4 resultados para Tin mines and mining
em Brock University, Canada
Resumo:
A shares certificate for Gladstone Mines and Reduction Company in the amount of 200 shares. The certificate is dated 13 March 1925 and is signed by the secretary F.J. Carr and the president Charles Stoddart. The price is one dollar per share and it is made out to W.H. Cowan.
Resumo:
Union Pacific Railway from Kansas City , Omaha, St. Joseph to Denver, San Francisco, Portland, Helena, Butte, Boise, Leadville, Durango, Deadwood and all cities and mining camps in the west schedule, Jan. 15, 1882.
Resumo:
Modifications to the commercial hydride generator, manufactured by Spectrametrics, resulted in improved operating procedure and enhancement of the arsenic and germanium signals. Experiments with arsenic(III) and arsenic(V) showed that identical reiults could be produced from both oxidation states. However, since arsenic(V) is reduced more slowly than arsenic(III), peak areas and not peak heights must be measured when the arsine is immediately stripped from the system (approximately 5 seconds reaction). When the reduction is allowed to proceed for 20 seconds before the arsine is stripped, peak heights may be used. For a 200 ng/mL solution, the relative standard deviation is 2.8% for As(III) and 3.8% for As(V). The detection limit for arsenic using the modified system is 0.50 ng/mL. Studies performed on As(V) standards show that the interferences from 1000 mg/L of nickel(II), cobalt(II), iron(III), copper(II), cadmium(II), and zinc(II) can be eliminated with the aid of 5 M Hel and 3% L-cystine. Conditions for the reduction of germanium to the corresponding hydride were investigated. The effect of different concentrations of HCl on the reduction of germanium to the covalent hydride in aqueous media by means of NaBH 4 solutions was assessed. Results show that the best response is accomplished at a pH of 1.7. The use of buffer solutions was similarly characterized. In both cases, results showed that the element is best reduced when the final pH of the solution after reaction is almost neutral. In addition, a more sensitive method, which includes the use of (NH4)2S208' has been developed. A 20% increase in the germanium signal is registered when compared to the signal achieved with Hel alone. Moreover, under these conditions, reduction of germanium could be accomplished, even when the solution's pH is neutral. For a 100 ng/mL germanium standard the rsd is 3%. The detection limit for germanium in 0.05 M Hel medium (pH 1.7) is 0.10 ng/mL and 0.09 ng/mL when ammonium persulphate is used in conjunction with Hel. Interferences from 1000 mg/L of iron(III), copper(II), cobalt(II), nickel(II), cadmium(II), lead(II), mercury(II), aluminum(III), tin(IV), arsenic(III), arsenic(V) and zinc(II) were studied and characterized. In this regard, the use of (NH4)ZS20S and Hel at a pH of 1.7 proved to be a successful mixture in the sbppression of the interferences caused by iron, copper, aluminum, tin, lead, and arsenic. The method was applied to the determination of germanium in cherts and iron ores. In addition, experiments with tin(IV) showed that a 15% increase in the tin signal can be accomplished in the presence of 1 mL of (NH4)2S20S 10% (m/V).
Resumo:
Joseph William Winthrop Spencer (commonly known as J.W. Spencer) was a geologist and geomorphologist best known for his work on the geology of southern Ontario and the Great Lakes. He was born in Dundas, Upper Canada in 1851, but moved to Hamilton, Ontario in 1867. In 1871, he began studies in geology at McGill College in Montreal. In 1875 he worked in the Michigan copper mines and shortly afterwards prepared a thesis on the copper deposits. He submitted this thesis to the University of Gottingen in Germany in 1877 and was awarded a doctorate in geology, the second Canadian to earn a doctorate in this field. In 1880, he became a professor of geology and chemistry at King’s College in Windsor, N.S. Subsequently, he taught at the University of Missouri, and then the University of Georgia, but moved to Washington, D.C. in 1894, where he worked as a consultant geologist. Spencer spent much of his life studying preglacial river valleys in Ontario and the origins of the Great Lakes, as well as the Niagara River and Falls. In 1907, he published a book titled The Falls of Niagara: their evolution and varying relations to the Great Lakes. His opinions in these areas differed from some of his contemporaries, namely the American geologist Grove Karl Gilbert. Gilbert published a review of the The Falls of Niagara that exposed some flaws and inaccuracies in Spencer’s estimate of the age of the falls. Spencer’s studies also took him to the Caribbean and Central America. In 1920 he moved back to Canada, but died the following year.