DE2534463A1 - Vacuum distn. column for refining metals - using graphite heating electrodes connected to three phase electricity supply - Google Patents

Abstract

Appts. for the continuous refining of metals, using a hermetically sealed, cooled and evacuated container for a distn. column fitted with multiple evapn. stages, the molten raw malt. being fed continuously into the top stage and flowing downwards to the outlet; electric heaters extend through the stages which are surrounded by perforated condensn. screens and a cooled condenser box. The novelty is the use of graphite rods in a three phase circuit for electric heating, the rods extending downwards through the evapn. stages whereas the melt flows downwards through the stages in a thin film. In the pref. appts., the evpn. stages consist of a vertical stack of baskets. For example, in refining tin to remove Pb and Bi, or the removal of Zn when refining lead. The graphite electrodes can be 75-710 mm dia. and by changing from a single phase supply to a three phase supply the power used in a protopyte plant could be raised from 250 kVA to 750 kVA without incurring any technical problems.

Description

1. Jurij Fedorowitsch Frolow, Novosibirsk / USSR 2. Jurij Anatolijewitsch Naryschkin, Novosibirsk / USSR 3. Vladimir Semenowitsch Tscherednitschenko, Novosibirsk / USSR 4. Jurij Fedorowitsch Piljukow, Novosibirsk / USSR 5. Gennadij Ivanovich Orlow, Novosibirsk / USSR 6. Aron Semenowitsch Mikulinskij, Istra Moskowskoj oblasti / USSR 7. Serafim Nikolajewitsch Suturin, Novosibirsk / USSR 8. Leonid Wladimirowitsch Slobodkin, Vostochno-Kazakhstan oblast, Ust-Kamenogorsk / USSR 9. Konstantin Stepanowitsch Daschkov, Vostochno-Kazakhstan oblast, Ust-Kamenogorsk / USSR APPARATUS FOR CONTINUOUS REFINING OF METALS The present invention relates to this Area of the non-ferrous metal smelting, especially the similar medium @ refining of Metals such as lead, zinc, tin and distillation processes involving vacuum apparatus (Electric ovens) to bark twisting.

iss are already devices for refining metals in a vacuum known (see e.g. USSR copyright certificate 268 651, class 40a, 25/08 and USSR patent application No. 1 330 861/22-I, Kl. 4oa, 9/04, on which a copyright has been granted), the consist of a distillation column, which consists of sturgeon i.e. plate evaporators, a central heating apparatus, perforated shields, a condenser and is put together in a condenser box.

The main structural element of the well-known vacuum stills (Electric furnace) forms a distillation column to be accommodated in an evacuated chamber, those made up of a series of separate, riog-shaped open ones placed one below the other Evaporation stages i.e. plates made from a graphitized carbonaceous Material consists on which the refining melt with the help of an inside, the focus the distillation column (in the form of a graphite rod or a tube executed) electrical resistance heater is heated. The beginning and that At the end of the heater there are power leads that are inserted into the through vacuum seals Output lines go into the apparatus, with those of the winding end8 of an infeed Single-phase stepping down transformer in connection.

When the molten metal overflows from plate to plate and with their Passage from top to bottom along the column develop from the melt Volatile additions in the plates that enter the condensation zone via steam pipes derived and then led out of the apparatus.

After leaving the column, the fine metal is in a separate Metal collection container collected and cooled.

To ensure a successive overflow of the melt in the Column, an opening is made in the bottom part of each plate through which the melt from the higher to the lower plate.

in the known apparatus (electric ovens) of this type, it thus settles the refining mechanism of the following interrelated processes together: a heating of the melt up to the distillation lotion temperature, the letting it stand isothermally at this temperature to ensure the evaporation process of volatile elements, their transition to the vapor state, the transfer this Vapors in the condensation zone and the condensate flowing out of the apparatus - and pure product derivation.

The apparatuses described have a number of design disadvantages on.

So are z. B. the design of the known evaporation / plate and their geometrical dimensions dimensioned so that large i.etall masses with a relative small evaporation area can be distilled. Under these conditions the Process of mass transport of the admixtures from the melt to the steam-melt interface difficult. The speed of material transport: in the volume of the Schemlze komat higher than the evaporation rate of the admixtures' which is a decrease in intensity brings about the distillation. The latter affects the goodness of L. metal refining and the performance of the electric furnace is detrimental.

