The process flow of the desulfurization vertical roller mill system is smooth, the investment is saved and the production management is easy. When selecting the production process plan and equipment selection of desulfurization limestone powder, mature and reliable new processes and technologies shall be adopted, which are economical, reasonable, practical and reliable. HCMilling(Guilin Hongcheng), as the scheme design and manufacturer of desulfurization vertical roller mill system, will introduce the desulfurization effect of vertical roller mill.

HLM desulfurization vertical roller mill

Several main factors affecting desulfurization efficiency:

1. Limestone grade

Limestone grade is determined by CaO content. The highest CaO content of pure limestone is 56%. The higher the limestone purity, the better the desulfurization efficiency. As a process designer, when designing the ingredients, you should not only calculate its chemical composition, but also understand its physical properties. The calcium oxide content of the first grade limestone is 48% – 54%; Limestone does not necessarily require a higher CaO content. Limestone with CaO>54% has high purity and is marmatized. It is not easy to grind and has strong chemical stability, so it is not suitable for use as a desulfurizer.

2. Fineness of limestone powder

The smaller the particle size of limestone powder, the larger the specific surface area. As the dissolution reaction of limestone is a solid-liquid two-phase reaction, and its reaction rate is proportional to the specific surface area of limestone particles, the finer limestone particles have good dissolution performance, higher various related reaction rates, higher desulfurization efficiency and limestone utilization, but the smaller the limestone particle size, the higher the crushing energy consumption. Generally, the passing rate of limestone powder passing 325 mesh sieve (44 microns) is 95%.

At the same time, the particle size of limestone powder is related to the quality of limestone. In order to ensure that the desulfurization efficiency and limestone utilization rate reach a certain level, when the impurity content in limestone is high, the limestone should be ground finer.

Limestone powder preparation technology using desulfurization vertical roller mill system:

For FGD process using limestone powder as desulfurizer, limestone powder needs to undergo solid liquid two-phase dissolution reaction, and the reaction rate is positive to the specific surface area of limestone particles. The smaller the particle size of limestone powder particles is, the larger the specific surface area by mass is. The limestone particles have good solubility, and various related reaction rates are high. However, the smaller the particle size of limestone, the higher the energy consumption of crushing. Generally, the passing rate of limestone powder passing 325 mesh sieve (44 microns) is 95%. At the same time, the particle size of limestone powder is related to the quality of limestone. In order to ensure that the desulfurization efficiency and limestone utilization rate reach a certain level, when the impurity content in limestone is high, the limestone shall be ground finer. The traditional tube mill technology is used to prepare limestone powder, which has large energy consumption, low output, complex process flow, and difficult to control the fineness and particle grading. With the development of grinding technology, the vertical roller mill grinding technology is adopted. Because of the material layer grinding principle, the energy consumption is low (20-30% lower than the power consumption of the tube mill), the chemical composition of the product is stable, the particle gradation is uniform, and the process flow is simple.

The limestone entering the plant is discharged into the hopper by truck or forklift, and the limestone is crushed in one stage. The limestone blocks are sent to the crusher through the plate feeder. The feeding particle size is generally controlled at 400-500mm, and the discharging particle size is controlled at about 15mm. The crushed limestone is sent into the limestone silo through the conveyor equipment, and the silo top is equipped with a single dust collector for dust removal. The crushed limestone is metered and batched by the speed regulating belt weigher at the bottom of the silo, and then fed into the vertical roller mill by the belt conveyor for grinding. The finished product is limestone powder with a fineness of 250 meshes. The limestone powder after grinding is transported to the finished product warehouse for storage. The top of the warehouse is equipped with a single dust collector for dust removal. The finished products are delivered to the bulk tank truck for delivery by the bulk machine at the bottom of the warehouse.

Desulfurization effect of vertical roller mill:

The grinding process of HLM vertical roller mill adopts the material layer grinding principle, with adjustable grinding pressure, low noise, low energy consumption, low wear, strong adaptability to materials, simple process flow and high system efficiency. The whole system is operated under negative pressure with little dust pollution. The grinding process of vertical roller mill has uniform grain grading, adjustable product fineness (product fineness can reach 600 meshes or more), and the product fineness can be quickly measured and corrected.

If you have related needs, please contact us for details of the equipment and provide follow information to us:

Raw material name

Product fineness(mesh/μm)

capacity (t/h)