JPH09176751A - Method and for treating material mixture possessing at least two phases having different boiling temperatures apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for surely separating components respectively having different boiling temps. from each other advantageous in terms of cost and safely to environment to same the energy without requiring inert scavenging gases, gaseous fuel and combustion air.

SOLUTION: A material mixture is treated under a starting pressure of <100 millibar and in a temp. range where only the phase at least mainly having the low boiling temp. is evaporated under intermittent measurement of the temp. in the material mixture in the absence of oxygen. The evaporated phase is condensed in a condenser K1 and is gathered to a shieldable vessel B1. The vessel B1 is shielded from the condenser K1 when the temp. transition in the material mixture is charged by the removal of the phase having the lower boiling temp. The material mixture is further treated at the further increased temp. to evaporate and condenser at least one kind of the heavy metals from the group of cadmium and mercury.

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method for treating a substance mixture having at least two phases having different boiling temperatures, which contains at least one heavy metal component of the group of cadmium and mercury, and to a higher boiling temperature. At least one component from the phase having a pressure below atmospheric pressure,
It relates to a method for recovering by vaporizing in a vacuum chamber and condensing the phases separately, in particular for recovering heavy metals from the aqueous phase of an electrolysis power supply.

[0002]

Up to at least 50% by weight solids and / or
Or a mixture of substances that consists of liquid mercury and cannot be circulated in the bulk is not limited to, for example:
It is present in metal casings, electrolytes with electrolyzed water and heavy metals, such as mercury and / or heavy metal compounds, such as recovered aged batteries, such as cadmium hydroxide, for example mercury batteries and nickel-cadmium batteries. In particular, the last two substances are highly toxic and environmentally harmful, so that strict rules have been issued for their disposal. Furthermore, such storage batteries have a filling material and / or a case made of plastic. All components have different vapor pressures and boiling temperatures that can be represented by so-called vapor pressure curves.

[0003] Plastics that meet this purpose can be decomposed into easily volatile components (hydrocarbons) and high molecular weight solids by increasing the temperature and decreasing the pressure, and at this time, the easily volatile components are vaporized and condensed. And the high molecular weight component remains in the residue of the substance mixture,
In it, it is converted to hydrocarbons at the corresponding temperature. Non-toxic metals, such as iron and zinc, also remain in the vacuum chamber at the end of the processing step, in a so-called "cake" forming material mixture.

Such a very heterogeneous mixture of substances is
It can be decomposed into individual components, which is very complicated, and furthermore, the decomposition products and the vaporizable components can also be separated from each other, which is also very complicated. Thus, for example, the treatment of highly dangerous mercury storage batteries by thermal, physical, mechanical and chemical methods or disposal is successful in experiments.

German Patent (DE) 3243813C2
According to the specification, a mercury-containing battery is used in a first treatment step at a pressure of 0.95 bar and under scavenging with an inert gas.
It is known to post-treat this storage battery by heating it to 00 ° C., opening it at that time and partially decomposing the plastic component contained as filler in the electricity storage material. The vapor generated at that time, in which mercury is also partially present, is introduced into the afterburner under the supply of air and combustion gas, in which the decomposition products of the plastic are separated from 1500 to 200.
Burn at a temperature of 0 ° C. Afterburner exhaust gas,
It is introduced into a cooling vessel in which mercury is condensed. Second
In the method step (1), the battery residue is heated to 415 ° C., the remaining plastic components being decomposed and the decomposition products, which also have other mercury contents, being conducted to the afterburner. Mercury is likewise condensed in a cooling vessel. In the third method step, the battery residue is heated to 510 ° C. and the remaining mercury content is squeezed out by a pressure pulsing from 0.5 to 0.05 bar. The mercury content emitted from the cooling container is finally collected in a special cooling trap.

