METHOD OF PRODUCING POWDER MATERIALS

Abstract: The invention is refered to the technology of obtaining solid dry materials, in particular, to the methods of getting dispersed-conditioning powder materials. It can be used in mining and construction industry. According to the invention, the method of getting dispersed-conditioning material, including electromagnetic conditioning of material polyfractional mechanical mixture, its separation, and collection of finished powder material, involves the conditioning by grinding conditioning mixture under its electroneutralization conditions. To achieve this, the conditioning mixture is undergone by electrical insulation with setting off the depolarizing electric potential in material polyfractional mechanical mixture. Here, the electric potential is in 10.0 DIVIDED 60.0 range.

Description: METHOD OF PRODUC ING POWDER MATERIALS Field of the Invention The present invention relates to the technology of getting solid dry materials, particularly, to the way of obtaining the dispersion-conditioned powder materials. It may be used in mining and building branches of industry. Background of the Invention Different mehod of physical action on the material treated are known. Thus, it is known the method of getting dispersion conditioned materials (1). The known method involves the electromagnetic conditioning of the material mechanical mixture formed, and its separation. The pecularity of the known method is that the electromagnetic conditioning of material mixture is carriad out as nonpenetrative one. The order to achieve the conditioning, short-wave electromagnetic radiation of light range is directed to the material mixture surfase (in particular the conditioning is carriad out by directing the ultraviolet light to the mixture). The main disadvantage of the known method is that technological transformation of mixture mass as to the depth of mixture particles is not full because of nonpetrative conditioning. Sand preparation to separation processing is known to be done by magnetization (2). Commercial application of the method may, however, pose difficulties as there are some design complexities. The prototype of the invention offered has been taken the method developed for producing powder materials (3). It comprizes electromagnetic conditioning of the polyfractional mixture of the processing material, its separation, and the collection of finished powder material. It should be noted that in the chosen as prototype method the electromagnetic separation is carriad out after the polyfractional mechanical mixture has been formed, i.e. the electromagnetic conditioning does not take place in the process of grinding. Such electromagnetic conditioning does not permit for concentrated field forces to work efficiently with structural defects of the processed material mixture, in particular, with point defects (4). Thus, as the action on the structural defects of the mixture treated being not enough, it is impossible to succeed in increasing its susceptibility to further separation. There is also no possibility of neutralizing electric couterpotentials on cracks and break fissures of the processing material during its grinding. The unneutralized potentials lead to partial fissure joining after mechanical treatment. As a result, the used for grinding energy is directed, instead of being used for breaking the particles, to their abrasion with their further rolling up to the spherical shape. In the process of separation as the rolled particles in their centrifugal rushing tend to rebound from separated material surface layer (wall layer), more undersize forming the finished product is taken away with separator flow. Thus, the undersereen materials appears to be of not enough close-cut fraction content. The peculiar feature of the chosen prototype method is that the electromagnetic conditioning unit is performed as a solenoid electromagnet of field concentrating and not fieled distributing type. Electromagnetic action concentration does not permit to eliminate along the section intensity distribution heterogeneity of conditioning effect on the processed material, that, in its turn decreases the degree of conditioned levelling of the mixture. Due to the reasons mentioned the main disadvantage of the accepted prototype method is its inability to give with high precision the discharged product of preferable metric fraction corresponding to the production of high quality. Disclosing of the Invention The essence of the offered method for getting the disperssed-conditioning material is the followinng: the conditioning is obtained by grinding the conditioning mixture under the conditions of its electroneutralization including the electromagnetic conditioning of the material polyfractional mechanical mixture, its separation, and the finished powder product collection. To achieve this, the conditioning mixture is undergone the electrical insulation, the same as with electrical circuit distributed capaciti element, by depolariaing electrical potential action on the material polyfractional mechanical mixture. Here, the electrical potential is set in preferable range of 10.0 ÷ 60.0 V. When the potential value is less than 10.0 V, the mixture can not be converted into the state of full perseptability to separation. But, if potential value is more than 60.0 V, it leads to parallel process of undesirable side reactions of electrochemical transformation of the material mixture. Dopolarizing electrical potential initiates the action of electroneutralization process. As during the collision of crushing bodies with material mixture, the breaking speed of contact surfaces is high, large electrostatic charges remain on the tearing-off surfase and by aglomeration the particles make the grinding and separation difficult, thus, preventing the conditioning of the product. When grinding is initiated by depolarizing electric potential the shock air ionization during collision of grinding bodies occurs, and the corona discharge of high capacity appears. Under the action of electrical field the ions are moving in the direction of charged material particles and are electroneutralizing them. The conditions are, therefore, created under which the fracture fissured surfaces developing in the particles in grinding are not saturated with excessive potentials. This phenomenon keeps developing the fissures due to avoiding their joining after collision under the action of surface polarized electric charges. Thus, more angular particles are formed, energy consumption for particle grinding decreases, and balled particle material is obtained. Separation is carried out at minimizing the reboud effect of conditioning angular grinding particles. In the process, the parasitic rebound dispersion of the material treated is put off to "undersereen fraction" which is used in formation of finished powder material. That the foul undersereen with rebound material is excluded creates the conditions of getting the finished powder material of more close-cut fractional content. It is also possible to carry out the separation together with parallel general auxiliary electroneutralization of processing mixture. It is achieved initiating the separation by electric potential depolarizing triboelectric charges, thus, the finished powder material of preferable mitric fraction is obtained. It corresponds to the production of higher quality. Industrial application Examples of using the method suggested. Example 1. For the technological process of the offered method to work it is carried out the preparation of rawmaterial composition to form the material polyfractional mechanical mixture. The preparation is oriented towards getting high standard cement powder of narrow fraction used in construction solutions containing 55÷65% of favorable metric fraction with particle size of 3÷30 μm, in particular, the cement of trade mark 500 has been adopted as State Standard 25238-82. The material mixture consisted of 95% mass, initial clinker and 5% mass. gypsum. As reverse flow the over size more than 80 μm entered the mill from the separator. The raw material composition having been prepared, electromagnetic conditioning of polyfractional mechanical mixture is being carried out. Under the condition of electroneutralization the mixture is being ground and the foreseen conditioning is performed. The cement ball mill of diamiter 2,6 m., length 13 m. has been used for grinding. Drum revolution frequency is 16 rev/min. The specific cement surface being 350,0 m /kg, the mill capacity was 26 t/hour. Depolarizing electric potential initiates the process of electrical insulation. To achieve this the depolarizing electric potential is given to material polyfractional mechanical mixture. Then, the separation of the obteined material polyfractional mechanical mixture is being performed. Mechanical centrifugal pneumatic method is applied to carry out the separation. In particular, mechanical centrifugal airventilating separator of scattering type is used. Separator diameter was 3,2 m., revolution frequency was 245 rev/min. Separator capacity was 30 t/hour. The separation being over, the collection of the final powder material takes place. The material is of thin metric fraction without coarse, not enough desintegrated, grains which should be sent to regrinding. In the course of technological process the current control on its parameters and transformation values is done. As a result, it is achieved more close-cut fraction of the cement produced. The shave of desirable valuable cement fraction of 3÷30 μm was 71 % mass, and that of high valuable cement fraction of 10÷30 μm was - 63%. Example 2. To carry out the method offered the technological process is accomplished as in Example 1 corresponding to all its regimes and parameters, but the depolarizing electric potential is taken equal to its maximum 60 V and in prefferable range. It has resulted in discharging the valuable cement fraction of 3÷30 μm up to 74% mass, and high valuable fraction of 10÷30 μm up to 65% mass. Example 3. The technological process is carried out as in Example 1 following all its regimes and parameters, but the depolarizing electric potential is taken in its inter mediate value of 40.0 V in desirable range. Here it has resulted in discharging 3÷30 μm valuable fraction for producing the cement up to 78% mass, and 10÷30 μm valuable fraction to produce up to 69 % mass. The Table shows and compares positive results achieved by the method offered and proved by the examples mentioned above. The figures are compared with those of the production process of cement of trade mark 500 according to State Standard 25238-82. The Table The best variant of the Invention realization From The Table it is seen that the best results of the method offered have been achieved in Example 3. In the technological process of the method offered during grinding under the conditions of electroneutralization at dopolarizing potential 40.0 V the discharge of valuable fraction of 3÷30 μm to get the cement up to 78% mass and that of high valuable fraction of 10÷30 μm with cement production up to 69% mass, has been achieved. LNFOFMATION SOURCES. i. Patent Germany JMQ 698574, N. cl. 61bl, 1996. 2. Author's Certificate USSR N° 1.613.162, I. cl. B03B 1 /00, 1987. 3. Author's Certificate USSR Jsfe 1.431.864, I. cl. B07B 1 /40 1988. 4. Levich V.G. "Theoretical physics" , M. Nauka, 1969, p. 75.

