Abstract: Disclosed herein are systems and methods from processing flue gas desulfurization (FGD) gypsum feedstock and ash feedstocks, either separately or together. FGD gypsum conversion comprises reacting FGD gypsum (calcium sulfate) feedstock or phosphogypsum, in either batch or continuous mode, with ammonium carbonate reagent to produce commercial products comprising ammonium sulfate and calcium carbonate. A process to separate the impurities and convert the calcium carbonate to a pure precipitated calcium carbonate is disclosed. These impurities include a concentrate of valuable Rare Earth Elements, and radioactive thorium and uranium. A process to convert calcium sulfite to calcium sulfate using oxygen and a catalyst is also disclosed. Ash conversion comprises a leach process followed by a sequential precipitation process to selectively precipitate products at predetermined pHs resulting in metal hydroxides which may be converted to oxides or carbonates.

Abstract: A new article of manufacture, for example a faucet or other article of hardware, has a specified decorative color, other than brass, and is resistant to corrosion, abrasion and attack by chemicals. The article includes a substrate, one or more corrosion resistant layers applied to the substrate, and an outer layer, applied by PVD, and chosen from only one or more of Zr, Hf, C and N. The outer layer provides the desired, other than brass, color of the article, the desired chemical and abrasion resistance, and which layer, when in contact with air or water becomes passive in a manner similar to chrome.