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E 2242 - 07 5.3 This test method is designed to mobilize potential contaminants present in the solids, so that the resulting extract can be used to assess leachate that could potentially be produced from mine rock in the field. 5.4 This test method has not been demonstrated to simulate actual site leaching conditions. 5.5 This test method produces extracts that are amenable to the determination of both major and minor (trace) constituents. When minor constituents are being determined, it is especially important that precautions be taken in sample preservation, storage and handling to avoid possible contamination of the extracts. 5.6 This test method is a comparative method intended for use as a routine method for monitoring mine rock. It is assumed that all who use this method will be trained analysts capable of performing skillfully and safely. It is expected that work will be performed in a properly equipped laboratory under appropriate quality control practices such as those described in Guide E 882. 6. Interferences 7.8 Water and Extract Containers, sufficient in size to contain the water added during extraction. Containers must be covered to avoid contamination. 7.9 Water Metering Device, a metering pump or constant head device to insure constant rate extraction fluid application during column percolation. 8. Reagents and Materials 8.1 Purity of Reagents-Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Commit- tee on Analytical Reagents of the American Chemical Society, where such specifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. 8.2 Purity of Water-Unless otherwise indicated, references to water shall be understood to mean Type H reagent water at 18 'C to 27 'C conforming to Specification D 1193. 6.1 This test method may not be suitable for obtaining extracts from finely divided solids (such as: finely crushed drill cuttings, clays, sludges, mill tailings, etc.), due to difficulty in obtaining a representative extract solution. If it takes more than 48 h for the column to produce an extract which has a mass equivalent to 70 % of the dry test sample weight, use of an alternate extraction procedure may be required, such as Method D 6234. 7. Apparatus 7.1 Drying Pans or Dishes, for moisture content determina- tions, 1 kg capacity. 7.2 Extraction Column, PVC column of 15-cm (6-in.) O.D. of sufficient height to contain a minimum of 5 kg of test sample with a feed particle size that just passes a 5-cm (2-in.) sieve and sufficient additional height to contain applied water volume should poor percolation occur. For a 5 kg test sample, a 15 cm O.D. X 45 cm high column is recommended. Additional column height will be required for test sample quantities greater than 5 kg. The bottom of the column must be sealed and a solution discharge outlet situated above the sealed bottom of the column and below a perforated support plate. A drawing of a suitable extraction column is shown in Fig. 1. 7.3 Filtration Device, of a composition suitable to the nature of the analyses to be performed and equipped with a 0.45 µm pore size filter. An assembly for pre-filtration or a centrifuge may be required if 0.45 µm filtration is difficult. 7.4 Filter Media, glass wool (inert) or a plastic fiber pad is placed onto the support plate before loading the laboratory sample into the column, to minimize fines migration, and onto the top of the test sample after column loading, to aid in making an even water distribution. 7.5 Laboratory Balance, capable of weighing to 1.0 g. 7.6 pH Meter, with a readability of 0.01 units and an accuracy of at least ± 0.05 units at 25 °C. 7.7 Tubing, surgical or synthetic tubing sufficient in diam- eter and length for the extraction column assembly (pump, column outlet). 9. Hazards 9.1 For precautions to be observed in the use of analytical methods associated with this standard, refer to Practices E 50. 10. Sampling and Sample Preparation 10.1 The amount of gross sample to be sent to the laboratory should he sufficient to perform the solids content determination as specified in 10.3, and to provide at least 5 kg of test sample on a dry weight basis for extraction. Gross sample weights in the range of 7 to 25 kg are appropriate. NOTE 1-Information on obtaining representative samples can also be found in Pierre Gy's Sampling Theory and Sampling Practice' and in Practice E 877. 10.2 In order to prevent sample contamination or constitu- ent loss prior to extraction, keep the samples in closed containers appropriate to sample type and desired analysis. 10.3 Moisture Determination-Remove the gross sample from the container and blend by coning or rolling to obtain a sample for feed moisture content with a minimum of 500 g dry weight. 10.3.1 Weigh the moisture test sample and dry to constant weight (± 0.05 %) at 105 'C ± 2 'C and record the weight. 10.3.2 Calculate the moisture content of the test sample as follows: M = 100(B - A) (1) B ' Reagent Chemicals, American Chemical Society Specifications , American Chemical Society, Washington. DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD. ' Pitard, F., Pierre Gy's Sampling Theory and Sampling Practice, Vols. I and II, CRC Press, 1989. Copyright by ASTM Intl (all rights reserved); Thu Jun 26 15:52:01 EDT 2008 Downloaded/printed by Camp Dresser Mc Kee pursuant to License Agreement. No further reproductions authorized.