 | 1896 - 1020 Seiten
...time. For accurate analyses the use of steel crushers and mortars is out of the question , because of the danger of contamination by particles of metal...after they have been in use a short time. Extraction of steel particles from the powder by aid of a magnet is quite inadmissible, since the rocks themselves,... | |
 | Geological Survey (U.S.) - 1896 - 1090 Seiten
...they have been in use a short time. Extraction of steel particles from the powder by aid of a magnet is quite inadmissible, since the rocks themselves,...contain magnetic minerals. The method of rough crushing found to be most satisfactory in practice is to place each fragment as received on a hardened steel... | |
 | Frank Wigglesworth Clarke, William Francis Hillebrand - 1897 - 342 Seiten
...of time. For accurate analyses the use of steel crushers and mortars is out of the question, because of the danger of contamination by particles of metal...after they have been in use a short time. Extraction of steel particles from the powder by aid of a magnet is quite inadmissible, since the rocks themselves,... | |
 | 1907 - 874 Seiten
...CRUSHING. For accurate analyses the use of steel power crushers and mortars is out of the question because of the danger of contamination by particles of metal...introduced into the powder is quite inadmissible, since the rooks themselves, almost without exception, contain magnetic minerals. a. SURVEY METHODS. For breaking... | |
 | Henry Gannett - 1906 - 644 Seiten
...CRUSHING. For accurate analyses the use of steel power crushers and mortars is out of the question because of the danger of contamination by particles of metal...almost without exception, contain magnetic minerals. a. SURVEY METHODS. For breaking large pieces of rock to small sizes a thick iron plate with specially... | |
 | William Francis Hillebrand - 1907 - 212 Seiten
...CRUSHING. For accurate analyses the use of steel power crushers and mortars is out of the question because of the danger of contamination by particles of metal...almost without exception, contain magnetic minerals. a. SURVEY METHODS. For breaking large pieces of rock to small sizes a thick iron plate , with specially... | |
 | Geological Survey (U.S.) - 1907 - 220 Seiten
...CRUSHING. For accurate analyses the use of steel power crushers and mortars is out of the question because of the danger of contamination by particles of metal...almost without exception, contain magnetic minerals. a. SURVEY METHODS. For breaking large pieces of rock to small sizes a thick iron plate with specially... | |
 | William Francis Hillebrand - 1910 - 252 Seiten
...CRUSHING. For accurate analyses the use of steel power crushers and mortars is out of the question because of the danger of contamination by particles of metal...almost without exception, contain magnetic minerals. a. SURVEY METHODS. For breaking large pieces of rock to small sizes a thick steel plate with specially... | |
 | Geological Survey (U.S.) - 1910 - 252 Seiten
...power crushers and mortars is out of the question because of the danger of contamination by partides of metal and the impossibility of cleansing the roughened...almost without exception, contain magnetic minerals. a. SURVEY METHODS. For breaking large pieces of rock to small sizes a thick steel plate with specially... | |
 | Samuel Stinson Gannett, David Henry Baldwin - 1910 - 490 Seiten
...power crushers and mortars is out of the question because of the danger of contamination by partides of metal and the impossibility of cleansing the roughened...after they have been in use a short time. Extraction, bv tlic aid of a magnet, of steel particles thus introduced into the powder is quite inadmissible,... | |
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B. CRUSHING. For accurate analyses the use of steel power crushers and mortars is out of the question because of the danger of contamination by particles of metal and the impossibility of cleansing the roughened surfaces after they have been in use a... 
