EP0082816A2 - Method and device for rounding off solid granular particles - Google Patents

Method and device for rounding off solid granular particles Download PDF

Info

Publication number
EP0082816A2
EP0082816A2 EP82810535A EP82810535A EP0082816A2 EP 0082816 A2 EP0082816 A2 EP 0082816A2 EP 82810535 A EP82810535 A EP 82810535A EP 82810535 A EP82810535 A EP 82810535A EP 0082816 A2 EP0082816 A2 EP 0082816A2
Authority
EP
European Patent Office
Prior art keywords
funnel
liquid
particles
rounded
nozzle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP82810535A
Other languages
German (de)
French (fr)
Other versions
EP0082816B1 (en
EP0082816A3 (en
Inventor
Werner J. Borer
Janos Lukacs
Hugo Spalinger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alcan Holdings Switzerland AG
Original Assignee
Alusuisse Holdings AG
Schweizerische Aluminium AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alusuisse Holdings AG, Schweizerische Aluminium AG filed Critical Alusuisse Holdings AG
Publication of EP0082816A2 publication Critical patent/EP0082816A2/en
Publication of EP0082816A3 publication Critical patent/EP0082816A3/en
Application granted granted Critical
Publication of EP0082816B1 publication Critical patent/EP0082816B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B11/00—Machines or devices designed for grinding spherical surfaces or parts of spherical surfaces on work; Accessories therefor
    • B24B11/02—Machines or devices designed for grinding spherical surfaces or parts of spherical surfaces on work; Accessories therefor for grinding balls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B31/00—Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor
    • B24B31/10—Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor involving other means for tumbling of work

Definitions

  • the present invention relates to a method for rounding off granular solid particles, in particular hard granulate.
  • Rounded particles are already manufactured using various processes.
  • a very common method is to spray molten material using a gas jet.
  • This process is mainly used for the production of spherical metal powders, but also for the production of powders from refractory materials.
  • the process has the disadvantage that it cannot be used generally for hard materials, including oxides, carbides, borides and nitrides or refractory metals with a Mohs hardness of> 7, since these materials sometimes have very high melting points and not all remain chemically stable in the molten state.
  • the formation of hollow spherical particles during spraying cannot always be prevented.
  • Another known method for the production of rounded particles is the surface melting and thus rounding of solids in a high energy beam, e.g. a plasma jet. Again, this method can only be used for materials with a stable liquid phase and, depending on the material, is also limited to particle sizes of approx. 10 - 200 p.
  • rounded moldings can be produced by agglomeration or build-up granulation of correspondingly fine starting powders and subsequent sintering in accordance with DE-OS 29 48 584.
  • Such a method is also disadvantageous because the material be previously milled to about 1 / 100th bis 1/1000 of the final desired particle size, in order for even a sinterable powder is obtained, and that the diameter range of the end product to about 0.4 to 5 mm is limited.
  • sol-gel process can only be used for certain materials. It is mainly used for the production of oxide spheres in the range of ⁇ 500 p.
  • the spraying process delivers products of insufficient quality. Usually only particles with low density can be produced due to the loose structure.
  • the inventors have therefore set themselves the task of specifying a method for rounding off granular solid particles of any grain shape, in particular hard material breakage granules, which does not have the disadvantages of the above-mentioned methods.
  • the proposed inventive method is characterized by the wording of claim 1.
  • the particle size of the starting material is advantageously in the range from 100 p to 5 mm.
  • the liquid chosen is one that is unable to dissolve or dissolve the starting grain.
  • water is preferred used.
  • the liquid jet must be so intense that the individual particles collide with one another, causing mutual abrasion.
  • a conical funnel 1 with a tubular lateral outlet 11 there is a nozzle 2 at the lower end for feeding the liquid and an overflow 3 at the upper end.
  • the nozzle 2 in its simplest embodiment is a cylindrical tube. This advantageously projects into the interior of the funnel 1. An increase in the rounding-off performance can thereby be achieved.
  • the cone-shaped part of the funnel 1 is divided in this arrangement in its height H into a lower zone A and an upper zone B.
  • the lower zone A is limited by the height h, which corresponds to the length of the part 22 of the nozzle 2 protruding into the conical part of the funnel 1.
  • the height h is about 1 / 10th of the height H.
  • those particles which are located in the lower zone A, are also involved in the rounding process is fed in by means of a tubular auxiliary nozzle 4 at intervals of time in addition liquid, whereby the in the lower zone A material at rest is conveyed into the upper zone B of the hopper 1, ie into the active zone.
  • the easiest way to switch the auxiliary nozzle 4 on and off is with a solenoid valve 5.
  • the overflow 3 is channel-shaped and has an outlet 6 at one point, where the liquid is removed together with the fine abrasion caused by the rounding. After the abrasion has been separated from the liquid in a manner known per se, the liquid can be fed back to the nozzle 2.
  • the liquid supply is interrupted for a short time and valve 7, advantageously a compressed air membrane valve, is opened so that the rounded material can flow out and (not shown) ) the liquid, which is pumped back into the funnel, is freed via a separating device.
  • valve 7 advantageously a compressed air membrane valve
  • the average sinking speed of the particles to be rounded off in the liquid used should be at least 10 times the speed of the liquid in the upper region b of the upper zone B of the funnel 1, that is to say in the vicinity of the overflow 3 Prevent discharge of the rounded particles from the funnel 1.
  • the amount per unit time rounded particles is as large as possible and on the other hand, all particles in mö g- lichst same extent, ie homogeneous rounded, it has proved to be advantageous, the half aperture angle ⁇ of the funnel 1 14-22 to put °, If the opening angle is too large, some of the rounded material remains on the funnel wall and is not moved. On the other hand, if the opening angle is too small, the Throughput smaller. A funnel angle of 18 - 19 ° is optimal. So that the particles to be rounded cannot leave the funnel 1 via the overflow 3, it is also advantageous to select the height H of the funnel 1 so that it is at least 2.5 times the grain size of the starting material in the idle state before the rounding process begins.
  • the velocity of the liquid in the upper zone B b is in the range with the aid of the nozzle 2 advantageously determined so that it does not than 1 / 20th of the average rate of descent of the particles to be treated is more in the liquid used.
  • the throughput of the amount of liquid through the auxiliary nozzle 4 should advantageously be at least twice as large as the throughput through the nozzle 2.
  • Example 2 Using the same device and under the same conditions as in Example 1, 50 kg of corundum, SN 24 grain (according to FEPA), corresponding to a grain size range of 0.6-0.84 mm, were treated. After 138 hours, a material could be removed which had a roundness of 0.6 and a surface smoothness (roundness) of 0.9. The yield of rounded grain was 68%.
  • the abrasion from the overflow 3 was collected in a sales basin and used for the production of micrograins.
  • the bulk density of granular materials can be increased significantly with short treatment times of less than 1 hour.
  • the bulk density of silicon carbide, grain size SN 8 (according to FEPA), corresponding to a grain size range of 2.0 - 2.8 mm, was 15% after 1 hour of treatment, and even 27% after 3 hours of treatment compared to the bulk weight of the untreated material.
  • Materials treated in this way are advantageously used in the refractory sector because they have an increased resistance to oxidation compared to untreated ones.
  • the toughness of the rounded grains is significantly higher than that of the non-rounded grains.
  • the rounded material could be used as proppants for gap filling in the petroleum industry.
  • the rounded hard materials produced by the process according to the invention can also be used to produce wear-resistant shaped bodies or layers, e.g. Linings of mills, classifiers, cyclones or conveyor lines can be used if they are used as filling material in plastic resin masses or adhesives.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Glanulating (AREA)
  • Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Cereal-Derived Products (AREA)
  • Confectionery (AREA)
  • Seeds, Soups, And Other Foods (AREA)

