Wealth from Waste

A story of the atom jugglers and the magic by which they transform the useless into the useful

W. A. IRWIN August 15 1931

Wealth from Waste

A story of the atom jugglers and the magic by which they transform the useless into the useful

W. A. IRWIN August 15 1931

Wealth from Waste

A story of the atom jugglers and the magic by which they transform the useless into the useful

W. A. IRWIN

NITROGEN-HYDROGEN

Sandwich, Ont., June 21, 1930. A very pretty wedding look place today at the home of Canadian Industries, Limited, when Purity Hydrogen, niece of the late Mr. Salt Water, of Sandwich Wells, was married to Mr. Gaseous Nitrogen, foster son of Mr. Ordinary Air. Sandwich. The ceremony was conducted by Rev. Dr. Catalyst, assisted by Dr. High Pressure Corn-

pressor. The bride was given in marriage by her guardian, Mr. Chemical Engineer. She carried a bouquet of flaming roses, and looked charming in a modernistic costume of tubular chrome steel adjusted to a pressure of five tons to the square inch. The wedding march was played by Maestro Electric Motor, who also sang during the signing of the register.

Born: To Mr. and Mrs. Gaseous Nitrogen

{née Hydrogen), of Sandwich, Ont., a daughter, Synthetic Ammonia.

Sandwich, Oni. Stricken suddenly by an attack of modern science, one of Size oldest resi dents of this section of Ontario passed away today in the person of Mr. By-product Waste.

Deceased was a man of wide business connections and of late years had been associated with the manufacture of chlorine. It is understood that the immediate cause of death was shock arising out of the recent NitrogenHydrogen marriage in which Mr. Waste was directly interested. He leaves a large estate, which will be divided among beneficiaries in the Can adzan chemical industry.

W HO says that Romance is dead? On the contrary. Witness the Sandwich affair above recordedthe somewhat naive citation is from the pages of Canadian Chemical Gossip. Here is a marriage by which modern science is combining the waters from under the earth and the air from above it to produce in the end the explosive power with which we mine our mines, dig our canals, blast the way for our railways. Without dynamite or its equivalent there would be no Canadian mining industry as we now know it, and dynamite is one of the ultimate products of the union of gases now taking place at Sandwich.

By way of contrast, follow other branches of the genealogical trees rooted in Sandwich salt wells and we find them bearing other products with which we make our soap, refine our petroleum, tan our leather, fabricate the artificial silk for the sheerest of lingeries, make our starch, purify our drinking water, galvanize our wash tubs, bleach the paper on which we record our store of knowledge.

Consider also the several alliances contracted within recent months by the progeny of Atom S—Atom S, otherwise known as common sulphur, being one of the mainstays of modern industrial chemistry. Trace the sulphur atom to his lair and we find the chemist taking sulphur dioxide from

the fumes of a smelter chimney to produce that which fertilizes our vineyards, makes two ears of com grow where but one grew before, “pickles” the girders for our skyscrapers, produces engravings such as those which illustrate this article, activates the self-starters on our motor cars, plates our silverware, purifies the oil which lubricates our locomotives.

The list of transformations is a long one and everywhere there are paradoxes. Ponder, for instance, the curious fact that the very nitroglycerine which fathers our dynamite also furnishes succor for the man afflicted with heart disease. Or the still more curious fact that from the coal which gives us heat we also draw a substance, ammonia, that freezes our hockey rinks, keeps our butter and eggs cool and fresh, chills our theatres.

To the layman such feats are near sorcery, and yet they are but the commonplaces of a world in which man juggles the elements to his own ends, the world in which chemists match wits with Nature in a struggle to turn waste into wealth, the useless into the useful.

Turning Discards Into Dollars

TO THE man who thinks in terms of dollars, this capitalizing of industrial waste is perhaps one of the most fascinating phases of th« chemist’s game of transformations. There was a time when coal was used only as a producer of heat. Now the by-products of the changing of coal into fuel gas and coke are the bases of industries producing enormous wealth.

Eighteen months ago hundreds of thousands of cubic feet of hydrogen were going to waste annually in the manufacture of chlorine and caustic soda from Sandwich brine. Now it is being combined with the nitrogen of the air to form ammonia, which in turn is combined with the oxygen of the air and water to form nitric acid worth $150 a ton.

