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Sulfur polymer cement

Sulfur Polymer Cement. SPC has been proven effective in reducing leach rates of reactive heavy metals to the extent that some wastes can be managed solely as low level waste (LLW). When SPC is combined with mercury and lead oxides (both toxic metals), it interacts chemically to form mercury sulfide, HgS, and lead sulfide, PbS, both of which are insoluble in water. A dried sulfur residue from petroleum refining that contained 600-ppm vanadium (a carcinogen) was chemically modified using dicyclopentadiene and oligomer of cyclopentadiene and used to make SC (58). This material was examined by the California Department of Health Services (Cal EPA) and the leachable level of vanadium had been reduced to 8.3 ppm, well below the soluble threshold limit concentration of 24 ppm (59). [Pg.126]

Sulfur polymer cement shows promise as an encapsulation and stabilization agent for use with low level radioactive and mixed wastes. Use of SPC allows accommodation of larger percentages of waste than PCC. As of this writing (1997), SPC-treated waste forms have met requirements of both the Nuclear Regulatory Commission (NRC) and the Environmental Protection Agency (EPA). [Pg.126]

BNL claims the following advantages of sulfur polymer cement ... [Pg.675]

A number of cement materials are used with brick. Standard are polymer resin, silicate, and sulfur-based materials. The most widely used resins are furane, vinyl ester, phenolic, polyester, and epoxies. Carbon-filled furanes and phenolics are good against nonoxidizing acids, salts, and solvents. Silicates and silica-filled resins should not be used in hydrofluoric or fluorosilicic acid applications. Sulfur-based cements are limited to 93°C (200°F), while resins can be used to about 180°C (350°F). Silicate-based cements are available for service temperatures up to 1000°C (1830°F). [Pg.37]

Polymer encapsulation is an ex situ S/S technique involving the application of thermoplastic resins such as bitumen, polyethylene and other polyelfins, paraffins, waxes, and sulfur-based cements, as opposed to cements and pozzolans. Polymer encapsulation has been used primarily to immobilize low-level radioactive wastes and those waste types that are difficult to immobilize in cement, such as Cl- and SO4-based salts. Bitumen (asphalt) is the least expensive and (hence) used most often. Thermoplastic encapsulation heats and mixes the contaminated soil with the resin at 130 to 230°C in an extrusion machine. Organic pollutants and water boil off during the extrusion and are collected for treatment or disposal. The final product, a stiff yet plastic resin, is then discharged into a drum or other container and land-filled (U.S. EPA, 1997). [Pg.583]

August 7, 1987 - Water was found leaking outside the 163-N building north wall to an area of the trench that had not been treated with polymer cement because of clearance restrictions due to the proportions of the trench. Sulfuric acid had corroded away exposed concrete (WHC 1987c). The extent of contamination, amount of sulfuric acid released, and the extent cf remediation is unknown. [Pg.140]

Many of the polymers formed from conjugated dienes are elastic and are used to manufacture synthetic rubbers. The raw polymers usually are tacky and of little direct use, except as adhesives and cements. They are transformed into materials with greater elasticity and strength by vulcanization, in which the polymer is heated with sulfur and various other substances called accelerators, with the result that the polymer chains become cross-linked to one another by carbon-sulfur and carbon-carbon bonds. Some of the cross-linking appears to occur by addition to the double bonds, but the amount of sulfur added generally is insufficient to saturate the polymer. With large proportions of sulfur, hard rubberis formed such as is used in storage-battery cases. [Pg.505]

In the melted state elementary sulfur is an excellent binder for aggregates such as sand, gravel, crushed stone, and similar materials. When a hot sulfur aggregate mixture is left to set, a material of concretelike hardness is obtained. This property leads to the term sulfur concrete or sulfur mortar, which is wrong strictly speaking, since the word concrete is used to refer to a product in which aggregates are bound with hydraulic products such as cement or with limestone. However, since polymer-bound aggregates recently developed to industrial maturity have been called polymer or synthetic resin concrete, the term sulfur concrete is maintained in this chapter. [Pg.61]

Finally some important properties of cement concrete, polymer concrete, and sulfur concrete are compared with each other. For the polymer concrete the data of a commercial polyester concrete were used. [Pg.83]

Table VIII. Comparison of the Important Properties of Cement, Polymer, and Sulfur Concretes... Table VIII. Comparison of the Important Properties of Cement, Polymer, and Sulfur Concretes...
Comparing the cost of the various concretes shows that at times of low sulfur prices, sulfur concrete can even compete with high-strength cement concrete. The costs of polymer concrete per cubic meter are quite enormous. Yet the substantially higher production costs of polymer concrete have not been considered yet. The prices used for this comparison are based on European conditions. To assess the sulfur concrete costs we used two extreme sulfur prices which had to be paid,in the last years. The total costs of DCP-modified sulfur concrete rose only negligibly with the addition of this plasticizer (Table IX). [Pg.84]