Abstract

Körnige Feststoffpartikel, insbesondere Hartstoffbruchgranulat, beliebiger Form werden in einem trichterförmigen Behälter (1) mit Hilfe eines Flüssigkeitsstrahls in ständige Relativbewegung versetzt und dadurch abgerundet. Die abgerundeten Partikel eignen sich als Füllstoff für verschleissfeste Schichten.Granular solid particles, in particular hard material crushed granules of any shape, are set in a funnel-shaped container (1) with the aid of a liquid jet in a constant relative movement and thereby rounded off. The rounded particles are suitable as fillers for wear-resistant layers.

Description

Die vorliegende Erfindung betrifft ein Verfahren zum Abrunden von körnigen Feststoffpartikeln, insbesondere von Hartstoffbruchgranulat.The present invention relates to a method for rounding off granular solid particles, in particular hard granulate.

Gerundete Partikel werden nach verschiedenen Verfahren bereits hergestellt. Ein sehr verbreitetes Verfahren ist das Verdüsen schmelzflüssigen Materials mittels eines Gasstrahls. Dieses Verfahren wird vorwiegend zur Herstellung von kugelförmigen Metallpulvern, aber auch zur Herstellung voh Pulvern aus Refraktärmaterialien eingesetzt. Das Verfahren hat den Nachteil, dass es für Hartstoffe, worunter Oxide, Carbide, Boride und Nitride oder refraktäre Metalle mit einer Mohs'schen Härte von > 7 verstanden werden, nicht generell einsetzbar ist, da diese Materialien teilweise sehr hohe Schmelzpunkte aufweisen und nicht alle im schmelzflüssigen Zustand chemisch stabil bleiben. Auch kann die Bildung von hohlkugelförmigen Partikeln bei der Verdüsung nicht immer verhindert werden.Rounded particles are already manufactured using various processes. A very common method is to spray molten material using a gas jet. This process is mainly used for the production of spherical metal powders, but also for the production of powders from refractory materials. The process has the disadvantage that it cannot be used generally for hard materials, including oxides, carbides, borides and nitrides or refractory metals with a Mohs hardness of> 7, since these materials sometimes have very high melting points and not all remain chemically stable in the molten state. The formation of hollow spherical particles during spraying cannot always be prevented.

Ein anderes bekanntes Verfahren zur Herstellung gerundeter Partikel ist das oberflächliche Anschmelzen und damit Runden von Feststoffen in einem Hochenergiestrahl, z.B. einem Plasmastrahl. Dieses Verfahren kann wieder nur für Materialien mit stabiler flüssiger Phase eingesetzt werden und ist zudem je nach Material auf Partikelgrössen von ca. 10 - 200 p begrenzt.Another known method for the production of rounded particles is the surface melting and thus rounding of solids in a high energy beam, e.g. a plasma jet. Again, this method can only be used for materials with a stable liquid phase and, depending on the material, is also limited to particle sizes of approx. 10 - 200 p.