. Six years ago all the sulphur burned out of the copper-nickel ores of the Sudbury basin in Northern Ontario was going up smelter stacks in fumes which were not only a waste but a menace, for they killed vegetation for miles around the smelter. Similarly, the fumes from the smelter at Trail, British Columbia, were causing such damage to orchards in the State of Washington as to entail court action and a subsequent payment of cash damages by the company concerned. Now a percentage of the Sudbury sulphur is being turned into sulphuric acid worth $15 a ton, and plans are nearing completion for the production of fertilizer from Trail sulphur on an enormous

Such developments indicate the coming of a new and significant stage in the evolution of Canadian industry. Heretofore the Dominion, having no free sulphur, has had to rely on other countries for her supply of this basic commo-

dity. Now every ton of domestic sulphur used in the production of sulphuric acid leaves Canadians that much less dependent on sources of supply over which they have no control—no small item in our national economy when we consider that free sulphur costs somewhere around $28 a ton when laid down in Toronto, and that in 1929 we imported 178,000 tons.

Similarly with nitrogen, which, although it is one of the most common of all elements, has long been one of the most difficult to capture in a form industrially serviceable. Three quarters of the air we breathe is nitrogen. Its derivatives are essential to the growth of all plant and animal tissues; its compounds are the basis of the power contained in the explosives with which man has built—and at times attempted to destroy—modem civilization; yet for centuries the industrial world’s chief and only easily accessible supply lay in the nitrate beds of Chile. Development of the coking process provided an additional source of supply, but only within the last thirty years has industry been able to tap the unlimited supply available in the atmosphere.

Until 1909 Canada was dependent on foreign sources for the great bulk of her requirements, but with the development of cheap electric power at Niagara Falls in that year Canadian electric furnaces started to transform atmospheric nitrogen into plant food in the form of a compound known as cyanamide. Manufacture by this process expanded enormously during the war and after, as is shown by the fact that in 1929 we exported cyanamide to a value of $6,400,000. For certain purposes, however, until last year we still had to rely on imported nitrates. Now, thanks to the latest additions to the plants of Canadian Industries, Limited, our own synthetic product is meeting the competition of the

nitrogen in Chilean nitrate and we have advanced still another step along the road to complete self-sufficiency in the matter of tapping the wealth which literally is as free as the air of which it forms a part, yet is so difficult of access.

But not without a struggle. To make these achievements possible, processes which in Nature require the might of the thunderbolt for their consummation have had to be brought first into the laboratory and then into the factory, where now they are controlled at the throw of a lever. Mechanical monsters capable of performing prodigious feats have had to be created. Precision instruments of an almost incredible delicacy have had to be devised. Mysteries unfathomable since the beginning of time have had to be solved.

And yet mystery remains.

The Guinea-Pig Rabbit Trick

CONSIDER, for instance, the hydrogen-nitrogen affair at Sandwich. In essence it’s quite a simple chemical marriage. Hydrogen, the kind of gas that lifts the dirigible R-100, and nitrogen, one of the components of air, are mixed, forced into one end of a long system of pipes and cylinders and pumps, and then squeezed and heated and cooled and squeezed again until eventually they appear at the other end of the system not as hydrogen and nitrogen, but as a clear, colorless liquid called anhydrous ammonia —anhydrous meaning “without water.”

Quite a neat little trick—like turning two guinea-pigs into a rabbit. A little disconcerting perhaps, but the really remarkable thing about it is that it has taken man just about a million years to discover how to do it, and now that he can do it he doesn’t know how it’s done. Which is nothing more than literal truth, as any chemical engineer will avow, for the vital factor in the process is a substance called a “catalyst” which must be present else the trick won’t come off. And although many have guessed, no man knows how catalysts work.

Catalysts, in fact, are one of the great unsolved mysteries of modern science. They may be almost anything— metals such as nickel or platinum, a bit of crystalline salt, a chunk of bog iron, a powder like mercuric oxide, a liquid like hydrochloric acid. On occasion even water may play the part. But whatever they are, theirs is the rôle of silent partner. To all appearances they take no part in the chemical reactions over which they preside; they may endure the fiercest of torments, giving nothing of their substance, taking nothing away; and yet without their presence the guinea-pigs remain guinea-pigs and the rabbit fails to materialize.

Before delving further into catalytic magic, however, let’s examine the “props” with which the stage for this particular trick is set. To begin with,

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there’s salt—salt which in some remote geological age was deposited in immense beds under what is now the westerly fringe of southwestern Ontario.

