SU884741A1 - Method of automatic control of disintegration process in drum mill - Google Patents

Description

I

The invention relates to methods for automatically controlling the process of fine grinding of materials in ball and tube mills with the addition of surfactants. (Surfactant) and can be used in chemical, mining, cement, and other industrial fields where fine grinding of materials is used.

Surfactants are fed to the mill to intensify the grinding process. In some cases, intensification is achieved as a result of a decrease in their strength at the coarse grinding stage, and in others, due to the disaggregating effect of the surfactant.

The known method of entering a surfactant in the first and second chambers of the mill P

This method is operational, but does not take into account the possibility of changing the zone of introduction of surfactants.

At the length of the mill with the drift of the physicomechanical properties of the milled charge. In addition, in some cases, the properties of the crushed mixture are such that the introduction of surfactant simultaneously in both zones is impractical because it does not give the expected effect due to an excessive amount of surfactant.

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The closest in technical essence to the proposed method is an automatic control of the grinding process in a ball mill with the introduction of surface-active substance, including changes in the flow rate of the starting material into the mill depending on the degree of grinding of the finished product and filling the first chamber of the mill with material and

20, the change in surfactant consumption depends on the filling of the first chamber of mill 2. 3 The disadvantage of this method is that the surfactant is continuously injected into the same grinding zone, i.e. the selective effect of eab on various materials is not taken into account. However, it is not always when grinding materials that the effect of an adsorption effect on reducing strength is desirable, since the introduction of surfactants into a large grinding area not only causes an increase in production, but the drink becomes much smaller, and this leads to both enhanced agglomeration of the smallest particles and physical changes. - mechanical properties of the finished cement. Thus, depending on the change of yours: the surfactant of the crushed material surfactant must be introduced into the grinding zone, where they give the greatest effect. It should also be noted that the dosage of surfactant in the desired grinding zone should be close to the amount at which mono-coating of the solid is achieved. In addition, if it is necessary to reduce disaggregation, and the surfactant is introduced into the head of the chamber first, then its quantity should be such as to provide zones of large and fine comminution. Thus, the surfactant concentration at the start of the mill is very high. At the stage of coarse grinding, this can cause not only enhanced dust emission, but also retardation of relativity (displacement of the surface atoms of the solid in the bulk), which will also worsen the grinding process. If the structure of the comminuted material is such that the surfactant will be used in the first grinding stage (the beginning of the mill) only slightly (in case of high contents of the head) and in a small amount than is required, it will go to the stage of finer grinding, then the pseudo-fluidity of the material will increase, which will reduce the effect of surfactant introduction or completely eliminate it. The purpose of the invention is to improve the quality of control. The goal is achieved by the fact that in the method of automatic control of the grinding process in a ball mill with the introduction of a surfactant, including a change in the flow rate of the source material into the mill depending on the grinding of the finished product and filling the first chamber of the mill active substance depending on the filling of the first chamber of the mill, additionally determine the change in the grindability of the starting material and change the distance from the beginning of the mill Itza to area of administration of surfactant in proportion to the grindability of the starting material. The drawing shows a block diagram of a device for implementing the method. The circuit contains the sensor 1 of the loading level of the first chamber of the mill with the material, the regulator 2 of the flow rate of the source material, the regulator 3 of the actuator of the source material, the regulator 4 of the surfactant consumption, the regulator of the actuator of the surfactant, Sensor 6 of the grindability of the source material, the regulator 7 of the introduction zone Surfactant, regulator 8 of the actuator for changing the surfactant introduction zone, sensor 9 of the grinding degree of the finished product, nozzle 10 surfactant, mill 11. Control of the grinding process in the step mill according to the method is performed as follows. The flow into the mill 11 of the material and surfactant is made by regulating the actuators of the source material 3 and surfactant 5 depending on the material loading level of the mill (sensor 1) and the grinding degree of the finished product (sensor 9) for the source material , and the level of loading for surfactants. Determination of material consumption and surfactant is carried out using the controllers in 2 and 4, respectively. If the grindability of the original product has decreased, i.e. a very hard material has gone, it is necessary to reduce its strength at the first grinding stage. The signal about the change in the grindability value of the sensor 6 is sent to the regulator 7, and from the regulator to the regulator of the executive mechanism for changing the supply area of the surfactant 8, which moves the nozzle 10 through which the surfactant enters. at the beginning of the mill. If the grindability of the material increases, then an increased formation of fine particles and their aggregation among themselves occur. In this case, to improve the grinding process, the effect of lowering the aggregation is more important than lowering firmly. In the case of well milled material, the grinding process is significantly impaired (for example, when grinding slag-portland cement clinker.) Thus, with an increase in the grindability of the starting material, the regulator 7 produces a signal, according to which the nozzle moves deep into the mill, where the amount of fines with a high grindability of the material is significant.The introduction of surfactants into this zone will increase the disaggregation of small particles, thereby improving the grinding process.

i The implementation of the proposed method will allow to achieve an adsorption decrease in strength of solid materials, to reduce the aggregation of small particles of materials, during grinding of which there is an increased dusting of the gels. This makes it possible to improve the performance of grinders847416

power unit and reduce the specific energy consumption for grinding.

Claims (2)

5 claims The method of automatic control of the grinding process in a ball mill with the introduction of a surfactant substance, including changing the flow rate of the source material into the mill depending on the degree of grinding of the finished product and filling the first chamber of the mill with material and changing the flow of surfactant depending on the filling of the first chamber of the mill , characterized in that, in order to improve the quality of control, the change in the grindability of the starting material is additionally determined and the p The distance from the beginning of the mill to the zone of introduction of the surfactant is proportional to the change in the grindability of the starting material. Sources of information taken into account in the examination, 1. USSR Author's Certificate for Application No. 2765363/33, cl. B 02 B 25/00, 1979. 2. USSR author's certificate number 657850, cl. B 22 C 25 / 00,1978.