Hi Vicente. Thank you for your question.

1. Limestone grade

The grade of limestone is determined by CaO content. The highest CaO content of pure limestone is 56%. The higher the purity of limestone is, the better effect of desulfurization gets. As a process designer, not only should you calculate its chemical composition, but also you should understand its physical properties. The CaO content of limestone grade 1 is 48%~54%, and limestone does not necessarily require higher CaO content. The limestone with CaO > 54% is not suitable for desulfurization because of its high purity, marble, non-grinding and strong chemical stability.

2. Fineness of limestone powder

The smaller particle size of limestone powder is, the larger the specific surface area is. Because the limestone dissolution reaction is a solid-liquid two-phase reaction, the reaction rate is proportional to the specific surface area of the limestone particles. The smaller the limestone particles are, the better the dissolution performance is. But the smaller the limestone particle size is, the more energy consumption of crushing is. The screening rate of limestone powder usually passed through 325 mesh sieve (44 m) is 95%.

At the same time, the particle size of limestone powder is related to the quality of limestone. In order to ensure the desulfurization efficiency and the utilization ratio of limestone to a certain level, limestone should be ground finer when the impurity content in limestone is higher. Liming mill is a very good choice.

Liming Heavy Industry (Shanghai)