Thesis--University of Missouri, School of Mines and Metallurgy, 1883. / A. Neustaedter determined to be Arthur Neustaedter from "1874-1999 MSM-UMR Alumni Directory". The entire thesis text is included in file. Holograph [Handwritten and illustrated in entirety by author]. Title from title screen of thesis/dissertation PDF file (viewed November 21, 2008)

The recovery of placer gold from 20 mesh to 150 mesh in common sluicebox configurations was investigated. Two types of riffles, 1-10H expanded metal (1.5"x.75"x.25") and 1.25" angle iron riffles (dredge riffles), were used in conjunction with 3/8" thick "Nomad" matting for 25 tests. The effects of variations in upper feed size, water flow rate, sluice gradient, and solids feed rate on the recovery of placer gold particles are documented. The gold and test gravel were obtained from the Teck Corporation sluicing operation on Sulphur Creek, Yukon Territory during July, 1985. Approximately nine troy ounces of placer gold and fifteen tons of gravel were transported to Vancouver.B.C. A test sluice facility was constructed in Coquitlam,B.C. to simulate operating conditions in a typical Yukon placer operation. The sluicebox was 12" wide and 8' long with clear plexiglass sidewalls. Screened gravel of either 3/4" or 1/4" upper feed size was fed to this sluice from a hopper at rates of up to 1260 lb/min. The water pumping capacity was a maximum of 400 USGPM. Between 75 and 90 grams of each of three sizes of placer gold (-20+28#, -35+48#, -65+100# ) were premixed with the gravel for most tests. The final test used 25 grams of -100+150 mesh gold. Sluicing, when properly controlled, was found to be a highly effective means of concentrating placer gold as small as 150 mesh. Expanded metal riffles were far superior to dredge riffles in concentrating gold of this size range. Recovery of the -65+100# size fraction frequently exceeded 90% when using expanded metal riffles. Visual observation of eddies formed downstream of the riffles showed that scour depth between riffles was the one characteristic of the slurry flow that gave the best indication of the resulting gold recovery. For expanded metal, scour depths between 1/2 and 3/4 of the riffle depth were found the most effective. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xii, 145 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 129-132).

Based on the author's master's and doctoral theses--Stanford University. / Includes bibliographical references.

Based on the author's master's and doctoral theses--Stanford University. / Includes bibliographical references.

Thesis (Ph. D.)--University of Western Ontario, 2008. / Includes Vita. Title from PDF title page (viewed on May 25, 2010) Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (leaves 86-89). Also issued in print.

D.Ing. / The research described in this thesis is an investigation into fundamental aspects of the mechanical excavation of hard rock using free rolling cutters, currently being undertaken at the Chamber of Mines of South Africa Research Organization. The motivation for undertaking this study was provided by the need to improve the effectiveness and operational efficiency of this type of tool with regards to its application in the South African gold mining industry. Earlier work has shown that the use of high-pressure water jets enhances the performance of mechanical cutting in hard rock. To assess the potential of this approach for use in conjunction with free rolling cutters, a series of laboratory tests was conducted using both disc and button type cutters, to determine the relative effects, on cutter performance, of variations in the relevant jet and cutting parameters. The parameters investigated were jet pressure, jet configuration, depth and spacing of cuts and cutting speed. Jets of diameter 1,2 mm were used singly and in combination of 2 and 4 jets at pressures in the range of 5 MPa to 40 MPa which gave flow rates of up to 0,3 lis per jet. Cut spacing, cut depth and cutting speed were varied between 15 mm and 90 mm, 2 mm and 6 mm, and 0,1 mls and 1,0 mls respectively. Tests were carried out on a linear rock cutting machine, purpose built according to specifications prepared from measurements made during underground field trials, which gave it the ability to test full-scale cutters under loading conditions representative of those found in the field. All the tests carried out were performed in the constant penetration, multiple pass (groove deepening) cutting mode, using dressed (smooth) and pre-conditioned (pre-roughened) rock surfaces.