At Sandwich the richest bed is about 200 feet thick and it’s down about 1,500 feet underground. This bed is tapped by a number of wells whose gangling derricks stand sentinel-like about a Canadian Industries plant which sprawls over several acres fronting on the Detroit River. The salt is brought to the surface by the simple expedient of forcing water down these wells and then pumping it up again as brine after it has dissolved all the salt it will carry. Part of this brine is transformed into various kinds of commercial salt by processes which need not concern us here. The remainder, after being purified, encounters chemical adventure in a devastating electric treatment known technically as electrolysis.

To understand this process even in a general way, one has to remember that salt is composed of sodium, a metal which "bums” in water, and chlorine, that greenish yellowish poison gas of dreadful memory; also that water is a chemical combination of hydrogen and oxygen. The brine mixture, when subjected to a powerful electric current in a specially designed cylindrical cell which to the untutored eye looks like an exaggerated ash-can with a domed top, breaks down into chlorine, hydrogen and a combination of sodium, oxygen and hydrogen called caustic soda.

At Sandwich the trick is turned on a wholesale scale in a great, long, low-ceilinged room containing nearly 3,000 of these cells set row behind row as if on martial parade and linked in one enormous organism by a maze of wires and piping. It’s an eerie sort of place where a portentous silence stills the tongue and footfall echoes hollowly, but we haven’t time to linger. Nor have we time to follow the chlorine and caustic soda as they take their divers ways through the maze of pipes to the plants where, liquefied in one case and solidified in the other, they are made ready for shipment to their various markets. Our immediate interest is the hydrogen, which, after negotiating its section of the maze, is stored in a big gas tank of the type one sees ranged about the ordinary city gas works. There it awaits summons to participation in the guineapig-rabbit performance, or, more properly, summons to participation in the catalytic synthesis of ammonia by the Casale process.

Magic in a Temple Built by Salt

ALL of which brings us logically to a Lx. curiously lopsided, red-brick building —lopsided because one wing rises five stories and the other only a modest two—where the high-pitched whine of speeding rotors and the hiss and swish of gases fleeing torture sing a song of synthesis. Throb—throb— throb. Scarcely audible in the rhythmic beat of plunging pistons. You feel it rather than hear it. Throb—throb—throb. Half mesmerized, you think of giant tom-toms beating barbaric litanies: of hawk-faced priests in a temple by the Nile burning camel-dung candles before Ammon’s altar, for, back in the days when the Sphinx was young, ammonia so derived was the Breath of Ammon—hence the name, Ammon-ia— and Ammon was a mighty god in Egypt.

“Now this,” says our engineer host with a gesture toward the throbbing black and scarlet monster which holds our fascinated gaze, “this is the compressor. As you see” —pointing toward its twin—“there are two units, but we run only one at a time. We mix the gases in that burner over there.” The gesture this time is toward a big steel cylinder standing upright in a corner of the room. “Part of the hydrogen is burned, with the air taking out the oxygen, and the remainder is mixed with the nitrogen in the proportion of three to one. We have to be careful, of course, to see that ...”

Dimly we begin to realize that Egypt’s was not the only age of marvels. That mixing of gases, for instance! A fiery tornado

under absolute control. Two gases in one, never halting to be measured, and yet at any given instant the operator has only to glance at a needle on a dial to know with mathematical exactitude how much there is of each. The compressor itself; Six gulps, six stages of compression to a stroke, and gas enough to fill an ordinary-sized room is squeezed into a volume not much greater than that of a large-sized pail. Terrific pressure. Seven hundred and fifty atmospheres, 10,500 pounds, five and a quarter tons to the square inch. Pressure equivalent to that on the floor of the Atlantic at a depth of four and a half miles opposed to every stroke of the weaving pistons; and yet not a quiver of the cylinders, not a tremble in the maze of connecting piping to indicate the enormous forces held in leash.

"Of course,” the voice of our friend the engineer breaks in again, “you understand that the work done in compression creates heat, a good deal of heat”—you remember the day when your bicycle pump got too hot to hold—“so we have to put the mixture through coolers between each stage of compression. If we didn’t . . .” He smiles as if to say that what would happen would be just too bad. “Leakage? No, we haven’t had much trouble. You see, the system’s built to provide a wide margin of safety. The joints are all welded and tested, in some cases up to 30,000 pounds to the inch. Now if you’ll just come this way ...”

We step through a doorway into the converter room.

