According to the best authorities, CaS2 and CaS3 do not seem to exist at all, at least not in aqueous solution. If it is made by heating CaCO3 in fumes of CS2 and CO2, and brought in contact with water, CaH2O2 and CaH2S2 are formed) the latter being readily dissolved. CaS cannot be obtained in the wet way or in solution. We find it almost everywhere stated that in boiling caustic milk of lime with sulphur the lower calcium polysulphides cannot be produced, because they are insoluble. Writers of metallurgical treatises, myself included, have repeated these errors like parrots-what else could they do! I will point out a few. Without such work material progress is not possible.ĭuring the last seven years a great number of papers on lixiviation have been published, containing a good deal of valuable information, but also many errors due to hasty and incomplete investigation without thorough analytical work. We know almost nothing of the composition of roasted ores before and after lixiviation of the constitution of the first wash water and of lixiviation-solutions after prolonged use of the chemistry of sodium and calcium sulphides of the composition of sulphide and carbonate precipitates. It is to be regretted that so little analytical work has been done in lixiviation. The inevitable result must be that the surplus of these dry silver-ores, especially those of low grade, will be reduced by processes cheaper than smelting and here the introduction of lixiviation has an excellent field, provided the muscular lixiviator has an able chemist for an assistant. By the exclusion of Mexican lead-ores, and their growing scarcity in the West, smelters have been forced to raise their charges on so-called dry silver-ores, and cannot handle the latter now in such unlimited quantities as formerly. ![]() ![]() In my opinion, this will change in the near future. It would be considered absurd, at present, to run a lead-smelter, a blast-furnace for pig-iron, or a Bessemer plant without the assistance of a well-equipped laboratory and a chemist but it is considered quite sufficient to provide amalgamation- or lixiviation- works merely with a crude assay-office, and an assayer who is paid less than a laborer in the mill. The “ muscular ” smelter has left the field forever! This state of affairs has been induced by sharp competition, i.e., by a complete separation of the industries of mining and reducing ores, not by the liberality and wisdom of directors and stockholders to provide laboratories and engage chemists, or by their love for scientific investigation. Account is even taken of the composition of the ashes obtained from the coke. Ores are mixed and fluxed to obtain a slag of desired composition. The great perfection of lead-smelting in the West, for instance, has only been accomplished by the analysis of ores, fluxes, slags and all products of the furnace. ![]() Metallurgical processes cannot be conducted successfully without the aid of analytical chemistry.
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