Sulfur pelletized

Sulpel [Sulphur pelletization] A process for making sulfur pellets. Molten sulfur is injected through nozzles into water containing a trace of a proprietary additive, which gives the resulting pellets a smooth, waterproof surface. Developed and offered by Humphreys and Glasgow, UK nine plants had been engineered as of 1992. 

In other sulfur recovery operations, better control of product particle size is obtained. The molten sulfur is chilled on a steel belt to produce a roughly 0.5-in.-thick flake sulfur, or sprayed into water or even tumbled in drums to obtain granulated sulfur. Pelletized sulfur, similar in particle size range to the granulated variety, is also obtained when a melt is sprayed into the top of a tower to form droplets of molten sulfur which harden into shot-sized beads as they fall through a current of air. In this form, it is referred to as prills [20]. The narrow size range of particles of prilled sulfur, as well as the negligible dust content in this form, makes it more convenient to use. It normally commands a price premium. 

Sulfur Pellets (0207), White Pho horus (0209), and Sufaigniter For Thermite (0211). 

The following igniters, found in chapter 3, may be used to initiate thermite Powdered Aluminum—Sulfur Pellets (0207), Magnesium Powder—Barium Peroxide Igniter (0210), and Subigniter forThemute (0211). 

A phosphorus pellet, made of red phosphorus and the same size as the sulfur pellet, is used for the calibration of the end-window Geiger-Mueller counter. The amorphous red phosphorus powder is mixed with a small amount of binder ( 4 w/o polyvinyl alcohol powder) before being pressed. The pressed pellet is also sprayed with Krylon. 

This is an accurate expression for the efficiency of both the phosphorus and sulfur pellets if Vp does not differ appreciably from Vg, the active volume of the sulfur pellet. If these volumes are quite different, the overall geometry factors of each pellet would differ also. Fortunately, this is not the case, for the densities of the two types of pellets are almost equivalent. 

To eliminate an beta produced by thermal activation in the sulfur pellet, a thin, 40-mg/cm absorber should be kept over the window when beta counting. This absorber must also be present for the counter calibration with the phosphorus pellets. 

Two separate runs are made, the first with the detectors covered with aluminum (bare), and the second with cadmium covers. An indium foil disc will be irradiated with the sulfur pellet in both irradiations. These detectors will monitor the flux to ensure that the power level is the same for both irradiations. The indium will also serve to compare the bare activations at positions (A), (B), and (C). From previous irradiations it has been found that the cadmium ratio is constant throughout the region where the detectors are placed. This indicates that the thermal-to-resonance flux ratio remains constant. The thermal flux at positions (A) and (C) should be approximately the same, since these locations are symmetrical about the horizontal centerline near the center of the core. 

Both the Toth and Alcoa processes provide aluminum chloride for subsequent reduction to aluminum. Pilot-plant tests of these processes have shown difficulties exist in producing aluminum chloride of the purity needed. In the Toth process for the production of aluminum chloride, kaolin [1332-58-7] clay is used as the source of alumina (5). The clay is mixed with sulfur and carbon, and the mixture is ground together, pelletized, and calcined at 700°C. The calcined mixture is chlorinated at 800°C and gaseous aluminum chloride is evolved. The clay used contains considerable amounts of silica, titania, and iron oxides, which chlorinate and must be separated. Silicon tetrachloride and titanium tetrachloride are separated by distillation. Resublimation of aluminum chloride is requited to reduce contamination from iron chloride. 

The productive stock, ie, the curable compound, is made up by mixing the nonproductive stock in the Banbury once more with the curative package (sulfur, accelerators, etc). This time the drop temperature is lower, in the range of 95—112°C. The productive stock is then sheeted or pelletized and coated with the dip coat, cooled, and finally stored, ready for further processing for final fabrication. 

The active phase, which is soHd at room temperature, is comprised of mixed potassium and sodium vanadates and pyrosulfates, whereas the support is macroporous siUca, usually in the form of 6—12 mm diameter rings or pellets. The patent Hterature describes a number of ways to prepare the catalyst a typical example contains 7 wt % vanadium pentoxide, 8% potassium added as potassium hydroxide or carbonate, 1% sodium, and 78 wt % siUca, added as diatomaceous earth or siUca gel, formed into rings, and calcined in the presence of sulfur dioxide or sulfur trioxide to convert a portion of the alkah metal salts into various pyrosulfates (81,82). 

Although it is not a catalytic process, the roasting of iron sulfide in fluidized beds at 650 to 1,100°C (1,202 to 2,012°F) is analogous. The pellets are 10-mm (0.39-in) diameter. There are numerous ants, but they are threatened with obsolescence because cheaper sources of sulfur are available for making sulfuric acid. 

For these reasons many research groups prefer to dry the chromatograms in a vacuum desiccator with protection from light. Depending on the mobile phase employed phosphorus pentoxide, potassium hydroxide pellets or sulfuric acid can be placed on the base of the desiccator, to absorb traces of water, acid or base present in the mobile phase. 

A cold mixture of sulfuric acid (98%, 4 g), and water (4 mL) was added to an amino-alcohol 25 (40 mmol) in water (2.4 mL) at 0-5°C. The mixture was heated to 120°C and then water was carefully distilled off in vacuo. The solid sulfate residue was treated with 6.2 M potassium hydroxide, and steam-distilled. The distillate was saturated with potassium hydroxide pellets and the upper organic layer, which separated, was fractionally distilled from potassium hydroxide through a short column to give a colorless oil aziridine 26 in 96% yield. 

A mixture of 20 g of 1 -bromo-3,5-dimethyladamantane, 75 ml of acetonitrile, and 150 ml of concentrated sulfuric acid was allowed to react overnight at ambient room temperature. The red reaction product mixture was poured over crushed ice, and the white solid which precipitated was taken up in benzene and the benzene solution dried over sodium hydroxide pellets. The benzene solution was filtered from the drying agent and evaporated to dryness in vacuo to yield 1 B.2 g of product having a melting point of about 97°C and identified by infrared spectrum as 1-acetamido-3,5-dimethvladamantane. 

Nitrogen is dried by passage through two Drechsel bottles containing concentrated sulfuric acid and potassium hydroxide pellets, respectively. 

The checkers used acetylene available from Matheson Gas Products. The gas was purified by passing it through concentrated sulfuric acid and then through a tower filled with potassium hydroxide pellets. The gas was then passed into a 1-1. safety flask which was connected to the gas inlet tube by means of rubber tubing. The checkers used a rotameter that was calibrated with air to determine the flow rate of acetylene. 

Fixed Bed Reactors. In its most basic form, a fixed bed reactor consists of a cylindrical tube filled with catalyst pellets. Reactants flow through the catalyst bed and are converted into products. Fixed bed reactors are often referred to as packed bed reactors. They may be regarded as the workhorse of the chemical industry with respect to the number of reactors employed and the economic value of the materials produced. Ammonia synthesis, sulfuric acid production (by oxidation of S02 to S03), and nitric acid production (by ammonia oxidation) are only a few of the extremely high tonnage processes that make extensive use of various forms of packed bed reactors. 

Thiophene (C4H4S) is representative of the organic sulfur compounds that are hydrogenated in the commercial hyditodesulfurization of petroleum naphtha. Estimate both the combined and effective diflfusivities for thiophene in hydrogen at 660 °K and 3.04 MPa in a catalyst with a BET surface area of 168 m2/g, a porosity of 0.40, and an apparent pellet density of 1.40 g/cm3. A narrow pore sized distribution... 

---