“Now this”—the indicated “this” looks like the barrel of one of the world’s largest cannons stuck up on end with its snout pointing toward a ceiling seventy feet above us—“this is the converter. ‘Long Tom’, some of the boys call it. The mixed gases come in under pressure through this pipe at the bottom. After they reach the required temperature, they come in contact with the catalyst, and are transformed into ammonia vapor which passes out through the top to the condensers you see over there”—what you see over there is another series of vertical cylinders beside which Long Tom is dwarfed into insignificance—“where it is liquefied and cooled and then forced out into the storage tanks.”

Shades of Egypt’s priests! As simple as all that; and not so much as one pungent whiff to indicate that Long Tom is spouting Ammon’s breath by the ton—seven tons in twenty-four hours, to be precise. And where are the priests? Suddenly you realize there’s not a man in sight. Then where are the guardians of this mystery? That’s simple,too. “Now if you’ll step this way ...”

Back to the outer chamber we go, and stand before a control board garnished with dials and valves, gauges and switches and meters. A hand reaches out and turns a knob. A needle moves. “That’s the temperature of the incoming gas.” Another turn; another flick of a needle. “That’s the temperature of the catalyst . . . this the

temperature of the converter shell . . . this the output record . . . How’s your pressure, George? Good. She’s been behaving like a lady all day today. Keep your eye on that reaction temperature, though.”

No; it’s not a miracle. Only the modern priests of Ammon working magic in a temple built by salt.

A Chemical Perpetual Motion Machine

THE scene shifts and we find ourselves divesting our pockets of matches in the office of C. I. L.’s explosives plant at Beloeil, Quebec, on the Richelieu River below Montreal. The ammonia born at Sandwich has successfully negotiated the intervening 600 miles in a railway tank car, and now awaits a further adventure in synthesis which has as its object the production of nitric acid destined for use in the manufacture of nitroglycerine and dynamite. And as before, the transformation is effected by the magic of catalysis.

Having demonstrated our non-combustibility, we are conducted to a scene of the

mystery—an oddly shaped, relatively small four-story building less than a year old, whose interior suggests the boiler room of a ship despite the incongruity of a flood of sunlight. There’s the same sibilant murmur of vapors surging under pressure, the same compactness, the same feeling of tension; and the illusion is heightened as one gazes upward through the gratings, which take the place of flooring, at a bewildering yet orderly array of piping and steel work. Only the pulse of beating engines is absent, and presently we realize that the whole complicated organism functions as a sort of chemical perpetual motion machine without benefit of high-powered compressors such as those we saw at Sandwich.

Down on one of the lower stories our guide points out an arrangement of piping which looks like the upper half of a giant letter D. “That,” he says, “is the converter. Take a look.”

We bend down and gaze into a leering glass eye set in a spy-hole in the elbow of the D. The interior of the pipe is a glowing mass of flame, an inferno in miniature.

“Now you’ve seen it—the oxidation of ammonia,” smiles the engineer as we straighten up. “Simple, isn’t it?”

Then, noting our look of astonishment;

“And it is simple—when you know how —and have a catalyst. The ammonia is mixed with air, and the mixture, after being heated, is passed through a platinum gauze screen. You can’t see it, but it’s set in the pipe there near the elbow. The platinum acts as the catalyst, and the nitrogen in the ammonia and the oxygen in the air combine to form oxides of nitrogen, which are then absorbed in water and acid to form the nitric acid. The absorption part of the business is carried out in that column over there”—pointing to a six-foot cylinder which towers upward through the gratings above us.

“The beauty of the whole process is that it just about runs itself. The heat of reaction —the temperature’s about 1,000 degrees centigrade—is used to heat the incoming gases, so that as long as the reaction continues it preheats its own fuel. To start it, all we have to do is to play a hydrogen flame on the platinum until it begins to glow—and then she’s away. Barring accidents, she’ll run indefinitely.”

Gradually the significance of the terse description begins to sink in. In Nature direct combination of nitrogen and oxygen is relatively rare and is brought about only by the terrific force of the thunderbolt. Here one man twiddles the controls and turns out ten tons of nitric acid every twenty-four hours ! Small wonder that philosophers stand aghast at the powers with which Science is endowing its pigmy master, man.

Nitroglycerine and Garden Crops

THIS, however, is a story of wealth wrung from waste by benefit of chemistry and not a philosophical essay; and Beloeil offers still another instance of chemical salvage, to wit, the transformation of by-product sulphuric acid from the making of nitroglycerine into fertilizer for the growing of field and garden crops. Formerly this sulphuric acid had practically no value after it had fulfilled its allotted task of absorbing water from the explosive in the making. Now it finds rebirth in the large-scale production of the plant food known as superphosphate which constitutes about sixty per cent of most commercial fertilizers.

