The Romance of Modern Chemistry

THE VALUE OF THE BY-PRODUCT the beginning of the chapter, are estimated to contain 8,000,000 tons of material. To the trouble which this waste brought upon the manufacturers of soda by Leblanc’s method there was added the menace of serious competition. The ammonia- soda process, as it is called, has during the last thirty years become a formidable rival of the Leblanc process, and at the present day considerably more than half the world’s production of soda is made by the newer method. Curiously enough, while the Leblanc process was a French patent which has been worked mostly in England, the ammonia-soda process was an English patent which com- mended itself first and foremost to the Germans. This later method of manufacturing soda has many advantages, and although we cannot go into details, we may mention that brine pumped directly from the salt beds is converted into soda in such a way that the product is a purer one than that yielded by the Leblanc method, and that there are no disagreeable waste products. The reader might suppose that the ammonia-soda process, with all these advantages, would speedily displace the older Leblanc process. But the latter has offered a stubborn resistance, a fact attributable to the once despised and obnoxious hydrochloric acid. The value of this by-product has kept the Leblanc process going. At the same time everybody concerned realised that, with this serious competition to face, all must be done to effect economies, and, if possible, recover that lost sulphur from the alkali waste. As one of the leading chemical manufacturers in this country said in 1881: “The recovery of sulphur from alkali waste, as a means of cheapening the cost of production by Leblanc’s process, has become of vital importance.” 278