The known methods are expensive and time consuming,
And that energy settlement is disadvantageous. That is to say, that an inert, heated scavenging gas is passed through the entire device, in particular after heating up to 2000 ° C., it is led to a cooling vessel, whereby the cooling vessel is thermally heated. This is because it is necessary to supply a large amount of fuel gas and combustion air that impose a considerable load. These gases are also conducted to the entire device, i.e. also to the cold trap, which in turn is considerably thermally loaded. In both mercury condensers, not only the heat of condensation of mercury but also the heat energy of the entrained large amount of gas is eliminated. In addition, the mercury vapor forced to high temperatures in the afterburner is extremely corrosive to most metals, which
This is because they lead to amalgam formation. No mention is made of the residual electrolyzed water that is necessarily present. No mention is made there of the treatment of cadmium-containing substance mixtures.

German Patent (DE) 4402499C1
According to the specification, a contaminated solvent bath liquid, i.e. a liquid, derived from the washing process of textiles, leather, furs, rawhides, parts, electronic devices, etc., having components consisting of water, low boiling substances and hydrocarbon solvents By vacuum distillation and by switching depending on the temperature, selectively using a first vacuum pump to a first condenser for water and low-boiling substances,
It is also known to feed a second condenser for solvent gas by means of a second vacuum pump and feed the unvaporized residue to a waste treatment step. In liquids, due to continuous operation, a very uniform temperature distribution predominates throughout the boiling process. Temperature in a steam room
When measured on a liquid, it shows its measured value for just the vaporized fraction, i.e. the temperature measurement starts at the value of the component with the lowest boiling point respectively and when the component is high, the transition is slow. is there.

There is no mention of vaporizing, condensing and recovering toxic heavy metals from the group of mercury and cadmium with considerably higher boiling points from non-recyclable beds of solids or sludges.

From US Pat. No. 4,401,463, a pyrolysis method is known, in which 3 to 12% of oxygen is supplied and a vacuum is not used, in order to recover metals from aging storage batteries, the storage batteries being used. Is first crushed, the waste is dried and preheated with hot air in a preheater, and the organic components are removed in a subsequent pyrolysis furnace at temperatures up to 500 ° C. In this case, the metal cadmium inevitably migrates to its oxide system. The gas formed here is post-combusted in a special furnace. Cadmium oxide is reduced back to cadmium by increasing the temperature up to about 900 ° C. and using a reducing atmosphere with hydrogen, which is subsequently distilled off. Finally, the cadmium vapor is condensed and cast into a mold into blocks. In this case, not only the organic components are lost, but also combustion gas and hot gas are inflicted on the environment, and the combustion gas is sent to the venturi scrubber for removing chlorine from the pyrolysis vapor. Make it conductive. Nickel remains in the very hot residue, which is exposed to the air stream provided for drying, for heat recovery. In doing so, nickel and other metals oxidize to dusty oxides under the action of significant heat. Nickel oxide, which is dusty and gives rise to a considerable amount of lumps, also reaches the atmosphere with dry air, which is no longer recognized today. No temperature measurements have been made to switch devices.

This method is very expensive not only in terms of equipment, but also in terms of energy and puts a considerable burden on the environment.

[0011]

On the other hand, the object of the present invention is to reliably and cost-effectively provide components having different boiling temperatures without the need for inert scavenging gas, fuel gas and combustion air. Advantageously, as well as energy-saving and environmentally safe separation from one another, a method of the kind mentioned at the outset is provided. Furthermore, the tube should not be clogged with condensate.

In particular, in the case of heavy metals having higher boiling temperatures and containing toxic constituents such as mercury and cadmium, it must be possible to recover these heavy metals safely in the equipment and the environment.

[0013]

The object of the invention is, according to the invention in the manner described at the outset, that according to the invention, in the absence of oxygen, a) the substance mixture is subjected to a continuous temperature measurement in the substance mixture of 100 mbar. Treated under a starting pressure of less than, at least predominantly, in a temperature range in which only the phase with the lower boiling temperature is vaporized, the vaporized phase is condensed in a condenser and the condensate is collected in a container capable of blocking. B) if the temperature profile in the substance mixture changes as a result of the removal of the phase with the lower boiling temperature from the remaining substance mixture, then the container is shut off against the first condenser, and c) it remains. The substance mixture is further treated at a higher temperature and here comprises at least one of the phases with a higher boiling temperature which comprises at least one component from a heavy metal from the group of cadmium and mercury. It was removed in vapor form and is solved by condensing the vapor thereof.

