Jenkinson. — Manufacture of Iron and Steel in Nev^' Zealand. 509 



Tlie question of iron and steel manufacture in New Zealand must be 

 considered in the liglit of these remarks. 



So far as our present scanty knowledge goes, the potential iron-ore fields 

 of the Dominion are — (1) the Parapara district, (2) the Taranaki ironsands, 

 (3) Mount Koyal, (4) Mount Peel, (5) the Cheviot district. Our knowledge, 

 however, of all iron sources save Parapara is where it was left by Sir James 

 Hector in 1873, and our crying need is for an organized survey of all 

 the likely deposits. Until that is accomplished we can only consider the 

 possibilities of Parapara and Taranaki. 



Parapara. 



Bulletin No. 3 (n.s.) of the Geological Survey Department establishes the 

 fact that Parapara, Onakaka, and Tukurua Blocks comprise an extensive 

 surface outcrop of at least 20,000,000 tons of ore, occurring in an easily 

 mined and smelted form and in an accessible position ; but the bulletin 

 gravely errs on the optimistic side when reference is made to the metal- 

 lurgical problem involved. The surface analysis given in the bulletin has 

 since been supplemented by tunnel analyses published in the 1914 Labora- 

 tory Report, and beyond material error we may assert that the ore has 



the following composition : — 



Per Cent. 

 Iron . . . . . . . . .. 48 to 50 



Alumina 



Phosphorus 



Silica 



Water 



Sulphur 



3 to 6 



0-15 

 10 to 15 

 10 



0-08 



Alumina 



Phosphorus 



Sulphur 



Such ore would need calcining or roasting to expel the water and sulphur, 



and a product would result — 



Per Cent. 

 Iron . . . . . . . . . . .. 50 to 55 



. . 11 to 16 

 3i to 7 

 . . 0-17 

 . . 0-03 



This product contains too much silica to be economically dealt with 

 in an electric smelting-furnace, and, while it could possibly be purified by 

 magnetic concentration after fine crushing, the treatment adds expense, 

 and the product could not compete for cheapness or piirity with Taranaki 

 ironsand. Small hot-blast furnaces using charcoal fuel are in use in America, 

 Sweden, and Styria, but there they work with exceptionally pure ore, 

 needing very little flux, and produce a very valuable steel-making pig in 

 a costly manner. Such a furnace would biirn all the timber off 1 acre of 

 forest for every 20 tons of pig made, and is only practicable in heavily 

 wooded districts within reach of navigable waters. With the impure ore 

 of Parapara, and in a country of dear labour and difficult transport, a 

 charcoal furnace is not economically possible. 



The roasted ore would give a white steel pig running — Phosphorus, 

 0-35 per cent. ; sulphur, 0-08 per cent. ; silica, 1 per cent. ; and worth 

 £2 15s. a ton: or, making grey foundry pig, would give — Phosphorus, 

 0-35 per cent. ; sulphur, 0-05 per cent. ; and worth £3 per ton.* 



* The prices given are based on those current in July, 1914, f.o.b. Glasgow. 



