118
Vol. 17, No. 2
INDUSTRIAL A N D ENGI MEERING CHEMISTRY
I n this connection the ostimate of Parr and Kressmad as t o the m o u n t of heat evoked in the oxidation of pyriticsulfuris of interest, in view of the bearing small increments of heat may have as a booster for further oxidation activities, both of the hydrocarbons and of the sulfur constituents. According to those calculations, 0.1 per cent of sulfur in the pyritic form upon oxidation will raise the mass through a temperature of 14.5" C.; hence the oxidation of so small an amount as 0.5 @am of sulfur would result in a heat rise of 71.5" C.-a really dangerous boost. The purpose of this paper is merely to point out that sulfur may he the initial source of heat after all, and that we need to suspend judgment in the matter until further evidence is in hand. The workof Yancey3shows the distribution of pyritic sulfur in microscopic form to be quite as common as in the massive fonn. Some work along this line in the writers' laboratory shorvs that mother of coal frequently hss a very high sulfur content. If it is also in the finely divided form, it is in an especially advantageous condition for starting oxidation. But
Carbon Dioxide as an Index of the Critical Oxidation Temperature for Coal in Storage' By S. W. Parr and C. C. Coons UNIYBRSlrY 01 ILLINOII. U R B I N A .
ILL
ROM the accompanying studies it is evident that coal is continuously reactive with oxygen to a greater or less degree, depending upon various factors, hut chiefly upon temperature. The two products most in evidence are, first, water and then carbon dioxide. An a p paratus that would give the initial appearance of these products of oxidation would be of both practical and scientific interest. The difficulties attending the indication for the appearance of water are far greater than those for carbon dioxide; hence it is the latter that will be considered a t this time. Apparatus and Procedure The apparatus devised for this purpose uses a solution of barium hydroxide as the indicating medium, while temperature control is obtained by an electric resistance coil so placed that the rise in temperature can he maintained evenly and a t any desired point. The mechanism for indicating the appearance of carbon dioxide is shown in Figure 1. Figure 2 is a photograph of the apparatus. In this apparatus, which embodies a number of features suggested by the investigations of FrancisZand also of Whceler,a there is a resistance furnace with a rheostat controlling the rise in temperature to about Lena of Pyrite from C u d Showing Sulfate Oxidation. VermUlon 10" C. per minute. Immediately below the furnace is the C w n f y Coal carbon dioxide detection assembly, as shown in Figure 1. The of especial interest is the fact that a study of the forms of other accessories are crystallization in the Illmois coal measures shows marcasite to for washing the gases he almost always present, if indeed it does not predominate used in the tests. Oxyover the usually assigned pyritic form of crystallization. gen thus purilied is led Even so, it is not clear from experiments in this laboratory into the upper part of that marcasitic sulfur is necessarily more susceptible to ox- the furnace and after idation than the pyritic form, when both arc in a fine state of passing through the coal is delivered below division. This point offers a field for investigation. A few illustrations are of interest in showing the presence of into the dioxide detectmarcasitic sulfur in pyritic masses in certain of the Illinois ing tube, through a 1-mm. capillary. This coal deposits. capillary is so placed Univcrsityof Illinois, Ens. Expt.Sta.. Bull. I6 (IOIO). that the gas from the 1 Tars Joumar,IS,501 (1924). coal impinges upon a drop of bafium hydroxNew Canadian Publication ide suspended from a The Canadian Department of Mines has issued a 310-page solid rod having a publication on "The Development of Chemical, Metallurgical, flat, ground tip. The and Allied Industries in Canada in Relation to the Mineral barium hydroxide soluIndustry," which sets a high standard in government publications tion is contained in a and presents in concise form much information of value to the chemical industry. The publication is provided with a number of separatory funnel hav- o r _ useful tables, such BS one upon the principal chemicals used in ing a tube filled with 1 industry, trade statistics of chemicals and allied products, and lime fitted into F i ~ u r el-Carbon Diorfde Detectloo Tubs charts which give in concise form information pertaining to "da the top of it in order electro products and some of their uses, the alkali industry, the to remove the carbon dioxide and moisture from the air as the industrial applicationsof lime, some of the many uses of alcohol, and products derived from coal. The discussion of primary solution is removed from the fnnnel. The barium hydroxide inorganic products contains information worthy to class this solution can he conducted to the lower end of the drip rod by publication as a source of reference reading, while primary or- a rubber and a glass tube, the latter being drawn out to a ganic products are treated in the same thoroughgoing manner. The parts devoted to manufacturing treat explosive mannfac- narrow tip which is placed so that it just touches the drip ture, the fertilizer, ceramic, and glass industries, besides a num- rod. In this way a h e r adjustment of the harinm hydroxber of those classed as miscetlaneaus and minor, so far as Canada ide can be obtained. The acid tube is placed directly.above is concerned. The metallurgical industries are treated in another part, as are food products and general manufacturing. The publication is recommended to those who find interest in such general as well as specific information which finds a proper place in a well-indexed government publication of this character.
F
I I
Rmived AvgUst 8. 1924. Parr and Frsnds, Univvsiiy of Illinois, Eng. Expt. Sta., Bull. %I
(1808). s J . Chcnr. Soc (Landon),11% 945 (1918).