Weiterhin können durch Agglomeration oder Aufbaugranulation von entsprechend feinen Ausgangspulvern und anschliessendes Sintern gemäss der DE-OS 29 48 584 gerundete Formkörper hergestellt werden. Ein derartiges Verfahren ist ebenfalls nachteilig, da das Material vorgängig auf ca. 1/100 bis 1/1000 der schliesslich gewünschten Partikelgrösse gemahlen werden muss, damit überhaupt ein sinterfähiges Pulver entsteht, und dass der Durchmesserbereich des Endproduktes auf ca. 0,4 bis 5 mm begrenzt ist.Furthermore, rounded moldings can be produced by agglomeration or build-up granulation of correspondingly fine starting powders and subsequent sintering in accordance with DE-OS 29 48 584. Such a method is also disadvantageous because the material be previously milled to about 1 / 100th bis 1/1000 of the final desired particle size, in order for even a sinterable powder is obtained, and that the diameter range of the end product to about 0.4 to 5 mm is limited.

Weitere in Frage kommende Verfahren wie das Sol-Gel-Verfahren und die Sprühgranulation sind ebenfalls mit Nachteilen behaftet. Das Sol-Gel-Verfahren lässt sich wieder nur für gewisse Materialien anwenden. Es wird vorwiegend für die Herstellung von Oxidkügelchen im Bereich von ≤ 500 p eingesetzt. Das Sprühverfahren liefert Produkte ungenügender Qualität. Meist können nur Partikel mit niedriger Dichte, bedingt durch den lockeren Aufbau, hergestellt werden.Other possible processes, such as the sol-gel process and spray granulation, also have disadvantages. Again, the sol-gel process can only be used for certain materials. It is mainly used for the production of oxide spheres in the range of ≤ 500 p. The spraying process delivers products of insufficient quality. Usually only particles with low density can be produced due to the loose structure.

Die Erfinder haben sich daher die Aufgabe gestellt, ein Verfahren zum Abrunden körniger Feststoffpartikel beliebiger Kornform, insbesondere Hartstoffbruchgranulat, anzugeben, welches die Nachteile der oben genannten Verfahren nicht aufweist. Das vorgeschlagene erfinderische Verfahren zeichnet sich nach dem Wortlaut des Anspruchs 1 aus.The inventors have therefore set themselves the task of specifying a method for rounding off granular solid particles of any grain shape, in particular hard material breakage granules, which does not have the disadvantages of the above-mentioned methods. The proposed inventive method is characterized by the wording of claim 1.

Vorteilhaft liegt die Partikelgrösse des Ausgangsmaterials im Bereich von 100 p bis zu 5 mm. Als Flüssigkeit wird selbstverständlich eine solche gewählt, die die Ausgangskörnung nicht auf- oder anzulösen vermag. Aus wirtschaftlichen und praktischen Gründen wird vorzugsweise Wasser verwendet. Der Flüssigkeitsstrahl muss derart intensiv sein, dass durch das Aufeinanderprallen der einzelnen Partikel ein gegenseitiger Abrieb bewirkt wird.The particle size of the starting material is advantageously in the range from 100 p to 5 mm. Of course, the liquid chosen is one that is unable to dissolve or dissolve the starting grain. For economic and practical reasons, water is preferred used. The liquid jet must be so intense that the individual particles collide with one another, causing mutual abrasion.

Weitere Vorteile, Merkmale und Einzelheiten der Erfindung ergeben sich aus den Unteransprüchen sowie der nachfolgenden Beschreibung bevorzugter Ausführungsbeispiele und an Hand der Zeichnung; diese zeigt schematisch im Schnitt die zur Durchführung des Verfahrens geeignete Vorrichtung.Further advantages, features and details of the invention emerge from the subclaims and the following description of preferred exemplary embodiments and with reference to the drawing; this shows schematically in section the device suitable for carrying out the method.

An einem kegelförmigen Trichter 1 mit rohrförmigem seitlichen Auslass 11 befindet sich an dem unteren Ende eine Düse 2 zum Einspeisen der Flüssigkeit und am oberen Ende ein Ueberlauf 3. Die Düse 2 ist in ihrer einfachsten Ausführungsform ein zylindrisches Rohr. Vorteilhaft ragt dieses ins Innere des Trichters 1 hinein. Dadurch kann eine Erhöhung der Abrundungsleistung erreicht werden. Der kegelförmige Teil des Trichters 1 wird bei dieser Anordnung in seiner Höhe H in eine untere Zone A und eine obere Zone B eingeteilt. Die untere Zone A ist durch die Höhe h begrenzt, wobei diese der Länge des in dem kegelförmigen Teil des Trichters 1 hineinragenden Teils 22 der Düse 2 entspricht. Vorzugsweise ist die Höhe h etwa 1/10 der Höhe H. Damit diejenigen Partikel, welche sich in der unteren Zone A befinden, auch am Abrundungsprozess beteiligt werden, wird mit Hilfe einer rohrförmigen Hilfsdüse 4 in zeitlichen Abständen zusätzlich Flüssigkeit eingespiesen, wodurch das in der unteren Zone A in Ruhe befindliche Material in die obere Zone B des Trichters 1, d.h. in die aktive Zone befördert wird. Das impulsweise Ein- und Ausschalten der Hilfsdüse 4 geschieht am einfachsten mit einem Magnetventil 5. Der Ueberlauf 3 ist rinnenförmig ausgebildet und hat an einer Stelle einen Ablauf 6, wo die Flüssigkeit zusammen mit dem durch die Abrundung entstandenen feinen Abrieb abgeführt wird. Nach Trennen des Abriebs von der Flüssigkeit in an sich bekannter Weise kann die Flüssigkeit wieder der Düse 2 zugeführt werden. (Trennvorrichtung und Kreislaufführung der Flüssigkeit sind in der Zeichnung nicht enthalten.) Wenn das Ausgangsmaterial hinreichend abgerundet ist, wird die Flüssigkeitszufuhr für kurze Zeit unterbrochen und das Ventil 7, vorteilhaft ein Druckluftmembranventil, geöffnet, so dass das abgerundete Material ausfliessen kann und (nicht eingezeichnet) über eine Trennvorrichtung von der Flüssigkeit, die wieder in den Trichter zurückgepumpt wird, befreit wird.On a conical funnel 1 with a tubular lateral outlet 11 there is a nozzle 2 at the lower end for feeding the liquid and an overflow 3 at the upper end. The nozzle 2 in its simplest embodiment is a cylindrical tube. This advantageously projects into the interior of the funnel 1. An increase in the rounding-off performance can thereby be achieved. The cone-shaped part of the funnel 1 is divided in this arrangement in its height H into a lower zone A and an upper zone B. The lower zone A is limited by the height h, which corresponds to the length of the part 22 of the nozzle 2 protruding into the conical part of the funnel 1. Preferably, the height h is about 1 / 10th of the height H. Thus, those particles which are located in the lower zone A, are also involved in the rounding process is fed in by means of a tubular auxiliary nozzle 4 at intervals of time in addition liquid, whereby the in the lower zone A material at rest is conveyed into the upper zone B of the hopper 1, ie into the active zone. The easiest way to switch the auxiliary nozzle 4 on and off is with a solenoid valve 5. The overflow 3 is channel-shaped and has an outlet 6 at one point, where the liquid is removed together with the fine abrasion caused by the rounding. After the abrasion has been separated from the liquid in a manner known per se, the liquid can be fed back to the nozzle 2. (Separating device and circulation of the liquid are not included in the drawing.) If the starting material is sufficiently rounded, the liquid supply is interrupted for a short time and valve 7, advantageously a compressed air membrane valve, is opened so that the rounded material can flow out and (not shown) ) the liquid, which is pumped back into the funnel, is freed via a separating device.

