A SOUTH AFRICAN IRON INDUSTRY. 



121 



The ores are rather phosphoric in character, containing 

 about .2 per cent, to .4 per cent, phosphorus. 



With regard to flux, a non-sih<:eous hmestone is required, 

 and this is scarce in South Africa. However, two large deposits 

 are known which are stated to be capable of affording millions 

 of tons ; one, the best, being at Taungs, and the other near Pot- 

 gietersrust. The former contains about i per cent, of silica, and 

 the latter 1J/2 per cent., with very little magnesium carbonate in 

 cither case. 



It would doubtless be possible also to utilize to some extent 

 the dolomite, which in places is sufficiently low in silica. Three 

 of the author's analyses show : — 



per cent. per cent. per cent. 



Silica . . 4.15 4.18 1.5 



Ferric oxide, alumina . . 4.00 1.05 1.70 



Lime 28.66 36.12 26.5 



Alagnesia 18.10 i5-05 ^0.5 



Fuel presents a greater problem ; expressed as percentage 

 it would be seen that nearly all the iron output of the world is 

 obtained by smelting with coke, and South Africa is deficient in 

 coking' coals. 



Natal, however, certainly possesses a very considerable ton- 

 nage o'f coking coal, and has at present three coke producers. 

 Judged by oversea standards, the coke is perhaps not quite of 

 the best quality, but nevertheless it is quite good enough for 

 iron smelting. Some analyses by the author are as follows : — 



per per per per j)er 



cent. cent. cent. cent. cent. 



Fixed carbon . . . 83.07 84.28 85.68 85.62 84.12 



Ash 13.78 14.32 11.25 11.50 13.45 



Sulphur 1.37 .79 1.59 1. 14 -7^ 



Cell volume . . , . 55 57 51 53 undet. 

 Specific gravity 



(apparent) . . 1.06 .87 .80 .85 undet. 

 Compressive 



strength .... 1,950 2,000 1,100 1,280 good 



lbs. per lbs. per lbs. per lbs. per but 



sq. inch. sci. inch sq. inch. sq. inch, undet. 



The last is representative of the present product of one 

 plant, though probably on the average sulphur would be higher. 

 Cokes of no better quality are in use for iron-smelting elsewhere. 



The coke output at present is small — not a quarter of the 

 demand of a prospective iron industry — and no by-products arc 

 obtained. The cost of production and price is therefore high. 



There is but little coking coal in the Transvaal, and 

 it might not be j^ossible to coke it extensivel}- in 

 competition with Natal ; but in this direction also authentic in- 



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