By means of the process according to the invention, the substance mixture charged is very reliably and, in particular, at low pressure and temperature.
It can be decomposed into individual components or phases and / or groups of components or groups of phases. The scavenging gas and the combustion gas and the combustion air, as well as the high combustion temperature, need only be small so that the condensation surface followed by the vacuum chamber does not carry a large amount of exhaust gas. The markedly lower maximum temperature of the method operation compared to the prior art also does not increase the reactivity of the vaporized components with respect to the device parts. This gives rise to a clearly more favorable energy balance, but nevertheless, possibly even further work-up, can ensure that the individual components are separated from one another.

In this case, it is important to measure the temperature at the center of the packing, since it is the coldest area of the packing which cannot be circulated. The heating is carried out by the jacket part of the furnace, i.e. via the margin strip of the packing. Since the lowest temperature zone reaches the predetermined boiling temperature or vaporization temperature at the corresponding pressure and the switching is performed for the first time, it is guaranteed that all the components that can be vaporized below the switching point can be vaporized. It

On the other hand, the packing temperature then does not take a higher value than the temperature heat-regulated in the furnace, due to the absence of oxidation reactions, so that the vaporization occurs mildly,
This is a great advantage for organic materials. Wet cleaning of the exhaust gas is not necessary either, since no thermal decomposition occurs and harmful substances such as chlorine compounds and dioxins cannot be liberated.

If higher boiling phases in the form of metal hydroxide or metal oxide compounds are present, these compounds are dissociated and / or reduced to the corresponding metal, which is vaporized,
It is particularly advantageous to condense with a metal condenser connected before the condenser for the condensation of the phases with a lower boiling temperature.

If mercury is present in the substance mixture of the mercury storage battery, firstly only the electrolyzed water is vaporized at the initial temperature and is constructed as a liquid condenser and is connected to the container via a shut-off valve. It is particularly advantageous to condense in a condenser and close the shut-off valve after the vaporization of water to raise the temperature of the residual substance mixture, vaporize the mercury and condense in the same condenser.

In this case, mercury is produced in the condenser in a substantially quantitative manner, while the electrolyzed water is condensed and present in the vessel and carries with it all of the non-vaporized and non-vaporized components. A cake-like residue consisting of the charged substance mixture remains in the vacuum chamber.

If cadmium hydroxide is present in the substance mixture, a) use a liquid condenser as the condenser for the electrolyzed water and pre-connect it with a metal condenser, b) first, the free electrolysis. Only water is vaporized and condensed in a condenser, c) after vaporization of free electrolyzed water, the temperature of the residual substance mixture is further increased so that cadmium hydroxide dissociates into cadmium oxide, and d) dissociation. The water resulting from the action is condensed in a condenser, and e) a reducing gas consisting of the group of hydrogen and hydrocarbons is supplied to the cadmium oxide to retain the cadmium and vaporize the reaction water, and to re-evaporate this. Condense in a condenser, f) collect all condensate in a container, and shut it off to the condenser, and finally g) lower the vacuum and warm It is particularly advantageous to vaporize the cadmium and to condense the cadmium vapor in the metal condenser by increasing the degree of the increase.

In this case too, the highly toxic cadmium is produced substantially quantitatively in the metal condenser, while the electrolyzed water and the further formed reaction water are present in a closed container, And the non-vaporized and non-vaporized residues of the charge mixture remain in the vacuum chamber.

Other advantageous embodiments of the method according to the invention emerge from the method of the remaining claims.

The invention comprises a heatable vacuum chamber, a condenser, at least one vacuum pump device following this, and at least one temperature sensor for measuring the temperature of the substance mixture and the dry mass. , Also to a device for carrying out the method of the invention.

In order to solve this same problem, the device according to the invention is such that the condenser is connected to the container via a shut-off valve and the temperature sensor is connected to the shut-off valve via a regulating device. The control device is designed in such a way that the shut-off valve closes when the temperature sensor detects a rise in temperature measured in the substance mixture after the end of the water vaporization.

