WO2012068647A2

WO2012068647A2 - Grinding body

Info

Publication number: WO2012068647A2
Application number: PCT/BG2011/000023
Authority: WO
Inventors: Petar Bodurov; Todor Penchev
Original assignee: Assarel-Medet Ad
Priority date: 2010-11-24
Filing date: 2011-11-21
Publication date: 2012-05-31
Also published as: BG110798A; WO2012068647A3; BG66577B1; WO2012068647A4

Abstract

The invention relates to a grinding body for crushing and grinding of ores, rocks or earth, inert and all other materials, in drum- and other types of mills. It finds application in ore enrichment, production of construction materials, waste processing and other industrial branches. The grinding body has a shape of or like a spheroidal tetrahedron which has six edges, four vertices and four semispherical faces. The six edges are usually arcs of a circle with equal lengths, but they may be embodied as versions in which the arcs of three of the edges coming out of the same vertex are of the same length, different from the arcs length of the other three edges, which are also arcs of equal length. The edges of the tetrahedrons may also be arcs of other geometrical curves such as arcs of a parabola, spiral, etc. In another version for better producibility e.g. by casting, on at least one of the faces of the grinding body there is a spot. The spot may be flat or round more or less convex or concave. A short cylinder with a flat top can be made on one of the faces of the body. In another version parts of a cylinder are performed through three of the vertices and on three of the faces. In another version at least one of the vertices of the tetrahedron is cut flat at a plane perpendicular or at an angle to the axis of the body. In another version the flat cut vertex is round more or less concave. In another version a short cylinder or a short prism with flat tops is made on the flat cut vertex. In another version a peripheral ring with a disk-like, triangle-like or rectangle-like cross section is made through three of the vertices and over three of the faces. All edges and vertices of the body may be convex or concave. The existence of edges and vertices makes the grinding body more efficient in crushing bigger particles of the ground materials. The greater area of the grinding body compared to the spherical grinding body and its greater density in a given volume increase significantly its productivity of grinding. A major advantage of the suggested grinding body is its producibility which allows its successful mass production.

Description

GRINDING BODY

FIELD OF THE INVENTION

The invention relates to a grinding body for fragmentation and grinding of ores, rock and earth mass and all other materials in drum- and other types of mills. It is applied in ore enrichment, production of construction materials, coal powder, waste utilization and in other industrial branches.

BACKGROUND OF THE INVENTION

The spherical shape grinding body for drum mills is widely known. Disadvantages of the spherical grinding body are their low productivity, slow crushing of bigger cobs due to absence of edges and low level of stuffing of the working space.

Other grinding bodies are known, of tetrahedron shape with flat or rounded faces [DE 440 198/1927, FR 811 408/1937, SU 1 388 088/1985, RU 2 305 597/2005], which have the disadvantage to be not easy and cheap for mass-production and for that reason have not been practically used yet. An International patent application WO/2010/094091 is known, which describes a tetrahedron grinding body, that overcomes the difficulties and high cost of production of the above mentioned body.

A cubic shape grinding body is also known - US 1 431 475/1920, which has not been used because of expensive and difficult production as well as worse milling results shown compared to the spherical grinding body (Norris G. C, Some Grinding Tests with Spheres and Other Shapes, Trans. Inst. Min. Metal, London, Feb. 1954, 63(567), pp. 197-209).

DESCRIPTION OF THE INVENTION

The objective of the invention is to create a grinding body with a convenient shape for mass production and which quickly and efficiently crushes and grinds the feed material. The objective is achieved through the invention of a grinding body of a spheroidal tetrahedron or similar shape. That grinding body has six edges, four vertices and four semispherical faces. The six edges of the tetrahedron are usually arcs of circles with equal lengths, but there may be cases when the arcs of three of the edges coming out of the same vertex have equal lengths, different from the lengths of the other three edges, which in turn are also of equal lengths. The centres of radii of the arcs of the edges of the tetrahedron may be placed inside or outside its vertices. The tetrahedron edges may be arcs of other geometrical curves e.g. arcs of a parabola, of a spiral, etc. In a subsequent version, for better producibility e.g. by casting, at least one of the faces of the tetrahedron is shaped as a flat spot with circular or other shape.

In another version a short cylinder with a flat top face is made on one of the faces of the tetrahedron.

In other versions the spot is more or less convex or concave to the face of the tetrahedron on which it is made.

