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Coal-Washing Investigations: Methods and Tests

Description: From Introduction: "The investigations described in this bulletin are confined to a study of the washing characteristics of bituminous coals. The washing characteristics of coals from many of the most important coal-producing fields of the Eastern and Central States were examined."
Date: 1929
Creator: Yancey, H. F. & Fraser, Thomas
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Method and Cost of Mining the Thick Freeport Coal in a Second Western Pennsylvania Mine

Description: From introduction: The purpose of this paper is to present a detailed description of the methods employed and the equipment used, with the results obtained in the operation of this mine in the thick Freeport bed on the northern end of the field, near the Alleghegny-Butler county line in western Pennsylvania. It may be classed as a captive mine, as the largest portion of the product is consumed at the by-product plants of the parent company
Date: July 1929
Creator: Paul, James Washington & Tomlinson, H.
open access

Ocher and Ochery Earths

Description: Report about ocher or ochery earth, "a natural mineral pigment composed largely of clay permeated with hydrated iron (ferric oxide)" (p. 2). It includes information about the uses of choer, substitutes, artificial ocher, mining and local deposits, import and export of ocher, and related information.
Date: May 1929
Creator: Santmyers, R. M.
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