Es hat sich gezeigt, dass die mittlere Sinkgeschwindigkeit der abzurundenden Teilchen in der verwendeten Flüssigkeit mindestens das 10-fache der Geschwindigkeit der Flüssigkeit im oberen Bereich b der oberen Zone B des Trichters 1, also in der Nähe des Ueberlaufs 3, betragen soll, um ein Austragen der abgerundeten Teilchen aus dem Trichter 1 zu verhindern.It has been shown that the average sinking speed of the particles to be rounded off in the liquid used should be at least 10 times the speed of the liquid in the upper region b of the upper zone B of the funnel 1, that is to say in the vicinity of the overflow 3 Prevent discharge of the rounded particles from the funnel 1.

Damit die Menge der pro Zeiteinheit abgerundeten Partikel möglichst gross wird und andererseits alle Partikel in mög- lichst gleichem Masse, d.h. homogen abgerundet werden, hat es sich als vorteilhaft erwiesen, den halben Oeffnungswinkel α des Trichters 1 zwischen 14 und 22° zu legen, denn bei zu grossem Oeffnungswinkel verharrt ein Teil des abgerundeten Materials an der Trichterwand und wird nicht bewegt. Bei zu kleinem Oeffnungswinkel wird andererseits der Durchsatz kleiner. Optimal ist ein Trichterwinkel von 18 - 19°. Damit die abzurundenden Partikel nicht den Trichter 1 über den Ueberlauf 3 verlassen können, ist weiterhin von Vorteil, die Höhe H des Trichters 1 so zu wählen, dass diese mindestens die 2,5fache Hohe der Kornschüttung des Ausgangsmaterials im Ruhezustand vor Beginn des Rundungsprozesses beträgt. Bei einer Höhe H von 150 cm wird die optimale Leistung erzielt, wenn die momentan im Trichter befindliche Materialmenge ca. 50 kg und der Massestrom des Flüssigkeitsstrahls 30 1/min betragen. Bei einem Massestrom des Flüssigkeitsstrahls von 50 1/min sind ca. 75 kg Ausgangsmaterial optimal, d.h. eine Erhöhung des Massestroms des Flüssigkeitsstrahls auf 50 l/min bringt eine etwa proportionale Erhöhung der Leistung mit sich, bzw. pro l/min bewegte Flüssigkeitsmenge können etwa 1,6 kg Ausgangsmaterial behandelt werden. Diese Beziehung ist praktisch vom Material unabhängig, wenn seine Dichte wenigstens 2 g/cm3 beträgt. Die Geschwindigkeit der Flüssigkeit in der oberen Zone B wird im Bereich b mit Hilfe der Düse 2 vorteilhaft so festgelegt, dass sie nicht mehr als 1/20 der mittleren Sinkgeschwindigkeit der zu behandelnden Partikel in der verwendeten Flüssigkeit beträgt. Der Durchsatz der Flüssigkeitsmenge durch die Hilfsdüse 4 sollte vorteilhaft mindestens doppelt so gross sein wie der Durchsatz durch die Düse 2.Thus, the amount per unit time rounded particles is as large as possible and on the other hand, all particles in mö g- lichst same extent, ie homogeneous rounded, it has proved to be advantageous, the half aperture angle α of the funnel 1 14-22 to put °, If the opening angle is too large, some of the rounded material remains on the funnel wall and is not moved. On the other hand, if the opening angle is too small, the Throughput smaller. A funnel angle of 18 - 19 ° is optimal. So that the particles to be rounded cannot leave the funnel 1 via the overflow 3, it is also advantageous to select the height H of the funnel 1 so that it is at least 2.5 times the grain size of the starting material in the idle state before the rounding process begins. At a height H of 150 cm, optimal performance is achieved when the amount of material currently in the funnel is approx. 50 kg and the mass flow of the liquid jet is 30 1 / min. With a mass flow of the liquid jet of 50 1 / min, approx. 75 kg of starting material are optimal, ie an increase in the mass flow of the liquid jet to 50 l / min brings about an approximately proportional increase in performance, or the amount of liquid moved per l / min can be approximately 1.6 kg of starting material are treated. This relationship is practically independent of the material if its density is at least 2 g / cm 3 . The velocity of the liquid in the upper zone B b is in the range with the aid of the nozzle 2 advantageously determined so that it does not than 1 / 20th of the average rate of descent of the particles to be treated is more in the liquid used. The throughput of the amount of liquid through the auxiliary nozzle 4 should advantageously be at least twice as large as the throughput through the nozzle 2.

