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T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
CURRENT INDUSTRIAL NEWS
V O ~j, . NO.1 2
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B y W. A. HAMOR
SULFITE WASTE LIQUOR PROBLEMS Paper for November 12, 1913reports that in the manufacture of chemical woodpulp by the sulfite process, half of every cord so treated is dissolved by the liquor in which the wood is boiled, and is discharged into the adjacent rivers as waste liquor. According t o the latest bulletin on pulpwood, issued by the Forestry Branch, Ottawa, the amount of pulpwood subjected to this chemical treatment in 1912was almost 290,000cords. Half of this amount was absolute waste. The average price of a cord of pulpwood is six dollars, SO that this waste, reduced t o its money equivalent, represents a loss t o Canada of over $8oo,ooo. Nor is this the only loss, for by this process 140 pounds of sulfur are required to dissolve the waste materials out of each cord of wood. Some of the gases generated in the process are recovered, but most of the sulfur passes off in the waste liquor, and no method has yet been found to recover it for use a second time. Sulfur costs twenty-five dollars a ton, and the loss in this particular is equivalent to a money loss of over half a million dollars on the total amount wasted. In view of the fact that each year more and more pulpwood is being manufactured into pulp by this process in Canada, the utilization of this waste liquor becomes an important problem. Even the most practicable method so far devised does not recover enough valuable products to make it pay. The waste liquor contains many materials, such as oxalic acid, tannin extracts, dyestuffs and alcohol constituents which, if they could be easily recovered, would make the liquor of great commercial value; but in spite of the tremendous amount of work has been done on the subject, especially in Europe, the problem still remains for the most part unsolved. As the liquor also contains carbohydrates, it should be possible to obtain turpentine, and eventually it may be possible to obtain rubber from it. I n furthering the solution of such problems and in eliminating other forms of wood waste, the new Forest Products Laboratories being established by the Dominion Government a t McGill University will doubtless play an important part. One use of the waste liquor mentioned above, that has been tried a t Grand’ MPre, Quebec, where the Laurentide Company has large pulp and paper mills, consists in its utilization for street-watering. Experience has shown it t o be as efficacious in keeping down dust as oil is, while the objectionable odor of oil is absent. NICKEL A BY-PRODUCT IN THE UNITED STATES The Geological Survey reports that there are no producing nickel mines in the United States. The output of nickel from domestic ores is merely a by-product from electrolytes of the copper refineries. Salts and metal equivalent to 328 short tons of metallic nickel were saved in domestic refineries in 1912from both foreign and domestic ores. Nickel ore, “imported for consumption,” is mostly from the Canadian deposits. ~
PRACTICAL CONSIDERATIONS AFFECTING CHOICE OF THERMOMETERS IN INDUSTRIAL PLANTS In The Institution of Mechanical Engineers, Whipple points out that questions of first cost, up-keep, etc., must be considered in the selection of thermometers for either high or low temperatures. As a rule the temperatures found throughout a steam plant may be taken with mercury thermometers, sockets, or mercury cups being placed in the steam pipes into which the mercury thermometers are placed. On the other hand, it is frequently troublesome to read the important thermometers in the plant,
and they often go unread. The thermometer a t the foot of the smoke stack, and the one on each side of the economizer, although giving valuable information as to the efficiency of the plant, are frequently unnoticed. For this reason it is advisable to install resistance thermometers, which can be easily read on a galvanometer mounted in the boiler or engine house. When dealing with high superheater temperatures, a recorder or an alarm thermometer will be found of service. Mercury thermometers are generally employed in cold storage work, but experience has shown that in the case of large stores -say ten rooms or over-it pays to install resistance thermometers. A great deal of time is spent in reading mercury thermometers throughout a large building which necessitates the opening and shutting of a number of doors, and which, in addition to the labor cost, is wasteful of power and tends to destroy the uniformity of temperature in the various rooms. The applications of pyrometers in works for the treatment of metals are very varied. One of the most important is the measurement of the temperature of the air in the hot air main of a blast furnace. If prime cost is not a n overwhelming consideration, then resistance thermometers should be used connected to a Callendar recorder. Thermocouples may be used, but if a n accuracy comparable to that of the resistance thermometers is desired, a scale control board, and various precautions with regard to cold junctions, etc., must be adopted. Unfortunately, although the temperature a t which a metal is cast is admitted to be of such great importance, yet there is no really satisfactory way of determining the temperature of the molten metal. The conditions, especially where a large crucible is used, make it practically impossible to insert a pyrometer into the metal, and the readings obtained with radiation or optical pyrometers are not consistent, owing to variations in the quality and quantity of the slag and the frequently great divergence from black-body conditions. The closed-tube radiation pyrometer can be safely used when small crucibles are employed; the thermocouple also, if protected by an outer salamander tube, may be employed for molten brass. The greatest field for the application of pyrometers lies in the heat treatment of metals, where the success of a pyrometer installation depends almost entirely on the mounting. Experience shows that, in the case of large furnaces, it is advisable to put the thermometer in the floor of the furnace in the following way: A slot is chopped into the furnace floor and into this a fire-clay tube is grouted, the space surrounding the tube being filled in with fie-clay flush with the bottom of the furnace. The pyrometer is slipped into the tube through the side of the furnace. The weight of the head of the pyrometer is taken by a flanged socket, which is screwed into the protective plating of the furnace, the pyrometer being held to the socket by means of readily removable bolts and nuts. Thus the pyrometer can be introduced between the gas ports of the furnace. In practically all porcelain works Seger cones are employed to control the firing. Although the information given by them is extremely valuable as showing the maximum temperature attained, yet they fail to show the rate a t which a kiln is being heated, and this is frequently of fundamental importance. Thermocouples are best employed for the measurement of the lower or preliminary temperature and radiation pyrometers for higher or finishing temperatures.
THE SALT INDUSTRY OF RUSSIA It is pointed out in The Times Russian Supplement, August I I, 1913, p. 8, that there is a great discrepancy between Russia’s salt production and her resources in this respect.
