This study discusses strength deterioration during the curing process of fly ash geopolymer and the use of CaSO4·2H2O (gypsum) as a deterioration remedy when the ash was synthesized using a 10M NaOH and Na-silicate solution. The strength decline was mainly due to the widespread formation of nanometer-sized cracks that were related to excessive Na and Si concentrations at an early age. Use of 2 ...

The present work describes the viability of a mortar binder based on two industrial by-products: poly(vinyl chloride) (PVC) particles from scrap and anhydrite (CaSO4) from fluorgypsum. Mortar composites were made incorporating different amounts of PVC particles and cured at constant room temperature during various periods of time. From X-ray diffraction, it was possible to follow the hydration ...

The conversion of CaSO4·0.5H2O to CaSO4·2H2O (gypsum) is great importance industrially, being the reaction behind plasterboard production and setting medical plasters. This hydration process inherently slow, ensure that it occurs on a practical timescale, “seeds” gypsum are typically added accelerate reaction. seeds used in industry mostly produced by milling quarried gypsum, resulting huge var...

Limestone Chemical Looping Combustion (L-CLCTM) is a novel process to burn sulfurous fuels with intrinsic desulfurization and CO2 capture. L-CLCTM based on using calcium-based sorbents as precursors for CaSO4 formation, which used an oxygen carrier. Its principle lies in the in-situ sulfur retention performed fluidized bed combustors burning solid high content. The target redox pair transferenc...

Week-old wheat seedlings absorbed at least 40% NO3from NaNO3 when preloaded with K+ than when preloaded with Na+ or Ca2". Cultures of Tnticum vulgare L. cv. Arthur were grown for 5 days on 0.2 ,M CaSO4, pretreated for 48 hours with either 1 mM CaSO4, K2SO4, or Na2SO4, and then transferred to 1 mM NaNO3. All solutions contained 0.2 mM CaSO4. Shoots of K+-preloaded plants accumulated three times ...

The copper pyrometallurgical industry faces the precipitation of un-soluble slimes containing bismuth, arsenic and antimony that can reduce purity. Ion-exchange resins are used to treat electrolyte avoid their precipitation. After resin saturation, a regeneration stage with 17%(w/w) hydrochloric acid bismuth (e.g. up 10 g/L) is currently limed. In this work, selective process was developed reco...

Between 2012 and 2015, a field experiment was conducted at the Brody Experimental Farm, Poznan University of Life Sciences, Poland. The following two experimental factors were used in duplicate: calcium sulfate (CaSO4) fertilization—two levels (0 500 kg ha−1); potassium (K) fertilization—four (0, 30, 60, 120 ha−1). soil pH (in H2O) enzyme activity (dehydrogenase, acid phosphatase, alkaline phos...