Im Betrieb mit Ansätzen von jeweils 50 kg abzurundendem Material bei Verwendung eines Trichters mit einer Höhe H von 150 cm und einem Winkel α. von 18,5° konnte nach 55 Stunden Behandlung eine Rundheit (sphericity) nach Krummbein (W. Krummbein, Measurement and Geological Significance of Shape and Roundness of Sedimentary Particles; Journal of Sedimentary Petrology, 2, 64 - 72, 1941) von über 0,6 erreicht werden.In operation with batches of 50 kg of material each to be rounded off using a funnel with a height H of 150 cm and an angle α. of 18.5 ° after 55 hours of treatment, a roundness (sphericity) according to crook leg (W. Krummbein, Measurement and Geological Significance of Shape and Roundness of Sedimentary Particles; Journal of Sedimentary Petrology, 2, 64-72, 1941) of over 0.6.

Beispiel 1example 1

50 kg Siliziumcarbid-Schleifkorn der Körnung F 14 (nach FEPA*), entsprechend einem Körnungsbereich von 1,19 - 1,68 mm, wurden in einem mit Wasser gefüllten Trichter 1 mit 150 cm Höhe und 100 cm grösstem Durchmesser (α =18,5°) eingegeben. Durch die zylindrische Düse 2, welche einen Innendurchmesser von 5 mm aufwies, wurden 30 1 Wasser pro Minute eingespiesen. Die Hilfsdüse 4, welche einen Innendurchmesser von 4 mm aufwies und 12 cm in den Trichter 1 ragte, wurde in Abständen von jeweils 10 Minuten während je 20 Sekunden mit einer Durchflussmenge von 60 1/min in Betrieb genommen. Nach einer Behandlung von 48 Stunden wurde das verbliebene Material - 60% der anfangs eingesetzten Menge - aus dem Trichter entnommen. Es wies eine Rundheit von 0,6 - 0,7 nach der Krummbein-Skala auf. Die mittelere Korngrösse betrug 1,2 mm.50 kg of silicon carbide abrasive grain of grain size F 14 (according to FEPA * ), corresponding to a grain size range of 1.19 - 1.68 mm, were placed in a funnel 1 filled with water with a height of 150 cm and a maximum diameter of 100 cm (α = 18, 5 °) entered. 30 l of water per minute were fed through the cylindrical nozzle 2, which had an inner diameter of 5 mm. The auxiliary nozzle 4, which had an inner diameter of 4 mm and protruded 12 cm into the funnel 1, was put into operation at intervals of 10 minutes for 20 seconds each with a flow rate of 60 l / min. After 48 hours of treatment, the remaining material - 60% of the amount initially used - was removed from the funnel. It had a roundness of 0.6 - 0.7 on the crook leg scale. The average grain size was 1.2 mm.

* Federation europeenne des fabricants de produits abrasifs * Federation europeenne des fabricants de produits abrasifs

Beispiel 2Example 2

Bei Verwendung derselben Vorrichtung und unter gleichen Bedingungen wie in Beispiel 1 wurden 50 kg Korund, Korn SN 24 (nach FEPA), entsprechend einem Körnungsbereich von 0,6 - 0,84 mm, behandelt. Nach 138 Stunden konnte ein Material entnommen werden, welches eine Rundheit von 0,6 und eine Oberflächenglattheit (roundness) von 0,9 aufwies. Die Ausbeute an gerundetem Korn betrug 68%.Using the same device and under the same conditions as in Example 1, 50 kg of corundum, SN 24 grain (according to FEPA), corresponding to a grain size range of 0.6-0.84 mm, were treated. After 138 hours, a material could be removed which had a roundness of 0.6 and a surface smoothness (roundness) of 0.9. The yield of rounded grain was 68%.

Höhere Ausbeuten konnten mit vorkubisiertem Korn als Ausgangsmaterial erreicht werden.Higher yields could be achieved with pre-cubed grain as the starting material.

Der aus dem Ueberlauf 3 anfallende Abrieb wurde in einem Absatzbecken aufgefangen und für die Herstellung von Microkörnungen weiter verwendet.The abrasion from the overflow 3 was collected in a sales basin and used for the production of micrograins.

