During decades, gypsum has been employed as construction material for its versatility and particle size. In the present work, the possibility of developing gypsum panels with the incorporation of pumice and polypropyl...During decades, gypsum has been employed as construction material for its versatility and particle size. In the present work, the possibility of developing gypsum panels with the incorporation of pumice and polypropylene as alternative materials has been investigated. Pumice as well as polypropylene allows obtaining lighter panels than those on the market and with a lower production cost. Each one of these materials was characterized separately. In the case of gypsum and pumice, their granulometry, pH and humidity were determined, whereas polypropylene was characterized by a traction-deformation essay. Then, panels composition （gypsum and pumice concentration）, particle size, water temperature and the way polypropylene was added, was assessed. Panels with a 70% of gypsum, with a particle size of 198 btm and with polypropylene added in a laminar fashion, presented a compressive strength of 350 kPa, which accords to the norm ASTM 1396 and with market requirements. Finally, it was proposed a block diagram of the process for the fabrication of 100 kg/day of formulated panels.展开更多
Titanium dioxide （TiO2） was recovered from ilmenite （FeO-TiO2） contained in ferrotitaniferous sands of Mompiche area, by the combination of the thermal treatments of oxidation and carbothermic reduction and the su...Titanium dioxide （TiO2） was recovered from ilmenite （FeO-TiO2） contained in ferrotitaniferous sands of Mompiche area, by the combination of the thermal treatments of oxidation and carbothermic reduction and the subsequent leaching with hydrochloric acid （HCI） of the thermally treated samples. This study was developed because of the large source of TiO2 that Ecuador has, but has not developed enough research to place an industry to produce this compound. The oxidation at 900 ℃ for 3 h yielded a content of 11% of TiO2, and the highest oxidation of ilmenite （82%） was achieved at 1,000 ℃ for 1 h. The carbothermic reduction with 15wt% carbon at 950 ℃ for 2 h achieved a content of 6% TiO2 and 21% ilmenite. The combination of thermal treatments did not increase the content of TiO2 but allowed to obtain more soluble minerals in HCl. The best results of leaching were obtained with 100 mL of 256 g/L HC1 for 6 h at 70 ℃ and 10% solids of the sample oxidized at 900 ℃ for 3 h and subsequently reduced with 15wt% carbon at 950 ℃ for 2 h. The optimum leaching time was 4 h, giving a TiO2 of 90% purity with a recovery of 43%.展开更多
文摘During decades, gypsum has been employed as construction material for its versatility and particle size. In the present work, the possibility of developing gypsum panels with the incorporation of pumice and polypropylene as alternative materials has been investigated. Pumice as well as polypropylene allows obtaining lighter panels than those on the market and with a lower production cost. Each one of these materials was characterized separately. In the case of gypsum and pumice, their granulometry, pH and humidity were determined, whereas polypropylene was characterized by a traction-deformation essay. Then, panels composition （gypsum and pumice concentration）, particle size, water temperature and the way polypropylene was added, was assessed. Panels with a 70% of gypsum, with a particle size of 198 btm and with polypropylene added in a laminar fashion, presented a compressive strength of 350 kPa, which accords to the norm ASTM 1396 and with market requirements. Finally, it was proposed a block diagram of the process for the fabrication of 100 kg/day of formulated panels.
文摘Titanium dioxide （TiO2） was recovered from ilmenite （FeO-TiO2） contained in ferrotitaniferous sands of Mompiche area, by the combination of the thermal treatments of oxidation and carbothermic reduction and the subsequent leaching with hydrochloric acid （HCI） of the thermally treated samples. This study was developed because of the large source of TiO2 that Ecuador has, but has not developed enough research to place an industry to produce this compound. The oxidation at 900 ℃ for 3 h yielded a content of 11% of TiO2, and the highest oxidation of ilmenite （82%） was achieved at 1,000 ℃ for 1 h. The carbothermic reduction with 15wt% carbon at 950 ℃ for 2 h achieved a content of 6% TiO2 and 21% ilmenite. The combination of thermal treatments did not increase the content of TiO2 but allowed to obtain more soluble minerals in HCl. The best results of leaching were obtained with 100 mL of 256 g/L HC1 for 6 h at 70 ℃ and 10% solids of the sample oxidized at 900 ℃ for 3 h and subsequently reduced with 15wt% carbon at 950 ℃ for 2 h. The optimum leaching time was 4 h, giving a TiO2 of 90% purity with a recovery of 43%.