A metal hydroxide present in the substance mixture, which is in the elemental state, eg mercury, must also be first dissociated and reduced to the elemental metal, eg cadmium. Or even in the form of an oxide compound, the condensing surface of the metal condenser is changed between the vacuum chamber and the condenser by the circulation pump, the heating device, the cooler and the switching of heating and cooling when the non-metal vapor passes through. Is connected to a circuit with a regulator designed to regulate the temperature at which condensation of non-metal vapors does not occur, and on entry of metal vapors, to the temperature at which metal condensation occurs It is particularly advantageous to install a metal capacitor.

In circulation, between the heating device and the cooler,
A particularly advantageous method operation is possible if a reversing valve is provided, which allows the liquid supplied to the circulation to be selectively passed through a bypass line to the cooler.

Two preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2 below.

FIG. 1 shows a diagram of a method for recovering mercury from a mercury storage battery, and FIG. 2 shows a diagram of a modified method for recovering cadmium and nickel from a nickel-cadmium storage battery.

In FIG. 1, the door 2 and the heat insulation jacket 3 are shown.
A heatable vacuum chamber 1 having a is described. Here, for example, a filling 4 of a substance mixture which cannot be circulated exists in a basket, and a temperature sensor T is stuck in the center thereof. The pressure sensor P is used for grasping the room pressure. The filling 4 is heated externally, ie the vacuum chamber 1 is equipped with a heating device or a heating device (not shown) is installed between the inner wall of the vacuum chamber 1 and the filling 4. There is. As a result, the coldest zone of the packing 4 during heating is the center of the packing 4.

A suction tube 5 leads from the vacuum chamber 1 to a condenser K1 having a condensation surface 6. Condenser K1
At the bottom of the container is a container B1 having a discharge valve 7 through a pipe
It is connected to the shutoff valve of.

A suction pipe leads from the condenser K1 to a pump set 9 having a roots pump 10, an intermediate pump 11 and a water ring pump 12. To the water ring pump 12 belongs a water circulation with a water cooler K2 and a water separator 13 connected to the outlet via a pipe 14. If desired, a gas purification device not mentioned, for example an absorber in which the decomposition products of the plastics are separated, can be connected in the middle.

The vacuum chamber 1 is first operated at a wall or heating device temperature below the boiling temperature at a given process pressure (eg 42.4 mbar), so that mercury does not vaporize.
The filling temperature must also not exceed the corresponding temperature of the wall or of the heating device. First, the electrolytic water is condensed in the condenser K1 and transferred to the container B1. The temperature rise is due to T
The shut-off valve V1 is closed by the regulating unit 15 when the residual substance mixture is shown to be sufficiently water-free in the middle. The fill temperature is then increased and the pressure is further reduced so that the boiling temperature of mercury is exceeded. Mercury is quantitatively condensed in condenser K1. The vaporizable decomposition products of the plastic packing of the accumulator are likewise separated in liquid form in the condenser K1. The high molecular weight decomposition products of the plastic packing of the battery and carbon and other metals remain in the dry substance in the vacuum chamber, the so-called "cake", and are worked up separately. No oxygen is supplied to the vacuum chamber.

In FIG. 2, the same parts as in FIG. 1 are given the same symbols, so that no repetition is necessary. But,
In this case, the condenser K1 is preceded by a metal condenser K3 having a condensing surface 16, to which a circulation pump 18, a heating device 19, a regulating device 20 and a cooler 2 are provided.
The cooling circuit 17 with 1 belongs. However, the cooler 21
Is an adjusting device 20, a reversing valve 22, and a bypass pipe 23.
Can also be processed by.

