RU116795U1 - CLASSIFICATING DEVICE FOR UNLOADING A BALL MILL AND HALF-MILLING MILLS WITH A MAGNETIC CATTENDER FOR METAL SCRAP - Google Patents

Abstract

A classifying device for unloading a ball mill and a semi-autogenous grinding mill with a magnetic metal scrap catcher, installed on the discharge neck of a semi-autogenous mill, characterized in that a classifier unit is attached to the discharge neck, which is a hydraulic drum screen, which can be made in the form of a multi-faceted drum or truncated pyramid), the side faces of which are sieves (perforated, metal, polyurethane), the removal of metal scrap is carried out using a magnetic catcher in the form of a sector installed between two screens, and the end screen, for large screening, can be made in the form of a cylinder, a polyhedral prism, truncated cone or truncated pyramid.

Description

The utility model relates to the enrichment industry and can be used in ball mills in semi-self-grinding mills in technological schemes for the disintegration of mineral, raw materials, as well as in the chemical industry.

It is known to classify a drum-type device, which is a two-day drum screen (Redistribution of grinding energy between stages under the conditions of Urupsky GOK / P.V. Malyarov, V.F. Stepurin, G.M.Soldatov, N.A. Konnik // Enrichment ore. 2006. No. 3. S.18-21.). The inner deck serves to remove large metal scrap, and the outer deck is used to separate by size the grinding products (Intensification of grinding processes in the conditions of the Talnakh processing plant / P.V. Malyarov, G.M.Soldatov, N.G. Kaitmazov, P.M. Baskaev, V.A. Ivanov, D.V. Kotenev // Ore dressing. 2008. No. 6, C.6-10.) A two-day drum screen allows rational distribution of the load between successive stages of ball grinding with separation of the discharge of the mill of the first stage into two classes.

The disadvantage of this design is:

1. The inability to separate the discharge of the mills into three classes, the need for which arises when using mills semi-grinding.

2. The inability to withdraw from unloading mills semi-self-grinding metal scrap in the form of fragments of worn and cracked balls smaller than the holes of the inner deck (butary).

The closest in technical solution is a hydraulic drum screen with a magnetic catcher for metal scrap (Certificate of the Russian Federation for utility model No. 110003, IPC V07V 1/18, 2011), which is a one-day drum screen fixed to a blank shell made of non-magnetic steel. In which the capture of metal scrap occurs due to a magnetic field formed by permanent magnets.

The disadvantages of this design are:

1. The inability to separate the grinding products into three fractions.

2. The magnetic catcher of the classification device is installed immediately after the discharge neck of the mill. In this case, the extraction of metal inclusions from the pulp, which has an increased viscosity, a significant volume and speed of movement, requires the creation of powerful magnetic fields. Which entails a rise in price and complexity of the design.

3. The diameter of the blind non-magnetic shell is overestimated and depends on the diameter of the discharge neck of the mill, on the other hand, the large sizes of the shell and, accordingly, the fixed part of the magnetic trap with magnets are dictated by the requirements of the capacity of the entire pulp volume that leaves the mill.

The technical result of a useful model of the claimed invention is to separate the grinding products of ball mills and mills of semi-self-grinding into three fractions, in accordance with the technological requirements of disintegration schemes, with the simultaneous extraction of metal scrap.

The specified technical result is achieved in that the classifying device for unloading a ball mill and a semi-self-grinding mill with a magnetic catcher of metal scrap consists of three zones according to the functional sign:

1st zone - a classifying device (screen) mounted on the discharge neck of the mill, which is a hydraulic drum screen (can be made in the form of a cylinder, a multifaceted prism, a truncated cone or a truncated pyramid). The side faces of which are sieves (perforated, metal, polyurethane). The screen is intended for separation according to boundary size when the class “minus” is sent for thin classification into hydrocyclones, and the class “plus” for regrinding and refinement.

