IRON 983 



hence an imperfect weld in the hammered mass and rolled bar is the result, and 

 although the iron may be chemically pure it is deficient in strength. By protracting 

 the process and wasting more iron, there is no doubt but that the iron might be im- 

 proved, for the cinder would become richer in oxide, more fluid, and consequently 

 offer less resistance to a perfect weld. Iron, on the contrary, with a small percentage 

 of silicon may be ' balled up' directly it is ' dried,' and the short time required for 

 that operation can be conducted at the highest part of the furnace. A good welding 

 of the mass is the consequence : such iron is strong, and the labour of the puddler in 

 obtaining it is much less than in the former case. Every pound of silica must have 

 twice its weight of iron to form a cinder sufficiently rich in oxide to allow the 

 particles of iron to become properly agglutinated. Such being the influence of 

 silicon on both the yield and the strength of wrought iron, and such being the waste 

 attendant on its removal in the refinery, it becomes an object of much practical im- 

 portance to prevent as far as possible the formation of a silicide of iron in the blast- 

 furnace, and the observations of MM. Janoyer and Gauthier on this point require 

 careful verification. 



Manganese. The presence of this element in pig-iron does not appear to exert 

 much influence either for good or for bad on the quality of the metal, and even when 

 it exists in quantity amounting to 4 or 5 per cent, in the crude iron, it disappears 

 almost entirely during the conversion of the cast iron into wrought or malleable. It 

 has already been observed that the cinder from iron smelted from manganiferous ores 

 contains, generally speaking, more sulphur than slags or cinders from iron ores con- 

 taining no manganese. We have had numerous opportunities of confirming this, and 

 have therefore on this account alone attached more importance to the existence of 

 manganese in iron ores ; but our attention has more recently been directed to another 

 point which we think especially worthy the notice of iron manufacturers, namely, to 

 the almost perfect removal of phosphorus from pig-iron containing a very large pro- 

 portion of that element, and at the same time a high percentage of manganese. We 

 shall merely here quote a few analyses in illustration of the purifying action we have 

 alluded to. 



Iron made from a highly phosphorised ore containing no manganese : 



Phosphorus 

 per cent. 



Pig 3-030 



Puddled bar 0-838 



Kough down bar .,.,.. 0*572 



The finished bar was cold-short im the highest degree, it was in fact nearly worthless. 

 Iron made from a highly phosphorised ore containing a large percentage of man- 

 Phosphorus. Manganese. 



Pig 2-60 : V ; - :> V '*-". ''^ 7'20 



Puddled bar . . . 0-30 * ' ," r . . \ A n 



Do 0-20 . . . .j><>' 30 



Finished bar . , .0-11 



The iron was carefully watched during the puddling process. It melted very thin, 

 and took rather more work than usual ; as soon as the boiling commenced it was very 

 violent, the metal forcing itself out of the door-hole until it was checked. When it 

 ' came to nature,' as the workmen term it, it worked beautifully and stood any amount 

 of heat, in fact the heat could with difficulty be raised to the requisite degree. The 

 yield was 22 cwts. 2 qrs. 24 Ibs. of pig to produce one ton (of 22 cwts.) of puddled bar ; 

 this is about the yield of good mine iron when properly puddled. The finished bar 

 exhibited none of the cold-short quality, it was exceedingly ductile, indeed excellent 

 horseshoes were made from it. The puddling cinder had the following composition : 



Silica ., L -" l; -- : - ''/ 8-240 



Protoxide of iron . . . .,,,..,.. , 1^- -,\ . 70*480 



Oxide of manganese . . i, ^" : ." -,,"' .12-800 



Phosphoric acid . . . .... ^ ..... . 7'660 



Sulphur . . . . ,; .."".-.., . -535 



99-715 



Other ^ observations have shown that highly manganiferous pig (without phos- 

 phorus) is puddled with difficulty, and sometimes with considerable waste, so that the 

 advantages of an alloy of manganese would seem to be confined to those varieties of 

 crude iron into the composition of which phosphorus largely enters. 