The condenser K1 again serves for the condensation of the electrolyzed water and is of three stages. First, free electrolyzed water is expelled at the temperature and pressure shown in FIG.
And let it condense. Then, the temperature of the filling is, for example, 40
Raised to 0 ° C., which converts cadmium hydroxide to cadmium oxide. The originally bound electrolyzed water liberated here is condensed in the second stage. In the third stage, the temperature of the filling is raised to 500 ° C. and a reducing gas consisting of the group of hydrogen and hydrocarbons is supplied, which reduces cadmium oxide to cadmium metal. The reaction water and the easily volatile decomposition products of the packing material of the storage battery generated here are similarly condensed in the condenser K1. The total amount of condensate is present in vessel B1. When the temperature sensor T indicates that the residual filling is water-free due to the temperature increase, the regulating device 15 closes the shut-off valve V1.

Via the adjusting pipe 24, the adjusting device 20 receives a command from the adjusting unit 15 to switch the cooling circulation 17: first, the condensing surface 16 is kept at a temperature of, for example, 80 ° C. without condensing water. , Then the temperature, for example 2
Cadmium is quantitatively separated in a metal condenser K3 by lowering to 0 ° C. Nickel remains in the residual packing in the vacuum chamber 1, the so-called cake, together with other metals, for example iron, and the high molecular weight decomposition products of plastics and the resulting carbon, in this regard the second embodiment. Now, a more detailed description will be given. Again, no oxygen is supplied to the vacuum chamber 1 at any point in the process.

Example I (mercury storage battery): In an apparatus of FIG. 1 having a volume of a vacuum chamber of 0.2 m ³ , 100 kg of an unground aging storage battery having a mercury content of 0.7 kg and an electrolytic water content of 9 kg was used.
It was placed in a vacuum chamber and it was first evacuated to 23 mbar. Subsequently, without supplying oxygen, 42.
A pressure of 4 mbar and a temperature of 40 ° C. were set. At this time, water vaporized but mercury did not vaporize. About 480
In minutes, 8.6 kg of water had condensed in condenser K1 and was transferred into vessel B1. here,
The temperature of the substance mixture was kept constant by correspondingly adjusted heating. The storage battery broke spontaneously during evaporation of water.
At the end of water evaporation, the temperature in the residual material mixture was raised.
These processes are tracked by a temperature sensor located in the center of the substance mixture, which allows the adjusting unit 15
Closed shutoff valve V1. Subsequently, the pressure was reduced to 10 ^-2 mbar without oxygen supply and the temperature was raised to 300 ° C. over 140 minutes by means of a heating device, whereby mercury was vaporized one after the other and likewise in condenser K1. Agglomerated. After 90 minutes there was 88.8 kg of dry mass with a residual mercury content of only 1.7 mg per kg of dry mass, which was mechanically ground. The iron content was screened with a magnetic separator and added to standard steel scrap of steel material. The manganese dioxide and zinc dust present were worked up in the zinc smelter.

Example II (nickel-cadmium battery):
In an apparatus according to FIG. 2 having a vacuum chamber volume of 0.015 m ³ , 10 kg of an unopened aged storage battery having a cadmium content of 2.1 kg, a nickel content of 2.0 kg and an electrolyzed water content of 1.8 kg was used. , Placed in vacuum chamber 1 and it was first evacuated to 20 mbar. Subsequently, without supplying oxygen, a pressure of 20 mbar and 50
The temperature was adjusted to ° C. At this time, water was vaporized, but neither cadmium nor nickel was vaporized. In about 120 minutes
1.65 kg of electrolyzed water is condensed in the condenser K1,
And it was transferred into container B1. Following this, the temperature was raised to 400 ° C. without oxygen supply to dissociate the cadmium bound as hydroxide and convert it to cadmium oxide. At that time, 0.15 kg of reaction water was further vaporized, and this was condensed in the condenser K1 and transferred to the container B1. Then, adjust the temperature to 500 ℃,
And, to the remaining substance mixture, methane was supplied as a reducing gas for 60 minutes until the cadmium oxide was reduced to metallic cadmium. The reaction water generated here was also vaporized and condensed in the condenser K1 to give an amount of 0.2 kg, which was transferred into the container B1. Again, in this case,
The battery already broke spontaneously during evaporation of water. The temperature produced by the heating in the substance mixture during the vaporization of water is continuously measured, and when an additional temperature rise as a sign of the dry mass of water-free begins, the vessel B1 is switched to the condenser K1 by means of the valve V1. I blocked it. Finally, the pressure is reduced to 10 ^-2 mbar, and the cadmium is vaporized at a temperature that gradually rises to 700 ° C, and the metal condenser K3 is used.
Condensed inside. Here, 2.1 kg of cadmium was obtained. The content of cadmium in the dry mass was 5.6 mg per 1 kg of the dry mass.