2nd zone - is a magnetic catcher for extracting metal scrap from the mill discharge, installed between two screens, consisting of a blank shell made of non-magnetic steel and a magnetic system (magnetic catcher) in the form of a sector based on permanent magnets. The magnetic system is mounted motionless and coaxial to the blind shell. In the magnetic field, the scrap moves together with the shell, and upon termination of the field, it breaks away from the shell and, due to gravitational forces, enters the hopper, and from there it is fed into a special box through the gutter.

3rd zone - end classifier (screen), mounted on the flange of a magnetic catcher, which is a hydraulic drum screen (can be made in the form of a cylinder, a multifaceted prism, a truncated cone or a truncated pyramid). The side faces of which are sieves (perforated, metal, polyurethane). The screen is intended for separation according to the boundary size of larger classes, when the minus class is sent to grinding in the mills of the subsequent stages, and the plus class is to be finished or circulating.

A schematic diagram of a classifying device for unloading a ball mill and a semi-self-grinding mill with a magnetic catcher of metal scrap is shown in figure 1 where:

1. Hydraulic drum screen;

2. A blank shell;

3. Magnetic system;

4. The bunker;

5. Trough;

6. The end roar.

A classifying device for unloading a ball mill and a semi-self-grinding mill with a magnetic catcher of metal scrap works as follows. From the discharge neck of the mill, grinding products fall onto a hydraulic drum screen (item 1). It can be made in the form of a cylinder, a multifaceted prism, a truncated cone or a truncated pyramid, whose side faces are sieves (perforated, bobbin, polyurethane). The screen is intended for separation according to boundary size when the class “minus” is sent for thin classification into hydrocyclones, and the class “plus” for regrinding and refinement. After the initial classification of the grinding products, the plus class is fed to the blank shell (item 2) made of non-magnetic material. Under the action of the magnetic field forces that are created by the magnetic system (item 3), the metal scrap rises together with the shell, and in the zone of termination of the magnetic field it breaks away from the shell and, due to gravitational forces, enters the hopper (item 4), from there the gutter (pos. 5) is fed into a special box (mold). From the blank shell, the pulp, cleaned of metal scrap, enters the end classification device (pos. 6), which is mounted on the flange of the magnetic catcher. It is a hydraulic drum screen (can be made in the form of a cylinder, a multifaceted prism, a truncated cone or a truncated pyramid). The side faces of which are sieves (perforated, metal, polyurethane). The screen is intended for separation according to the boundary size of larger classes (secondary classification), when the minus class is directed to regrinding in the mills of the subsequent stages, and the plus class is added for refinement or is used as a circulating load.

The proposed utility model makes it possible to extract metal scrap from mill grinding products. According to experimental data, its content in the circulating load is 8-10%. Removing scrap from dehydrated large classes has a positive effect on the quality of separation. It is worth noting that large classes account for up to 20% of the volume of mill discharge products and this allows the use of a lower magnetic field. By eliminating metal scrap, we increase the loading of the mill with the initial feed, and therefore its productivity. In addition, the extraction of metal scrap will allow not only to use sand pumps for transportation, but also to increase their service life and the service life of the hydrocyclones into which they feed the pulp. It will allow to divide the grinding product of the mill into 3 classes, which will simplify the technological schemes of disintegration, improve the quality of the finished class and allow rationally redistributing the grinding energy.

Claims (1)

A classifying device for unloading a ball mill and a semi-self-grinding mill with a magnetic catcher of metal scrap, mounted on the discharge neck of a semi-self-grinding mill, characterized in that a classifier unit is attached to the discharge neck, which is a hydraulic drum screen (can be made in the form of a round cone, or a truncated pyramid), the side faces of which are sieves (perforated, metal, polyurethane), the output is metallic Scrap is carried out using a magnetic catcher in the form of a sector mounted between two screens, and the end screen, for large screening, can be made in the form of a cylinder, a multifaceted prism, a truncated cone or a truncated pyramid.