Sulfate method

Several continuous digestion processes have been proposed [2.26]. A proven method is to continuously feed a mixture of ilmenite and water together with the add 

Dissolution and Reduction. The cake obtained by digestion is dissolved in cold water or in dilute acid recycled from the process. A low temperature must be maintained ( 85 °C) to avoid premature hydrolysis, especially with the product from ilmenite. Air is blown in to agitate the mixture during dissolution. With the ilmenite product, the Ti02 concentration of the solution is 8-12 wt%, and with the slag product between 13 and 18 wt%. 

The trivalent iron is hydrolyzed together with the titanium compounds, and adheres to the titanium oxide hydrate. Therefore all the Fe3+ is reduced to Fe2+ by scrap iron during dissolution of the ilmenite product, or immediately afterwards. Reoxidation of the iron during subsequent processing is prevented with Ti3 + which is obtained by reducing a small part of the Ti4+. Alternatively, reduction of Ti4+ to Ti3+ can be carried out in part of the solution under optimized conditions this 

With both ilmenite and titanium slag, mixed digestion can be carried out in which the Ti3+ content of the slag reduces all the Fe3+ to Fe2 +. The dissolved products obtained from the separate digestion of ilmenite and titanium slag can also be mixed [2.28], [2.29], 

The iron sulfate is used in water purification, and as a raw material for the production of iron oxide pigments. Alternatively, it can be dehydrated and thermally decomposed to give iron(III) oxide and sulfur dioxide. 

The titanium-bearing raw materials are dried to a moisture content of 0.1%. Drying is mainly intended to prevent heating and premature reaction on mixing with sulfuric acid. The raw materials are ground in ball mills to give a mean particle size of 40 pm. 

Raymond mill or sf-eam jet mill Coarse size reduction, wet tubular mill 

Several continuous digestion processes have been proposed [2.24]. A proven method is to continuously feed a mixture of ilmenite and water together with the acid into a double-paddle screw conveyor. After a relatively short dwell time ( 1 h), a crumbly cake is produced [2.25]. This process utilizes a more limited range of raw materials than the batch process because they need to be very reactive. 

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Although gravimetric methods have been used traditionally for the determination of large amounts of tellurium, more accurate and convenient volumetric methods are favored. The oxidation of teUurium(IV) by ceric sulfate in hot sulfuric acid solution in the presence of chromic ion as catalyst affords a convenient volumetric method for the determination of tellurium (32). Selenium(IV) does not interfere if the sulfuric acid is less than 2 N in concentration. Excess ceric sulfate is added, the excess being titrated with ferrous ammonium sulfate using o-phenanthroline ferrous—sulfate as indicator. The ceric sulfate method is best appHed in tellurium-rich materials such as refined tellurium or tellurium compounds. 

Although widely used in the past and still used in special cases, the industrial sulfation with chlorosulfonic acid presents several problems which have caused the decline of this technique in favor of the more advantageous sulfation method with sulfur trioxide. These problems consist of evolution of the highly corrosive hydrogen chloride, heat transfer characteristics of the reaction, and the comparatively high level of chloride ion in the sulfated product compared with alcohol and alcohol ether sulfates obtained with sulfur trioxide. 

Some properties of the rock used in this study were measured The cation exchange capacity (cec) was determined by the barium sulfate method as described by Mortland and Mellor (33). Surface area was measured by using a Digisorb Meter (Micromeritics Instrument Corporation) through nitrogen adsorption. Estimation of mineral composition and indentification of the rock were performed by X-ray diffraction. 

Ceric ammonium sulfate, 5 674 Ceric fluoride, 5 674 Ceric hydroxide, 5 676 Ceric oxide, 5 670, 675 Ceric rare earths (RE), 74 631 Ceric sulfate, 5 674 Ceric sulfate method, for tellurium determination, 24 415 Cerium (Ce), 5 670-692 74 630, 63 It, 634t. See also Cerium compounds analysis, 5 679-680 color, 7 335... 

Salas-Solano, O., Tomlinson, B., Du, S. B., Parker, M., Strahan, A., and Ma, S. (2006). Optimization and validation of a quantitative capillary electrophoresis sodium dodecyl sulfate method for quality control and stability monitoring of monoclonal antibodies. Anal. Chem. 78(18), 6583-6594. 

Afore Nitro group can also be detd by Titanous Sulfate Method, which is offered as an alter-... 

It can also be detd by the ferrous sulfate method (which gives ANN). This method eliminates detn of sulfuric acid by evapn, because it can be detd by difference knowing total acidity and nitric acid content... 

Clarification by removal of casein with such agents as calcium chloride, acetic acid, cooper sulfate, or rennin has often been employed to obtain a serum more suitable for refractometric measurements. Obviously the composition, and hence the refractive index, of such sera will depend on the method of preparation. Furthermore, some of the serum proteins may be precipitated with the casein by some of the agents used, particularly if the milk has been heated. Refractive index measurements of such sera are not generally considered as satisfactory as freezing point measurements for detection of added water (David and MacDonald 1953 Munchberg and Narbutas 1937 Schuler 1938 Tell-mann 1933 Vleeschauwer and Waeyenberge 1941). Menefee and Overman (1939) reported a close relation between total solids in evaporated and condensed products and the refractive index of serum prepared therefrom by the copper sulfate method. Of course, a different proportionality constant would hold for each type of product. 

Rapid method for the detn of N content in NC s by the ferrous ammonium sulfate method, using as the "standard a NC of known N content, previously detd by nitrometer) 19)K.Thinius, Farbe u Lack 56, 3-9(1950) CA 44, 4817 (1950)(Luminescence analysis for indentification of NC, cellulose, cellulose acetate, ethylcellulose methylcellulose) 20)L.B.Genung, AnalChem 22, 403(1950) CA 44, 6l21(1950)(Detn of N content by nitrometer) 21)R.Leclercq J. 

International Standard Organization. 2006. Water quality. Determination of sulfate. Method by continuous flow analysis (CFA). ISO 22743. International Organization for Standardization, Case Postale 56, CH-1211, Geneva 20 Switzerland. 

Kirci, H., Bostanci, S., and Yalinkilic, M. K., A new modified pulping process alternative to sulfate method alkali-sulfite-antraquinone-ethanol (Asae). Wood Sci Technol 1994, 28 (2), 89-99. 

Protoporphyrin and its derivatives, because of their labile vinyl substituents, are susceptible to acid-catalyzed hydration. For this reason aqueous solutions should be avoided in the preparation of protoporphyrin dimethyl ester from protohemin, and subsequent reinsertion of the iron. Thus the direct esterification of protohemin under basic conditions appears to be the method of choice. More stable porphyrins such as H2oep are most conveniently prepared by the direct insertion of iron(lll) ion using the iron(III) chloride method5 the resultant Fe(IIl) (oep)Cl can be separated directly from the reaction medium as shining purple crystals. However, this method fails to give successful results with protoporphyrin derivatives. In general, the iron (II) sulfate method is the mildest and should be used for all prophyrins unless one is certain that the more rapid alternatives [boiling DMF with iron(II) chloride, or preferably the more stable iron(II) perchlorate] will have no ill effect on the peripheral substituents. 

It can also be detd by the ferrous sulfate method (which gives ANN). This method eliminates detn of sulfuric acid by evapn, because it can be detd difference knowing total acidity and nitric acid content Nitroso can be detd by titrating a sample of MA drowned in w (without loss of fume with std KMnO, solo until the appearance of permanent pink coloration 3HNOSO4+2KMnO + 2H,0 K,S04 + 2MnS04 + 3HNO, + 2H,S04... 

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