Patent pending announcement., page-4

https://www.researchgate.net/public...ed_from_Fly_Ash_A_Potential_Proppant_Material

High Strength Lightweight Glass-Ceramics Sintered from Fly Ash: A Potential Proppant Material

Article (PDF Available) in Transactions - Indian Ceramic Society 72(2):124-129 · August 2013 with 207 Reads
DOI: 10.1080/0371750X.2013.817582

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  1st P. Chen
  
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  2nd H.-Y. He
  41.69 · Shaanxi University of Science and Technology
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  3rd Z. He
  

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Abstract
High strength lightweight glass-ceramics were sintered with fly ash as the main raw material. The effects of utilization rate of fly ash, nucleating agents, sintering temperature and heating rate were studied. The optimum utilization rate was found to be 60%. The nucleating agents enhanced the properties of the proppant in the order: Fe2O3 > TiO2 > MnO2 > Cr2O3. The enhancement was much pronounced with the use of 6 wt% Fe2O3 or 5 wt% Fe2O3 along with 1 wt% TiO2. The sample sintered at 1400°C for 30 min at a heating rate of 5°C.min–1 showed optimum properties, viz. high strength (120.97-125.45 MPa), low water absorption (0.57-0.82%) and low density (1.32-1.56 g.cm–3). The fabricated glass-ceramics may be assumed to be a promising proppant material for hydaulic fracturing production of petroleum.​