Evening Republican, Volume 21, Number 92, Rensselaer, Jasper County, 26 April 1918 — TURNING SMOKE and DUST INTO MONEY [ARTICLE+ILLUSTRATION]

TURNING SMOKE and DUST INTO MONEY

by Robert H.Moulton

Scientist Has Discovered Wau to Stop Enormous Waste of Fuel

a MERICA sends billions “up in smoke” yearly because of the enormous waste in the fuel used by our indus~tries. On the other hand, there is a man in Washington who has discovered I how to turn smoke into I money and he is now busily engaged teaching the rest of the country how to perform the same trick. He does this by means of devices which, through electrical precipitation, not only reclaim vast wealth from the smoke, dust and fumes of smelters and other plants, but at the same time redeem thousands of acres of near-by land. As a matter of fact, the curb which he has put upon the smoke and dust nuisance —his original aim—now actually blds fair to be, in some directions, the primary reason for the running of certain of our industries. The smoke wizard who has accomplished these remarkable things is Dr. Frederick G. Cottrell, chief metallurgist of the bureau of mines. Doctor Cottrell’s experiments began several years ago when, as a member of the staff of the University of California, he was called upon to solve the problem of helping a smelter located on San Francisco bay. The waste gases and vapors from this smelter, resulting from the sulphuric acid parting process used in treating gold and silver bullion, were declared a nuisance by neighboring farmers and seemed likely to provoke costly litigation and possibly lead to a shutdown of the plant. The gases discharged into the air amounted to substantially 5,000 cubic feet per minute and held in suspension an Important proportion of sulphuric acid in the form of a fine mist. The corrosive action of the sulphuric acid was shown throughout the entire zone swept broadcast by the shifting winds, pnd both the agriculturists and the people generally had ample reason for complaint. The smelter was a profitable one and the management was anxious to find some way to abate a nuisance that was both a menace to health and hurtful to vegetation. Laboratory Meets Industry. Doctor Cottrell’s preliminary work brought up some puzzling situations. Up to a certain stage matters went well enough on the miniature scale of the investigational tests, but beyond this was the question of meeting the practical situation presented by a large commercial smelter. A big part of Doctor Cottrell’s achievement lay in spanning the gap between the laboratory and the industrial plant and in finding ways to control the enormous pressures of the necessary electric current, mounting up to 100,000 volts. - The problem was solved, however, and so well was the precipitator installed at this smelter designed that it has been doing Its work satisfactorily ever since. Further, by mere chance Doctor Cottrell attacked at that plant what is commonly admitted to be the most difficult of all problems of smoke or fume abatement, viz., the precipitation of acid mist. The good results obtained in this first instance soon became widely known and a new line of application was opened a few years later when the great copper smelter at Balaklala, Cal., was threatened with fume litigation by the United States forestry service. “Fume,” or fine particles in the form pf smoke, and sulphur dioxide gas, invisible to the eye, given off from the stacks of the smelter, had swept the neighboring country bare of vegetation for miles, and it was a case of either a shutdown or a suppression of these destructive discharges. A full-sized plant of the Cottrell type was, accordingly, installed. The voluine of the gases treated averaged

between 200,000 and 300,000 cubic feet per minute, and during the filtration tests made of the gases throughout a period of nine months it was found that the electrical precipitator recovered between 80 and 00 per cent of the suspended matter. With improvements in detail of construction, the efficiency later was raised well up into the nineties. Great Wastage in Smofte. The general public has only the faintest notion of the wastage represented in the fumes and smokes from belching stacks quite apart from the beneficient economies following from their abatement where the nature of these outpourings is harmful to man and vegetation. In the smelting of lead the fume contains anywhere from 3 to 10 per cent of the volatilized metal in the form of lead oxide and lead sulphide, with compounds of arsenic and antimony. This percentage is well worth recovering. Doctor Cottrell is authority for the statement that not less than 36 valuable substances are found in fumes which, if not collected, would be lost during the smelting and refining of various ores, etc. At Great Falls, Mont., there was at one time a daily loss in dust from the stacks of one of theTarge smelters of 3,775 pounds of copper, 106 ounces of silver, and 0.71 ounces of gold. By an adequate provision for dust recovery, this smelter was able to save ip the course of a single year metallic values amounting to $130,263. The blighting gas, sulphur dioxide, given off from the stacks of copper smelters can be transformed into useful substances by turning the gas into sulphuric acid or sulphur. Sulphuric acid is largely made here by treating pyrites, and we now consume annually in the neighborhood of 6,250,000 tons of 50 per cent sulphuric acid. To a great extent this corrosive fluid is a prime constituent in the preparation of fertilizers, especially where phosphate rock is treated for this purpose. It Is also used in converting the ammonia by-products of cooking ovens into ammonia sulphate. Sulphuric acid is in great demand by explosive factories, oil refiners, steel mills and varied industries engaged in the making of heavy chemicals. Sulphuric acid is likewise extensively employed by smelters and the latter are paying as high as S3O a ton today for the stuff. Sulphur dioxide is used in the preparation of wood pulp for paper making, both as a disintegrating and bleaching agent. In dealing with noxious or objec-

tionable gases not! necessarily harmful a! new aspect of precip-' itation arises. Thei electrical treater cam handle only fluids or substances in theshape of particles, and cannot cause the' precipitation of gases,! per se. But these' gases can be made to 1 condense upon mists’ In the forn) of steam or finely sprayed wa-i ter or upon extremely I fine pow’der or dust| purposely thrown in-i to the sw’eep of the! gases to effect this.l In this way It Is pos-' slble to deal with va-' ried conditions and!

to abate nuisances that bid fair to cause the shutdown or removal of costly plants. In dealing with dust alone, the first direct effort along this line had to do with a Portland plant near Riverside, Cal. An electrical treater was installed there a few years ago by way of experiment, and a couple of years later was collecting something like a hundred tons of dust dally. Prior to that the dust had been scattered broadcast and settled upon the groves of adjacent orange growers, leading to extent slve litigation. Analysis of the recovered dust disclosed the presence of! an appreciable percentage of potash,, but this attracted no marked attention at the time. Since then, particularly! now that It Is no linger possible for us to get potash from our prima source, Germany, this element so essential to a balanced plantfoou Is ini great demaiid. Last year the plant at Riverside started full blast to actually create dust as its first concern in order to recover the potash which previously had been only a by-product In the manufacture of cement. Cement Becomes By-Product. This is certainly a romantic development of modern Industry, where an apparatus installed for the purpose of saving the life of the factory turns out to be the center of operations around which the entire plant is adjusted. In other words, the cement becomes for the once the by-product and the profits on the potash furnish an ample revenue, while the cement is just so much additional gain. Anyone at all familiar with the average cement plant and the gray powdered appearance of the near-by territory can realize the boon that w'ould be conferred by the general adoption of electrical precipitators not only in preventing the escape of the dust but in saving the potash which is so much desired. Perhaps the most interesting part of the whole story of Doctor Cottrell’s success is the fact that he has presented to Smithsonian institute at Washington all of his valuable patents relating to the electrical precipitation of dust, smoke and fumes. The purpose of this munificence on his part was that any profits resulting from the practical application of the patents shquld go to the upbuilding of a fund to aid in the advancement of scientific research. In short, to help genius and to develop inventions where the needful financial aid might otherwise be lacking.