Date of Award

6-1990

Document Type

Union College Only

Degree Name

Bachelor of Science

Department

Chemistry

Language

English

Abstract

Four samples of dolemitic limestone ore, provided by the Thorne-Smith Company were analyzed for trace elements. Composition of limestone is important because this ore is often found with ground water (a primary source of drinking water); and in acidic conditions, certain elements can leach out of the ore and into the water supply, possibly in toxic levels, depending on the element. The elements that were found are: aluminum, iron, manganese, tin, and chromium. This last element is of particular concern because it appears in the ore in relatively high concentrations, and chromium can be a very toxic substance if its concentration is above 0.5 micrograms per liter of water. The Thorne-Smith Company provided the compositions of their ores as weight percents of silica, MgO, CaO, and R203. The R203 term takes into account all the trace elements. The goal of this project was to assign actual oxides to this term. The elements listed above comprised 60-90% (depending on the sample) of the trace element group. Using this data, a local (upstate New York) sample of limestone ore was analyzed for some of the elements listed above. The elements were found in the same approximate concentrations as they were in the prepared samples. This means that a model of limestone can be made up, that indicates probable levels of trace elements in dolomitic limestone ore. All samples were analyzed on the SpectraSpan IV, a direct current argon plasma spectrometer. The SpectraSpan was chosen because it provided excellent detection limits, and gave superior resolution and dispersion. These qualities of the instrumentation allowed for a good quantitative analysis of the ores. This project was as much a learning experience in operating the instrument, as it was in analyzing the ores.

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