SU693575A1 - Apparatus for separating and purifying substances - Google Patents

Abstract

A DIVISION DEVICE - AND CLEANING CLEANINGS directional solidification of the melt, containing a sealed tubular container with a substance to be cleaned, mounted for rotation around an axis, and a heater, characterized in that, in order to increase the efficiency of separation and purification of substances by reducing the surface load knowledge of a growing crystal, the container is provided with a centrifuge, the axis of which is located at a distance from the axis of the container equal to or greater than the radius of the container.

Description

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The invention relates to devices for the separation and purification of substances

A known installation for the purification of substances by directional melt crystallization. This device has a horizontally installed hermetic tubular container, a heater, and a drive for rotating the container around the horizontal axis 1. Such a device does not allow obtaining materials of high purity, for example, during crystallization of semiconductor metals, since in the process of crystallization impurities are displaced mixing (or mechanical) from the crystallization front and the impurity is mainly concentrated near the growing crystal, forming the so-called diffusion layer. This results in contamination of the resulting material.

The purpose of the invention is to increase the efficiency of separation and purification of substances by reducing the surface of the growing crystal contamination.

The goal is achieved by the fact that the container with the substance to be cleaned is equipped with a centrifuge, the axis of which is located at a distance from the axis of the container equal to or greater than the radius of the container. This allows the use of centrifugal forces arising from rotation, under the action of which impurities are removed from the crystallization front. The effect of removing impurities from the diffusion layer is the greater, the higher the density of the removed impurities, if the crystallization front moves from the center to the periphery.

Figure 1 schematically shows the proposed device; in fig. 2 is a plot of the impurity distribution versus the rotational speed of the centrifuge.

A cocToliT device from a sealed, horizontally mounted container 1 with a substance to be cleaned, placed in a centrifuge 2. To create a molten zone, a heater 3 is designed as an oven, for which movement and rotation mechanism 4 is provided along the container 1.

The device works as follows.

The container 1 is loaded with the substance to be cleaned, then the container 1 is placed in a centrifuge

2. The heater 3 is turned on, made in the form of a furnace of the molten zone. After the substance is melted, the centrifuge 2 is turned on, the rotation speed of which is set depending on

required purity of the substance. After this, the mechanism 4 for moving and rotating the furnace is switched on, moving the latter along the crystallizing substance. As a result of this movement, the crystallization front shifts from the center to the periphery. When the heater 3 reaches the end of the container 1, the movement mechanism 4 and the centrifuge 2 are turned off. The container 1 is removed from the centrifuge 2 and released from the purified; substance.

The proposed device for cleaning and separating in order to obtain pure materials, such as semiconductors and metals, makes it possible to increase the cleaning efficiency several times. It can be seen from the above graph that, for example, when cleaning a substance without using a centrifuge, the amount of impurity in the resulting substance was 10 wt. %, which corresponds in the graph to the distribution indicated

0 light circles.

When using a centrifuge, the amount of impurities in the resulting substance decreases sharply to a value of the order of.%, Depending on

FROM the spin speed of the centrifuge. Thus, the use of the proposed device allows to obtain materials of high purity.

Claims (1)

DEVICE FOR SEPARATION • AND CLEANING OF SUBSTANCES by directional crystallization of the melt, containing a sealed tubular container with the substance to be cleaned, mounted for rotation around the axis, and a heater, characterized in that, in order to increase the efficiency of separation and purification of substances by reducing the surface of contamination growing crystal, the container is equipped with a centrifuge, the axis of which is located at a distance from the axis of the container, equal to or greater than the radius of the container.