Sulfuric acid elemental content

Assay of beryUium metal and beryUium compounds is usuaUy accompHshed by titration. The sample is dissolved in sulfuric acid. Solution pH is adjusted to 8.5 using sodium hydroxide. The beryUium hydroxide precipitate is redissolved by addition of excess sodium fluoride. Liberated hydroxide is titrated with sulfuric acid. The beryUium content of the sample is calculated from the titration volume. Standards containing known beryUium concentrations must be analyzed along with the samples, as complexation of beryUium by fluoride is not quantitative. Titration rate and hold times ate critical therefore use of an automatic titrator is recommended. Other fluotide-complexing elements such as aluminum, sUicon, zirconium, hafnium, uranium, thorium, and rate earth elements must be absent, or must be corrected for if present in smaU amounts. Copper-beryUium and nickel—beryUium aUoys can be analyzed by titration if the beryUium is first separated from copper, nickel, and cobalt by ammonium hydroxide precipitation (15,16). 

An alternative process for opening bastnasite is used ia Chiaa high temperature roastiag with sulfuric acid followed by an aqueous leach produces a solution containing the Ln elements. Ln is then precipitated by addition of sodium chloride as a mixed sulfate. Controlled precipitation of hydroxide can remove impurities and the Ln content is eventually taken up ia HCl. The initial cerium-containing product, oace the heavy metals Sm and beyond have been removed, is a light lanthanide (La, Ce, Pr, and Nd) rare-earth chloride. 

The pyritic sulfur in coal can undergo reaction with sulfate solutions to release elemental sulfur (see Sulfurremoval and recovery). Processes to reduce the sulfur content of coal have been sought (75). The reaction of coal and sulfuric acid has been used to produce cation exchangers, but it was not very efficient and is no longer employed. Efforts have turned to the use of hot concentrated alkaH in a process called Gravimelt. 

Thomas and Hill (16) showed that sulfur dioxide fumigation of alfalfa increased the sulfate content of the leaves. In later work Thomas et al. (H) reported that the pH of alfalfa leaf tissue fluids was lowered 0.3 pH unit after fumigation with sulfur dioxide. Similar responses occur when lemons are incubated in sulfur dioxide gas, or when they are treated with elemental sulfur or with hydrogen sulfide (18). Likewise lemons treated with dilute sulfuric acid gave similar responses. 

Determination of the level of total sulfur in a rubber can give information on the type of cure system used, for example, elemental sulfur plus accelerator or sulfur donor system, etc. The ISO 6528-1 1992 method — Rubber — Determination of total sulfur content — Part 1 Oxygen combustion flask method is often employed. The principle of the method is oxidation by ignition in an atmosphere of oxygen in the presence of hydrogen peroxide, conversion of sulfur to sulfuric acid and determination of the sulfate by titration with barium perchlorate. The method is... 

Contact Sulfuric Acid Process Monsanto, Parsons, Davy Powergas, others Can accept elemental sulfur, or H2S and S02-bearlng streams down to about 5Z sulfur content A double contact/double absorption plant can recover up to 99.8Z of the sulfur fed to it. All sulfur compounds handled... 

Elemental composition Cu 79.88%, O 20.12%. Copper(II) oxide is dissolved in nitric or sulfuric acid and copper content may be determined by AA or ICP spectrometry following appropriate dilution of the acid extract. It may be alternatively analyzed nondestructively by x-ray methods. 

Elemental composition Mn 63.19%, 0 36.81%. The pure oxide may be characterized by x-ray crystallography. The Mn02 content in pyrolusite may be measured by titration. An excess of a standard solution of oxalic acid is added to a solution of Mn02 in sulfuric acid. After all solid Mn02 dissolves, the excess oxalic acid is measured by titrating against a standard solution of potassium permanganate (see Reactions). 

Tellurium metal, its alloys, minerals or the teUurides may be dissolved in warm concentrated sulfuric acid or cold fuming sulfuric acid to form a red color, the intensity of which is proportional to the tellurium content in the substance. When this red solution is poured into water, black elemental tellurium metal precipitates out of solution. Oxidized tellurium does not respond to this test. 

Elemental composition Zn 55.68%, C 20.46%, N 23.86%. A small and measured amount is treated with dilute sulfuric acid. Hydrogen cyanide generated is swept with a purging gas and collected in sodium hydroxide solution. The solution is analyzed for cyanide by a colorimetric method using pyridine-barbituric acid reagent or by cyanide ion-specific electrode (See Hydrogen Cyanide, Analysis). The acid solution may be analyzed for zinc to measure its content in the compound. 

The production of domestic sulfur values (elemental recovered sulfur and the sulfur content of acid) will total about 18 million long tons per year by the year 2000. By region (Petroleum Administration for Defense districts), except for the east coast (PAD I), there will be no deficit areas in the U. S. Major contributors are sour natural gas and the refining of heavier, sour, crude oil. Proximate, scenario dependent sources, are electric utilities and coal-based synfuels. Shale oil, domestic tar sands and heavy oil, and unconventional sources of natural gas will be small suppliers. 

Sulfuric acid from manufacturers 1 and 6 were sent to our laboratory for analysis by a client who had yield problems when using sulfuric acid from manufacturer 1 but no problems with sulfuric acid from manufacturer 6. The total trace element concentration in the sulfuric acid from manufacturer 1 was about four times higher than that from manufacturer 6. Low trace element concentrations were also found in sulfuric acids from U.S. (manufacturer 7) and Japanese (manufacturer 8) manufacturers. Sulfuric acid from manufacturer 9 had the lowest trace metal content. This sulfuric acid was processed through an acid reclaim system and was purer than the unused sulfuric acid put into the reclamation unit. 

Another test method for the determination of mercury in coal (ASTM D-6414) involves (method A) solubilizing of the mercury in the sample by heating the sample at a specified temperature in a mixture of nitric and hydrochloric acids. The acid solutions produced are transferred into a vessel in which the mercury is reduced to elemental mercury. The mercury vapor is determined by flameless cold-vapor atomic absorption spectroscopy. An alternative method (method B) involved solubilization of the mercury by heating the sample in a mixture of nitric acid and sulfuric acid with vanadium pentoxide. The acid solution is then transferred into a vessel in which the mercury is reduced to elemental mercury. The mercury content is determined by flameless cold-vapor atomic absorption spectroscopy. However, mercury and mercury salts can be volatilized at low temperatures, and precautions against inadvertent mercury loss should be taken when using this method. 

The nomenclature reform of the French chemists was of fundamental importance, replacing the old body-spirit terminology with new terms, based on oxygen. The calx was now termed the oxide, and the spirit of vitriol became sulfuric acid. The assumption that oxygen was the acid generator, as its name implied, was flawed, but the systematic nomenclature based on the increase of acidity with increase of oxygen content lived on, e.g. the acidic component of the sulfides, sulfites, and sulfates. The definition of a chemical element as the latest term whereat chemical analysis has arrived ... 

The source of the problem, highly contamined acid drainages from disposal of mineral wastes from coal extraction, has been thoroughly documented. Tables 1, 2, and 3 show the mineralogy, trace element content, and leaching concentrations of the trace elements for a typical coal waste derived from mining high-sulfur Appalachian coal in western Pennsylvania. 

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