Long-term stability of earthen materials in contact with acidic tailings solutions

Peterson, S.R.; Erikson, R.L.; Gee, G.W.

doi:10.2172/6671735

Cited by 3 publications

(32 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The materials and experimental methods used in obtaining the data used to compare with the modeling results have been abundantly documented elsewhere (Gee et al 1980, Peterson et al 1982, and Serne et al 1983. Results of the physical and chemical characterization work performed on the geologic materials and uranium mill tailings solutions that were used to provide the interactions modeled in this document are presented in Tables 1 and 2.…”

Section: Methodsmentioning

confidence: 99%

“…This report documents the use of a solid phase assemblage to predict the aqueous effluent compositions from columns of subsoil materials percolated with uranium mill tailings solutions. Previous geochemical modeling efforts (Nordstrom et al 1979, Gang and Langmuir 1974, Peterson and Krupka 1981, Peterson et al 1982, and Deutsch et al 1982 have confined themselves to examining saturation indices in the quest for solid phases that could be in equilibrium with their dissolved constituents. Little effort has been expended to use these solid phases as a model of a heterogeneous material.…”

Section: Executive Summarymentioning

confidence: 99%

“…Previous efforts in applying geochemical modeling to uranium mill tailings are discussed in Peters on and Krupka (1981) and Peterson et al (1982). Peterson and Krupka (1981) modeled batch solutions in which synthetic tailings solution, actual tailings solution, and H2S04 interacted with natural and treated clay materials.…”

Section: Prior Effortsmentioning

confidence: 99%

“…Ion speciation/solubility modeling was found to be an effective tool in helping delineate the chemical reactions purportedly responsible for the observed reductions in permeability. Peterson et al (1982) modeled effluent solutions from permeability cells packed with the Morton Ranch clay liner and contacted with synthetic and actual tailings solutions. The purpose of this study was to compare the solubility controls identified in the static batch experiments with those controls identified in the dynamic column experiments to see if the same solubility controls were operating in both types of experiments.…”

Section: Prior Effortsmentioning

confidence: 99%

“…Some of the more recent programs include MINEQL (Westall et al 1976), PHREEQE (Parkhurst et al 1980), WATEQ3 (Ball et al 1981), and MINTEQ (Felmy et al 1983). Several such computer programs have been successfully used to help evaluate possible solid phase controls on solution composition (Nordstrom et al 1979, Gang and Langmuir 1974, Peterson and Krupka 1981, Peterson et al 1982, and Deutsch et al 1982. However, very little work has been done in exercising these geochemical computer codes in a flow-through system to predict the aqueous phase compositions resulting from solution interaction with an assemblage of solid phases.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Predictive geochemical modeling of interactions between uranium-mill-tailings solutions and sediments in a flow-through system: model formulations and preliminary results

Peterson¹,

Felmy²,

Serne³

et al. 1983

Self Cite

View full text Add to dashboard Cite

An equilibrium thermodynamic conceptual model consisting of minerals and solid phases was developed to represent a soil column. A computer program was used as a tool to solve the system of mathematical equations imposed by the conceptual chemical model. The combined conceptual model and computer program were used to predict aqueous phase compositions of effluent solutions from permeability cells packed with geologic materials and percolated with uranium mill tailings solutions. Initial calculations of ion speciation and mineral solubility and our understanding of the chemical processes occurring in the modeled system were used to select solid phases for inclusion in the conceptual model. The modeling predictions were compared to the analytically determined column effluent concentrations. Hypotheses were formed, based on model ing predictions and laboratory evaluations, as to the probable mechanisms controlling the migration of selected contaminants. An assemblage of minerals and other solid phases could be used to predict the concentrations of several of the macro constituents (e.g., Ca, so 4 , Al, Fe, and Mn} but could not be used to predict trace element concentrations. These modeling conclusions are applicable to situations where uranium mill tailings solutions of low pH and high total dissolved solids encounter either clay liners or natural geologic materials that contain inherent acid neutralizing capacities .

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Executive Summarymentioning

confidence: 99%

Section: Prior Effortsmentioning

confidence: 99%

Section: Prior Effortsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Predictive geochemical modeling of interactions between uranium-mill-tailings solutions and sediments in a flow-through system: model formulations and preliminary results

Peterson¹,

Felmy²,

Serne³

et al. 1983

Self Cite

View full text Add to dashboard Cite

show abstract

Interactions Between Acidic Solutions and Clay Liners: Permeability and Neutralization

Peterson¹,

Gee²

1985

Hydraulic Barriers in Soil and Rock

View full text Add to dashboard Cite

Liner failure, defined as an increase in liner permeability, was not found to be a problem when acidic uranium mill tailings solutions percolated through clay liner materials for periods extending up to three years. Liner materials taken from mill sites in Wyoming decreased in permeability with time in the laboratory columns when permeated with tailings solution. One clay liner decreased in permeability from one half to over two orders of magnitude, depending on the given clay sample and contacting solution. These decreases in permeability were attributed to pore plugging resulting from the precipitation of minerals and solids and to soil particle dispersion. The clay liner material from Morton Ranch, Wyoming, exhibited a residual buffering capacity that was able to maintain column effluent pH values at higher levels than the influent pH values for extended time (in excess of 30 pore volumes). A likely cause for the elevated pH is the redissolution of iron and aluminum hydrous oxides. Redissolution of iron and aluminum hydrous oxides consumes hydrogen ions.

show abstract

Laboratory measurements of contaminant attenuation of uranium mill tailings leachates by sediments and clay liners

Serne¹,

Peterson²,

Gee³

1983

Self Cite

View full text Add to dashboard Cite

We discuss FY82 progress on the development of laboratory tools to aid in the prediction of migration potential of contaminants present in acidic uranium mill tailings leachate. Further, empirical data on trace metal and radionuclide migration through a clay liner are presented. Acidic uranium mill tailings solution from a Wyoming mill was percolated through a composite sediment called Morton Ranch Clay liner. These laboratory columns and subsequent sediment extraction data show: 1) As, Cr, Pb, Ag, Th and V migrate very slowly; 2) U, Cd, Ni, Zn, Fe, Mn and similar transition metals are initially immobilized during acid neutralization but later are remobilized as the tailings solution exhausts the clay liner's acid buffering capacity. Such metals remain immobilized as long as the effluent pH remains above a pH value of 4 to 4.5 but they become mobile once the effluent pH drops below this range; and 3) fractions of the Se and Mo present in the influent tailings solution are very mobile. Possible controlling mechanisms for the pH dependent immobilizationmobilization of the trace metals are discussed. More study is required to understand the controlling mechanisms for Se and Mo and Ra for which data were not successfully collected. Using several column lengths {from 4.5 to 65 em) and pore volume residence times {from 0.8 to 40 days) we found no significant differences in contaminant migration rates or types and extent of controlling processes. Thus, we conclude that the laboratory results may be capable of extrapolation to actual disposal site conditions.

show abstract

Long-term stability of earthen materials in contact with acidic tailings solutions

Cited by 3 publications

References 14 publications

Predictive geochemical modeling of interactions between uranium-mill-tailings solutions and sediments in a flow-through system: model formulations and preliminary results

Predictive geochemical modeling of interactions between uranium-mill-tailings solutions and sediments in a flow-through system: model formulations and preliminary results

Interactions Between Acidic Solutions and Clay Liners: Permeability and Neutralization

Laboratory measurements of contaminant attenuation of uranium mill tailings leachates by sediments and clay liners

Contact Info

Product

Resources

About