Colorimetric Determination of Titanium with Disodium-1,2-dihydroxybenzene- 3,5-disulfonate

Yoe, John H.; Armstrong, Alfred R.

doi:10.1021/ac60002a009

Cited by 144 publications

(48 citation statements)

References 10 publications

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“…1:160000 dilution; a TiO2 precipitate occurs in 3-4 days. Negative interference by fluoride ion on the Ti-Tiron complex occurs when F is 10 p.p.m, or more in the final solution (Yoe and Armstrong, 1947), but the concentration of F was far below this amount, in the diluted H2TiF6 solution. If the concentration of Ti was less than 16"5~ by weight, TiO2 was added in 10 g increments.…”

Section: Methodsmentioning

confidence: 99%

Anatase and Rutile Determination in Kaolinite Deposits

Sayin

Jackson

1975

Clays and clay miner.

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Abstract--Hexafluorotitanic acid (H2TiF6) selectively dissolves kaolinite and most other phyllosilicate minerals of soils and sediments, concentrating free crystalline (Ti, Fe)O2 minerals (partially substituted anatase and rutile) in the residue. A series of H2TiF6 reagents was standardized by analysis of the Ti content and by tests with pure anatase and commercial kaolinites. The Ti in the H2TiF6 solution selected (made from 49% HF + reagent TiO2) was 16.5% by weight as analyzed by the Tiron method. Treatment of pure anatase with the reagent H2TiF6 resulted in a 98% by weight recovery of TiO2 in the residue. The fraction of TiO2 recovered in the residue of commercial Georgia kaolinites was 88-101}/o after treatment with the selected H2TiF6 reagent. Isolates from nine Georgia kaolinite samples with varying amounts of TiOz and Fe203 were examined by X-ray powder diffraction, scanning electron microscopy and elemental analysis. The main constituent of the (Ti,Fe)O2 isolates was anatase for all samples, with minor amounts of coarser rutile and mica from coarser kaolinite. The anatase and rutile isolates contained 74-93% (Ti,Fe)O~ with 0-5-3-1% Fe. The other constituents of the isolates were muscovite of mica (0"3-7~o), quartz (0-9~o) and amorphous relics of vermiculite and/or kaolinite (6-19%). Rutile, muscovite and quartz appear to be detrital but the anatase and relics are probably authigenic. Fine anatase appears to stick on the muscovite flakes as revealed by scanning electron microscopy and heavy liquid data for separation of these two minerals. The (Ti,Fe)Oz isolates from kaolinites which passed with the first magnetic concentrate of anatase were coarse, on the order of a few microns dia., as revealed by the scanning electron microscopy. Those passed with subsequent extensive magnetic concentrates from the same samples were finer. The anatase isolated from kaolinite purified by removal of as much of the impurities as possible by magnetic means was extremely fine, most of the particles being on the order of 0.1 #m dia. More than one third of the total FezO 3 in kaolinites magnetically separated in the first pass was extracted by the citrate-bicarbonate-dithionite treatment after hot NaOH dissolution of 5~74% of the kaolinite, showing that the Fe203 had been mainly associated within the kaolinite. Only 2-6% of the total Fe203 was extracted from magnetically purified kaolinite after 40-50~o of this kaolinite had been dissolved, indicating that most of the Fe is in the anatase and futile fraction.

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Section: Methodsmentioning

confidence: 99%

Anatase and Rutile Determination in Kaolinite Deposits

Sayin

Jackson

1975

Clays and clay miner.

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“…These samples were digested with reagent grade 48% HF in platinum crucibles on a sandbath at 150~ After complete dissolution of the sample, 8 ml of l0 N H2SO4 were added to each crucible and the digest was heated to light fuming on a sandbath at 230~ The contents of the crucible were transferred to a 100-ml volumetric flask, diluted to volume with distilled water, and a suitable aliquot was transferred to a second 100-ml volumetric flask, the acidity being adjusted to approximately 0.4N with 4 N HCI, and then diluted to volume with distilled water. A 5-ml aliquot from this solution was transferred to a 50-ml volumetric flask containing 20ml of pH 4.7 HOAc-NaOAc adjusted to pH 4.7), 5 ml of 4% Tiron (disodium pyrocatechol-3, 5-disulfonate) solution (Yoe and Armstrong, 1947) were added and the solution was diluted to volume with distilled water. The solutions were allowed to stand for 24hr, after which approximately 25 mg of Na~S~O4 were added to each flask to reduce ferric to ferrous iron.…”

Section: Ti Determinationmentioning

confidence: 99%

Titanium as Free Oxide and Substituted Forms in Kaolinites and other Soil Minerals

Dolcater

Syers

Jackson

1970

Clays and clay miner.

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Abstract-Titanium in TiO2 minerals was differentiated from that isomorphously substituted into minerals by the use of dihydrogen hexafluorotitanate (hydrofluotitanic acid, H2TiF6), which selectively dissolved minerals containing substituted Ti 4+, leaving free crystalline TiO2 minerals in the residue. Titanium analyses on the original samples and the residues remaining after H2TiF6 treatment, by both wet chemical (Tiron) and neutron activation methods, indicated that an average of 86 per cent of the titanium in seven kaolinite samples was present in the residual TiOz form (largely anatase), whereas only 28 per cent in two bentonites was present in the TiO2 form. Residual Ti accounted for 100 per cent of the Ti in synthetic anatase and for 92 per cent of the Ti in coarse clay sized futile, the latter value suggesting that about 8 per cent amorphous TiO2 was removed from the mechanically dry ground rutile by the H2TiF6 reagent. The Ti present as residual TiO2 in a variety of other samples ranged from 0 to 100 per cent.

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“…The intensity of the yellow-colored Tiron-titanium complex is unchanged over the pH range 4.3 to 9.6 (Yoe and Armstrong, 1947). Interference due to iron is obviated by reduction of iron (III) to iron (II) and determination of titanium at pH 4.5 (Sandell, 1959).…”

Section: Discussionmentioning

confidence: 95%