Organic polysulfanes are also important constituents of polysulfide polymers of the Thiokol type, of vulcanized rubber, and of sulfur cement. In addition, there are a few special applications in the oil industry and in medicine. Sulfur-containing polymers have been extensively reviewed by Tobolsky and MacKnight in 1965 and by Duda and Penczek in 1987. ... [Pg.4695]

The polysulfanes formed on reaction of DCPD with liquid sulfur have been studied by extraction of sulfur cement and analysis by LC, H-NMR, MS, and other techniques.The initial products are trisulfane and pentasulfane derived from DCPD by addition of S3 or S5 units to the norbomenyl double bond. These monomers are believed to further react with elemental sulfur to form low-molecular mass polymers (CS2 soluble), and on further heating form an insoluble material. The cyclopentenyl unsaturation of DCPD is much less reactive and is still present in the CS2-soluble products. endo-T>CP D reacts more slowly with liquid sulfur at 140 °C than eco-DCPD, while the cyclic trisulfanes of endo- and gxo-DCPD react at almost the same rate with liquid sulfur at 140°C. The stmctures of DCPD-S3, DCPD-S5, and the hkely stmcture of the low-molecular mass polymer, are shown in Figure 8. [Pg.4697]

The reagent acetyl sulfate for these studies was generated in two ways. In one case acetic anhydride and concentrated sulfuric acid were mixed at a temperature below 0°C, the thick solution warmed to about 10°C, and the preformed neat reagent added to the EPDM solution (cement). In the second case, the acetyl sulfate was generated in situ, i.e., acetic anhydride was added to the EPDM cement and then the concentrated sulfuric acid was dripped in. With the polymers previously described and according to the following procedures, results with the preformed and the in situ reagents were fully equivalent. [Pg.9]

The polymeric sulfur allotropes are extremely important in the use of sulfur as a fertilizer coating material, because the allotropes cement the orthorhombic sulfur crystals into mechanically stable coatings. It would be difficult to form a stable coating of wholly crystalline sulfur because of its comparatively poor mechanical properties. Increasing the polymeric sulfur content could improve the coating properties of the sulfur, particularly if the degree of polymerization could be controlled. Too much polymer could make the coating too plastic. [Pg.39]

OTHER COMMENTS the dihydrate form of calcium sulfate is generally referred to as gypsum the dihydrate form of calcium sulfate is used in water and soil treatment, paints, enamels, polishing powders, paper, insecticide dusts, pharmaceuticals, and animal feed has also been utilized in the manufacture of Portland cement, plaster of Paris yeast, artificial marble, calcium carbide, ammonium sulfate, sulfuric acid, and polymers the food and pharmaceutical grade is also used as a source of calcium in foods. [Pg.654]

NR latex, and cements, EPDM sponge compds. activates thiazole accelerators flotation collector for sulfide ores acid inhibitor intermediates synthetic organic pharmaceuticals sulfur dyes heat stabilizer for PVC in food-pkg. adhesives accelerator for food-contact rubber articles for repeated use stabilizer for food-grade polymers Regulatory FDA 21CFR 175.105, 177.2600, 178.2010... [Pg.1507]

Glyceryl behenate Hydrogenated cottonseed oil Hydrogenated palm oil binder, carbon arc-light electrodes Potassium silicate binder, carpet backing Styrene/butadiene polymer binder, catalysts Silica, colloidal binder, caulks Vinyl acrylic copolymer binder, cement Polyacrylamide Sulfur binder, cementitious surfaces Potassium silicate binder, ceramic Ethylene/MA copolymer binder, ceramic fibers Silica, colloidal binder, ceramic glazes Hydroxyethylcellulose Methylcellulose binder, ceramic paste Ethyl silicate... [Pg.4896]

Specialty concrete contains specialized binders such as K silicate, calcium aluminate, sulfur, and oxysulfate or polymer resins. In contrast to conventional construction products, specialty concrete is not based on Portland cement. Instead, specialty concrete is composed of specialty cement such as potassium silicate that is mixed with water, a coarse aggregate such as gravel or crushed stone, and a fine aggregate or sand. [Pg.197]


See other pages where Sulfur polymer cement is mentioned: [Pg.923]    [Pg.949]    [Pg.126]    [Pg.905]    [Pg.126]    [Pg.923]    [Pg.923]    [Pg.949]    [Pg.126]    [Pg.905]    [Pg.126]    [Pg.923]    [Pg.523]    [Pg.282]    [Pg.385]    [Pg.675]    [Pg.344]    [Pg.348]    [Pg.84]    [Pg.90]    [Pg.32]    [Pg.468]    [Pg.257]    [Pg.367]    [Pg.220]    [Pg.572]    [Pg.1190]    [Pg.244]   


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