Claims: CLAIMS 1. The method of obtaining dispersed - conditioning powder materials including electromagnetic conditioning of produced material polyfractional mechanical mixture, its separation, and collection of the finished powder material differing that foreseen conditioning is carried out by grinding the conditioning mixture under its, electroneutralization conditions, to do this electrical insulation of conditioning mixture is performed by initiating its action with depolarizing electric potential. 2. The method of point 1, differing that depolarizing electric potential is in the range of 10.0÷60.0 V

Inventors: GLOUKHAREV NIKOLAI FEDOROVICH, LEVINSON VALERY GRIGORIEVICH, MOROZOV VYACHESLAV SERGEEVICH, ZAROGATSKY LEONID PETROVICH, GLOUKHAREV, NIKOLAI FEDOROVICH, LEVINSON, VALERY GRIGORIEVICH, MOROZOV, VYACHESLAV SERGEEVICH, ZAROGATSKY, LEONID PETROVICH
Applicants: GLOUKHAREV NIKOLAI FEDOROVICH, LEVINSON VALERY GRIGORIEVICH, MOROZOV VYACHESLAV SERGEEVICH, ZAROGATSKY LEONID PETROVICH, GLOUKHAREV, NIKOLAI FEDOROVICH, LEVINSON, VALERY GRIGORIEVICH, MOROZOV, VYACHESLAV SERGEEVICH, ZAROGATSKY, LEONID PETROVICH
Application year: 1998
Main classification: B02C19
IPC codes: B01J2, B02C19, B02C23, B03B1, C04B7