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THE INDIA RUBBER WORLD 



[August 1, 1913. 



LAMP BLACK AND CARBON BLACK. 



THE valuable and interesting paper read by Mr. Godfrey L. 

 Cabot, of Boston, at the recent New York Congress of 

 Applied Chemistry, on the subject of "Lamp Black and Carbon 

 Black," deals with the question under its technical and industrial 

 aspects. 



According to the definition in Webster's dictionary, lamp black 

 is the fine impalpable soot obtained from the smoke of carbon- 

 aceous substances only partly burnt. This definition is correct 

 from the chemist's point of view, covering also the substance 

 known to the trade in this country and elsewhere as "carbon 

 black." In his title Mr. Cabot has used both names, because in 

 the American trade the term "lamp black" is usually understood 

 to be a soot deposited by the smudge process and made from oil, 

 resin, or some other solid or liquid raw material. "Carbon black," 

 on the other hand, is the term applied to a black deposited by 

 actual contact of a flame upon a metallic surface. 



LAMP BLACK. 



Using the term "lamp black" in its wider sense, as embracing 

 any commercial form of soot, it may be prepared in three dif- 

 ferent ways — first, by the combustion of dead oil of tar, pitch, 

 resin or some other carbonaceous raw material with an in- 

 adequate supply of air, and the collection of the floating par- 

 ticles of soot which escape unburncd from the flame and slowly 

 deposit themselves on the walls and floors of the collecting cham- 

 bers; or second, it may be formed by the direct impact of a flame 

 upon a collecting surface; and third, it may be formed by heat- 

 ing carbonaceous vapors to a decomposing point, apart from the 

 air or flame. 



Soot has ceased to be used for its former purposes, its com- 

 position of 50 per cent, of grit, empyreumatic matter and other 

 impurities rendering it unsuitable. 



Considering "lamp black" in its more restricted sense of a 

 commercial soot, deposited by the smudge process from various 

 dead oils, from IS to 35 per cent, of its weight can be obtained 

 in the form of lamp black by deposition in suitably arranged 

 chambers. 



The quality of the black is determined by the size and shape 

 of the furnaces in which the oil is burned, by the heat to which 

 it is subjected and other attendant circumstances. It has been 

 found that the best grades of black, generally speaking, are ob- 

 tained in furnaces of moderate size. 



Mechanical devices have been used for churning the air, and 

 causing the condensation of the smoke in masses sufficiently 

 large for it to deposit itself. 



Resin, resinous woods, tar, pitch and other raw materials are 

 to a certain extent used in the manufacture of lamp black, but 

 the quality is greatly inferior to that obtained from the dead 

 oil of tar and other substances. 



Still another source of lamp black is acetylene gas, obtained 

 from the refuse of carbide of calcium factories. This process is 

 very hard on the apparatus, the black produced being very in- 

 ferior in color and strength to that obtained from natural gas. 

 The irregularity of its supply and price limits its use to cases 

 where its bluish tinge obtains for it a preference in certain 

 trades. 



CARBON BLACK. 



Carbon black, as already remarked, is the trade name given in 

 this country, and to a certain extent abroad, to lamp black 

 made upon the surfaces of metal or stone by direct impact of 

 flame. The first carbon black produced in this country and 

 sold commercially was made in 1864 by J. K. Wright, an ink 

 maker of Philadelphia, for use in printing ink. This industry is 

 thus a comparatively new one in this country. Mr. Wright 

 made black on sheet iron cylinders, revolved over gas jets, from 

 which the black was removed 1)y stationary scrapers. 



The first process of commercial importance patented was that 

 of John Howarth, who received in September, 1872, a patent 

 for the manufacture of carbon black from natural carbureted 

 hydrogen gas. Owing to the cheapness of the raw material, as 

 compared with the artificial gas previously employed, the price 

 gradually dropped from $5 to $1.25 per pound. 



Mr. Howarth worked his patents with success at New Cum- 

 berland, West Virginia, and later at Saxonburg, Pennsylvania. 

 Owing to his superior ability, Mr. A. V. Nolan, who had started 

 a competing factory at West Cumberland, West Virginia, bought 

 out the original company. In 1883, L. Martin & Co., of Phil- 

 adelphia, became interested in a plant at Foster's Mills, Penn- 

 sylvania. 



A factory was started by Samuel Cabot about the same time 

 at the village of Worthington, Pennsylvania, where eflforts were 

 made to confine and economize the gas. Owing, however, to the 

 inefficiency of the foreman, the plant remained to a great ex- 

 tent fruitless for some years. 



The Grantsville, West Virginia, works of Samuel Cabot 

 now produce about 10,000 pounds of black a day, and are 

 operated by five gas engines. This is said to be the largest 

 factory in existence. The leading position of this factory 

 was largely due to the system it had introduced of 24 inch 

 plates, with a rotating burner and a black box radially placed. 



In 1883 E. R. Bland, of Warren, Pennsylvania, began mak- 

 ing black on the roller principle, the details of manufacture 

 being subsequently improved by his son's processes, until the 

 black has been shown to possess some valuable qualities, and 

 is very profitable to its owners — the Peerless Carbon Black 

 Co., of Pittsburgh. This company was for many years the 

 only one in this country making carbon black from natural 

 gas, but there are now three such factories. 



In the decade 1883-1892 the process of making carbon 

 black introduced by Mr. A. R. Bland, became the most im- 

 portant as to output and total value of black produced. The 

 prices of black rapidly fell, reaching 7 cents per pound in 

 1887 and 4 cents in 1889. They then considerably improved, 

 the total output at the close of 1902 reaching about 10,000 

 pounds a day, worth at that time on the average about 6 

 cents per pound. 



TOTAL PRODUCTION. 



The total value of the carbon black made in a year would, 

 it is said, represent about one million dollars, while the total 

 value of the world's output of lamp black would probably be 

 two or three times as much. Yet the real importance of these 

 two commodities to humanity is inadequately represented by 

 these figures. These articles form the basis of black printing 

 inks, are largely used in black paints and for coloring rubber, 

 leather and other substances. Each has its distinct uses; 

 carl)on black being preferred for black ink, stove polish and 

 vulcanized rubber. Lamp black is much better for coloring 

 oilcloth, leather and certain forms of rubber, being much 

 more widely used in paint than carbon black. 



Within the last ten years the Pennsylvania factories (with 

 three unimportant exceptions) have all been moved to West 

 Virginia. 



The total value of United States imports of carbon black, 

 gas black and lamp black were: 1908. $493,907; 1909, $514,951; 

 1910, $679,607: 1911, $640,911: 1912, $907,623. 



Such are a few of the points brought out by Mr. Cabot in 

 his interesting paper. 



FRENCH EXPORTS OF RUBBER GOODS TO TTNITED STATES. 



In a recently issued report. Consul General Frank H. Mason, 

 of Paris, calls attention to the increased exports to the United 

 States of rubber goods from his district. The figures were : 

 1911, $272,836; 1912, $474,850. 



