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
  • 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
  • B24B31/12—Accessories; Protective equipment or safety devices; Installations for exhaustion of dust or for sound absorption specially adapted for machines covered by group B24B31/00
  • B24B31/14—Abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
  • B24C11/00—Selection of abrasive materials or additives for abrasive blasts

Definitions

• the invention relates to a process for the production of a silica-free and iron-free blasting agent for surface treatment, in particular of austenitic steels, with a grain size of at most 0.5 mm from melt chamber slag granules derived from hard coal furnaces.
• abrasives are used for the surface treatment, in particular of austenitic steels, such as electro-corundum, zircon sand and glass beads that are almost iron-free.
• austenitic steels such as electro-corundum, zircon sand and glass beads that are almost iron-free.
• the iron oxide content is limited to a maximum of 0.1% by weight.
• the object of the invention is to enable the production of a further silicon-free and iron-free abrasive which is also particularly suitable for the surface treatment of austenitic steels and is not very expensive. This is said to be the starting material in coal-fired furnaces resulting melt chamber slag granules are used.
• Magnetic separation in which a thin layer of raw material is preferably passed over magnetic drums, can be carried out in one or more stages depending on the layer thickness and the grain size distribution present; in many cases, a single-stage magnetic separation is sufficient to achieve or fall below the required metallic iron content of at most 0.1% by weight.
• the surprising result achieved with the proposed method is that the above-mentioned maximum proportion of metallic iron can be maintained with the specified, less complex measures, although the total iron content of the raw material present after comminution is several times the factor 10 greater than the maximum proportion to be observed.
• the surfaces achieved by means of the abrasive are kung (surface roughness of the irradiated surface) can be adjusted by changing the grain size distribution of the blasting agent; a lower surface roughness can be achieved in particular by reducing the maximum permissible grain size.
• the process can in particular be carried out in such a way that the desired grain fractions are sieved off only after magnetic separation; However, it is also possible to sieve the raw material before carrying out the magnetic separation and to separate the resulting grain fractions from one another using suitable magnetic separators. Grain screening can take place, in particular, in the fractions that comply with the regulation according to D IN 8201 for electro-corundum.
• the process can in particular also be carried out in such a way that the melt chamber slag granules are comminuted into a raw material with a grain size of at most 0.25 mm before magnetic separation (claim 2);
• the melt chamber slag granulate is preferably comminuted as a raw material to a grain size which is predominantly in the range between 0.06 and 0.25 mm (claim 3).
• the layer of raw material which is subjected to magnetic separation has a thickness of at most five times, preferably two to three times, the maximum grain size (claim 5).
• the layer in question should be set as thin as possible in order to be able to carry out the deposition of metallic iron as effectively as possible and, if possible, already in a single deposition stage.
• the layer thickness can be adjusted in particular by suitable coordination between the amount of comminuted raw material fed in and the speed of the magnetic separator (s).
• the abrasive produced from hard coal furnaces according to the teaching of the invention using melt chamber slag granules has the following typical chemical composition; the individual components are each given in% by weight:
• the particle size distribution of the abrasive is as follows:
• the abrasive therefore consists of approximately 70% grains in the range between 0.5 mm and 0.1 mm.
• an abrasive of the listed composition has a significantly larger total iron content than, for example, zircon sand used for comparison (total iron content only about 0.2% by weight), its use for blasting stainless steels on these does not lead to extraneous rust formation if the melt chamber slag granulate serving as the starting material , which has been converted into a sufficiently comminuted raw material, the metallic iron is essentially removed beforehand by magnetic separation.
• the manufacturing method according to the invention described at the outset can in particular be further developed in that the raw material is additionally subjected to a drying process at a suitable time, in particular also simultaneously with or after the magnetic deposition.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Processing Of Solid Wastes (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Glass Compositions (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6188344

Family Applications (1)

Country Status (3)

Cited By (4)

Citations (4)

• 1983
  • 1983-01-15 DE DE3301172A patent/DE3301172C1/de not_active Expired
• 1984
  • 1984-01-07 AT AT84100095T patent/ATE42055T1/de not_active IP Right Cessation
  • 1984-01-07 EP EP84100095A patent/EP0116272B1/fr not_active Expired

Patent Citations (4)

Non-Patent Citations (2)

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