This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 Excerpt: ...WHEN HEATED IN AIR. Nickel is by far the hardest metal to eliminate in scorification and none of the above figures exactly explain this. It is very much harder to slag than either copper or cobalt 1 In Oxygea. Notes. 1. Litharge being a strong base has a groat affinity for the silica of the scorifier and especially when mixed with copper oxide it attacks it readily. When scorifying matte and copper bullion it is often necessary to add powdered silica to the charge to prevent a hole being eaten through the scorifier. 2..Some assayers add litharge to the scorification charge especially with pyriticores. On heating, the litharge is reduced to metallic lead, the sulphur of the pyrite being oxidized. Scorification Assay of Silver Ore. Procedure:--Empty the bottle or envelope of ore onto a sheet of glazed paper or oil cloth and mix thoroughly by rolling. Take three scorifiers, 2, 2f, and 3 inches in diameter respectively. Weigh out on the flux balance three portions of granulated lead 35, 4.5, and 55 grams respectively. Divide each lot of lead approximately in halves, transfer one half of each to the corresponding scorifier and reserve the remaining portions. Weigh out three portions of exactly 0.1 A. T. of ore on the pulp balance and place On top of the lead in the scorifiers. Mix thoroughly with the spatula and cover with the remaining portions of lead. Scatter one or two grams of borax glass on top of the lead. The scorifiers are now ready for the muffle, which should be bright red or yellow before the charges are put in and this temperature should be maintained during the roasting period. Fusion Period. Place the scorifiers well back in the muffle, close the door and allow the contents to become thoroughly fused. Roasting Period. When thoroughly fused, open t...