DE2635161A1 - PROCESS FOR THE RECOVERY OF MAGNETIC HEAVY PARTICLES FROM A SUSPENSION - Google Patents

Description

VONKREISLER SCHONWALD MEYER EISHOH). FUES FROM KREISLER KELLER SELTING

PATENT LAWYERS Dr.-Ing. by Kreisler + 1973

Dr.-Ing. K. Schönwald, Cologne Dr.-Ing. Th. Meyer, Cologne Dr.-Ing. K. W. Eishold, Bad Soden Dr. J. F. Fues, Cologne Dipl.-Chem. Alek von Kreisler, Cologne Dipl.-Chem. Carola Keller, Cologne Dipl.-Ing. G. Selting, Cologne

Sch-DB / To.

5 Cologne ι, 4. August 1976

DEICHMANNHAUS AT THE MAIN RAILWAY STATION

ANGLO AMERICAN CORPORATION OF SOUTH AFRICA LIMITED, 44 Main Street, Johannesburg, Transvaal, South Africa

Process for the recovery of heavy magnetic particles from a suspension

The invention relates to heavy beet separation, in which magnetic particles are used as the heavy material.

The sword beet separation is a well-known one Process for the separation of solid particles of different densities in a mixture. As sword beet serves as a suspension of heavy materials in a liquid. The particle mixture to be separated is with the suspension mixed so that the various particles can sink or float. The process can e.g. take place in a cyclone (separator). When it comes to gross parts, the separation of the parts is the underflow (sinking material) and the overflow (floating material) from the heavy beet are unproblematic by simply sieving.

709808 / 08U

Telephone: (0221) 23 4541-4 Telex: 8882307 dopa d Telegram: Dompalent Cologne

ORIQJNAL iNSPECTSD

If the heavy beet separation for particles over 1000 / rev is used, the greater part of the pulp can be recovered for immediate reuse by sieving alone will. The magnetite particles adhering to the washed product can be brushed off, and the so generated Magnetite thin turbidity can be seen in magnet see idem cleaned and be focused.

When trying to get solid particles of the grain class

- Wash <1000 / U, can be an effective separation of the cleaned particles from the pulp cannot easily be achieved by simply sieving. Otherwise results due to the adhesion of the magnetite due to the large surface area of the cleaned particles serious problem. Therefore, it has been proposed in washing systems for cleaning lOOOyU particles that the entire separation of the purified products from the pulp is achieved by magnetic separation.

For an acceptable recovery of the heavy beet, however, large separation zones and considerable dilution are required tion of the suspensions is required. This is an expensive step. J

A method for recovering heavy magnetic!

substances from a suspension that contain these particles and.-:

i which contains lighter particles, is according to the invention · characterized in that the suspension has at least one single-stage "high relative density separation" (High relative density separation) is subjected, so that one essentially only contains heavy substances first fraction and a second containing most of the other particles and some heavy matter Fraction received, and that the second fraction a magnetic separation to regenerate the remaining heavy particles learns.

709808 / 08U

The density separation can be in one, two or three stages' be performed. In the case of multi-stage processes, the task is expediently dewatered at each subsequent stage.

Each level of "high specific gravity separation" can be in a cyclone. According to one embodiment of the invention, a conical separator is preferred: i.e. a cyclone with a cone angle in the range of 60 ° to 180 °.

The inventive method can be used for the separation of

Fine coal particles from a heavy beet are used, ι

whose heavy materials consist of magnetite. For example ■

it can be used to treat the overflow from a heavy;

cloudy process for processing fine coal; are set.

In this case, the method can also be used to treat the underflow, i.e. to separate the magnetite particles from, the discard particles are used.!

The invention is described below with reference to the stream-j picture of a plant for the processing of fine coal explained in more detail j.

Raw coal grits to be processed are mixed with an aqueous suspension of magnetite in a tank 2. The feed mixture is fed to a cyclone 4 for conventional heavy beet processing of fine coal. The underflow of the cyclone h contains a suspension of waste material and magnetite particles, while the overflow contains a mixture of washed fine coal and magnetite particles. Both the underflow and the overflow ·;

a further similar treatment are subjected to i in order to separate them contained in magnetite from the other \ lighter particles (coal or committee).

