Complete Practical Treatise on Acids, Alkalies, and Salts Volume 2; Their Manufacture and Application Being V.1, PT. 3-5 of Chemical Technology Or, Chemistry in Its Application (Paperback)

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. 1867 Excerpt: ...of twenty--four hours, the water is drawn off and a fresh supply added, until that which runs ofl' contains only 1 per cent. of salt petre; the trough is then re--filled. The charge in troughs of the above dimensions, calculated at 8 lbs. in 5 cubic feet, must contain altogether 256 lbs. of nitrate, which must produce a lye of about 10 per cent.; with rather more than an equal bulk of water. The subsequent weaker lye is concentrated in the second trough, until it is fit for boiling. The exhausted earth is used in the construction of the heaps or walls, in the manner already explained. 1 he Orurle L3/e.--The lye for boiling, technically called crude lye, is, as the method of preparing it indicates, not only a solution of saltpetre, but contains all the soluble portion of the saltpetre earth, and its state of concentration must be regulated by the price of fuel. Besides the nitrates of potash (soda), lime, magnesia, and ammonia, it contains chloride of potassium, chloride of sodium, chloride of calcium, chloride of magnesium, carbonate of ammonia, and peculiar brown colouring matters of organic origin, which have not been examined, and which are usually classed together under the very indefinite term extractive. Thenard found in the dry residue of crude lye from the gypsum debris of Paris: Nitrate of potash and chloride of potassium. 10 Nitrate of lime and magnesia..... 70 Chloride of sodium........ 15 Chlorides of calcium and magnesium... i 100 The presence of carbonate of ammonia is not surprising after what has been said with reference to the production of saltpetre. It explains what would otherwise be remarkable, viz., the absence of nitrate of alumina in the crude lye, for alumina is more abundant in the saltpetre-earth than any other base. The prec...