DD241557A1 - PROCESS FOR PROCESSING SILICON MONOXIDE - Google Patents

Abstract

The invention relates to a method for the mechanical processing of high-purity silicon monoxide (SiO) for the electronics industry. The object of the invention is to achieve an improved mechanical processing of pre-broken, high-purity silicon monoxide into several particle size classes by comminution and sieve classification, in which the mass fraction is increased in the desired particle size classes and impurities of the processing product are largely avoided. According to the invention, this object is achieved in that a multi-stage stress in a nip at certain roll diameters and with the number of stress levels decreasing crushing ratio and the nip takes place, wherein the roll material and associated with the SiO system components of high purity, the chemically similar to the SiO Consist of materials.

Description

Field of application of the invention

The invention relates to a method for the mechanical processing of high-purity silicon monoxide (SiO) for the electronics industry.

Characteristic of the known technical solutions

The mechanical processing of lumpy materials to grain fineness of certain fineness usually consists of a crushing and classifying with appropriate intermediate transport and storage. The comminution behavior of SiO and the high purity requirements of the process stages of mechanical processing require basic process engineering solutions that are not usually practiced and are not known based on SiO. Polycrystalline silicon monoxide has a "Larrrellenstrükiur" with pronounced crystallite grain boundaries. This microstructure and the relatively low crystallinity grain crystallinity of high crystallinity grain preclude effective comminution processing into particle size classes of between about 0.5 mm to about 6.0 mm for most crushing principles, where friction, impact, impact, shear predominate Types of stress are. It immediately attracts a high proportion by mass of fine grain less than 0.5 mm, which can no longer be used for further use. The most favorable processing conditions prove in the compressive stress, without the technical possibilities lead to a satisfactory mass fraction of Nutzfraktion.

In addition, it is to be complained that the usual materials for the machinery and equipment of mechanical processing, preferably metal, ceramic or plastic materials that contaminate high purity silicon monoxide in hard to influence degree. This applies to the comminution unit as well as to the conveyor and container devices and to the screening devices.

Object of the invention

It is the object of the invention to increase by a comparison with the prior art improved mechanical processing of pre-broken, high-purity silicon monoxide into several particle size classes by a stress between two rollers and Siebklassierung the mass fraction in desired particle size classes and to avoid contamination of the processed product largely.

Explanation of the essence of the invention

The invention has for its object to develop a process engineering solution of the mechanical processing of pre-broken, high-purity silicon monoxide, which allows to achieve a high mass fraction in several grain size classes between 0.5mm and 6.0 mm and to avoid contamination of the processed product largely so that this SiO can preferably be used in the electronics industry.

The object is achieved in that it is assumed that a mechanically pretreated to 5 to 30mm high-purity silicon monoxide, in several particle size classes, preferably 0.5-1.0 mm; 1.0-2.0 mm and 2.0-4.0 mm to disassemble. The mechanical processing is carried out in a multi-stage stress between two rolls in a nip at Waizendurchmessern of 70-100mm with roll material from a high-purity, the ground material chemically similar material with ground or polished roll surfaces, each of which a Siebklassierung is interposed. With the number of stress levels in the nip, the crusher ratio, defined as the ratio of the upper grain size of the material to be crushed to the width of the nip, is reduced from 3: 1 to 1: 1, whereby the reduction of the nip between each stress level is between 20-40%. the previous gap width is. The classification follows between each stress level by separating the undersize, the grain and the oversize. The oversize is in each case the feed material for the next stress level in the nip.

It has proved to be a further advantageous solution to use as a roll material for the mechanical processing of silicon monoxide crystalline silicon. With this measure and the design of the conveyor and container devices on the same basis of highly pure, the grinding material chemically similar materials succeeds largely avoiding impurities for mechanical processing to less than 10 ppm, preferably less than 5 ppm, for one element of atomic number 11 bis 29 (Na to Cu) in the periodic table of the elements.

embodiment

High-purity SiO, mechanically pretreated to a particle size of 10 mm to 30 mm, is processed in a roll mill (roll diameter 75 mm) with a roll material made of crystalline silicon with ground roll surface multi-stage with respective intermediate classification, wherein the oversize> 4.0 mm in each case the Aufgabekörnung for the next processing step:

machining gap Zerklei Kornanteiie 0.5-1 1-2 Wt .-% > 4 tungs- width nerungs- <0.5 mm mm 2-4 mm step mm relationship mm 4.6 3.7 6.4 6.8 4.2 4.5 11.6 14.4 mm 68.8 59.0 23.8 19.8 1 2 3 4 10 6 4 3 3: 1 1.7: 1 1.5: 1 1.3: 1 10.2 11.3 13.7 12.3 12.2 21.5 44.5 46.8

',,. ..... Upper grain size of the feed material in mm

Crushing ratio = ² =

Gap width in mm

From the total mass balance of all 4 processing stages, an undersize fraction <0.5 mm of 24.7 Ma follows from the table values.

The processing from the mechanical processing, consisting of the described material-modified roller unit and also material-modified conveyor and container devices and the sieve set with mesh sizes 4.0 mm; 2.0 mm; 1.0 mm; 0.5 mm and the sieve bottom, are always below 5 ppm per element of atomic number 11 to 29 (Na to Cu) of the Periodic Table of the Elements. The conveying device used was a vibrating conveyor trough lined with silicon wafers for setting a constant throughput, and a container for collecting containers likewise lined with silicon wafers. The same method of lining was applied to the screens and the sieve bottom, with the screen fabric being made of Cr-Ni steel. To prevent contamination by the mesh, the sieving time was limited to 10 seconds.

Claims (5)

Invention claim: 1. A method for the mechanical processing of pre-broken, high-purity silicon monoxide (SiO) in several particle size classes between 0.5mm and 6.0mm by a stress between two rolls and Siebklassierung, characterized in that a multi-stage stress in a nip at Waizendurchmessern of 70-100 mm, a crushing ratio decreasing with the number of stress steps from 3: 1 to 1: 1 with a reduction in the nip load level by 20-40%, wherein the roll material is made of high purity, the · SiO is chemically similar materials with ground or polished roll surfaces. 2. The method according to item 1, characterized in that siekiassiert between each stress level and the resulting oversize grain is the feed material for the next stress level. 3. The method according to item 1, characterized in that the conveying and container devices in the process sequence of the multi-stage stress in the nip and intermediate Siebklassierung in its surface of high purity, the millbase chemically similar materials. 4. The method according to item 1 and 3, characterized in that the rollers are made of crystalline silicon and the conveying and container means and the screen frame and the sieve bottom are lined with discs of the same material. 5. The method according to points 1-4, characterized in that the impurities from the mechanical processing for each element of atomic number 11 to 29 of the Periodic Table of the Elements below 10 ppm, preferably below 5 ppm, are.