A Handbook of Gold Milling |
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Common terms and phrases
acid alloy amalgam amount angle arrangement arrastra assay auric belt blanket bolts bottom brittle buddle bullion calcined cam curve cam shaft carried cast-iron cent centre chloride clean concentrates consists containing copper cost crucible crushing cupel cyanide diameter discharge driving drops per minute employed feet friction furnace gold grains head heat Huntington mill hydrochloric acid inches iron labour latter lay shaft length less lift machine means melted mercuric chloride mercury metal method minerals mortar box nitric acid obtained ore-feeder ounces oxide particles piece plates portion possible potassic practice precipitate produced proportion pulley pulp quartz retort revolutions per minute rock-breaker sand Scale screwed shoe short ton shown in Fig silver slimes sodium amalgam soluble solution specific gravity square stamp mill stamp stem stamp-mill steel sulphide sulphurets sulphuric supply surface tailings taken tappet tons treated usually vanners vertical weight whilst wooden zinc
Popular passages
Page 315 - with a block of wood until every portion of oxide is removed and the plate has a uniform red surface, care being
Page 89 - It is impossible to say, in the present state of our knowledge, whether
Page 315 - fine emery paper folded over a block of wood. A perfectly clean dry surface is thus produced. A mixture
Page 368 - be well marked, and the two should be of equal size. Should they be unequal the fault will be found to be either in that the belt is not accurately level across, that the distributor is not doing its work
Page 315 - not to scratch it. The sand is then washed off, and the plate dried and polished
Page 315 - the plate with a piece of canvas or blanket, when amalgamation will at once
Page 368 - or that some of the working parts have not been properly tightened up, so that there are other motions than the normal ones communicated to the
Page 316 - hydrated oxide of copper, with sometimes some carbonate ; probably, when water containing sulphates is used, a basic sulphate may also form. It is soluble in a number of substances, such as dilute acids, ammonia, and
Page viii - Under these circumstances it is hardly to be wondered at that the
Page 315 - and clean pure mercury is sprinkled into it by squeezing through canvas.