Antimony-containing solutions, effect

Figure 8. Effect of glue addition on current efficiency (12) of zinc electrowinning for antimony-containing solutions ((A) 0.0 mg/L Sb (B) 0.04 mg/L Sb and (C)...

Loss of antimony flow. The effect of nickel accumulation on the catalyst has already been reviewed. To offset the effect of metals, an antimony containing solution may be injected into FCCU feed. If you observe a loss in catalyst selectivity, such as a sudden increase in hydrogen in the wet gas, check the antimony pump. 

Another approach has been deactivation of the metals as they form. Thermal deactivation is a possibility, but this is often destructive to the catalyst. One highly successful solution ts to use an additive in the feedstock. Antimony-containing materials, which deposit on the catalyst and effectively passivate the metals, are added to the feed. This has resulted in substantial savings in operations. 

Antimony, by itself, cannot produce any effect upon the human stem, but only as a salt capable of being decomposed by the fluids of the body, especially in the tartarised form, which,. being the most soluble, has properly superseded other forms. According to Orfila, Flandin, Danger, and Milon, the solutions of antimony salts rapidly permeate the animal system and are readily eliminated with the urine. Under certain circumstances the salts of antimony contained in the solutions are deposited in the tissues, especially in the liver, the spleen, and the kidneys. 

Selenium is extracted as diethyldithiocarbamate complex from the solution containing citrate and EDTA [5]. Ohta and Suzuki [6] found that only a few elements, such as copper, bismuth, arsenic, antimony, and tellurium, are also extracted together with selenium. They examined this for effects of hundredfold amounts of elements co-extracted with the selenium diethyldithiocarbamate complex. An appreciable improvement of interferences from diverse elements was observed in the presence of copper. Silver depressed the selenium absorption in the case of atomisation of diethyldithiocarbamate complex, but the interference of silver was suppressed in the presence of copper. The atomisation profile from diethyldithiocarbamate complex was identical with that from selenide. 

Tin and lead are the most rapid precipitants of metallic silver from the nitrate cadmium, zinc, copper, bismuth, and antimony axe moro slow in their operation, and mercury still more tardy. Chloride of silver is rapidly reduced by most of the metals which form soluble chlorides, such as zinc, iron, cadmium, cobalt, and arsenic. Zinc, copper, and arsenic rapidly reduce the ammoniacal solution of oxide of silver. Of all the metallic precipitants, zinc and cadmium are the most effective but when zinc or antimony aro used, the separated silver contains these metals. 

Preparation.—The main source of rubidium compounds is the residual mother-liquor obtained in the extraction of potassium chloride from carnallite. The solution contains rubidium-carnallite, RbCl,MgCI2, a substance transformed by addition of aluminium sulphate into rubidium-alum, RbAl(S04)8,12H20. Separation from the potassium and caesium salts also present is effected by fractional crystallization of the alum,8 of the chloroplatinate 8 Rb2PtCl8, of rubidium-iron-alum,4 and of the double chloride with stannous chloride5 or with antimony trichloride.6... 

In an alternative procedure the decomposition is effected by the use of concentrated sulphuric acid and potassium sulphate, followed by the addition of 30% hydrogen peroxide. The solution is adjusted to 6 N with respect to hydrochloric acid and antimony is extracted with diisopropyl ether. Colour is developed by the addition to the ether phase of 0.02% Rhodamine B in IN hydrochloric acid . Compounds containing trivalent antimony which are unstable in oxygen or moist air may be stabilized by exposure to sulphur for 8-48 h in vacuo and the resulting compounds are examined by pyrolysis . 

Christie et al. (53) reported data on the catalytic performance which may also be related to the solid state properties of tin-antimony oxide. A material containing 6% antimony in a batch reactor showed maximized specific activity and low selectivity toward propylene. Above 10% antimony the selectivities exceeded 60% and increased little with increasing antimony content. It is interesting that the " Sn Mossbauer parameters (17) showed similar trends, which were attributed to effects in the solid solution. 

The effect of iron, nickel, and vanadium on the signals obtained from antimony solutions in 50% sulfuric acid was investigated. Antimony signals from solutions containing 15 ng Sb/ml and 28.2 /xg/ml each of iron, nickel, and vanadium were suppressed by 14% compared with those obtained when no metals were added. Consequently, the method of standard additions was adopted to compensate for interferences of this type. 

Freshly distilled antimony trichloride (3t- grams), chlorobenzene (510 grams) and xylene (400 c.c.) are mixed, and the solution is divided equally between the reservoir and the reaction vessel. In the latter case, 600 c.c. of xylene are added as diluent. Sodium (210 grams), covered with 500 c.c. of xylene, is placed in the sodium container, and the preparation of the stibine effected at 70° C. After filtering off in the Bornett press the dark grey, granular sodium chloride, the filtrate, on distilling up to 220° C., leaves a residue of triphenylstibine (M.pt. 4.8° to 50° C.). 

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