Carbon sulfur analyzer

The primary components of automobiles are steel or aluminum, so one of the fastest methods for analysis with the least amount of preparation of the sample is the emissions spectrometer. From Table 2.1, we can see that a carbon sulfur analyzer, such as a Leco, or atomic absorption spectrophotometer scanning electron microscopy (SEM) x-ray and GC-MS are also used for this type of analysis. However, an emissions spectrophotometer is most often used because of its lack of sample preparation. Again, it is not our attempt here to go into great detail on each method. Within an automotive analytical laboratory, however, speed is a priority so that a material is identified and classified rapidly. An emissions spectrophotometer is such an instrument. 

Like cements, the elemental composition is determined by XRF or AAS techniques. The XRF bead is made using lithium tetraborate at 1050°C. Sulfide content cannot be determined by XRF. Sulfite, SO3 , and sulfate, S04 , are safely analyzed by XRF. Na2C03 -I- K2CO3 fusion is carried out for Ca, Mg, Fe, and A1 analysis by AAS. Lanthanum chloride is used as a sulfate interference suppressant. Gravimetric sulfate determinations are also carried out by precipitation as barium sulfate. The Leco Carbon-Sulfur Analyzer can also be used for quality control purposes. The fluoride is determined by XRF or a pyrohydrolysis method. The measurement of particle size distribution is carried out in a manner similar to that for cements and clays. 

X-ray microprobe, neutron activation, and electro-analytical methods have been mentioned in the literature. For irons and steels the carbon and sulfur level is determined by a Leco carbon/sulfur analyzer or similar in addition to the elemental analysis. Similarly, the hydrogen content is measured in aluminum by a hydrogen analyzer. Table 4 summarizes the elements determined for various metals and alloys. 

Samples are oven dried at 100°C after which they are weighed in order to measure water content. TC and TS are measured by introducing dried samples to the Carbon Sulfur (CS) automatic analyzer (Eltra CS-800) instrument. Subsequently, 2g of each sample is introduced in preweighed high temperature porcelain crucibles and is introduced to a high temperature muffle furnace for the removal of carbonates at 900C. Samples are then introduced to the CS automatic analyzer for measurement of organic residual carbon. 

The presence of high-molecular weight p-sulfur with chain structure seemed improbable since the sulfur was not extractable with boiling toluene. The p-sulfur is known to convert to the soluble ring structure (Sg) rather rapidly at 115°. Wibaut (119) thought the formation of a carbon-sulfur complex similar to the surface oxide formed with oxygen very likely. He was not able, however, to analyze definite surface groups. Hofmann and Nobbe (123) established that the sulfur content was dependent on the specific surface area. Enoksson and Wetterholm (124) confirmed by X-ray diffraction that no crystalline sulfur was present in exhaustively extracted charcoal with 13% sulfur content. 

Figure S. Carbon sulfur ratios (wt/wt) in three cores from the north basin of Little Rock Lake. Carbon and sulfur concentrations were determined by LECCO analyzers. Cores were collected at 5 m (NB-5), 7 m (NB-7), and 9 m (NB-9). The two shallow cores are from epilimnetic sites at which the overlying water remains oxic throughout the year. The bottom water at NB-9 is anoxic in late summer.

Lopez-Gonzalez et al. [218] also failed to cite the study by Humenick and Schnoor [216], but they analyzed in some detail the effect of carbon-oxygen and carbon-sulfur surface complexes on the uptake of mercuric chloride, which is very weakly ionized in aqueous solution. (The effectiveness of sulphurized carbons in removing mercury from air or water streams had been demonstrated earlier by Sinha and Walker [219], Humenick and Schnoor [216], and more recently by G6mez-Serrano and coworkers [208].) Their key results are summarized in Fig. 9. There was a noticeable uptake decrease when the activated carbons were oxidized with H Oi (AO). This decrease was not due to a reduction in the surface area and is contrary to the behavior of cationic metallic species, whose uptake is typically enhanced as a consequence of a lower pHp/x of the oxidized carbon. Upon subsequent heat treatment in helium at 873 K (A-873), the adsorption ca-... 

There may be many types of chemical species of interest for a given test. The most common types of analyzers associated with combustion equipment are contained in a rack or cabinet as seen in Figure 33.4. The typical analyzers found in one of these cabinets are a paramagnetic oxygen analyzer, infrared absorpfion carbon monoxide analyzer, UBH analyzer, and a chemiluminescent nitrogen oxide analyzer. Commercial sulfur dioxide analyzers based on infrared or ultraviolet absorption are also readily available to fit into one of these racks. The... 

In general, nitrogen and carbon are analyzed together from the same sample, while sulfur is analyzed separately. The oxidation and reduction tubes can be packed with different materials for different applications [2,32]. 

Internal surfaces were covered with a tan deposit layer up to 0.033 in. (0.084 cm) thick. The deposits were analyzed by energy-dispersive spectroscopy and were found to contain 24% calcium, 17% silicon, 16% zinc, 11% phosphorus, 7% magnesium, 2% each sodium, iron, and sulfur, 1% manganese, and 18% carbonate by weight. The porous corrosion product shown in Fig. 13.11B contained 93% copper, 3% zinc, 3% tin, and 1% iron. Traces of sulfur and aluminum were also found. Near external surfaces, up to 27% of the corrosion product was sulfur. 

Gases analyzed include hydrocarbons, carbon monoxide, carbon dioxide, sulfur dioxide, sulfur trioxide, nitrogen oxides (also nitrous oxide, N2O), hydrogen chloride, hydrogen cyanide, ammonia, etc. 

On evaporating the alcoholic solution under reduced pressure from a water bath held at 50-60° (Note 6) the residue weighs about 540 g. A mixture of 600 cc. of absolute alcohol and 10 cc. of concentrated sulfuric acid (Note 7) is then added. The mixture is then heated on the water bath under a reflux condenser for three hours. The excess of alcohol and some of the water formed are removed by distillation under reduced pressure and the residue again heated for two hours with 300 cc. of absolute alcohol and an additional 4 cc. of concentrated sulfuric acid. The alcohol is removed by distillation under reduced pressure, and when the ester has cooled to room temperature, the sulfuric acid is neutralized with a concentrated solution of sodium carbonate the ester (upper layer) is separated, and the aqueous solution extracted with ether, or preferably benzene about one-tenth of the yield is in the extract. The combined products are placed in a i-l. distilling flask and distilled under reduced pressure after the solvent and alcohol and water have been removed. The ester is collected at 94-990, chiefly at 97-98°/x6 mm. (Note 8). The yield of a product analyzing about 97-98 per cent ethyl cyanoacetate amounts to 474-492 g. (77-80 per cent of the theoretical amount) (Note 9). 

The iron formed in a blast furnace, called pig iron, contains impurities that make the metal brittle. These include phosphorus and silicon from silicate and phosphate minerals that contaminated the original ore, as well as carbon and sulfur from the coke. This iron is refined in a converter furnace. Here, a stream of O2 gas blows through molten impure iron. Oxygen reacts with the nonmetal impurities, converting them to oxides. As in the blast furnace, CaO is added to convert Si02 into liquid calcium silicate, in which the other oxides dissolve. The molten iron is analyzed at intervals until its impurities have been reduced to satisfactory levels. Then the liquid metal, now in the form called steel, is poured from the converter and allowed to solidify. 

---