22 ANNUAL OF SCIENTIFIC DISCOVERT. 



By taking the nitrate of soda, the quantity of carljon to be removed 

 can be regahited at will by the quantity of nitrate used, and the 

 alkaline residue would " give rise to the formatiou of silicate of 

 soda, sulphide of sodium, and phosphide of sodium.'" 



The tirst experiments were instituted at the Widnes Foundry. 

 On finding that the oxygen from the nitrate of soda and the chlo- 

 rates of potash and soda is evolved so rapidly that it was dan- 

 gerous at once to pour the molten iron upon them, the use of clay 

 as a diluent, and a retarder of the action of the chemicals, occurred 

 to Mr. Hargreaves. Its successful action in this way in its turn 

 suggested the substitution for it of hematite ore. A cheap oxide 

 of iron would thus, while diluting the action of that oth«sjr chemi- 

 cal, offer an additional supply of oxygen and an increased yield 

 of metal. The nitrate of soda is therefore mixed with a portion 

 of hematite in order to retard its action, and the slightly moist 

 paste thus composed is pressed into tlie bottom of a vessel lined 

 with fire-brick. This paste is then dried into a solid block, either 

 by means of the heat left in the vessel after the last operation, or 

 specially produced. When dry, the molten iron is poured into the 

 vessel, and the layers of the composition scraped up. The high 

 ferrostatic pressure soon carries portions into the mass of molten 

 metal, and the reactions take place between them. The molten 

 metal appears to boil, and a frothy slag, said to contain " the im- 

 purities extracted from the iron," rises to the top, in company with 

 some oxide of iron and compounds of soda. The metal can then 

 be tapped out. In order to be enabled to apply the process of the 

 puddling furnace, and thus employ established plant, he got over 

 the difficulty of the bottom of the puddling furnace being too hot, 

 and hence at once uselessly decomposing the salt, by making the 

 converting materials into hard, dry blocks. Several such blocks 

 are successively pushed to the bottom of the molten metal in the 

 furnace, the products, of course, rising up as in the fixed vessel. 

 By this means it is said that the puddling operation is shortened, 

 with an attending saving of labor and fuel ; and, above all, that 

 the yield is better, from "the soda forming a base which readily 

 combines with the silicic and phosphoric acids eliminated from the 

 iron." Mr. Hargreaves states that he can make refined iron for 

 puddling by the use of about 3 per cent, of nitrate and 6 per cent, 

 of peroxide of iron; steel, by 8 to 10 per cent, of nitrate and an 

 equal weight of binoxide of manganese ; and malleable iron, by 8 

 per cent, of nitrate and 20 per cent, of peroxide of iron, — in each 

 case iron with 5 per cent, of carbon being used. The bulk of the 

 slag produced is materially increased by the presence of the sili- 

 cate of soda. — Engineer. 



Mr. Hargreaves further says, that he can by his process obtain 

 a larger yield and a better quality of steel, using iron costing IG 

 to 20s. per ton less than anything Mr. Bessemer can use, with less 

 cost of plant and labor. 



The supply of nitrate of soda is unlimited, a single source in 

 Peru having been estimated to contain G3 millions of tons. 



A somewhat similar ms^thod, called the " Heaton Process," is 

 thus spoken of by the " jNliiiing Journal " : — 



