I,\-DliSTRISL
May, 1925
A S D ENGINEERISG CHEMISTRY
Figure 2 shows a double-effect evaporator of special design. The vertical effect is of the patented basket type, 24 inches inside diameter by 8 feet high. The heating surface is an internal drum made throughout of l/Anch steel plate and fitted with an auxiliary cylinder and umbrella deflector. The tubular surface consists of twenty-four 2 inch X 13 gage X 30 inch charcoal iron tubes expanded in the head of the drum. The horizontal effect is 19 X 27 inches and 7 feet 6 inches high, and is heated with a steam chest containing one hundred d/4 inch X 27 inch X 18 gage colddrawn copper tuber, so arranged that any number may be blocked off. The unit is provided with vacuum pump. water-cooled
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surface condenser, four 200-gall011 condensate receivers, vapor lines, by-passes, etc. It is so installed that either unit may be used as the first effect or they may be used separately. The laboratory floor is constructed with positive drainage, sloping to large screened openings connecting directly to the trunk sewer. Leading from the trunk sewer a t definite intervals under the concrete are smaller drain pipes, with openings a t the walls and in the higher sections of the floor, for the discharge of cooling water or condensate. The elimination of exhaust steam pipes leading from the kettles to the floor openings greatly increases the convenience of the laboratory and improves its appearance.
A Process for Sulfur in Coal' Lead Oxide-Reduced Iron-Iodate Method By W. J. G . Meade ZENITH
FURNACE CO.,WEST DULUTH, SlINN.
RIXD well in a mortar 5 grams of pig iron low in sulfur and mixed well with 6 grams of lead oxide. Weigh 0.5 gram of coal low in sulfur, or 0.25 gram if high. Transfer to the mortar containing the mixture and mix well with a pestle. Brush into a small porcelain crucible that has been lined with approximately 2 grams of zinc oxide. Clean out the mortar with a little lead oxide, using this as a cover and put on a tight-fitting porcelain lid. The heating apparatus is best described as a sheet iron chimney lined A with asbestos (see figure). In the first stages heat the mixture in the chim4 neyfor 15 minutes, with the flame a t least 2.5 em. from the bottom of the crucible. Using this low flame a t the beginning 11ill eliminate any errors caused through the sulfur passing off with the volatile m a t t e r . There s h o u l d be no visible fumes. Gradually increase the heating, letting the flame touch the crucible for 10 minutes, then apply extra heat for five minutes, but not enough to cause reddenSheet 1ron:Asbestos-Lined Chimney ing of the whole crucible. ;i-Porcelain crucible Although all coal gas B-Iron holder contains small C-Asbestos lining D-Standard Bunsen burner of Sulfur, this 'does not E-Air holes (1.27 cm. dhmeter) Seem to affect the resuits, especially when a good-fitting porcelain lid is used. The success of the process depends upon this heating, and therefore great care must be used here. Cool the crucible in a desiccator for 10 minutes, and then empty the into an agate mortar* The mixture now looks like a compressed lead and coal button, which drops out easily from the crucible. The lining also will come out on tapping the crucible against the mortar. crush button
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Received April 4 , 1914.
and lining with a pestle and brush into a sulfur flask through a funnel. Mix the contents with a little distilled water. Connect with a rubber cork, funnel tube, and delivery tube. Place the delivery tube in a 100-cc. beaker or tumbler containing 150 cc. of distilled water and 8 cc. of cadmium chloride solution. Pour through the funnel tube 100 cc. of 1:1 hydrochloric acid. Heat a little a t first to start the action, but then discontinue the heat until action has almost ceased. Resume heating very gently until the delivery tube gets hot. Disconnect and wash contents into a 800-cc. titrating jar containing 250 cc. of distilled water. Add 1 cc. of starch solution, 100 cc. of 1 : l hydrochloric acid, and titrate immediately with a standard solution of iodate, stirring well to a deep blue color. Solutions
STAXDARD IoD.iTE-i\reigh 0.56 gram potassium iodate, 6.0 grams potassium iodide, and 0.5 gram potassium hydroxide. Dissolve the salts in distilled water and make up to 1 liter. Each cubic centimeter equals approximately 0.0056 per cent sulfur. Standardize in the usual way, using 5 grams of standard pig iron. STARcH-lIix 6.0 grams of wheat starch to a paste with a little cold distilled water and add to 1 liter of boiling water containing 15 cc. of 10 per cent sodium hydroxide. This solution must be made up in advance and used when cold. AMMOXIUMCADMIUhf CHLORIDE-50 grams cadmium chloride, 1500 cc. ammonium hydroxide, and 1000 cc. water. Add the water to the cadmium chloride and dissolve with ammonium hydroxide. Keep the solution in a dark bottle. Precautions
Care must be taken during the heating. The solution in the absorbing beaker must be kept alkaline. The solution must not be heated too fast during evolution. Notes-The iodate solution is made up on the &gram basis. A blank determination is run from time to time and the sulfur found is subtracted from results obtained from each sample analyzed. The use of the zinc oxide lining prevents the mixture from having the direct heat, especially a t the first stages, and also helps to absorb any sulfides which otherwise the crucible would absorb, The grade of iron used is best selected from a No. 2 foundry iron heat and should be low in It should also be cooled carefully so that it can be drilled and ground easily. A quantity of this could be stored in a bottle with a tight-fitting cork. The residue remaining in the flask after evolution is complete is soft and light. During the first stages of evolution it is helpful to shake the flask a little, giving the acid a chance to act on all the sulfides.
