In the act of 1894 the duty was reduced from 4 to 3 cents per pound. This was followed by an increase of 50 per cent in the imports. The duty was again fixed at 44 cents in the act of 1897. The increase in imports was checked temporarily but, although there were large fluctuations from year to year, the general level of imports was not affected. From 1903 to 1909, inclusive, the average importation was a trifle under 140,000 pounds annually, as compared with approximately 150,000 pounds under the act of 1894, and about 100,000 under the act of 1890. Only a slight reduction (cent per pound) was made in the duty by the act of 1909. The statistics of imports show so great fluctuation that it is difficult to trace any effect of the tariff change. In the act of 1913 the specific rate was changed to an ad valorem duty of 20 per cent. As can be seen from the equivalent rates on page 9, this change in the character of the duty did not greatly affect the amount. The valuation per pound was from 16 to 20 cents, so the reduction was only from 43 to 33 or 4 cents. COMPETITIVE CONDITIONS. The domestic manufacturers of chrome colors are not handicapped to any large degree by the very slightly greater cost of bichromate in the United States as compared with foreign countries. They are apparently on an even more nearly equal footing with respect to all other raw materials that go into the manufacture of chrome yellow, chrome orange, and chrome red. The raw materials represent approximately 70 per cent of the cost of the finished product. Under prewar conditions the raw material cost was almost evenly divided between the cost of lead acetate and the cost of the chromate in the case of chrome yellow containing no excess of lead. Naturally, when the normal chromate is mixed with additional lead salts, as usually happens, the cost of lead salts forms the most important item in the cost. As regards the manufacture of chrome green, however, the domestic manufacturer is in a less advantageous position. Assuming that he can, under existing conditions, meet foreign competition in the home market for chrome yellow and orange, he has a less opportunity in the case of green because the latter color also contains Prussion blue. The manufacture of Prussian blue prior to the war was handicapped by the relatively higher cost of raw material in the United States as compared with Germany, France, and Great Britain. That this situation existed is evidenced by the fact, already referred to above, that most of the chrome colors imported into the United States have consisted of chrome green. Chrome yellow and chrome orange and green-Production in United States-Official source 2 Chrome yellow. 3 Chrome orange and green. 1 Included with "other dry colors." Chrome yellow, chrome green, and all other chromium colors in the manufacture of which lead and bichromate of potash or soda are used, in pulp, dry, or ground in or mixed with oil or water-Imports for consumption-Revenue. 1897... 48 Chrome colors, etc.-Rates of duty. Tariff classification or description. Rates of duty, specific and ad valorem. 25 per cent ad valorem. Colors and paints, including lakes, whether dry or mixed, or ground In pulp or mixed with water, 44 cents per pound on the material con- Chrome yellow, chrome green, and all other chromium colors in which Do. 3 cents per pound. Chrome yellow, chrome green, and all other chromium colors in the 4 cents per pound. 1909.... 46 Chrome yellow, chrome green, and all other chromium colors in the 43 cents per pound. 1913.... 54 COURT AND TREASURY DECISIONS. 20 per cent ad valorem. A green paint composed of sesquioxide of chromium was held dutiable as chrome green (G. A. 1621, T. D. 13200, of 1892), so was so-called Blaugrun or Guignet's green, a dark bluish-green pigment in the condition of paste (G. A. 4591; T. D. 21720, of 1899), but oxide of chromium containing no lead or potassium bichromate, classified as chrome green, was held dutiable as a color (Abstract 37081; T. D. 35020, of 1914). MISCELLANEOUS. CHEMICAL STRUCTURE OF THE CHROME COLORS. Light chrome yellow.-(1) PbSO: PbCrO,; (2) 2PbCO, Pb (OH), : PbCrO1; (3) lead citrate-PbCrO1; (4) lead tartrate-PbCro. Medium chrome yellow.-PbCrO, (neutral lead chromate). Orange chrome yellow.-PbCrO,-n PbO (wherein n is any number less than 1). Chrome red.-As above but wherein n equals 1, and also containing water of constitution. Hence the formula: Pb2(OH),CrO1. PHYSICAL QUALITIES OF THE CHROME COLORS. The chrome colors differ even more markedly in their physical qualities than they do in their chemical constitution. The two extremes are (1) a slimy light yellow precipitate absolutely devoid of crystalline structure and (2) a dense, highly crystalline red precipitate. Practically every variation between these two extremes is possible. This physical as well as chemical variation is a very important complication in the process of manufacture of the chrome colors in solution. Any mechanical operation that assists in the formation of an amorphous precipitate tends to make light shades and vice versa. For example, in the direct process of making chrome orange (i. e., precipitation from solution), a darker shade will be produced from the same proportions of the several reagents, if (1) the solutions are at a boiling temperature; (2) the solutions are comparatively concentrated; (3) the solutions are mixed with a minimum amount of stirring (agitation); and (4) the precipitate is left in the mother liquor for digestion. MANUFACTURE OF CHROME ORANGE. In the preparation of chrome orange according to the reaction 2PbCrO,+2NaOH= PbCrO, PbO. H2O+Na,CrO, the sodium chromate formed is difficult to remove from the darkened product. It is very tenaciously retained, even after repeated washing. The difficulty is, therefore, obviated in many plants by using a chrome yellow containing definite amounts of lead sulphate. The final products in this case will be (1) basic lead chromate (orange chrome), as before, and (2) sodium sulphate instead of chromate. The latter is easily washed out of the product and can be run to waste. The end reaction may be expressed as follows: PbCrO, PbSO +2NaOH = PhCrО ̧· PbO· H2O+Na2SO, The above process is somewhat more expensive than the one based upon the direct production from basic lead acetate with chromate of soda or potash, and the results are more advantageous. The orange chrome obtained is much brighter and exhibits a very smooth and compact fracture and relatively high covering power_properties that are not invariably found in commercial chromes. By adjusting the relative amounts of lead sulphate, chromate, and alkali, shades from the palest yellow to the darkest red can be obtained. No equipment is required beyond that necessary for the production of chrome yellow. The process is not attended by any special difficulties in operation. During the digestion process steam is used for both heating and stirring. SUBSTANCES MIXED WITH LEAD CHROMATE. In addition to the lead salts shown in the tabulation on the preceding page other substances are added to the lead chrome colors. The lead salts, since they are necessary for the production of certain shades, can not be called adulterants. Other adjuncts, however, are generally added with a view of reducing the cost of production. The Fighter shades of chrome can hold a surprising quantity of filler without the shade being affected in the least. Barytes, gypsum, and china clay are the usual "adulterants." Diatomaceous earth (calcined) is occasionally employed. When lead sulphate is the only extender the colors are termed "chemically pure." The darker chromes, because of their more crystalline nature, do not permit the addition of such large amounts of these inert extenders without impairing the color. These adulterants can be and usually are added to the vat liquor immediately after the precipitation of the chromate and are thoroughly incorporated with the color during the washing, filtering. drying, and grinding of the product. The only exception to this is gypsum, which would react with the excess lead acetate. |