Investigating the Effect of Temperature on Sulfur Deportment in Nickel Laterite Calcination

Inhibition of Sulfur Transfer from Fuel to the Calcine in Nickel Laterite Calcination Using a CaCO3 Absorbent

“…The results presented in Figure show that the presence of CaCO 3 considerably decreases the transfer of sulfur from the input gas mixture to the calcine due to sulfur absorption by CaCO 3 . Prior to the application of the sulfur absorbent, the increasing temperature in the range of 700–900 °C results in lower %S in the calcine due to sintering of the ore particles and surface area reduction. ,, In addition, recrystallization of magnesia silicates causes a considerable reduction in the surface area of the solid at 800–820 °C. − During the recrystallization process, short-range order is transferred to the long-range crystallographic order involving crystal growth, which results in the reduction of the surface area. , Therefore, by increasing the temperature from 700 to 900 °C at a constant processing time (60 min), the surface area of ore particles is decreased, which consequently declines the kinetics of gas–solid reactions and impedes the absorption of sulfur from gas to the solid. However, the addition of CaCO 3 changes the behavior of the calcine with respect to the absorption of sulfur.…”

“…Sulfur is a prevalent impurity in coal with a concentration of 0.2–10%. − Considering the low level of sulfur (∼0.01) in laterite ores, it is inferred that sulfur originates from added fuel and reductant in the calcination step . Coal combustion results in oxidizing sulfur and generating sulfur dioxide (SO 2 ). ,− Subsequently, the reaction between SO 2 and the ore results in the absorption of sulfur from the atmosphere to the calcine. − Sulfur is a deleterious impurity in ferronickel that interacts with alloy components and decrements the mechanical properties of the alloy . Hence, controlling the sulfur concentration of the calcination product is necessary to obtain an appropriate level of sulfur in the final product.…”

“…Hence, controlling the sulfur concentration of the calcination product is necessary to obtain an appropriate level of sulfur in the final product. Aside from recent works in our group, − there is no available literature on sulfur deportment in nickel laterite calcination. The lack of a comprehensive investigation on the behavior of sulfur during nickel laterite calcination creates a gap in proposing solutions for controlling the sulfur content of the calcine.…”