In a lime kiln, the reaction goes to completion primarily due to two factors: high temperature and sufficient time.
High temperature: Lime kilns are operated at high temperatures, typically ranging from 900°C to 1200°C (1652°F to 2192°F). At these elevated temperatures, the reactants have high thermal energy, which increases their kinetic energy and collision frequency. This leads to more effective collisions between the reactant particles, enhancing the reaction rate and facilitating the completion of the reaction.
Sufficient time: Lime kilns allow for an extended residence time of the reactants inside the kiln. The reactants, usually limestone (calcium carbonate, CaCO3), are heated for a prolonged duration within the kiln. This extended time allows for a greater number of collisions and interactions between the reactant particles. Over time, the reactants have the opportunity to undergo multiple collisions, promoting the completion of the reaction.
These two factors, high temperature and sufficient time, work in combination to drive the lime kiln reaction to completion. The high temperature provides the necessary energy for the reaction, while the extended time allows for a higher degree of reactant conversion. As a result, the reactants are effectively converted into the desired product, which is usually quicklime (calcium oxide, CaO) in the case of a lime kiln.