Have questions? SBM sales representatives are available for live chat now WELCOME TO SBM MACHINERY!

Slag Grinding Mill

Slag Grinding Mill

Effect of water content of ore on the crushing effect of Slag Grinding Mill

Since the Slag Grinding Mill has been successfully applied in the cement industry, it has been widely used. The main role of the grinding method in the grinding method depends on the interaction between the dense layers and the intergranular stress transmitted. In addition, the compactness between the layers also plays an important role in the lamination pulverization. The compactness must exceed 45%, or even 70% to 80%, in order to cause the lamination pulverization behavior. According to the structural characteristics of the vertical mill, the pressure in the width direction of the roll surface is not fixed when the equipment is in normal operation. Generally, the center pressure of the roll surface is high, and the pressure at the edge of the roll surface is low. The low grinding powder pressure on the edge of the roll surface and the baffle on both ends of the roller body increase the sliding friction of the material at the edge of the roll surface, and the crushing effect of the material layer is weakened. The edge product is coarser than the middle material, which is close to the traditional roll mill. Machine products, causing “edge effects”.

The main factors affecting the crushing effect of the Slag Grinding Mill include the ore properties, the ore size, the ore water content, the roll surface pressure and the roll surface speed. There is no consensus on the influence of the water content of the mine on the crushing effect of the material. Some people think that the effect of water content on the milling ratio and energy consumption is not obvious; some people believe that the water content of the ore will play a role in lubricating the crushing of the Slag Grinding Mill and have a certain promoting effect on the crushing. The following Shanghai Shibang vertical mill manufacturer conducts research on crushing test of Slag Grinding Mill for hematite ore, focusing on the influence of ore water content on ore crushing effect. The research results have certain guiding significance for the practical application of Slag Grinding Mill.

1. Effect of water content of ore on the moisture content of pulverized products

After the material is crushed by the Slag Grinding Mill, the moisture content of the middle material is lower than that of the original ore, and the moisture content of the raw material is increased compared with the original ore. With the increase of the water content of the ore, the water content of the middle material and the edge material increase linearly, and the water content increase rate of the edge material is much larger than the water content of the middle material. When the water content of the ore reaches 7%, the moisture content of the edge material is as high as 10.47%. The difference in water content between the middle and the side material is mainly due to the uneven distribution of the pressure on the roll surface. The ore is pressed tightly during the crushing process of the Slag Grinding Mill (the compactness is as high as 85%), part of the water in the ore is squeezed out, and flows from the high pressure central zone to the low pressure edge zone under the axial pressure gradient.

2. Influence of mine water content on unit energy consumption and processing capacity of Slag Grinding Mill

The relationship between the unit energy consumption and the processing capacity of the Slag Grinding Mill under different ore-bearing water content is different, and the mutual influence relationship is also different. With the increase of the water content of the ore, the unit energy consumption of the Slag Grinding Mill increases and the processing capacity decreases. Because the moisture absorbs a part of the energy during the pulverization of the layer, the energy consumption of the Slag Grinding Mill increases. In addition, the presence of moisture is more likely to cause discharge agglomeration, resulting in a lower discharge rate, thereby reducing the processing capacity of the Slag Grinding Mill. Overall, the unit energy consumption and processing capacity of the Slag Grinding Mill are not significantly changed with the water content of the ore.

3. Influence of ore water content on particle size distribution of pulverized products

The particle size distribution of the middle material changes with different water content of the ore. With the increase of the water content of the ore, the uniformity coefficient of the middle material increases and the particle size distribution is more concentrated. As the water content of the ore increases, the milling ratio of the medium material decreases. The increase of the water content of the ore makes the fine fraction of the middle material lower, the coarse fraction increases, and the particle size distribution is more concentrated in the intermediate fraction. As the water content of the ore increases, the uniformity coefficient of the edge material decreases, and the particle size distribution becomes wider. As the water content of the ore increases, the milling ratio of the edge material increases and the particle size becomes finer.

4. Influence of the water content of the mine on the particle size of the closed loop product

The hectic iron ore was subjected to a closed-circuit pulverization test of the edge crushing of the Slag Grinding Mill, and the width of the edge material area accounted for 40% of the entire width of the press roll. The particle size distribution of the closed-circuit products in the open-circuit products with no moisture and 3% moisture content changes. Compared with the materials in the open-circuit products, the balance between the uniformity coefficient and the milling ratio increases, the product size becomes finer and the distribution is more concentrated. This rule is not affected by the water content of the ore.

When the edge material is closed and pulverized, the uniformity coefficient increases and the milling ratio decreases when the 3% water content of the ore is compared with the pulverized product without moisture. It indicates that the fine-grained content of the pulverized product is reduced, the coarse-grained content is increased, and the particle size distribution of the product is more concentrated in the intermediate-grained grade, which is consistent with the variation of the material in the open-circuit product.

When the ore particles are compacted in real time under high pressure stress, the water is replenished to the surface of the mineral. The mineral particles use their surface adsorption force to pull the water around themselves. The contact between the two particles causes the water to flow between the particles due to the adsorption force. The squeezing is carried out in the gap to enclose the particles, and the fine particles in this case are inferior in grinding effect. On the one hand, it is protected by moisture, and the confining pressure is reduced; on the other hand, the friction between the particles and the particles is also reduced, and the fine particles are easily slid under the moisture entrapment and are not easily squeezed. In this case, the coarse particles have a better grinding effect because the coarse particles are bulky and cannot be wrapped by the water of the gap, but the pores between the particles and the particles can be reduced, so that the pulverized material is more compact and coarse. The friction between the two is also relatively increased, and the water acts as a pressure transmitting medium for the coarse particles, which promotes the grinding of the coarse particles. In addition, under the action of high pressure, moisture will enter the pores and cracks inside the particles, creating additional pore pressure, which can reduce the compressive stress of the particles and reduce the compressive strength of the particles, thus facilitating the crushing of the ore.

During the crushing of the hematite ore by the Slag Grinding Mill, part of the water in the ore will be squeezed out and flow from the high pressure central zone to the low pressure marginal zone under the axial pressure gradient, resulting in the moisture content of the intermediate material compared to the ore. When the water content of the edge material is lower than that of the original ore, the moisture content of the edge material increases much faster than the middle material. With the increase of the water content of the ore, the unit energy consumption of the Slag Grinding Mill increases, and the processing capacity decreases, but the overall change is not obvious. As the water content of the ore increases, the uniformity coefficient of the middle material increases, the milling ratio decreases, the fine fraction of the middle material decreases, the coarse fraction increases, and the particle size distribution concentrates more on the intermediate fraction; The uniformity coefficient of the material is reduced, the milling ratio is increased, the particle size of the edge material is thinned, and the distribution is broadened. After the water is supplied to the mine, the particle size distribution of the balanced closed loop product is consistent with the open material.

Get Price And Support

Simply complete the form below, click submit, you will get the price list and a SBM representative will contact you within one business day. Please also feel free to contact us by email or phone. ( * Denotes a required field).