Ammonium sulfate 90 percent

Cyclohexanone oxime is converted quantitatively to caprolactam by Beckmann rearrangement in the presence of oleum, which is of sufficient strength to consume the several percent water in the molten oxime. The reaction mass is neutralized with aqueous ammonia to a cmde caprolactam layer and a saturated solution of ammonium sulfate. Approximately 1.5 kg of the total 4.4 kg ammonium sulfate per kilogram of caprolactam is produced in this step. Purification is by multistage vacuum crystallization from aqueous solution in neatly quantitative yield. 

FIGURE 3-5 Hourly variatioiis of secondary aerosol organics, nitrates, sulfates, and ammonium as percent of total aerosol. Pasadena, Califixnia, July 25, 1973. Reprinted with permis from Grosjean and Friedlandn. ... 

Results For the St. Louis data, the target transformation analysis results for the fine fraction without July Uth and 5th are given in table 6. The presence of a motor vehicle source, a sulfur source, a soil or flyash source, a titanium source, and a zinc source are indicated. The sulfur, titanium and zinc factors were determined from the simple initial test vectors for those elements. The concentration of sulfur was not related to any other elements and represents a secondary sulfate aerosol resulting from the conversion of primary sulfur oxide emissions. Titanium was found to be associated with sulfur, calcium, iron, and barium. Rheingrover ( jt) identified the source of titanium as a paint-pigment factory located to the south of station 112. The zinc factor, associated with the elements chlorine, potassium, iron and lead, is attributed to refuse incinerator emissions. This factor could also represent particles from zinc and/or lead smelters, though a high chlorine concentration is usually associated with particles from refuse incinerators ( ). The sulfur concentration in the refined sulfate factor is consistent with that of ammonium sulfate. The calculated lead concentration in the motor vehicle factor of ten percent and a lead to bromine ratio of about 0.28 are typical of values reported in the literature (25). The concentration of lead in... 

Evidence was also obtained for a non-cytochrome nitrosamine demethylase. This material was best obtained from "pH 5 enzyme" supernatant (25) by precipitation in 33 percent ammonium sulfate. This preparation requires NADPH but in contrast to cytochrome P-450 enzymes (26), it is not inhibited by carbon monoxide. 

Satonaka and Ito (53) obtained reduced smoke from fir and oak treated with either ammonium sulfate or diammonium phosphate, or with the commercially used formulations pyresote or minalith. (Pyresote consists of zinc chloride 35 percent, ammonium sulfate 35 percent, boric acid 25 percent, and sodium dichromate 5 percent. Minalith consists of ammonium sulfate 60 percent, diammonium phosphate 10 percent, boric acid 20 percent, and borax 10 percent.) They also obtained reductions in carbon monoxide and carbon dioxide levels compared to the untreated wood with each of the four treatments at the two pyrolysis temperatures employed, 400°C and 700°C. 

Zinc chloride will add considerably to the equilibrium moisture content of wood in the range of 30 to 80 percent relative humidity (8). Ammonium sulfate will add at relative humidities exceeding 65 percent, and borax and boric acid will attract water at lower humidities. Phosphate salts affect hygroscopicity mostly when relative humidity exceeds 80 percent (58). 

In hardwood plywood, the glue mix is typically formed by adding water and soft wheat flour at rather high proportions with a minor addition of filler, such as nut shell flour to the urea-formaldehyde resin. Urea-formaldehyde resins are usually shipped in 60 - 65 percent non-volatile solids form. Acid salts such as ammonium sulfate are added to increase the rate of cure of the urea-formaldehyde resin when under pressure and subsequently heated in hot presses. Some acid salts cure the urea-formaldehyde sufficiently well under ambient "cold" press conditions. It is evident this type of plywood would be oriented toward interior use such as furniture. If water-proof type bonds are required of hardwood plywood, then melamine-formaldehyde resins are used in similar mix form but with higher resin solids... 

World ammonia capacity increased by nearly 14 percent from 1984 to 1996 and capacity for urea, the primary downstream nitrogen product, increased by 45 percent. The increases were due primarily to (1) a desire by some major importing countries to become more self-sufficient and (2) the construction of export-oriented capacity in the Middle East and in the former Soviet Union. Ammonium nitrate capacity declined by 2 percent from 1984 to 1996 and ammonium sulfate capacity declined by 8 percent.35 Ammonium phosphate capacity increased by 9 percent during this time. 

Trade is an important component of the world nitrogen industry, and trade in each of the nitrogen products analyzed (ammonia, urea, ammonium nitrate, ammonium sulfate, and ammonium phosphates) increased substantially between 1986 and 1998. The percentage of production that is traded internationally varies from 10 percent for ammonia up to 40 percent for ammonium phosphates.35... 

Caprolactam. Caprolactam is used principally in the production of nylon-6 fibers. In the production of caprolactam, ammonia is used to maintain a reaction pH of 7 in one step, and in another step it is used to neutralize sulfuric acid. Both of these steps result in the production of a low-grade ammonium sulfate fertilizer. In the classical process 5 kg of (NH4)2S04 are produced per kilogram of caprolactam. In 1992 about 33 percent of... 

