NEW ZEALAND’S IRON.

Taranaki Herald, Volume LXIII, Issue 144815, 20 October 1915, Page 4

NEW ZEALAND’S IRON.

GOOD HOPE FOR IRON-SAND.

(From the Evening Post.) No subject is more misunderstood among Uni public of New Zealand than the matter of iron-ore deposits. Who has not heard of the Parapara "mpuutam of iron’’ and the "611110118 of tons of rich iron-sand along the beaches of Taranaki;-' Many-Mahomets have gone to the mountain of Parapara, and they have prophesied on era of stupendous prosperity by the working of tne iron measures, lint, alas, they predicted “without the book.” In a lecture, to the Philosophic Institute on Wednesday evening, Mr. S. H.' Jcnkinson. who has been a close student of iron problems for some years, exposed several popular fallacies about the Parapara bodies of ore. The speaker referred to the mcagreness of trustworthy metallurgical information about the quality of tins ore, and he proved the incorrectness of certain statements commonly accepted. He marshalled facts and figures to lead up to a conclusion. which he stated thus: —“The Parapara iron ore presents a very difficult metallurgical problem to the steelmaker ; its content of sulphur and phosphorus is such that it can hardly be honed that high-class steel will bo made from it; tho prices of fuel and transport in New Zealand arc at present prohibitive to the foundation of a large iron and steel industry; and the value of tho ore is too low to encourage the idea that it will ever nay to expert it.” Turning to tho iron-sand, Mr. Jenkinson opened up an avenue of hope, by intelligent attention to the fact that a' finely-divided ore has to be treated. Discussing electrical processes, ho remarked:— "Electrical heating is notoriously costly, except when very high temperature is reached, and it scorns: an obvious improvement to utilise fuel for tho greater part of the heating and reserve electricity for that field in which it reallv is economical —the giving of a filial -kick' to the already high temperature of partially reduced and smoked ore. "Since Providence Ims obligingly powdered these ores for us. let us take advantage of the fact and use powdered [iic ! also, the cheapest form of fuel and the most economical method of using it. If highly preheated ore, powdered coal, and blast wore introduced into the ton of a furnace shaft, or into tho end of a rotating kiln, the red hot sintered and partly reduced product would require very little electrical energv to be thoroughly melted, and the electrical energy required could he easily provided from the combustion of the waste furnace gases under a boiler. Tho necessity of maintaining a reducing flame in’ the shaft means that tho fuel must-be burned to not more than 1 part carbon dioxide to 2-2 J parts of carbon monoxide; hence the calorific value of the waste gas is just 50 per cent, of that of the original fuel. Now the blast furnace could smelt one ton cf pip from a solid ore as pure as Taranaki concentrate for 15 ewt. of hid, and in this ease, as in tho above, only 50 per cent, of the heat value of that fuel is taken out of it. That means that tho total heat energy of 7) ewt. of coal is necessary in practice to smelt pure ore. I cannot believe that p furnace such ns I have indicated—if the sensible heat was used for dry heating the blast, and if all the materials were highly preheated—would he so uneconomical' that it would require oyer 30 ewt. (four times as much) of powdered fuel. This fuel could tie obtained for 20s a ton. dried and powdered, even in Taranaki. and even assuming that ten tons of sand have to he handled for one ton of pig. we would find the cost of the pig iron nor ton to he;— ,C Si d,

Ore l 10 tons (mining 2s 6d, drving 6d. concentrating Is 6d) 2 S O Fuel 1 10 0 Labour at furnace 0 10 0 Repairs 0 2 0 Interest 0 2‘ 6 • £4 9 6

Say £5 a ton for pig worth £5 16s f.o.ni., Swedish ports. ‘•But tho beauty of this process is the fact, tliat it can he applied in ♦very small units and at a very small rost. and further that the purity of the ore lends itself to the production of steel castings of the highest quality. Wo are thus in tho happy position of making molten metal worth from £lO to £IOO a ton, and labour and transport costs do not assume such a prohibitive aspect. Adding an electric'refining furnace and assuming an output- of 3000 tons of steel castings a year, we could attain onr result on a capital of £25.000. Personally f believe, that tho ore could be found in commercial quantities mueh more rich in magnetite than 1 have assumed, and nig, at under £4 a ton is. I think, in sight, even on such a small scale of working as this.”