Eine Verwendung des erfindungsgemässen Verfahrens besteht darin, dass schon mit kurzen Behandlungszeiten von weniger als 1 Stunde das Schüttgewicht von körnigen Materialien wesentlich erhöht werden kann. So gelang es z.B., das Schüttgewicht von Siliziumcarbid, Körnung SN 8 (nach FEPA), entsprechend einem Körnungsbereich von 2,0 - 2,8 mm, nach 1 Stunde Behandlung um 15%, nach 3 Stunden Behandlung sogar um 27% gegenüber dem Schüttgewicht des unbehandelten Materials zu erhöhen. Solchermassen behandelte Materialien werden mit Vorteil im Feuerfestbereich eingesetzt, da diese eine erhöhte Oxidationsbeständigkeit gegenüber unbehandelten aufweisen. Beim Einsatz als Schleifkorn ergeben sich ebenfalls Vorteile, da die Zähigkeit der gerundeten Körner wesentlich höher ist als die der ungerundeten. Für die Oberfläcnenbearbeitung von Metallen (Shot Peening) sind nach dem erfindungsgemässen Verfahren gerundete Hartstoffe ebenfalls geeignet. Des weiteren könnte das gerundete Material als Proppants zur Spaltenfüllung in der Erdölindustrie eingesetzt werden.One use of the method according to the invention is that the bulk density of granular materials can be increased significantly with short treatment times of less than 1 hour. For example, the bulk density of silicon carbide, grain size SN 8 (according to FEPA), corresponding to a grain size range of 2.0 - 2.8 mm, was 15% after 1 hour of treatment, and even 27% after 3 hours of treatment compared to the bulk weight of the untreated material. Materials treated in this way are advantageously used in the refractory sector because they have an increased resistance to oxidation compared to untreated ones. There are also advantages when used as abrasive grains, since the toughness of the rounded grains is significantly higher than that of the non-rounded grains. For surface processing of metals (shot peening) hard materials rounded by the method according to the invention are also suitable. Furthermore, the rounded material could be used as proppants for gap filling in the petroleum industry.

Die nach dem erfindungsgemässen Verfahren hergestellten abgerundeten Hartstoffe können auch zur Herstellung von verschleissfesten Formkörpern oder Schichten, z.B. Auskleidungen von Mühlen, Sichtern, Zyklonen oder Förderleitungen, eingesetzt werden, wenn sie als Füllmaterial in Kunststoffharzmassen oder Klebern verwendet werden.The rounded hard materials produced by the process according to the invention can also be used to produce wear-resistant shaped bodies or layers, e.g. Linings of mills, classifiers, cyclones or conveyor lines can be used if they are used as filling material in plastic resin masses or adhesives.

Beispiel 3Example 3

Es wurden auf Verschleiss beanspruchte Teile einer Rührwerkskugelmühle mit einer ca. 1,5 mm dicken Schicht Epoxydharz versehen, das 55 Vol.% nach dem erfinderischen Verfahren hergestellte abgerundete SiC-Partikel-mit einem mittleren Durchmesser von 355 µ als Füllstoff enthielt. Nach den ersten 500 Betriebsstunden der Rührwerksmühle war an den Schichten praktisch kein Verschleiss feststellbar.Parts of a stirred ball mill subjected to wear and tear were provided with an approximately 1.5 mm thick layer of epoxy resin which contained 55% by volume of rounded SiC particles with an average diameter of 355 μ as filler produced by the inventive method. After the first 500 hours of operation of the agitator mill, there was practically no wear on the layers.

Claims (7)

1. Verfahren zum Abrunden_von körnigen Feststoffpartikeln, insbesondere von Hartstoffbruchgranulat, dadurch gekennzeichnet, dass Partikel beliebiger Kornform in einem trichterförmigen Behälter (1) mit Hilfe eines Flüssigkeitsstrahls in ständige Relativbewegung versetzt werden.1. A method for rounding off granular solid particles, in particular hard granulate, characterized in that particles of any grain shape are set in constant relative movement in a funnel-shaped container (1) with the aid of a liquid jet. 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass die Bewegungsgeschwindigkeit der Flüssigkeit in der oberen Zone (B) im Bereich (b) nicht mehr als 1/10, vorzugsweise 1/20. der mittleren Sinkgeschwindigkeit der zu behandelnden Partikel in der verwendeten Flüssigkeit beträgt.2. The method according to claim 1, characterized in that the movement speed of the liquid in the upper zone (B) in the region (b) is not more than 1/10, preferably 1/20. the mean sink rate of the particles to be treated in the liquid used. 3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass mittels einer Hilfsdüse (4) in Zeitabständen das in der unteren Zone (A) des Trichters (1) befindliche Material in die obere Zone (B) des Trichters (1) gebracht wird.3. The method according to claim 1 or 2, characterized in that by means of an auxiliary nozzle (4) at intervals the material located in the lower zone (A) of the funnel (1) is brought into the upper zone (B) of the funnel (1) . 4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, dass der Durchsatz der Flüssigkeitsmenge durch die Hilfsdüse (4) mindestens doppelt so gross ist wie der Durchsatz der Flüssigkeitsmenge durch die Düse (2).4. The method according to claim 3, characterized in that the throughput of the amount of liquid through the auxiliary nozzle (4) is at least twice as large as the throughput of the amount of liquid through the nozzle (2). 5. Vorrichtung zur Durchführung des Verfahrens nach mindestens einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass ein trichterförmiger Behälter (1), dessen halber Oeffnungswinkel ( α ) zwischen 14 und 22", vorzugsweise zwischen 17 und 20u, liegt, mit Ueberlauf (3) in der Längsachse eine Düse (2), deren oberes Teil (22) maximal 1/10 der Höhe (H) in den Behälter (1) hineinragt, und im Auslauf (11) eine Hilfsdüse (4) aufweist.5. Device for performing the method according to at least one of claims 1 to 4, characterized in that a funnel-shaped container (1), the half opening angle (α) of which is between 14 and 22 ", preferably between 17 and 20 u , with overflow (3) a nozzle (2) in the longitudinal axis, the upper part (22) of which projects at most 1/10 of the height (H) into the container (1) and has an auxiliary nozzle (4) in the outlet (11). 6. Vorrichtung nach Anspruch 5, dadurch gekennzeichnet, dass die Höhe (H) des trichterförmigen Behälters (1) mindestens die 2,5fache Höhe der Kornschüttung des Ausgangsmaterials im Ruhezustand beträgt.6. The device according to claim 5, characterized in that the height (H) of the funnel-shaped container (1) is at least 2.5 times the height of the grain bed of the starting material in the idle state. 7. Verwendung der gemäss mindestens einem der Ansprüche 1 bis 4 abgerundeten Materialien als Füllstoff für verschleissfeste Schichten, insbesondere aus Kunstharzmassen.7. Use of the rounded materials according to at least one of claims 1 to 4 as a filler for wear-resistant layers, in particular of synthetic resin compositions.
EP82810535A 1981-12-23 1982-12-09 Method and device for rounding off solid granular particles Expired EP0082816B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH8244/81 1981-12-23
CH8244/81A CH667223A5 (en) 1981-12-23 1981-12-23 METHOD AND DEVICE FOR ROUNDING DOWN GRANULAR SOLID PARTICLES.

