DD144868A1 - VERTICAL PIPE REACTOR FOR CONTINUOUS THERMOCHLORATION - Google Patents

Abstract

It is a device for continuous Thermochlorating cleaning of free-flowing raw materials, such as Quartz raw materials. The device can be used in the Processing of mineral raw materials. The device is drawing characterized by an optimal heat cycle. In addition, a Ingress of oxygen into the chlorination zone avoided.

Description

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Title of the invention

Vertical tube reactor for continuous thermochlorination

Field of application of the invention

It is a continuous system for the thermochlorination of free-flowing, preferably mineral raw materials, such as Ouarzrohstoffen, for the purpose of reducing pollutants or the recovery of useful components,

Characteristic of the known technical solutions

It is known that mineral raw materials by chlorination at higher temperatures of impurities such as TiO, Fe _? 0 "among other things freed or that valuable components, such as Ti, B or rare elements, can be separated by this process, this results in a number of equipment problems. For this Thermochlorierung 3 different types of apparatus come into question: rotary kiln, fluidized bed and shaft furnace.

The rotary kiln is suitable for the chlorination of finely divided raw materials, but difficult to seal against the escape of chlorination gases (Kowa-Seiko-Verfahren, Ohkubo, Y., 0. Min Metallurg. Inst, of Oapan 82 (1966) No. 939 S. 601). The fluidized bed furnace is used in the chlorinating ore processing with the characteristic high substance conversions (BRD-AS 1 75S 473).

In addition, shaft furnace are known which are used for the extraction of non-ferrous metals from iron ores. Here, for example, in BRD-OS i 931 649 a device (shaft furnace) is described in which the chlorinating gases at the top and bottom in the

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migrating ore are fed and withdrawn by generating a negative pressure in the middle of the shaft. The disadvantage of this solution is that due to the negative pressure of the suction, a reduction of the partial pressure of chlorinating agent and thus a reduction in the reaction rate occurs.

Furthermore, air is sucked into the chlorination zone by the negative pressure. Thus, there is the risk of regression of the contaminating metal oxides from the chlorides.

In addition, it must be taken into account that fluctuations in the suction pressure result in chlorination gases at the top of the reactor or that chlorides are deposited on the colder pipe sections above the reaction zone, which must be periodically removed.

On the other hand, a shaft furnace is known for the extraction of non-ferrous metals from iron ore ore (BRD-AS 1 160 622 and BRD-AS 1 583 895). In this, the sealing of the reaction zone by constriction of the furnace cross-section, and an overpressure of cooling and Aufheizgas is maintained, so that the escape of chlorine gas from the reaction space is prevented in the heating and cooling zone. The disadvantage here is that the entry of atmospheric oxygen into the chlorination zone is possible.

Object of the invention

The aim of the invention is to develop a reactor which is suitable for the continuous thermochlorination of free-flowing raw materials and which does not have the disadvantages of the known reactors, in particular the risk of oxygen entering the chlorination zone.

Explanation of the essence of the invention

This object is achieved by a vertical tubular reactor for the continuous thermochlorination of free-flowing raw materials, in which the raw material successively passes through a preheating zone, a thermochlorination zone and a cooling zone and the heat of the exiting to the incoming raw material

The reactor is transferred before and after the chlorination zone

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has a constriction is prevented by the invention by the generation of an inert gas pressure in the constriction above and below the Thermochlorierzone both the entry of reactive gases from the cooling zone in the Chlorierzone and chlorination gases from the Chlorierzone in the two adjacent zones.

Suitable raw materials are in particular those such as quartz raw materials, glass sands or feldspars.

The free-flowing raw material passes through the reactor from top to bottom.

To seal the reaction zone, an inert gas, such as pure nitrogen, or a noble gas is injected above and below it. In this case, the inert gas can be added via nozzles or pipe rings in the constriction zone before and after the chlorination zone.

In order to keep the heat losses as low as possible, the amount of heat discharged with the hot raw material after the chlorination is transmitted through an air flow in the heat exchange vessel to the raw material which is located in the preheating vessel. By using the waste heat considerably less energy is required for the indirect heating in the chlorination zone and / or preheating zone. At high throughputs is due to the poor thermal conductivity of the mineral raw materials to move the heating in the interior of the chlorinating zone, z. B. in the way that the reactor tube contains shielded against the interior heating elements.

By an overlap of the discharge pipe for the Chlorierur.gsabgase in the upper part of the Chlorierraumes and the raw material inflow a cavity is present in the reactor, in which collect chlorination gases including gaseous chlorides before their expulsion.

The advantage of the solution according to the invention is that the penetration of O »into the chlorination zone is prevented and thus the regression of the contaminating metal oxides from the chlorides is avoided *

Embodiment examples "2Ü 4 4S2

example 1

Based on the reactor shown in Fig. 1 in vertical section, the invention will be explained in more detail.

The free-flowing raw material slips out of the exchangeable storage vessel (1) into the heat exchange vessel (2). Here it is preheated by the in the cooling vessel (6) heated by (7) to (2) directed air flow in countercurrent and, if necessary, dried. The nitrogen gas fed in (3) prevents both the entry of atmospheric oxygen into the chlorination zone (4) and the exit of chlorination gases from this zone. The same nitrogen gas occlusion (5) is located at the exit of the chlorination zone. The raw material slips after passing through the chlorination zone into the cooling vessel (6), where it is cooled in countercurrent by an air flow and this is introduced via the heat-insulated line (7) in (2). The heat losses are compensated by the indirect heating of the chlorination zone and preheating zone, which may be crossed by heating channels (8). Chlorination gases are introduced at (9). From the gas space (10) of the chlorination zone, the chlorination products are discharged downwards (11) for further processing or neutralization. The residence time of the raw material in the chlorination zone is controlled by known metering devices which are mounted on the outlet side.

Example 2

The following depletion of pollutants from mineral resources was achieved in the laboratory reactor tube made of quartz glass:

Content of raw material ^Fe 2 ° 3 ( ⁱⁿ P ^pm ) TiOp (in ppm)

Silica glass raw material, before

Thermochlorination 260 37

Kieseiglasrohstoff, after the

Thermochlorination 38 4

Glass sand, before thermochlorination '153

Glass sand, after thermochlorination 55

Claims (1)

invention claim 1. V.rtlk.ler tubular reactor for continuous! , ner _n och -rung of free-flowing _ähig e _n raw materials, in which, _Roh. "One after the other passes through a prehistoric zone, a zone of the chlorination and a cooling zone, and the Reten of rea.tionsf _ä hi _g s _G AEEN from de _{r Abkü} hIL Γ'η Cl, r _{"on signal RLON, as well as} from the Chlorierungsgasen Chlorine in the adjacent zones oeiden verhindeTt _{verti- cular tubular} reactor according to point _lf characterized by d «: -rd! ^{nert9aa Rein} - '<"=" - a ₆ del _gss verwel- " See drawings!