Diamond drilling

Both macrocrystalline WC and the fused WC—W2C eutectic (Fig. 1) are important in the manufacture of diamond drill bits used in the mining, oil and gas, and constmction industries, and in hardfacing rods and electrodes. The properties of WC are Hsted in Table 1. 

Diamond Bit Design. Diamond drill bit geometry and descriptions are given in Figure 4-144 [49]. Diamond core bit geometry and descriptions are given in Figure 4-145 [50]. 

Diamond drill bits with special designs and features include ... 

Figure 4-144. Diamond drill bit nomenclature [49], (Courtesy Hughes Christensen.)...

Figure 4-162 shows a natural diamond drill bit which has a long outer taper and medium inner cone, radial flow fluid courses, and five to six stones per carat (spc) diamonds set with a medium placement density. Using the definitions in Figures 4-156, 4-158, 4-159, and 4-160, the characteristics of this bit are coded D 2 R 5 as follows ... 

Diamond Drill Bit Technology, student manual, Christensen, Inc. 

Gold mineralization at MGR has been delineated by trenching and diamond drilling over a strike length of >500 m and is open below 276 m. Visible gold has not been observed, so it is assumed that Au occurs as submicroscopic inclusions and (or) as refractory gold in sulfides. 

Nearly 900 fresh diamond drill core samples were collected from multiple drill holes along two or more cross sections through each of the deposits under investigation. Field determinations for ferroan carbonate were made on all fresh... 

It would not be possible to carry out a project of this scope without the assistance of the Victorian mineral exploration and mining industry. The following companies have provided access to diamond drill core material ... 

The primary dispersion halo and wallrock alteration around the Elura deposit was established from integrated petrographic, mineralogical and geochemical (major-, minor- and trace-element) analysis of diamond drill core samples. Seventy eight samples of variably altered and unaltered host rocks, as well as 67 near-surface weathered equivalents, were analysed for major elements using fusion disc. X-ray fluorescence analysis (XRF). Trace elements were determined by pressed powder XRF analysis. Carbonate carbon... 

Archived lithogeochemical data was obtained from four diamond drill holes (DDH) in the Plymouth Fe-Mn deposit. The Fe/Mn ratios from these cores were found to decrease sharply at the lower contacts between the Mn siltstone and surrounding strata. A strong inverse correlation between AI2O3 and Fe203 + MnO occurs within the manganiferous siltstone (Fig. 2). 

The 2007 2008 NFR diamond drilling campaign highlighted new mineralization styles at the Nucleus and Stoddart zones. 

Tameapa property has been confined to the 12 km area surrounding the Pico Prieto and Venado prospect areas. Exploration by MinCore and previous operators has included geologic mapping, geochemical and geophysical surveys, and 43,000 m of drilling in 144 diamond drill holes. MinCore plans to systematically explore the entire property area during the 2009 and 2010 field seasons. 

During 2008, 13,300 metres of diamond drilling and greater than 5,200 analyses of the core and historical samples were completed for WO3, M0S2, Sn, In, Zn, Cu, Pb, Bi, and As. An additional 1900 historical samples were analysed for Indium only (Boyd 2008). Seven samples obtained from a wide variety of... 

Copeland, D.A. Newport, A. 2005. Supplementary year assessment report on soil sampling, prospecting, geological mapping, trenching and diamond drilling on the Golden Promise Property, central Newfoundland NFLD/2910. 

Two diamond drill cores, designated DDH-A and DDH-B were obtained from central Colorado. DDH-B is from the vicinity of Redstone, Gunnison County, and core DDH-A is from the vicinity of Somerset in Delta County. These samples were particularly interesting since there is a transition from unaltered high volatile bituminous coal to natural coke at the igneous contacts. Both cores are of Cretaceous age coal. All core samples are from depths in excess of 1500 feet below the surface. 

Drilling. Glass is drilled with carbide or bonded-diamond drills under a suitable coolant such as water or kerosene. Other drilling processes include a metal tube rotating about its axis (core drilling), an ultrasonic tool in combination with an abrasive slurry, or an electron beam. Tolerances less than 0.1 mm are readily obtained with diamond-core drilling and, if required, holes smaller than 25 Jlm-dia can be made with the electron-beam method. 

In order to provide liquid access to the microfluidic chips, holes are usually created on the cover plate. These access holes are usually created on glass by drilling using diamond drill bits. However, other methods have also been used, and these are summarized in Table 2.4. 

Fig. 12-3. Geological cross sections at Woodlawn showing the location of diamond drill holes through ore and country rock with the Hg content of rocks and stringer sulphide minerals S =sphalcritc, C = chalcopyritc, P = pyritc, MS = massive sulphide (reproduced with permission of Economic Geology, v. 74 6, p. 1473, Fig. 2, Ryall, 1979b).

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