In another version parts of cylinders are made over three of the vertexes and on three of the faces of the tetrahedron.

In another version at least one vertex of the tetrahedron there is flatly cut perpendicular or at angle to the axis of the tetrahedron passing through the vertex before cutting and through the centre of the tetrahedron.

In another version the cut vertex is more or less concave - round in the cut part.

In another version a short cylinder or a short prism is made over the cut vertex; the prism has a triangle - like cross section and both have flat tops.

In another version a peripheral ring is made on three of the faces through three of the tetrahedron vertices; the ring has a disk-like cross section and is more or less convex. In another version the perimeter round ring has a triangle-like cross section, more or less convex. In another version the perimeter round ring has a rectangle-like cross section, more or less convex.

The edges and vertices of the described versions of grinding bodies with spheroidal tetrahedron-like shape may also be round and the roundness may be as a part of a circle, a spiral or of another geometric curve.

The suggested grinding body may be produced from a variety of materials e.g. metals, ceramics, glass, etc., and the technologies most often used for mass making of such products are suitable for its production.

The main advantage of the suggested grinding body in this invention is its producibility which allows its successful mass production by the most often used for such products technologies such as casting, forging, rolling, etc. Other advantages of that grinding body are the existence of edges and vertices which even cut flat or rounded help for faster crushing of bigger cobs of the grinded materials. Another advantage of the grinding body is its ability, due to its specific shape, to stuff more densely in a given volume, i.e. the same volume would take a greater number of tetrahedron grinding bodies compared to the spherical grinding bodies which is also a precondition for greater productivity of grinding. Additionally the geometry of that body provides greater contact area between the grinding bodies and between the bodies and the mill walls. The surface area of the suggested grinding body is greater than that of the spherical body at equal volume and mass which also provides greater productivity of milling compared to the presently used spherical grinding body.

DESCRIPTION OF THE FIGURES

The invention is illustrated in details with exemplary drawings of grinding bodies, shown in the figures included, where:

- Figure 1 represents a front view of a grinding body with a spheroidal tetrahedronlike shape which has a flat cut spot on one of its faces;

- Figure 2 represents a top view of the tetrahedron on Fig 1 ;

- Figure 3 represents a front view of a grinding body with spherical tetrahedron-like shape and a short flat top cylinder on one of the faces;

- Figure 4 represents a front view of a grinding body with spherical tetrahedron-like shape with a more or less convex more or less rounded spot on one of the faces;

- Figure 5 represents a front view of a grinding body with spherical tetrahedron-like shape and a concave rounded spot on one of its faces;

- Figure 6 represents a front view of a grinding body with spherical tetrahedron-like shape with fragments of a cylinder, placed around three of the vertices and around three of the faces of the tetrahedron;

- Figure 7 represents a front view of a spheroidal tetrahedron-like grinding body with at least one vertex cut flat;

- Figure 8 represents a front view of a spheroidal tetrahedron-like grinding body with one vertex round concave cut flat;

- Figure 9 represents a front view of a spheroidal tetrahedron-like grinding body with one vertex cut flat and a round ring passing through three non-cut vertices of the tetrahedron and over three of the faces and has a disk-like cross section;

- Figure 10 represents an A-A cross section of the round ring on Fig 9, which is a disklike cross section, more or less convex to the faces and edges of the tetrahedron; - Figure 11 represents a front view of a spheroidal tetrahedron-like grinding body with one vertex cut flat and a round ring passing through three non-cut vertices of the tetrahedron and over three of the faces and has a triangle-like cross section;

- Figure 12 represents a B-B cross section of the peripheral ring on Fig 11, which has a triangle-like shape;

- Figure 13 represents a front view of a spheroidal tetrahedron-like grinding body with one vertex cut flat and a round ring passing through three non-cut vertices of the tetrahedron and over three of the faces and has a rectangle-like cross section;

- Figure 14 represents a C-C rectangle-like cross section of a round ring from Fig 13.

PREFERRED EMBODIMENTS OF THE INVENTION

Fig. 1 shows a preferred embodiment of a spheroidal tetrahedron-like grinding body, 1 marking the flat spot on one of the faces 2 of the tetrahedron. Edges 3 and vertices 4 are also marked. Fig. 2 represents a top view of the grinding body from Fig. 1 and faces 2, edges 3 and vertices 4 are pointed.

