Chemicals pouring

H2SO4 reacts with water and generates heat. When using this chemical, pour it slowly into the water. 

One of the greatest challenges to do with practical risk analysis is defining the scope of the hazard term. For example, with respect to the second hazard in the above list—an overflow of T-100—more detail is needed. Clearly there is an enormous disparity between having a few drops spill into a closed drain system and having thousands of liters of the chemical pour on to the ground and then flow into the local waterways. 

The apparatus to use is seen in figure 13 which consists of a burette, thermometer, Erlenmeyer flask and a two-holed rubber stopper that has a small V-shaped wedge cut out of one side of the rubber stopper to allow the inside contents to vent. 31.5g of orangy-red fuming nitric acid (see chemicals section) is poured into the Erlenmeyer flask and the rubber stopper with its burette and thermometer is placed on to the... 

Testing. Chemical analyses are done on all manufactured abrasives, as well as physical tests such as sieve analyses, specific gravity, impact strength, and loose poured density (a rough measure of particle shape). Special abrasives such as sintered sol—gel aluminas require more sophisticated tests such as electron microscope measurement of a-alumina crystal si2e, and indentation microhardness. 

C. S. Read with T. Gibson and Z. Sedaghat-Pour, "Acetone" in Chemical Economics Handbook, SRI International, Menlo Park, Calif., 1989, p. 604.5000 H. 

A fundamental requirement in powder processing is characterization of the as-received powders (10—12). Many powder suppHers provide information on tap and pour densities, particle size distributions, specific surface areas, and chemical analyses. Characterization data provided by suppHers should be checked and further augmented where possible with in-house characterization. Uniaxial characterization compaction behavior, in particular, is easily measured and provides data on the nature of the agglomerates in a powder (13,14). 

Fluid Chemical composition Temperature range, °C Min Max Viscosity, mPa-s(= cP) Vapor pressure, kPA Pour point, °C Flash point, °C Fire point, °C ait/ °C... 

Perfluoroall lpolyethers. While high cost has limited general use, these fluids are remarkably stable chemically, have good viscosity—temperature characteristics, low pour poiats, and quite low vapor pressures (42,43). 

The modulus of elasticity (MOE) is related to the strength and can be used as a nondestmctive quaUty control test on high cost special refractory shapes such as sHde gate valves employed in the pouring of steel (qv). The sHde gate type must be selected to ensure chemical compatibiUty and it must be used in a way to reduce thermal shock. The performance of a properly selected and used sHde gate is direcdy related to its strength and therefore predicted by its MOE. 

Dry basis natural mbber compound recipe, in part by wt high ammonia natural latex mbber concentrate, 100.0 potassium hydroxide, 0.5 Nacconal 90F (alkylarenesulfonate (AHied Chemical Co.)), 1.0 zinc oxide, 3.0 sulfur, 1.0 ZMBT, 1.0 zinc diethyldithiocarbamate (ZEDC) (trade names Ethazate (Uniroyal, Inc.), Ethyl Zimate (R. T. Vanderbilt), 0.3 antioxidant, as indicated. Wet-basis natural mbber compound recipe, in parts by wt natural latex (NC 356), 167.9 potassium hydroxide, 2.5 Nacconal 90F, 5.0 zinc oxide, 5.45 sulfur, 1.65 ZMBT, 2.0 ZEDC, 2.0 antioxidant, as indicated. AH films poured from freshly mixed compounds, dried overnight in place, then lifted and dried 1 h in air at 50°C before curing. 

Most antiperspirant sticks are molded. Sticks dominate in the U.S. market, whereas lotion and cream antiperspirants are preferred in Europe. Stick antiperspirant products may include suspending agents, coupling agents to wet the antiperspirant chemical (about 20—25%), and emoUients. The blend is prepared at about 65°C and poured at about 55°C. Antiperspirant (64) and deodorant (65) compositions have been pubHshed. 

Fluid or Pour-Tjpe Resins. Fluid or pour-type resins are modified acryHc systems that can be cured chemically. A fine-particle-size polymer powder consisting mostly of high molecular weight material is preferred to prevent a rapid increase in viscosity during mixing and pouring. Polymerization occurs in flexible... 

The most commonly used combination of chemicals to produce a polyacrylamide gel is acrylamide, bis acrylamide, buffer, ammonium persulfate, and tetramethylenediarnine (TEMED). TEMED and ammonium persulfate are catalysts to the polymerization reaction. The TEMED causes the persulfate to produce free radicals, causing polymerization. Because this is a free-radical driven reaction, the mixture of reagents must be degassed before it is used. The mixture polymerizes quickly after TEMED addition, so it should be poured into the gel-casting apparatus as quickly as possible. Once the gel is poured into a prepared form, a comb can be appHed to the top portion of the gel before polymerization occurs. This comb sets small indentations permanently into the top portion of the gel which can be used to load samples. If the comb is used, samples are then typically mixed with a heavier solution, such as glycerol, before the sample is appHed to the gel, to prevent the sample from dispersing into the reservoir buffer. 

Vitrified-Clay Sewer Pipe This pipe is resistant to very dilute chemicals except hydrofluoric acid and is produced as standard-strength and extra-strength (ASTM C700). It is used for sewage, industrial waste, and storm water at atmospheric pressure. Elbows, Y branches, tees, reducers, and increasers are available. Assembly is by poured joints which allow for ample angular deflection. Joint com-... 

Human-made sources cover a wide spectrum of chemical and physical activities and are the major contributors to urban air pollution. Air pollutants in the United States pour out from over 10 million vehicles, the refuse of over 250 million people, the generation of billions of kilowatts of electricity, and the production of innumerable products demanded by eveiyday living. Hundreds of millions of tons of air pollutants are generated annu ly in the United States alone. The five main classes of pollutants are particulates, sulfur dioxide, nitrogen oxides, volatile organic compounds, and carbon monoxide. Total emissions in the United States are summarized by source categoiy for the year 1993 in Table 25-10. 

Tetrahydrofuran, anhydrous, 99.9t (water content <0.006t) was purchased from Aldrich Chemical Company, Inc., and used as received. The vinyl bromide solution was prepared In a 500-mL, round-bottomed flask fitted with a glass stopper. The stoppered flask containing the tetrahydrofuran was chilled to about 5 C and weighed. The vinyl bromide, also chilled to about 5°C, was rapidly poured Into the tetrahydrofuran until the desired amount had been added. The flask was stoppered, the contents mixed by shaking, allowed to warm to about 16°C, and then added to the pressure-equalizing addition funnel. 

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