Reaction mechanisms of low-grade molybdenum concentrate during calcification roasting process

Formation mechanism of Fe-Mo master alloy by aluminothermic reduction of MoS2-Fe2O3 in the presence of lime

“…It seems that the presence of this endothermic peak arises due to the release of volatile matters and moisture content especially in lime/slaked lime and molybdenum sulfide raw materials. It should be noted that in the similar research carried out by Gan et al, the reason for the presence of these endothermic peaks in this temperature range was attributed to the release of moisture and volatile matters [22]. Also in Fig.…”

“…They also conducted studies on ferromolybdenum production through a two-step hydrogen reduction method [21]. Gan et al, have also studied the reaction mechanism of molybdenite during calcification roasting process [22].…”

“…In the next step, formation of CaMoO 4 compound as another exothermic reaction could also be considered in accordance with reaction 4 [22]:…”

“…In addition, according to the available references and thermodynamic calculations, the probability of the presence of the CaSO 4 phase in this temperature range should not be ignored with respect to the following reactions [22] 2CaS + 4O 2 = 2CaSO 4 + Q (6) And the main reaction (7) is obtained from the combination of these two reactions (5) and (6):2CaO + MoS 2 + 4.5O 2 = 2CaSO 4 + MoO 3 +Q 7Reaction (7) can also be derived from the integration of chemical reaction (3) with the following equation.…”

“…It should be noted that the decomposition of CaSO 4 phase is highly dependent on the temperature and partial pressure of O 2 and SO 2 . For example, in the atmospheric air (PO 2 = 0.21) and very low partial pressure of SO 2 it begins in the temperature range of 800-900°C, and with increasing the SO 2 partial pressure shifts to higher temperatures value [22,34].…”