709808/081 k

- 4 The procedure is as follows:

The underflow from the cyclone 4 is fed to a screening stage 6 so that coarse defective fractions, i.e. fractions that exceed a predetermined grain size of e.g. 1000 / U, be eliminated. The overflow from the screening stage 6, which contains the coarse defective fraction, is discharged and the underflow reaches a first separator 8.1. The overflow from separator 8.1 becomes a drainage stage 10 and then fed to a second separator 8.2. The screening stage 6 has a shower system 6.1, which with Water from the dewatering stage 10 is fed. Of the The underflow from the shower system 6.1 is added to the overflow from the separator 8.1 before it enters the drainage stage 10 entry. The underflow of each separator 8.1, 8.2 is adjusted so that it forms a fraction, which contains essentially only magnetite particles. This fraction is via a thick beet container 14 and a Collection box 16 returned to tank 2. The overflow from the second separator 8.2 forms a second fraction, which contains most of the waste and some lighter particles. The second fraction comes to one Magnetic separator 12, in which the remaining magnetite particles are recovered. The recovered magnetite is from Magnetic separator 12 returned to tank 2 via the thick beet container 14 and the collecting tank l6. The misalignment Fine material is derived.

The overflow from separator 4 is treated similarly. He arrives at a screening stage 18 for the separation of coarse coal fractions, i.e. those fractions which have a j

exceed a predetermined grain size of, for example, lOOOyU. Of the! Overflow from the screening stage 18, which contains the coarse Kohlefrak- ■ tions is discharged and it is supplied to the underflow, a first discriminator 20.1. The overflow from this separator 20.1 feeds a dewatering stage 22j and then a second separator 20.2. To the sieve!

709808 / 08U

2635Ί61.

level l8 includes a shower system I8.I, which is supplied with water ''

is fed from the dewatering stage 22. The underflow from the shower system I8.I is the overflow from
Separator 20.1 added before entering the dewatering stage 22. The lower reaches of the Scheidern 20.1
and 20.2, which contain essentially only magnetite particles, are returned to tank 2 via the thick beet container 14 and the collecting box 16. The overflow: from separator 20.2 contains most of the coal particles and some magnetite particles. He gets to
a magnetic separator 12 for recovering the magnetite particles. The recovered magnetite is over the
Thick beet container 14 and the collecting box 16 to the tank 2 | returned, while the cleaned fine coal is discharged, ι wear. !

The separators 8.1, 8.2, 20.1 and 20.2 are designed as wide-angle cyclones with a cone angle in the area is from 60 ° to 180 °. ι

The magnetite 1 used to produce the heavy beet particles have the conventional ones for such processes! Size not exceeding 100u. !

The fine coal for which the method is particularly applicable has a particle size that is the order of magnitude
of 1000 Ai does not exceed, and in which the grain size ι of the main component - = c500 u . Particles of this size j oppose common separation techniques, eg foam flotation, and require heavy beet separation | and thus magnetic separation of the magnetite materials from the coal and the defective materials in the overflow or underflow.

In a number of attempts, an essentially

pure underflow, which contained only a small amount of contaminating coal, is achieved when aqueous suspensions of coal - j

and magnetite particles in the mentioned orders of magnitude, 709808/081 A

Cutters with cone angles of 160 ° to 180 ° have been fed.

The above magnetic separation treatment of the underflow and overflow from heavy beet processing with high separation densities has the advantage that the magnetic separator loads are considerably reduced. Therefore Magnetic separators with lower capacities, which are correspondingly cheaper, can be used ..

709808 / 08U

Claims (8)

- 7 claims fit · A process for the recovery of heavy magnetic materials from a suspension containing these materials and other lighter particles, characterized in that the suspension is subjected to at least one single "high relative density separation" so that a first fraction containing essentially only heavy materials and a major amount of the other particles and some heavy matter containing the second fraction receives, and that the second fraction undergoes a magnetic separation to regenerate the remaining heavy matter. 2. The method according to claim 1, characterized in that a two-stage "high-relative density separation" is carried out. J5. Method according to claim 2, characterized in that that the overflow from the first stage is drained before introduction into the second stage. 4. The method according to claims 1 to 3s characterized * that each stage of the "high-relative density separation" is carried out in a separator (cyclone), 5. The method according to claim 4, characterized in that * I
is l80 °, the cone angle of the separator in the range from 60 ° to 6. The method according to claims 1 to 5 *, characterized in that that the magnetic materials are magnetite particles. 7. The method according to claims 1 to 6, characterized in that the suspension of the overflow of a heavy beet process for the preparation of coal is. 7 0 9 8 0 8/0 8 H. 8. The method according to claims 1 to 6, characterized in that the suspension is the underflow of a heavily turbid process for processing .von Feinkrohle. 7 0 9808 / 08U