Product Code Database
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.1918 Excerpt: ... dish with as little water as convenient, and let boil for 30 minutes. Then render alkaline with ammonia, and add ammonium oxalate in quantity sufficient to precipitate all the lime, cool, and make up to 500 cc. and mix well. Filter and take of the filtrate lots of 25 or 50 cc. according to requirements. Evaporate these down in platinum dishes after acidifying with sulphuric acid, finally igniting the residue until white. Dissolve in a littb water, which should give a clear solution; acidify with a drop or two of hydrochloric acid; add 5 cc. of platinum chloride, evaporate to a pasty condition; add 30 cc. or more of strong alcohol (80 per cent or over), allow to stand cold for some time, and then decant on weighed ''filter and add fresh alcohol, and repeat two or three times, and then transfer to filter and wash with ether; dry, cool in desiccator, and weigh. From total weight deduct weight of filter-paper,, or a Gooch crucible with asbestos filter may be used. Precipitate is KsPtClo. In place of alcohol a mixture of alcohol and ether is preferable in proportions of 2 to 1. Regarding the examination of phosphatic materials to be used in the manufacture of fertilizers, a few suggestions may be desirable. Spent bone-black and other materials containing carbon or carbonaceous material as well as phosphate rock, may be ignited to burn off the organic substances, then dissolved in hydrochloric acid, and in general treated essentially as recommended for the determination of total phosphoric acid. With phosphatic slags the first hydrochloric acid solution should be evaporated to dryness in order to remove the silica (which would otherwise appear in gelatinous form). Before proceeding with phosphate rock, the proportion of iron and alumina oxides is of much importanc...
|
