Development of coatings from zircon sand by oxyacetilene flame spraying for application on refractory bricks
In this paper, the experimental development used to flame sprayed coatings from mineral zircon sand (ZrSiO4) and a mixture of ZrSiO4 with 50 wt.% of commercial alumina Oerlikon Metco 105 SFP is presented. The ZrSiO4 sand was milled and sieved to obtain the particle sizes distribution corresponding to -37 +25 m and -25 m. Different parameters of thermal spraying process were simulated with the Jets & Poudres SPCTS software version 2002-2009 and the conditions with the greatest potential to obtain coatings were verified experimentally. The coatings elaborated on silico-aluminous refractory substrates were characterized by SEM and XRD, finding that those deposited from the lower size distribution, using a flame produced with 22 and 70 L / min of acetylene and oxygen respectively, at a spray distance of 10 cm and with a displacement of the gun of 0,275 cm/s and with a rotation of the substrate of 34,57 rpm were those that presented the best structural characteristics. The porosities of coatings sprayed from ZrSiO4 sand and the mixture of ZrSiO4 with Al2O3 were 30,5 ± 6,6% and 20.3 ± 9.2% in area and their Vickers hardness were 3.06 ± 0.70 GPa and 6.0 ± 0.30 GPa, respectively. From the results obtained it was concluded that it is possible to use this mineral as a raw material in the Oxy-acetylene flame thermal spraying process.