pH Testing Methods for Sulfidic Mine Wastes

pH tests are useful screening tools for assessing the characteristics of first flush waters draining sulfidic rocks and waste materials at mine sites. Rinse and paste pH tests are part of a suite of static tests used in acid-base accounting assessments. This study presents a comparison of eleven different pH tests (e.g., rinse and paste pH tests as well as soil tests of the International Organization for Standardization ISO 10390:2005, American Society for Testing and Materials ASTM D4972-01(2007) and Standards Australia AS4969.2-2008) using three different sulfidic rock samples and the acid-base accounting standard KZK-1. We show that different rinse and paste pH methodologies using different grain sizes and extraction solutions can result in different risk classification for ARD assessments. We suggest pH testing should be standardized in their grain size and solid to solution ratio. pH tests conducted using unweathered materials (e.g., drill core) should be carried out using a 0.01 M CaCl2 solution.

[1]  W. Salomons,et al.  Trace metal analysis on polluted sediments , 1980 .

[2]  P. Hageman.  U.S. Geological Survey Field Leach Test for Assessing Water Reactivity and Leaching Potential of Mine Wastes, Soils, and Other Geologic and Environmental Materials , 2007 .

[3]  K. Lapakko,et al.  EFFECTS OF PARTICLE SIZE ON DRAINAGE QUALITY FROM THREE LITHOLOGIE , 2006 .

[4]  Malcolm E. Sumner,et al.  Measurement of soil pH: Problems and solutions , 1994 .

[5]  M. Conyers,et al.  OBSERVATIONS ON SOME ROUTINE METHODS FOR SOIL pH DETERMINATION , 1988 .

[6]  D. Kissel,et al.  Comparison of Soil pH Methods on Soils of North America , 2010 .

[7]  W. C. Maehl,et al.  2000 Billings Land Reclamation Symposium MATERIAL CHARACTERIZATION AND PRIORITIZATION OF REMEDIATION MEASURES AT THE ZORTMAN/LANDUSKY MINE SITES , 2000 .

[8]  A. Parbhakar-Fox.  Establishing the value of an integrated geochemistry-mineralogy-texture approach for acid rock drainage prediction , 2012 .

[9]  E. Teller,et al.  ADSORPTION OF GASES IN MULTIMOLECULAR LAYERS , 1938 .

[10]  George E. Rayment,et al.  Soil Chemical Methods – Australasia , 2011 .

[11]  Oliver L. Raymond,et al.  Pyrite composition and ore genesis in the Prince Lyell copper deposit, Mt Lyell mineral field, western Tasmania, Australia , 1996 .

[12]  D. Dzombak,et al.  Comparison of dissolution under oxic acid drainage conditions for eight sedimentary and hydrothermal pyrite samples , 2008 .

[13]  P. Weber,et al.  SHORT-TERM ACID ROCK DRAINAGE CHARACTERISTICS DETERMINED BY PASTE pH AND KINETIC NAG TESTING: CYPRESS PROSPECT, NEW ZEALAND 1 , 2006 .