Siderite, oxidation, and neutralization potential determination /
Due to the nature of native soils overlying lignite seams in Texas, mixed overburden is allowed as a topsoil substitute. Determination of suitable topsoil replacements is based on chemical analysis, including neutralization potential (NP), a component of acid-base accounting (ABA). The presence of s...
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
2001.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Summary: | Due to the nature of native soils overlying lignite seams in Texas, mixed overburden is allowed as a topsoil substitute. Determination of suitable topsoil replacements is based on chemical analysis, including neutralization potential (NP), a component of acid-base accounting (ABA). The presence of siderite (FeCO₃) contributes to an overburdens NP, which may result in false positive ABA values, leading to overestimation of neutralizing minerals and therefore, may result in acid drainage / acid soils. Mineralogy and chemistry of overburden samples from Texas lignite mines were characterized for use in (NP) determination studies. Samples were obtained from the Northwestern Resources (NWR) mine in Jewett, Texas Utilities (TXU) mines at Oak Hill and Big Brown, and Intermountain Laboratories (IML) in College Station. The IML samples all contained FeCO₃ and had high ABA values. The FeCO₃ rock obtained from the NWR mine has cation substitution for Fe in the lattice. The conducted research examined reactions of FeCO₃ under various testing conditions as related to NP determination as well as accuracy of the NP method. The effects of hydrogen peroxide (H₂O₂), potassium persulfate (K₂S₂O₈), and potassium permanganate (KMnO₄) on the NP of mixed overburden containing FeCO₃ were studied. Hydrogen peroxide produced variable results depending upon complete removal of excess oxidant. Oxidation with K₂S₂O₈ produced lower NP values that the standard method. KMnO₄ reduced the NP significantly when FeCO₃ is present in the soil. However, dissolution of minerals other than FeCO₃ may increase NP if 0.5 M HCl is for digestion before oxidation. |
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| Item Description: | "Major subject: Soil Science". Vita. |
| Physical Description: | xii, 106 leaves : illustrations, map ; 28 cm. Also available online. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references (leaves 99-102). |