By means of the circulation 17 connected to the metal condenser K3, in the control device 20, the condensing surface 16 of the metal condenser K3 is heated to 80 ° C. by the heating device 19 when water vapor passes through. The temperature was adjusted and, in the case of the ingress of the cadmium vapor, the cooling device 21 was operated to adjust the temperature to 20 ° C. at which quantitative condensation of cadmium occurs. Iron and nickel remained in the dry mass and this was worked up in the steel material.

[Brief description of the drawings]

1 shows an embodiment of an apparatus for recovering mercury from a mercury accumulator according to the method of the invention.

FIG. 2 shows an embodiment of an apparatus for recovering cadmium and nickel from a nickel-cadmium storage battery according to the method of the present invention.

[Explanation of symbols]

1 vacuum chamber, 9 vacuum pump device, 15 regulator, 17 circulation, 18 circulation pump, 19 heating device, 21 cooler, B1 container, K1 condenser, K3 metal condenser, T temperature sensor, V1 cutoff valve

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Erwin Vanetsky Federal Republic of Germany Grosscrozenburg Robert-Koch-Strasse 4

Claims (12)

[Claims] 1. A substance mixture having at least two phases with different boiling temperatures, which contains at least one heavy metal component from the group of cadmium and mercury, is treated, and at least one of the phases with the higher boiling temperature is treated. In a process for recovering components by vaporizing in a vacuum chamber (1) at subatmospheric pressure and condensing the phases separately, a) in the absence of oxygen Under continuous temperature measurement in the mixture, under a starting pressure of less than 100 mbar, at least mainly in the temperature range in which only the phase with the lower boiling temperature is vaporized, the vaporized phase is treated with a condenser (K1). The substance mixture as a result of condensing in and collecting the condensate in a blockable vessel (B1), b) removing the phase with the lower boiling temperature from the remaining substance mixture. If the temperature profile of the above changes, the container (B1) is shut off against the first condenser (K1), and c) the remaining substance mixture is further treated at a higher temperature, with the addition of cadmium and mercury. A group of cadmium and mercury, characterized in that at least one of the phases with a higher boiling temperature containing at least one component from a heavy metal of the group is removed in the form of vapor and the vapor is condensed. Treating a mixture of substances having at least two phases with different boiling temperatures, comprising at least one component from a heavy metal consisting of at least one component from a phase with a higher boiling temperature, a pressure below atmospheric pressure. In the vacuum chamber (1) and recovering by condensing the phases separately. 2. When a high-boiling phase in the form of a metal hydroxide or metal oxide compound is present, the compound is dissociated and / or reduced to the metal and then the metal is vaporized and the boiling temperature is lower. Having a metal capacitor (K1) pre-connected to the capacitor (K1) for condensation of the phase having
The method according to claim 1, wherein the condensation is performed in 3). 3. When mercury is present in the substance mixture of a mercury storage battery, firstly only the electrolyzed water is vaporized at an initial temperature and designed as a liquid condenser and via a shut-off valve (V1) a container ( After condensing in a condenser (K1) which is combined with B1) and after the end of the vaporization of water, the shut-off valve is closed, the temperature of the residual substance mixture is increased, the mercury is vaporized, and in the same condenser (K1) The method according to claim 1, wherein the method is condensed. 4. When cadmium hydroxide is present in the substance mixture: a) As a condenser (K1) for condensing electrolyzed water, a liquid condenser is used, which is preceded by a metal condenser (K1). Connection, b) first vaporize only the free electrolyzed water and condense in a condenser (K1), and c) after vaporize the free electrolyzed water, the temperature of the residual substance mixture is oxidized by cadmium hydroxide. Further increase so as to dissociate into cadmium, d) condense the water from the dissociation process in a condenser (K1), and e) supply cadmium oxide with a reducing gas consisting of a group of hydrogen and hydrocarbons to retain cadmium. Then, the reaction water is vaporized, and this is condensed again in the condenser (K1). F) All the condensed water is collected in the vessel (B1), and this vessel is collected in the condenser (K1). 3.) and finally g) further reducing the vacuum and raising the temperature to vaporize the cadmium and condense the cadmium vapor in the metal condenser (K3). the method of. 5. The condensing surface of the metal condenser (K3),
