WEALTH IN WASTE THINGS.

Taranaki Daily News, 14 April 1917, Page 7

WEALTH IN WASTE THINGS.

GERMAN WAR DISCOVERIES, "NECESSITY THE MOTHER OF INVENTION." The Teutons have left no stone unturned to make well-nigh everything of service, and in this way, a Scientific American" investigator tells us, they are disclosing possible uses for waste products and applications of a variety of raw materials that heretofore have been generally neglected. As is well known, the Germans have made tremendous strides in the fixation of atmospheric nitrogen, and in the production of nitric acid and ammonia they have relied principally upon the cyanide process, in which calcium carbide has likewise found a widespread field of service as an illuminant in the household and elsewhere, in place of kerosene. Oil lamps have been converted into acetylene lamps by a cheap and simple burner.

In consequence of this tremendous increase in the employment, of calcium carbide tlio technical experts have striven to find some profitable ways to utilise the residual carbide sludge which was commonly thrown away. This sludge is a slimy stuff left in the water after the acetylene gas has been released from the carbide. Chemists have experimented and have found that when this sludgo is mixed with 40 per cent, of building sand it makes an excellent mortar. It hardens quickly and effectually binds stone work. ~- POWDERED PITCH.

Tn the distilation of tar there remains a by-product in the form of a hard pitch, which haR commonly lent itself to but very few uses. Since the beginning of the war the. Germans have discovered that this stuff makes excellent fuel for industrial purposes. To utilise it, the pitch is pulverised, and because of its friable nature but little power is required for this purpose. Indeed, much less energy is needed than would be the case in powdering coal. This fuel is fed into the furnace by means of compressed air, and owing to its lightness a moderate pressure suffices for the' work. The heating power of this pitch dust is a good deal higher than that of coal, and, in fact, is more nearly like, than of crude oil. As the stuff burns without producing slag or ashes, it is a iabor-saver, ana therefore distinctly economical. This tar by-product has lately been found by the Teutons to be available for domestic use in combination with coke waste in tho form of small pieces of powder. In the past this pulverised or granular coke waste has been used as a substitute for sand in mixing concrete. Now this eoke and hard pitch can bo combined and pressed into briquettes by means of machinery already existing. The cost of this briquetting is very low, and the. fuel so formed is admirably adapted to the requirements of the household. The one essential desideratum is a good draught, and this is generally to be found in all up-to-date buildings. By this means the Germans have made it possible to utilise every particle of coal consumed in gas plants and other places manufacturing coke, either directly or indirectly. As a means towards the conservation of the mine output this adaptation of waste products is of almost universal interest.

The Cockerill works at. Seraing, Belgium, have had their blast furnaces converted into tar-burners, owing to the scarcity of coal since the Germans took possession of them. Tests were first made with a furnace having a capacity of 12 tons. The tar-burners were installed in pairs, and the fuel was injected under a pressure of one and a half atmospheres and atomised at the burners by compressed air of three atmospheres. In this furnace 2000 tons of steel, in 215 heats, was handled in less than three months. The tar consumption was at the rate of 202.51b per ton of molten metal, including the fuel required to heat up the furnace and to maintain the blast. Later a 25-ton furnace was arranged to burn tar.

Eope is a daily necessity for power transmission, in many forma and for a

variety of purposes. Gorman cordage /ias been made in the past mainly from jute imported from the tropics. The war blockade substantially cut off this source of supply. The Teutons then turned their attention to finding a vegetable fibre within the Fatherland capable of playing the part of a more or less perfect substitute. This they have now discovered in abundance in a native plant, and they claim for the new fibre qualities quite as desirable as those of jute.

NETTLES NOW MAKE BEAUTIFUL CLOTHING.

The fabric problem has been a serious one in Germany since cotton and wool have been either requisitioned for military purposes or the- supplies from without substantially stopped. Necessity again drew attention to former experiments having to do with I he employment of the fibrous parts of the common'nettle or thistle. The technical difficulty lay in separating the fibrous matter from the vegetable matter. To this end muriatic acid was tried, and also a process of dedication, but the fibre became brit tie and quite unfit for fabrication. Since the outbreak of war, however, a German chemist has overcome these difficulties, and has succeeded in weaving materials from nettle fibre that are both thin and strong. Not only that—the cloth is lustrous and soft.

A process has recently been discovered in Germany by which leather scrap can be converted into a very valuable nitrogenous fertiliser, and, at the same time, it is possible to recover from the leather waste 20 per cent, of the tannin, Before the extraction of the tannin the leather has comparatively little valutas a fertiliser. The waste material is chopped fine, freed of grease, and given an alkaline bath at a temperature of from 50 to 00 degrees Centigrade. In this manner most of the tannin is withdrawn, and by further heating and the addition of a suitable alkali the stuff becomes an excellent plnnt food, which is readily disintegrated in the soil. The tannin solution obtained by the process is evaporated, and in this way the dilute bath is made to yield up 20 per cent of tannin. Inasmuch as tannin is expensive the Germans find the twofold process well worth their while.