Astounding Science Fiction, British Edition — page 66: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

64 There is the matter of magnesium, the metal taken from sea water which may eventually replace steel and even aluminum. The ideal spot for a mag- nesium refinery would be on the Moon because it works best in a high vacuum, (That also applies to titanium, zirconium and _ other refractory metals now coming into use.) Sawings and coarse grinding of magnesium castings may produce sparks capable of igniting the fine dust. This in turn may touch off the castings. Spillage of molten magnesium metal on a damp floor or mold is quite likely to cause a fire. And a water stream played on the blaze is pretty certain to result in an explosion. The biggest bang of all can be expected when a large piece of magnesium is mistaken for aluminium and tossed into a smelter. Have these and other hazards proved insurmountable? Far from it. Good housekeeping and ingenuity have solved many of the major diffi- culties. Extinguishing powders and . gases such as boron trichloride have been substituted for water. Dust. is sucked away from lathes by ingenious vacuum cleaners and turned into sludge until it can be taken to a safe place for burning. A silver nitrate spray turns black on magnesium and enables it to be weeded out of alumi- num scrap. Only non-sparking tools are used in working the metal and supplies are stored in small quantities in fire-resistant buildings. Uranium—that is U238, the “‘tame’’ kind—is even more of a problem child. xc 33 pyrophoric, which means that in finely divided form it may ignite spontaneousiy on contact with air. This may occur even if the powder is dry. The resulting fire burns at 2300°F. Uranium may be stored under water but this releases free hydrogen, another bad actor. Oil is better, but if any of the metal sticks above the “water ASTOUNDING SCIENCE FICTION line” it will ignite. About the only safe way to ship large quantities of uranium dust is in specially con- structed explosion-safe dry boxes filled with a nonreactive gas such as argon. Despite its value, some manufacturers won’t even consider trying to recon- vert the dust. They burn it with extreme caution in small quantities, either under water or spread out on a thick steel plate. (It can burn in an atmosphere of pure carbon dioxide so extinguishers containing that gas are of no value. Neither are those using carbon tetrachloride, soda acid or foam.) More intrepid dealers oxidize the scrap to comparatively harmless uranyl nitrate by means of nitric acid, Others. degrease the powder and briquette it under high pressure. Then they ship the stuff by courier and equip him with a plentiful supply of G-1 powder—a commercial prepara- tion with a graphite base—graphite chips, powdered talc or dry sand under which to bury the argon-filled container in case it becomes restive. The fire doctors disagree when they talk about the best ways to deal with atomic explosions or blazes involving radioactive materials. The Joint Fire & Marine Insurance Committee on Radiation has put out a tentative report. The International Association of Fire Chiefs has published two of them. But, since nobody has been told the size or power of A or H-bombs that may be expected to fall if another war comes and since the Atomic Energy Commission exercises the strictest kind of control over ship- ments of more than one hundred different kinds of radioactive isotopes, the whole discussion seems academic. Dr. L. G. Cook, of the Chemistry Branch, Atomic Energy Project, National Research Council, neatly summed up the situation in a recent speech to members of the Canadian Cconmicloooks CON