Use of superphosphate has been growing steadily in Canada during recent years, but until last August all our supplies had to be imported. In that month, however, the big mixer of C. I. L.’s first unit at Beloeil started to tum out superphosphate at the rate of 25,000 tons a year, and double that amount will shortly be available from a second plant now being constructed at Hamilton, Ontario. Still another and even larger plant is being developed by Consolidated Smelters at Trail, B.C.; which means that the Dominion in the near future will be able to meet not only all her domestic needs but to

produce for export should occasion offer Chemically, this further venture in the elimination of waste is relatively simple. Ground phosphate rock, a dun-colored rock which to the layman’s eye looks like any other dun-colored rock, is imported from Morocco, Florida, and brought up the Richelieu River in barges. Once arrived at Beloeil, it is deposited in a storage shed, whence in due season it finds its way into the interior of a massive rotating oven wherein it is “cooked” with the sulphuric to the tune of a great grumbling and groaning. In the process an atom of hydrogen from the sulphuric gets so badly knocked about that it leaves its host and forms a new alliance with the emigrant from North Africa or the brother from Florida, as the case may be. Result: acid phosphate of lime or superphosphate, which upon discharge from the lumbering monster is mixed with certain other chemicals, ultimately assuming the character of a spring tonic for tomatoes and sundry other vegetables.

Rather a bizarre corollary to the concoction of nitroglycerine when one stops to think about it.

“A Neat Bit of Juggling”

STILL more bizarre, however, is the chemical legerdemain which roasts an ore to make a smoke that makes a liquid that makes a salt that cracks the ore that made the smoke to make a metal—not a technical description, perhaps, but nevertheless a reasonably accurate summary of the latest adventures encountered by the sulphur atom in connection with the production of sulphuric acid from smelter fumes at Copper Cliff, Ontario.

Spectacular is a mild word when it comes to describing this further example of the atom juggler’s art. Many of us think of the mining country as a land where man is but a dwarf toiling in the vastness of a wilderness. So it is. But here at Copper Cliff the dwarf has played a Titan’s rôle and created an industrial behemoth.

Here in the mammoth pile of steel and stone and brick that constitutes International Nickel Company’s new smelter is monumental evidence of the richness of a North Country once called barren. Here is a colossal agglomeration of machinery which, seen and heard in action, leaves the beholder dazed with wonder at the works of man. Here are furnaces capable of consuming 8,000 tons of ore a day. Here, set in the midst of the rock-ribbed wilderness, is the tallest industrial structure of its kind in the British Empire—a gigantic chimney which rises a sheer 512 feet from its foundations, a monstrous column of brick whose mouth even at that great height is as wide as a city street, a chimney whose crown is thirty-six feet higher than the tallest skyscraper in Canada, the Bank of Commerce building in Toronto.

But why, one asks, why such an enormous vent? The answer: sulphur. Bum an oldfashioned sulphur match and you get an acrid smelling gas which your nose recognizes as sulphur dioxide. Roast the coppernickel ores of the Sudbury basin and you get —sulphur dioxide. And roast you must, for both nickel and copper have to be sulphur free if ever they are to be useful. Hence that gigantic stack which, incredible as it may seem, annually spews out sulphur dioxide containing three times as much sulphur as we at present use in the whole of Canada.

The wastage is terrific, but it’s one thing to hatch your sulphur dioxide and still another to catch your sulphur and fit it to the uses of industry. Which is why Canadian Industries’ new contact acid plant, hard by Inco’s smelter, is regarded as a triumph of chemical engineering.

As might be suspected in view of what has gone before, here again the trick resolves itself into a marriage by benefit of catalysis. But what a setting for even a catalytic marriage !

Picture if you can a building about the

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size and shape of a hockey arena, two thirds of whose interior is literally crammed with a tangle of steel and lead and iron, mounting seventy feet above the floor. Pipes. Big pipes and little pipes; pipes as thick as a sewer main, pipes no thicker than a lead pencil. Enormous cylindrical towers; tiers of cylindrical towers held in grotesque embrace by arms of steel strangely convoluted. More cylindrical towers; squat towers, fat towers, lean towers. Pumps, blowers, motors; uncouthly gross um-shaped converters, rows of cooling coils, batteries of heat exchangers, fretwork of steel stairways, soaring steel columns. The whole, one huge labyrinthine symphony in reds and blacks, in greens and browns and silvery greys. The voice of the place, a weird cacophany—whir of motors, hiss of gases, babble of cascading waters, belch of blowers, sullen grumble of metal straining under labor.

