NEW ZEALAND IRON.

New Zealand Mail, Issue 1157, 4 May 1894, Page 37

NEW ZEALAND IRON.

Just before leaving London Sir Walter Buller had an opportunity of getting a bar of New Zealand iron tested at Lloyd’s. The original report of the test he sent to the Agent-General, and he has now favoured the Premier with a copy for the information of the Government. We understand that the iron was smelted at the Onehunga Ironworks from Taranaki titanic sand. The report is as follows : Sample of cast iron received from Mr De Costa (from the New Zealand Court, Imperial Institute): This piece of cast iron, which was about ten inches long, and one inch square, has been tested as follows Placed on supports of nine inches apart, with the planed side in compression, it broke with a load of 28 cwt. suspended at the centre. The two broken pieces were prepared for tensile tests by being turned down to '627in diameter for a parallel length of two inches. One piece broke with a load of 3‘l tons, the other with a lead of 2*65 tons, giving a strength of 10 tons per square inch respectively. These results show the strength to be pretty equal to the average of cast iron. The broken pieces were afterwards submitted to analysis by two independent technical chemists, who report the composition to be as follows : —Silicon, No. 1,2700; No. 2, 2770; phosphorus, No. 1,'880; No. 2, P 490 ; sulphur, No. 1, ‘065 ; No. 2, '062 ; manganese, No. 1, *900; No. 2, *922; carbon (graphite), No. 1, carbon (combined), No. 1, The amount of phosphorus is so large as to render the iron altogether unsuitable for the manufacture of steel by either the acid Bessemer, or the acid Siemens process, while it is not sufficient to enable it to be treated by the Thomas Gilchrist process (Bessemer basic) without its being first heated in a regenerative furnace. For steel making with the pig, the only process which could be applied is the open hearth basic, which would probably have to be combined with the Saniter process for the elimination of the sulphur. The large amount of silicon, however, would probably be destructive of the basic lining of the furnace, rendering frequent repairs and consequent expense necessary.—B. Maktell, Chief Surveyor ; J. T. Milton, Chief Engineer. London, 27-10-93.