A VALUABLE FERTILISER

Shannon News, 9 October 1928, Page 4

A VALUABLE FERTILISER

BASIC SLAG FROM BELGIUM. One of the most valuable/fertilisers that has come into general use in recent years is tmsic slag, a by-product of the steel industry. The chief oourco of New Zealand's supplies of basic slag is Belgium, whose steel mills produce high grade slag of high solubility. In an address to farmers during his recent visit to the Dominion, Sir John Russell, director of Rothamsted research station, and an eminent' authority on soils, said basic slag owed its fertilising value to its phosphate content, and also to certain other elements which were not exactly known. Figures supplied by Mr. Armand Nihotte, Consul in New Zealand fol Belgium, show the growth of the export trade of Belgium in artificial fertilisers as follows: —

By far the greatest part of the above production was sent to Germany. Last year 47,000 tons of basic slag was imported from Belgium into New Zealand.

The bulk of the basic slag production in Belgium comes from the great steel mills of the John Cockerill Company, of Seraing, which bears the name of its English founder, last year celebrated its centenary, and to-day employs 10,000 workers. Phosphoric Content of Slag.

Mr. Nihotte recently received from Brussels a copy of a report to the Minister of Foreign Affairs, from the John Cockerill Company, on-the quality of the basic slag produced for the New Zealand trade, which is of interest to Dominion farmers.

The report states that the total annual output of the Cockerill works is approximately 100,000 tons of .basic slag, containing an average percentage of 17 to 19 per cent, of totally solublo phosphoric acid in mineral acids, with a minimum of 85 per cent.' of solubility and fineness. "Until now," "continues the report, "we have plated very little slag in New Zealand on account of the sales

■"".onditions imposed over there, ■and especially because the richness of our slag in phosphoric acid, soluble, in citric acid 2 per cent. Wagner process, enables" us to phec the totality of our output in countries buying on tiini basis. With regard to the sales conditions, it is necessary to remember that basic slag is not a nuinufactuivii product. It is only a by product of I hi' fabrication of steel. It is this last fabrication which is regulated and do:;ed by the producers, and analysis of the by-product, the slag, being what tt can be in the conditions where theproducer has judged that the elaboration of the steel had to be made. The amount of phosphorus in the slag i.s consequently essentially variable, a:ij the imposition of a fixed amount is equivalent to favouring either fraud o; mixing.

- "We understand perfectly well that the minimum percentage should be imposed in order to eliminate slag which would bo -judged the pborcr, either from the fertilising point of view or the transport expenses, but the rational mode of payment is the integral payment per unit, based on the analysis ■ffectcd under Government control, or by an arbitrator known to be experienced in the matter. The percentage of the slag being variable, it is practically impossible for the producer to realise the fixed percentage of 17 po:> cent., and to remedy this inconvenience, Hlicr the shipments lire not made of the slag with a regular percentage of 17 pei cent., or to cover kimhclf for the excess of percentage which would not oc paid, the supplier quotes his prico per ton consequently. It appears more ;md more evident that, alone, the phos jhorie acid solublo in citric acid' 2 per I'cnt. process Wagner has an imiuedi ate fertilising value. "Concerning the packing, until now we have supplied in different circumstances our slag in 2001 b double bags, and we have never received any claim from the customers. With regard to the supply in double bags (1(5 bags to the ton), it is only a question of getting a supply of suitable bags of that, type. This method, of course, entails supplementary bagging expenses, and lias an influence on the sale price."

1925 .. 1926 .. 1827 .. Superphosphates, tons .. .. 176,240 .. . . 282,329 .. .. 255.564 Basic" Sing. tons S02.S35 913.827 1.005,956