Fig. 3 shows an example embodiment of the grinding body with a protruding short cylinder 5 with a flat top 6 on one of the faces 2. The versions of grinding bodies on Fig. 1 and 3 are best produced by casting.

Fig. 4 shows a front view of a grinding body with a round spot 7 having a circular shape, more or less convex to the face 2 on one of the faces of the tetrahedron. Fig 5 shows a front view of a grinding body with a round spot 8 having a circular shape, concave to the face 2 on which it is made. Figure 6 represents a front view of a spheroidal tetrahedron-like grinding body with parts of a cylinder 9 which are drown peripherally through three of the vertices 4 and on three of the faces 2 of the tetrahedron. Figure 7 represents a front view of a grinding body with a flat cut vertex 10. Figure 8 represents a front view of a spheroidal tetrahedron-like grinding body with a flat cut and round concave vertex 1 1. The versions of grinding bodies on Fig. 4, 5, 6, 7 and 8 are suitable for production through forging on presses and hammers.

Figure 9 represents a front view of a spheroidal tetrahedron-like grinding body with a flat cut vertex 10 and a peripheral ring 12 with a disk-like cross section. Figure 10 represents an A- A cross section of the peripheral ring 12 on Fig. 9, which has a disk-like cross section, more or less convex to the faces 2 and edges 3. Figure 11 represents a front view of a spheroidal tetrahedron-like grinding body with one vertex 10 cut flat and a peripheral ring passing through three non-cut vertices of the tetrahedron and over three of the faces and has a triangle-like cross section. Fig. 12 represents a B-B cross section of the peripheral ring 13 on Fig. 11, which has a triangle-like shape. Figure 13 represents a spheroidal tetrahedron-like grinding body with one vertex 10 cut flat and a peripheral ring passing through three non-cut vertices of the tetrahedron and over three of the faces and has a rectangle-like cross section. Fig. 14 represents a C-C rectangle-like cross section of a peripheral ring 14 from Fig. 13. The Fig. 9, 11 H 13 are most suitable for mass production on automated hammering and forging machines.

Other technologies are also applicable for production of the grinding bodies, shown on the figures, i.e. through rolling, etc.

The above examples do not use up the possible versions for technical embodiment of the grinding body.

References:

1) DE 440 198/1927.

2) FR 811 408/1937.

3) SU 1 388 088/1985.

4) RU 2 305 597/2005.

5) WO/2010/094091(26.08.2010).

6) US 1 431 475/1920.

Claims

1. A spheroidal tetrahedron-like grinding body, characterized in that the three equally long arcs of the edges (3), coming out of the same vertex (4), have equal or different length to/from the arcs of the other three edges, which are also equally long and on at least one of the faces there is a flat spot (1) and/or a short cylinder (5) with a flat top (6) and parts of a cylinder (9) are made peripheral on three of the faces (2) and through three of the vertices (4), or a peripheral ring is put (12, 13 and 14).

2. A grinding body according to Claim 1, characterized in that the arcs of the edges

(3) of the body are parts of a circle or of another geometrical curve.

3. A grinding body according to Claims 1 and 2, characterized in that the centres of radii of the arcs of the edges (3) may be situated inside or outside the vertices (4) of the tetrahedron.

4. A grinding body according to Claim 1, characterized in that at least one of the vertices (4) of the body is cut flat (10) with the plane perpendicular or at an angle to the axis of the tetrahedron.

5. A grinding body according to Claims 1 and 4, characterized in that on the flat cut vertex (10) of the body a short cylinder or a short prism with a triangle-like cross section is formed, each one having a flat top.

6. A grinding body according to Claims 1 and 4, characterized in that the flat cut vertex (10) of the body is more or less round-concave (11).

7. A grinding body according to Claim 1, characterized in that the spot (1) has a circular or other shape and is flat or round more or less convex (7) or concave (8) to the face (2) on which it is situated.

8. A grinding body according to Claim 1, characterized in that the peripheral ring (12) has a disk-like cross section, more or less convex.

9. A grinding body according to Claim 1, characterized in that the peripheral ring (13) has a triangle-like cross section, more or less convex.

10. A grinding body according to Claim 1, characterized in that the peripheral ring (14) has a rectangle-like cross section, more or less convex.

11. A grinding body according to Claims 1 to 10, characterized in that all edges and vertices of the body may be rounded on part of a circle, a spiral or of another geometrical curve.