Sulfur construction materials

In conclusion, it would appear that sulfur construction materials technology developed largely in North America and is ideally suited for rapid implementation in the Middle Eastern construction industry. 

Highway Construction. The preparation and use of sulfur—asphalt (SA) paving materials have been reviewed (45,46). In the 1930s, asphalt (qv) was easily available and priced lower than sulfur. As of the 1990s, this is no longer the case. There are four different types of sulfur paving materials. 

J. E. Paulson and co-workers. Sulfur Composites as Protective Coatings and Construction Materials, American Chemical Society, Washington, D.C., 1978. 

Uses. In construction materials manufacture of steel, aluminum, and magnesium as a scrubbing agent to remove sulfur dioxide emissions from smokestacks manufacmre of glass, paper, and industrial chemicals in fungicides, insecticides, and lubricants... 

McBee, W. C., Saylak, D., Sullivan, T. A., and Barnett, R. W., "Sulfur As A Partial Replacement for Asphalt in Bituminous Pavements", New Horizons in Construction Materials ... 

In order to meet the demand and reduce extra cost for upgrading poor quality of construction materials used, the utilization of an existing alternative material such as sulfur is highly recommended. 

Sulfur tetrafluoride is thermally stable up to 600 °C. Within the temperature range 600-1000 C, less than 1 % undergoes disproportionation to sulfur hexafluoride and sulfur.24 Most of the common construction metals, such as copper, nickel and steel, are resistant to sulfur tetrafluoride. Mercury also does not react with sulfur tetrafluoride.3 The recommended construction material for work with sulfur tetrafluoride is Hastelloy or stainless steel and, at low pressure,... 

Not all of the interest in mineral matter in coals is stimulated by its detrimental effects during coal use. In several instances coal is a source of desired elements and materials. Uranium has been produced from lignite germanium and sulfur could be produced from coal and coal ash has been used for construction materials such as brick, lightweight aggregate, and road paving material. 

Sensitivity to contaminants, both in fuel and oxidant and in fuel cell construction materials, surprisingly has not been studied enough. There is a very corrosive environment inside a fuel cell (hot, humid, and presence of sulfuric acid) which limits the choice of materials. Both catalyst and polymer membrane may be extremely sensitive to contaminants, particularly metal ions. More research in this area is required. 

T or many years scientists and engineers have attempted to modify the properties of sulfur so that it might be of value as a construction material, but until recently these random efforts lacked direction. Frequently the objectives of work described in many published papers could not be reconciled with the experimental design. For example, authors cited availability, low cost, and low toxicity as reasons for evaluating sulfur as a construction material. The same authors would then proceed to modify sulfur with additives which were in short supply, expensive, and highly toxic. The aging characteristics of sulfur concretes beyond a 28-day period were never examined, and durability outside the laboratory environment was seldom considered. With these limitations, the data were of little value to the construction industry. 

In the late 1960s experiments were made again to produce sulfur concrete. Now, the emphasis was on developing a construction material (6,7). The first products had a sulfur content of about 30 wt % and had compressive and flexural strengths in the order of 250 kp/cm2 and 35 kp/cm2, respectively. These first experiments were followed by more research (8, 9,10,11). 

Because of the large supply of sulfur, there is increased interest in its possible use in the construction industry (7-13). This chapter reviews research at The University of Calgary concerned with sulfur in civil engineering applications. Large volumes of materials are required for construction. The amount of sulfur which is available may be compared with the consumption of some of the principal construction materials (Table I). In Canada the annual production of sulfur is already a sizeable fraction of the yearly consumption of some of these materials. For example the annual sulfur production is about half that of raw steel and about three quarters that of portland cement. Elsewhere sulfur production is much smaller than that of presently used construction materials, but there are indications that sulfur production will be increasingly important. 

Sulfur Composites as Protective Coatings and Construction Materials... 

Hphe unique properties of elemental sulfur make it a desirable base for coatings and construction materials. Among its attributes are hardness, resistance to chemical attack, high strength, and a low melt viscosity (J). Few, if any, common materials have this combination of useful properties. The commercial use of sulfur in these applications has been limited because of its brittleness, lack of resistance to thermal shock, and poor weatherability. 

Chevron has demonstrated that it is commercially feasible to use sulfur composites as protective coatings and construction materials. This was done with large-scale field installations using special equipment and application procedures. Future efforts will focus on the commercial development of Chevron Sucoat products for these and other practical uses. 

Oulfur foam can be used to protect the permafrost by using a combina- tion of sulfur foam and local embankment materials for road, airfield, and other construction to reduce both the overall cost and the amount of embankment material that needs to be quarried in the arctic wilderness. The use of sulfur foam as subbase insulation prevents thawing of permafrost, which can cause subsidence during the warmer months. Another application uses sulfur foam with conventional pavement construction material for subbase insulation in frost-susceptible areas to prevent frost heave which is caused by freezing of the underlying soil. 

Sulfur is inexpensive, readily available, and has unique physical and chemical properties which make for a promising construction material as reported by Fike (18,19) and others (11,15,20,21). Rennie et al. (21) reported that the strength of sulfur varies from 200 to 1300 psi (1380-8970 kN/m2) depending on the temperature, as shown in Figure 10. Therefore, sulfur impregnation improves the natural weaknesses of the bamboo culm as used for engineering applications. 

Mild steel is a satisfactory construction material for all equipment in Ziegler chemistry processes except for hydrolysis. If sulfuric acid hydrolysis is employed, materials capable of withstanding sulfuric acid at 100 °C are required lead-lined steel, some alloys, and some plastics. Flow diagrams for the Vista and Ethyl processes are shown in Figures 3 and 4, respectively. 

Elemental sulfur is an inexpensive material available in high purity and large quantities, and has repeatedly been suggested for new uses in the civil engineering field. It is used as an extension to asphalt in road pavements and as an insulating material, but use as a construction material requires modification with additives designed to stop the embrittlement that occurs with pure elemental sulfur. If pure liquid sulfur is cooled to ambient temperature, monoclinic octasulfur (/S-Sg) is instantaneously formed, which then slowly converts to orthorhombic a-Sg. Because of the difference in densities between a- and )3-Sg, a brittle material results. Many additives have been proposed to modify elemental sulfur, nearly... 

The most important alkene in this context is DCPD or a mixture of di- and tricyclopentadienes. The addition of 5-10% by mass to elemental sulfur, followed by heating to 140 °C results in a complex mixture of polysulfanes and sulfur, which after cooling to 20 °C is no longer brittle but of extremely high mechanical strength (sulfur cement). When the liquid sulfur cement is mixed with suitable pre-heated mineral fillers and cooled to ambient temperature a very useful construction material is obtained (sulfur concrete). 

In sulfuric acid production, acid brick lining of membrane coated mild steel tanks and reaction vessels is considered the most durable and versatile construction material for the sulfuric acid plant. Such linings wiil reduce the steel shell temperature and prevent erosion of the normally protective iron sulfate film that forms in stagnant, concentrated (oxidizing) sulfuric acid. Dilute (red uC ing) sulfuric acid solutions are very corrosive to carbon steel, which must be protected by impermeable (e.g., elastomeric) membranes and acid brick lining systems. Such acid brick linings often employ membranes comprising a thin film of Teflon or Kynar sandwiched between layers of asphalt mastic. 

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