Assay With the aid of about 25 mL of water, transfer about 125 mg of sample, accurately weighed, into a 300-mL Erlen-meyer flask. Add 50.0 mL of 0.5 N potassium dichromate, mix, then carefully add 100 mL of sulfuric acid, and heat to boiling. Remove the mixture from the heat, allow it to stand at room temperature for 15 min, cool it in a water bath, and transfer it into a 250-mL volumetric flask. Dilute almost to volume with water, cool to 25°, then dilute to volume with water, and mix. Titrate a 50.0-mL aliquot with 0.1 iV ferrous ammonium sulfate, using 2 or 3 drops of orthophenanthroline TS as the indicator, and record the volume required, in milliliters, as S. Perform a blank determination (see General Provisions), and record the volume of 0.1 N ferrous ammonium sulfate required, in milliliters, as B. Calculate the percent cellulose in the sample by the formula... 

Transfer 50 mL of filtrate to a 250-mL flask. Add 2 mL of 6 N nitric acid, 5 mL of nitrobenzene, and 10 mL of standardized 0.1 N silver nitrate solution. Shake the flask until the silver chloride coagulates. Prepare a saturated solution of ferric ammonium sulfate, and add just enough concentrated nitric acid to discharge the red color add 1 mL of this solution to the 250-mL flask to serve as the indicator. Titrate with 0.1 N ammonium thiocyanate solution that has been standardized against the silver nitrate solution until the color persists after shaking for 1 min. Calculate the weight percent of sodium chloride, P, by the equation... 

Prepare a plot of percent GOT recovered versus percent ammonium sulfate saturation using the data from tubes 2 to 7 with the use of the following equation ... 

Determine the highest percent ammonium sulfate saturation that gave less than 20% GOT recovered. This will be a good percent ammonium sulfate saturation to use for the first cut on Day 3 (when the bulk of the GOT is still soluble). Next, determine the lowest percent ammonium sulfate saturation that gave more than 80% GOT recovered. This will be a good percent ammonium sulfate saturation to use for the second cut on Day 3 (when the bulk of the GOT will precipitate out of solution). This information will he critical for the experiment performed on Day 3, so these calculations must he completed prior to the beginning of the next experiment. 

Finally, the quantity of ammonium sulfate added must be considered. A number of methods have been proposed to express the quantities of salt added. Figure 10-6 depicts an approach based upon the degree of saturation. At 25 C a saturated solution of ammonium sulfate is 4.1 M in ammonium sulfate (767 g of salt/liter of water). The table indicates the amount of ammonium sulfate that must be added per liter of solution, either free of ammonium sulfate or at some initial concentration, to yield any of the final concentrations listed. Concentrations shown are in terms of percent saturation at 25°C. Since the solubility of ammonium sulfate does not decrease significantly as the temperature drops (3.9M at 0°C), these values are useful regardless of the temperature. If saturated solutions of ammonium sulfate are used the amount to be added may be calculated using the equation... 

ProteTns are often purified by differential precipitation with neutral salts. Ammonium sulfate is the most common salt used for this purpose, although occasionally NaCl is used. The concentration of ammonium sulfate used to salt out proteins is almost always expressed in terms of percent saturation."... 

A crude cell-free extract of skeletal muscle contained 32 mg orotein/ml. Ten microliters of the extract catalyzed a reaction-aJL rate of. mole/min ) under standard optimum assay conditions, (gifty millilitei ot qhe extract were fractionated by ammonium sulfate precipitation. The fraction precipitating between 20% and 40% saturation was redissplved in 10 ml. This solution was found to contain 50 mg protein/ml. Ten microliters of this purified fraction catalyzed the reaction ata rate of 0 65 mole/min. Calculate (a) the percent recovery of the enzyme in the purified fraction, and (b) the degree of purification obtained by the fractionation (the purification factor). 

The table gives the milliliters of saturated ammonium sulfate solution to be added to one liter of solution to produce the desired change in percent saturation. The volume changes on mixing are negligible. The pH of a saturated ammonium sulfate solution is about 5.5. The pH can be adjusted to 7 by adding a few drops of concentrated NH4OH. 

Initial concentration of ammonium sulfate in the preparation (percent saturation)... 

The reactor exit gas is air-cooled to 200°C and then passes to a quench scrubber (B) through which an aqueous solution containing ammonium sulfate 30 wt percent and sulfuric acid 1 wt percent is circulated. The exit gas temperature is thereby reduced to 90°C. 

A measured portion of about 50 ml of the standard ceric ammonium nitrate solution is mixed with 25 ml of dilute perchloric acid in a 250-ml beaker and cooled in an ice bath to about 5°C. A known weight (about 0.65 g) of dry lead azide in a 1 -ml weighing bottle or porcelain crucible is dropped into the cooled solution and covered immediately with a watch glass in order to prevent loss of solution by effervescence. The mixture is stirred occasionally to dissolve the lead azide, after which the solution is removed from the ice bath. After the addition of two drops of the ortfto-phenanthroline-ferrous ammonium sulfate indicator, the solution is titrated with the ferrous ammonium sulfate solution until a color change from light blue to red is produced. The percent lead azide in the sample, on a moisture-free basis is given by... 

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