The cover plate of flotation machine impeller is the main part of flotation machine, which is similar to the negative pressure area of the vacuum chamber of the pump. During the operation of the flotation machine, the impeller is in a state of high-speed rotation. The negative pressure generated in the central area of the impeller blade will make the air continuously inhale the gas to the outside, while the cover hole and side hole will continuously inhale the slurry, forming the solid-liquid-gas three-phase flow. Under the action of centrifugal force, the three-phase flow keeps moving outward, which will cause serious impact and corrosion to the impeller cover of flotation machine.
Under the action of centrifugal force, the three-phase flow keeps moving outward, which will cause serious impact and corrosion to the impeller cover of flotation machine. This is also the key reason affecting flotation performance, so improve the flotation machine impeller cover corrosion resistance is the key, so how to improve? This needs to be considered from the material. At present, the commonly used materials of flotation machine impeller cover are mainly cast iron impeller cover, nylon impeller cover, polyurethane impeller cover and rubber impeller cover. How to choose these kinds of impeller cover material?
Cast iron impeller cover plate is one of the early flotation machine commonly used material, the advantages of high hardness, high wear resistance, but its brittleness is big, so can’t bear impact load, and poor corrosion resistance, in the process of flotation, due to the impact of the material abrasion, and corrosion of flotation reagents, lead to short service life of the cast iron material, with high switch frequency, generally for a quarter to replace impeller plate at a time.
After using the cover plate of cast iron impeller for a period of time, due to serious abrasion, the gap between the impeller and cover plate will increase, resulting in insufficient flotation machine filling capacity and stirring strength, and finally flotation machine pulp flow is not smooth, flotation liquid surface “turning over” phenomenon.
Because the comprehensive utilization rate of cast iron impeller cover is poor, has been gradually eliminated, now more used for nylon impeller cover, polyurethane impeller cover and rubber impeller cover.
Flotator impeller cover plate of nylon material with high mechanical strength, high hardness, high toughness, high hardness, good mechanical damping capacity, good sliding, good wear resistance, aging resistance and other advantages, the main is nylon flotator impeller cover plate for strong acid strong alkaline material has good impedance, the use of acid and alkaline the mineral processing reagents, give priority to choose nylon material flotator impeller cover plate.
Polyurethane is a kind of high strength wear-resistant material, it has the high elasticity of rubber, but also has the strength of plastic, as the flotation machine impeller cover material, can effectively extend the flotation machine impeller cover life. The life cycle of polyurethane can be extended 5~6 times longer than that of cast iron. Polyurethane oil resistance is very strong, really on molybdenum flotation, in the flotation operation to choose kerosene as the choice of polyurethane flotation machine impeller cover is more suitable.
The impeller cover made of rubber is mainly made of wear-resistant rubber. Wear-resistant rubber impeller cover mainly adopts the new “liquid nano formula • normal temperature and high frequency curing” rubber production process, which has good effects in terms of wear resistance, resilience, tearing, etc. Its abrasion resistance index reaches 128%, rebound reaches 80%, tensile strength reaches 23.5mp, tear strength reaches 168N/mm.
Wear-resistant rubber impeller cover strong tear resistance, wear resistance, for the treatment of strong corrosive materials is relatively weak, therefore, in addition to the corrosive materials or agents of metal, non-metal ore can choose the flotation machine impeller cover materials.
The elaboration of cast iron, nylon, polyurethane and rubber impeller cover plate edge characteristics of several kinds of material and the direction of choice, only for reference and learning, in the practical choice, need by mineral processing test, such as to determine the final preparation process and the mineral processing reagents, need to consider and then select eligible flotator impeller cover plate.