Publications (3)

Publication Number Publication Date
EP0082816A2 true EP0082816A2 (en) 1983-06-29
EP0082816A3 EP0082816A3 (en) 1985-05-22
EP0082816B1 EP0082816B1 (en) 1988-05-11

Family

ID=4337364

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82810535A Expired EP0082816B1 (en) 1981-12-23 1982-12-09 Method and device for rounding off solid granular particles

Country Status (8)

Country Link
US (2) US4476071A (en)
EP (1) EP0082816B1 (en)
JP (1) JPS58122032A (en)
CA (1) CA1231928A (en)
CH (1) CH667223A5 (en)
DE (2) DE3241459C1 (en)
ES (1) ES8503526A1 (en)
NO (1) NO156114C (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0461469A2 (en) * 1990-05-31 1991-12-18 H.C. Starck GmbH & Co. KG Composite containing hard particles
EP3738673A1 (en) * 2019-05-15 2020-11-18 NETZSCH Trockenmahltechnik GmbH Grinding device for rounding particles

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3345983C2 (en) * 1983-12-20 1986-09-04 Wolfgang 4600 Dortmund Seidler Method and device for the production of spherical metallic particles
JPH0657310B2 (en) * 1987-03-24 1994-08-03 ホソカワミクロン株式会社 Method of sizing inorganic crystalline particles
FR2732674B1 (en) * 1995-04-10 1997-05-09 Alcatel Fibres Optiques PROCESS AND DEVICE FOR SPHEROIDIZATION OF SILICA GRANULES
FR2902767B1 (en) * 2006-06-22 2008-09-19 J P B Creations Sa DEVICE FOR CONDITIONING A PRODUCT BASED ON GLUE
CN103302563B (en) * 2012-03-14 2015-11-25 富泰华工业（深圳）有限公司 Sanding apparatus and use the manipulator of this sanding apparatus

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE459595C (en) * 1924-12-23 1928-05-08 Hartstoff Metall A G Hametag Rounding off metal powder particles
US2460918A (en) * 1942-12-12 1949-02-08 Jr Albert G Bodine Method-of and apparatus for cutting and the like
DE1202171B (en) * 1959-07-03 1965-09-30 Dr Guenter Friese Process for surface processing of workpieces
US3436868A (en) * 1965-03-19 1969-04-08 Christensen Diamond Prod Co Rounding and polishing apparatus for crystalline carbon bodies
DE1427553A1 (en) * 1960-02-19 1969-08-28 Ajem Lab Inc Process and apparatus for surface transformation using grain suspension
FR2157555A5 (en) * 1971-10-21 1973-06-01 Roto Finish Sarl
DE2329335A1 (en) * 1972-07-20 1974-01-31 Barkas Werke Veb METHOD FOR MANUFACTURING PLASTIC SLIDING BEARINGS
GB1389380A (en) * 1972-05-25 1975-04-03 Aakronite Decoratives Ltd Protective surfaces

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1601898A (en) * 1925-07-09 1926-10-05 Roy E Wiley Granular product and method of producing same
US2186659A (en) * 1936-07-17 1940-01-09 Micro Products Corp Magnetic powder for iron dust cores
US2304221A (en) * 1940-03-27 1942-12-08 Celanese Corp Drying apparatus
US2874950A (en) * 1954-03-16 1959-02-24 Pyzel Fitzpatrick Inc Hydraulic cement process
US3207818A (en) * 1963-12-27 1965-09-21 Western Electric Co Methods of forming spherical particles of crystallizable thermoplastic polymers
JPS518876B2 (en) * 1972-10-03 1976-03-22
JPS5535062Y2 (en) * 1976-01-09 1980-08-19
US4165473A (en) * 1976-06-21 1979-08-21 Varian Associates, Inc. Electron tube with dispenser cathode
JPS5542734A (en) * 1978-09-19 1980-03-26 Inoue Japax Res Inc Barrel grinding method
CA1117987A (en) * 1978-12-13 1982-02-09 Robert J. Seider Sintered high density spherical ceramic pellets for gas and oil well proppants and their process of manufacture
US4246208A (en) * 1979-03-22 1981-01-20 Xerox Corporation Dust-free plasma spheroidization
JPS5626975A (en) * 1979-08-14 1981-03-16 Asahi Glass Co Ltd Display element