Twenty million cubic feet of smelter fumes a day go coursing through the maze, and in the end each twenty-four hours see a hundred tons of sulphuric acid salvaged from the flow.

How’s it done? Only Nature knows the inner secret, but baldly stated what happens

The mixture of air and sulphur dioxide in the fumes is cleaned, dried, heated and then led to the catalyst, platinum or vanadium molded in pellets about the size of aspirin tablets. These, by some mysterious alchemy beyond the ken of man, induce a third atom of oxygen to join hands with the two already in combination with the sulphur. Result— sulphur trioxide, another gas which is then combined with water to produce the liquid sulphuric acid.

It’s a neat bit of juggling, but it took a lot of learning. In the beginning all sorts of obstacles had to be overcome. Arsenic is a notorious loiterer in the smelter fumes, and let so much as one part of arsenic in sixty million get through to the catalyst and the platinum is “poisoned” and goes on strike. Which meant that an extraordinarily meticulous anti-arsenic cleaning process had to be devised.

Worse still was the dust, dust so fine that it could not be “scrubbed” out of the system by ordinary washing processes. Only a few pounds of it in many tons of gas, and yet it had to be removed else the maze got clogged. Ultimately this puzzle was solved by subjecting the flowing vapor to a 50,000 volt electric current. Thus treated in a huge contrivance dedicated to the search for the infinitesimal, the invisible motes do a dancing act and literally hop out of the mixture of their own accord.

And, as at Sandwich, the whole gigantic mechanism marches without aid of manual labor. Three men per shift can guide the controls. A glance at a needle here, a touch of a finger there, a twist of the wrist yonder —so it goes hour after hour, with ton after ton of fume-bom fluid pouring into storage to await the call of a world in need of Atom S.

One more wedding and we have done. This time it’s a forced marriage; a rather comical affair, as a matter of fact, arising out of the very skill of the chemical engineer as a matchmaker and involving an atrocious matrimonial tangle within the Sulphur-Nickel connection. So atrocious, in truth, that here we find the grandchild of a nickel ore fathering nickel metal derived from the same ore that produced the grandchild. Seems impossible but here’s the explanation;

Years ago it was discovered that the only solvent which would separate the copper from the nickel in the Sudbury basin ores was a salt known as nitre cake or acid sodium sulphate, another member of the sulphur family, you’ll note. Until recently this was readily and cheaply obtainable, being a by-product of the old-fashioned method of making nitric acid from Chilean nitrate and sulphuric acid. Then along came the masters of catalytic magic with their new-fangled notions about making nitric from hydrogen and air and water, as we have seen it made at Sandwich and Beloeii. Whereat the oldfashioned nitric process began to go out of style and the nitre cake market began to make whoopee, much to the concern of the nickel men, who not only watched the price soar but foresaw the time when supplies would approach the vanishing point.

What to do?

“That’s easy.” retorted the troublemaking chemists. “Look in your own smoke-

It wasn’t quite so easy as that, as we have seen from our observations in the sulphuric acid plant, but in the end, with some considerable assistance from the proper quarters, the smokestack produced that which was demanded.

Now the nickel men are digging up natural sulphate from a bed at Horseshoe Lake, Saskatchewan, and trundling it down to Copper Cliff by the train load. There they turn it over to the C. I. L. engineers, who pour it into a battery of stills where it meets sulphuric acid diverted for the purpose from the acid plant. Follows much bubbling and fuming, resulting in the marriage of smelterbom sulphuric and Saskatchewan sulphate to form the much desired nitre cake. It pours from the stills as an inky black liquid which solidifies into neat little bricks in a multitude of pans linked together on a series of slowly moving endless chains. After which, back to the smelter, to the appointed

Thus ends the story of the ore that makes a smoke that makes a liquid that makes a salt that cracks the ore that made the smoke to make a metal.

And the moral of the tale is this; “He who looks in his own smokestack may there find waste that can be turned into wealth.”

Note—The writer of this article desires to express his appreciation to the members of the engineering staff of Canadian Industries, Limited, who generously assisted in its preparation.