矿山喷射混凝土技术的过去和现在的现状及未来的前景。肯定了喷射混凝土与当今可用的各种技术与工艺 ,即与各种材料、设备和喷射方法相结合而获得卓有成效的应用 ,使得北美的采矿工业可以充分利用这种具有高度可塑性、易变性的材料完成各种修复工作     

The Early Development of Passive Treatment Systems for Mining-Influenced Water: A North American Perspective

This paper reviews the early history (first 20 years) of passive treatment of mine water, from its beginnings, when it was viewed as a possible way to treat small flows of circumneutral and mildly acidic coal mine drainage, to its use for much larger flows and more contaminated mine water from metal mines. The original concepts of passive treatment have since been modified and used successfully to treat a wide range of mine water quality and quantities, far more than we would have believed possible.

     

Correction to: The Early Development of Passive Treatment Systems for Mining-Influenced Water: A North American Perspective

Mine Water and the Environment -     

The Mesozoic Welding Process between South and North Dabie Blocks:An Evidence from Pb Isotopes of Yanshanian Granites

正The Pb isotope compositions of K-feldspar in granites is paid more and more geologists'attention,due to their importance of tracer.It is a fact that South Dabie Block(SDB)and North Dabie Block(NDB)had exited since Indosinian epoch(Wang et al.,1992;Cong et al,1994;Zhai et al.,1995;Chen et al.1995;Zhang et al,1996,Wang et al,1997).However,the welding process between SDB and