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE459595C (en) * 1924-12-23 1928-05-08 Hartstoff Metall A G Hametag Rounding off metal powder particles
US2460918A (en) * 1942-12-12 1949-02-08 Jr Albert G Bodine Method-of and apparatus for cutting and the like
DE1202171B (en) * 1959-07-03 1965-09-30 Dr Guenter Friese Process for surface processing of workpieces
DE1427553A1 (en) * 1960-02-19 1969-08-28 Ajem Lab Inc Process and apparatus for surface transformation using grain suspension
US3436868A (en) * 1965-03-19 1969-04-08 Christensen Diamond Prod Co Rounding and polishing apparatus for crystalline carbon bodies
FR2157555A5 (en) * 1971-10-21 1973-06-01 Roto Finish Sarl
GB1389380A (en) * 1972-05-25 1975-04-03 Aakronite Decoratives Ltd Protective surfaces
DE2329335A1 (en) * 1972-07-20 1974-01-31 Barkas Werke Veb METHOD FOR MANUFACTURING PLASTIC SLIDING BEARINGS

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0461469A2 (en) * 1990-05-31 1991-12-18 H.C. Starck GmbH & Co. KG Composite containing hard particles
EP0461469A3 (en) * 1990-05-31 1992-05-06 Lonza Ag Composite containing hard particles
EP3738673A1 (en) * 2019-05-15 2020-11-18 NETZSCH Trockenmahltechnik GmbH Grinding device for rounding particles

Also Published As

Publication number Publication date
DE3241459C1 (en) 1983-07-21
ES518042A0 (en) 1985-03-16
JPS6359735B2 (en) 1988-11-21
JPS58122032A (en) 1983-07-20
NO156114B (en) 1987-04-21
NO156114C (en) 1987-08-05
EP0082816B1 (en) 1988-05-11
US4592707A (en) 1986-06-03
DE3278460D1 (en) 1988-06-16
EP0082816A3 (en) 1985-05-22
US4476071A (en) 1984-10-09
NO824296L (en) 1983-06-24
ES8503526A1 (en) 1985-03-16
CA1231928A (en) 1988-01-26
CH667223A5 (en) 1988-09-30

Similar Documents

Publication Publication Date Title
DE2908136A1 (en) METHOD AND DEVICE FOR MANUFACTURING UREA CORES
CH647422A5 (en) AGITATOR MILL FOR GRINDING A PROCESS MIXTURE.
DE3216022A1 (en) JET MILL WITH LIMITED VEGETORS
DE60311152T2 (en) METHOD FOR SELECTIVELY REMOVING A MATERIAL PRESENT IN ONE OR MULTIPLE LAYERS ON A SUBJECT AND DEVICE FOR CARRYING OUT THIS METHOD
EP1721019B1 (en) Method for the production of a raw sintering mixture
DE1209931B (en) Process for the production of aqueous clay and / or bentonite-containing slurries of a certain density
EP1808231A1 (en) Separation of minerals
EP0082816B1 (en) Method and device for rounding off solid granular particles
DE3140294A1 (en) Method and device for separating a mixture of materials into components having differing degrees of grindability
DE2821517A1 (en) PROCEDURE AND DEVICE FOR THE INDEPENDENT REGULATION OF A PNEUMATIC CONVEYOR
DE102012024316A1 (en) Treatment of regrind for comminution in a press mill
EP2463058B1 (en) Blasting nozzle for a device for blasting-machine or abrasive blasting objects
EP3455177B1 (en) Method for producing hollow glass microspheres
DE2451775C2 (en) Process for the recovery of metal
DE3538991A1 (en) METHOD FOR MINIMIZING MINERAL SUBSTANCES AND DEVICE FOR IMPLEMENTING THE METHOD
DE2133802A1 (en) Separating granulates by density - using liquid flowing upward through perforated vibrating trough
DE3007292C2 (en) Method and device for the continuous production of granules formed from the dry matter content of a solution or suspension
DE1932094B2 (en) DEVICE FOR MIXING POWDERED AND MASHED GUETER
DE19718668C2 (en) Process for separating and continuously removing difficult-to-disperse components
EP2230004A1 (en) Cascade-type coating device for powdery material, and related method
DE3310709A1 (en) Sifter for classifying bulk material
EP0267975B1 (en) Process for the continuous production of granules from a solid material in a fluidized bed
DE19724142B4 (en) Process for the production of granulated mixed fertilizer
DE102010060135A1 (en) Blasting nozzle for a device for blasting objects
DE1901746B2 (en) Dry grinding for granular material eg - cement clinker

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): BE CH DE FR GB IT LI NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): BE CH DE FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19851108

17Q First examination report despatched

Effective date: 19860708

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH DE FR GB IT LI NL SE

REF Corresponds to:

Ref document number: 3278460

Country of ref document: DE

Date of ref document: 19880616

ITF It: translation for a ep patent filed

Owner name: SOCIETA' ITALIANA BREVETTI S.P.A.

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19940530

Year of fee payment: 12

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19941231

Ref country code: CH

Effective date: 19941231

EAL Se: european patent in force in sweden

Ref document number: 82810535.3

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19961118

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19961216

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19961220

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19961231

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19970120

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19970124

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971209

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971210

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19971231

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971231

BERE Be: lapsed

Owner name: SCHWEIZERISCHE ALUMINIUM A.G.

Effective date: 19971231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980701

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19971209

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19980701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980901

EUG Se: european patent has lapsed

Ref document number: 82810535.3

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST