Thermal study of low-grade magnesium hydroxide used as fire retardant and in passive fire protection

Low-grade magnesium oxide by-products for environmental solutions: Characterization and geochemical performance

“…Other impurities such as silica and iron were uniformly present in dust materials (LG-MgO and LG-F). It is also worth mentioning the average sulphur content of 8 wt.% in both dust materials but significantly lower levels (~2 wt.%) in LG-F, the origin of which is mainly attributed to the petroleum coke used as fuel for calcination in the kilns, as previously reported by Formosa et al (2011). Loss on ignition (LOI) differed substantially among the three by-products as a consequence of the duration of calcination.…”

“…Fernández et al (1999) described a method to obtain basic magnesium carbonates by means of the carbonation of LG-MgO slurries with the aim of using them as an additive for pigments and papermaking or as a flame retardant in polymers. In the same way, the use of LG-Mg(OH) 2 has been tested with very promising results as a flame retardant filler in polymers and as aggregates in the formulation of fire-protecting mortars (Fernández et al, 2009;Formosa et al, 2011).…”

Natural fibers

“…The dilution of the polymer by using a high filler loading reduces the volume content of combustible organic material within a composite, thereby reducing its flammability [52]. Magnesium compounds, as with ATH, need to be present in a large amount (30-60 wt%) to provide significant fire retardancy.…”

Magnesium Phosphate Cements formulated with a low-grade MgO by-product: Physico-mechanical and durability aspects

“…The presence of calcium and silica should also be noted. The diffraction pattern of the magnesium by-product shows periclase -MgO-as the major phase and unburned magnesite -MgCO 3 -as a minor one, as well as dolomite -MgCO 3 ÁCaCO 3 -, quartz -SiO 2 -and calcite (or aragonite) -CaCO 3 -, which occurs in natural magnesite, and lime -CaO-and anhydrite -CaSO 4 -generated during the calcination of dolomite [54,55]. Hence, taking into account the total percentage of MgO determined by XRF (see Table 2) and the content of this MgO in the carbonated phases observed in previous studies, the MgO available to form the MPC formulated with LG-MgO is approximately 57.50%.…”