Iron content

We used a two-tailed test. Upon rereading the problem, we realize that this was pure FeO whose iron content was 77.60% so that p = 77.60 and the confidence interval does not include the known value. Since the FeO was a standard, a one-tailed test should have been used since only random values would be expected to exceed 77.60%. Now the Student t value of 2.13 (for —to05) should have been used, and now the confidence interval becomes 77.11 0.23. A systematic error is presumed to exist. 

The amount of Fe in a 0.4891-g sample of an ore was determined by a redox titration with K2Cr20y. The sample was dissolved in HCl and the iron brought into the +2 oxidation state using a Jones reductor. Titration to the diphenylamine sulfonic acid end point required 36.92 mL of 0.02153 M K2Cr20y. Report the iron content of the ore as %w/w FeyOy. 

Industrial Analysis UV/Vis molecular absorption is used for the analysis of a diverse array of industrial samples, including pharmaceuticals, food, paint, glass, and metals. In many cases the methods are similar to those described in Tables 10.6 and 10.7. For example, the iron content of food can be determined by bringing the iron into solution and analyzing using the o-phenanthroline method listed in Table 10.6. 

The flow sheet can be tailored to the specific characteristics of the ore. The unit operations can be combined or modified in many ways to upgrade the total iron content in the ore from levels as low as 20—38% up to levels of 65—70%. 

Metallization is defined as the percent of total iron in the DRI which has been converted to metallic iron. For example, DRI having a total iron content of 92% and a metaUic iron content of 85%, has 92.4% metaUization. 

The soft weathered granodiorite and pegmatites can vary in color from white to pink, depending on iron content and type of feldspar present. The mica content of these deposits ranges from 6—15% and varies in particle size from tiny (<44 specks to thumbnail size. Large books of mica that weigh several hundred kilograms have been found in these deposits. 

Aluminum obtained by electrolysis of cryoHte baths contains iron [7439-89-6] and siUcon [7440-21-3] as impurities. Iron content may vary from 0.05 to 0.4% and siUcon from 0.05 to 0.15% depending on the raw materials and the age and condition of the reduction cell. Primary aluminum metal also contains small, usually not to exceed 0.05% in total, amounts of many other elements. Some of these trace impurities are Cu, Mn, Ni, Zn, V, Na, Ti, Mg, and Ga, most of which are present in quantities substantially below 100 ppm. 

Typically, ore bodies are relatively low in iron content. Iron minerals are finely divided in a gangue matrix. Wet grinding is usually required to Hberate the iron minerals, although some beach sands may have Hberated iron mineral values. Wet dmm separators are limited to the treatment of material <10 mm. The magnetic dmm separators appHed are usually related to the grinding circuit required to Hberate the iron mineral, and are typically designated by appHcation as cobbers, roughers, or finishers. 

Finishers. Magnetic finishing dmms are designed to produce the highest possible iron content in the concentrate. Typically, the feed size has been reduced to a nominal size of —74 fim (—200 mesh) or —44 fim (—325 mesh) in a ball mill circuit. The feed tank and feed arrangement of the finisher separator is usually of the semicountercurrent design. The objective is to disperse the feed particles in order to obtain maximum rejection of nonmagnetic particles. Both 762 and 914 mm dia dmms have been used in finisher appHcations. Dmm covers frequendy are not used in finisher constmction because of the material size. 

ThioglycoHc acid can be identified by its in spectmm or by gas chromatography. Most of the by-products and self-esterification products are also detected by liquid chromatography, eg, thiodiglycolic acid, dithiodiglycolic acid, linear dimers, and polymers. Iron content can be assayed by the red sensitive complex of 1,10-phenanthroline [66-71-7] and ferrous ion of a mineralised sample. Ferric ion turns an aqueous ammonia solution deep red-violet. 

The resultant slag, a complex mixture of titanates, may contain 70—85% Ti02- The slag route is particularly useful when ilmenite is closely associated with haematite, from which it cannot economically be separated mechanically. Because the iron content of the slag is low, its use reduces the quantity of iron sulfate in the Hquid effluent of sulfate process plants. Slag used as a feedstock for TiCl production must be low in magnesium and calcium. A variety of other ilmenite beneficiation or synthetic mtile processes have been pursued, primarily to provide alternative chloride process feedstocks. Low grade ilmenite... 

With respect to magnetic properties, the intrinsic magnetic susceptibiHty of pure chrysotile is very weak. However, the presence of associated minerals such as magnetite, as weU as substitution ions (Fe, Mn), increases the magnetic susceptibiHty to values around 6 x 10 m /kg. With amphiboles, the magnetic susceptibiHty is much higher, mainly because of the high iron content typically, amosite and crocidoHte exhibit susceptibiHty values of 100 and 75 X 10 m /kg, respectively (23). 

The final product has a low ash and/or low iron content achieved by raw material selection or special processiag. 

Korea. More graphite is mined on the Korean peninsula than any other region in the world, except China. Geologists estimate the reserves of both flake and amorphous, but predominantly amorphous, graphite on the order of millions of tons. The iron content of Korean graphite is low and the ash is a distinctive white. 

Special purpose and blended Portland cements are manufactured essentially by the same processes as ordinary Portland cements but have specific compositional and process differences. White cements are made from raw materials of very low iron content. This type is often difficult to bum because almost the entire Hquid phase must be furnished by calcium aluminates. As a consequence of the generally lower total Hquid-phase content, high burning-zone temperatures may be necessary. Past cooling and occasionally oil sprays are needed to maintain both quaHty and color. 

The acid may be shipped in tank cars, tank tmcks, iso-tainers or dmms via common carrier (40). The shipping ha2ard class is Corrosive Material, the DOT labels and placards required are Corrosive and Poison. The UN number is 1754. When iron content and color are not of concern, the acid may be stored and shipped in steel equipment. The iron content is generally 25—50 ppm and the color is pale yellow to amber. 

The molecular absoi ption spectra, registered at a lower temperature (e.g. 700 °C for iodide or chloride of potassium or sodium), enable one to find the absorbance ratio for any pair of wavelengths in the measurement range. These ratios can be used as a correction factor for analytical signal in atomic absoi ption analysis (at atomization temperatures above 2000 °C). The proposed method was tested by determination of beforehand known silicon and iron content in potassium chloride and sodium iodide respectively. The results ai e subject to random error only. 

The stabilised nitrate may then be bleached with sodium hypochlorite, centrifuged to remove much of the water in which the polymer has been slurried and dehydrated by displacement with alcohol while under pressure in a press. It is interesting to note that in these processes approximately 35 000 gallons (160000 litres) of water are used for every ton of cellulose nitrate produced. Control of purity of the water is important in particular the iron content should be as low as 0.03 parts per million since iron can adversely affect both the colour and heat stability of the polymer. 

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