During the vaporization of water, the temperature at which water does not condense is maintained, and when vaporization of cadmium is started after the vaporization of water, cadmium quantitatively determines the temperature of the condensation surface of the metal condenser (K3). The method according to claim 4, wherein the value of condensation is adjusted. 6. The pressure during vaporization of electrolyzed water is 20 to 50.
After adjusting to a value of mbar, shutting off the valve (V1) to the condenser (K1), the pressure is reduced to below 20 mbar, and the mercury is vaporized under increasing temperature of the residual mixture and the condenser (K1). The method of claim 3, wherein the method condenses therein. 7. The method according to claim 6, wherein the temperature of the residual substance mixture is raised under vacuum to a maximum of 400 ° C. in order to produce a substantially mercury-free dry mass. 8. A) adjusting the pressure for vaporizing the free electrolyzed water to 20-50 mbar and the temperature below 100 ° C., b) subsequently changing the temperature for the dissociation of cadmium hydroxide. Increase to values above 100 ° C. up to 400 ° C. c) then reduction of cadmium oxide to cadmium,
Using a reducing gas consisting of hydrogen or a group of hydrocarbons, 50
Carrying out at a further temperature increase up to 0 ° C., d) stopping the temperature generated in the substance mixture during vaporization and, while increasing the temperature, the vessel (B1) to the condenser (K1) with the valve (V1). Against, and finally, e) for the vaporization of cadmium, the pressure is reduced to a value below 20 mbar, and the cadmium is vaporized at elevated temperature and condensed in a metal condenser (K3), The method of claim 4 for recovering cadmium from an electrolyte containing nickel-cadmium storage battery. 9. The process according to claim 8, wherein the temperature of the residual substance mixture is raised to a maximum of 800 ° C. under vacuum to produce a dry mass substantially free of cadmium. 10. A heatable vacuum chamber (1), a condenser (K1), at least one vacuum pumping device (9) following them, for measuring the temperature of a substance mixture and a dry mass. Device for carrying out the method according to any one of claims 1 to 9, comprising at least one temperature sensor (T), a condenser (K1).
Is connected to the container (B1) via a shutoff valve (V1), and the temperature sensor (T) is connected to the adjusting device (1).
5) is connected to a shut-off valve (V1) via a regulator (15) in which the temperature sensor (T) detects the temperature rise measured in the substance mixture after the end of the vaporization of the water. It then comprises a heatable vacuum chamber (1), a condenser (K1) and at least one vacuum pump device (9) following them, which is designed to close the shut-off valve (V1) immediately. Apparatus for carrying out the method according to any one of claims 1 to 9, and having at least one temperature sensor (T) for measuring the temperature of the substance mixture and the dry mass. 11. A vacuum chamber (1) and a condenser (K1).
By switching between the circulation pump (18), the heating device (19), the cooler (21) and the heating to the cooling, the condensing surface of the metal condenser (K2) is A regulating device (2) which is designed to be adjusted to a temperature at which condensation of non-metal vapor does not occur and, when invading metal vapor, to a temperature at which metal condensation occurs.
Device according to claim 10, characterized in that a metal capacitor (K3) connected to the circulation (17) with 0) is installed. 12. A heating device (1) in the circulation (17).
A reversing valve (22) is provided between the cooling device (9) and the cooling device (21), which allows the liquid supplied to the circulation to be selectively conducted to the cooling device (21) side via a bypass pipe. The device of claim 11, which is installed.