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Description: Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ({approx}$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not recommended for treatment of wastes containing high concentrations of ...
Date: August 22, 2001
Creator: Kalb, P.
Partner: UNT Libraries Government Documents Department

Agriculture: Bioconversion of sugar cane molasses

Description: Auxein Corporation is demonstrating for commercial use an organic acid phytochelate, derived from what would otherwise be a discarded portion of sugar cane, that could increase the domestic sugar industry's profit margin from near zero to 7%. Along with helping a struggling industry, the phytochelate will bring substantial improvements to crop and tree production and greatly reduce the environmental threat posed by nitrogen-based fertilizers. Currently, the amount of fertilizer used produces harmful levels of run-off that contaminates ground water with unwanted nitrogen. By utilizing organic acid phytochelates, which assist plant growth by unlocking minerals stored in soil, fertilizer use can be dramatically reduced. This would improve crop yields, remove environmental threats to ground water, and cut fertilizer costs by as much as 50%.
Date: September 29, 1999
Creator: Simon, P.
Partner: UNT Libraries Government Documents Department