In addition, as is well known, the metal is depleted in the movement of the, as a result, the proportions of the constituents of the molten metal in the furnace become highly volatile Change the ingredients # in the vapor phase depending on the length of the evaporator and the height of the oven. the The construction of the existing apparatus takes no account of this phenomenon, which has a detrimental effect on the quality and intensity of the distillation.

The known devices (electric furnaces) of the type mentioned are single-phase executed and therefore have limited performance.

When their output increases, electricity occurs in the feeding three-phase network. and voltage imbalance, @@@@ uneven phase load. According to the electrotechnical Norms, for example, the voltage asymmetry is to be limited to a value of 2% the increase in performance of the single-phase appliances (electric furnaces must therefore have the asymmetry eliminated by using controlled or uncontrolled balancing devices which makes the system more expensive.

When solving the question of connecting a single-phase load to the feeding three-phase network, it is necessary to take into account that the line currents in two phases at one times stronger than the line currents when feeding a three-phase load of the same power, while the current of the load in question is absent in the first phase.

With the same line resistance of the feeding system, therefore the effective energy losses when feeding kin-phase apparatus (electro-hearing) be twice as large as when feeding a three-phase appliance of the same power.

When the single-phase device is connected to the three-phase network, the latter also uses an equivalent three-phase power that is around the is rapidly higher than that of the sin-phase load. Therefore, if the remaining loads are three-phase, the installed power of the supply network must also be reduced The overall performance of all consumers will be increased and accepted more highly.

This is another important disadvantage of the single phase apparatus.

as described above, is the balancing of the single-phase devices (Electric ovens) are strictly necessary depending on the increase in their output. That he has not encountered this problem earlier, can not only be explained by the proportionate small power of working single-phase apparatus (electric furnaces), but also before explain mainly by the fact that according to the previously applicable norms there was a much greater asymmetry (5%) than was currently permissible.

In many countries (especially in the case of inefficient supply networks) The demands made on the performance asymmetry are even tougher, which is why the question the balancing of performance when delivering the apparatus (electric furnaces) to such Countries can be decisive.

With the existing apparatuses, the uniformity of the changes Heat development from the center to the periphery of the evaporation divider in wide limits what no no no good full power delivery and qualitative and r removal intensive distillation process @ of harmful additions results.

In addition, the limited performance of the single phase apparatus imposes limitations the dimensions of the evaporation plate, which in turn are the absolute and relative The size of the areas of the condensation screens is important. The relatively small ones Surfaces of the condensation screens do not produce effective probing and removal of harmful admixtures.

It is therefore the purpose of the present invention to remedy the disadvantages mentioned with the well-known apparatuses term and a new perfected design of apparatus for continuous refining of metals.

The present invention is based on the object of the construction the evaporation stages of the distillation column and the system of To change the electric heater in the apparatus in such a way that aie the performance and the quality of the The process of metal refining in the melt can be greatly increased.

According to the invention to solve this problem, an apparatus for continuous Refining of metals proposed that a hermetically sealed, gein dem Cooled housing to be evacuated inside, a distillation column with evaporation stages is arranged, to the top of which the melt of the refined material continuously is supplied, as the pure flows in through all stages to the outlet of the apparatus, an electric heater that goes through the evaporation stages to evaporate the impurities passes through the metal, perforated condensation screens that surround the steps, and includes a refrigerated condenser box according to the invention; this apparatus draws # in the fact that the evaporation stages mentioned in the hone of the distillation column from a group of graphite bars of the three-phase connected electric heater are penetrated, the steps are carried out in such a form that the melt of the refined material from the upper intake level to the lower level as a thin layer Film flows down.

This technical improvement enables a progressive refining process of such metals as Lead, tin and the like in the form of a thin layer Filmes, which enlarges the evaporation surface of the vapors of the impurities and thus increases the quality and effectiveness of the refining process.

In addition, the connection of the electric heater in three-phase connection offers the ability to compare aie performance and efficiency of the apparatus to considerably increase the usual single-phase apparatus and at the same time one to create uniform loading of the electrical supply network.

According to one of the variants of the present invention oich the apparatus for the continuous refining of metals in that the evaporation stages in the form of elongated baskets placed one on top of the other, the rods of the heater are arranged along the longitudinal axis Ges bottom part of the baskets are, each basket has a long side, which is used to create the metal drain is inclined on aen mentioned bottom part, an aazu opposite exit side, never in the form of an overflow threshold for the overflow of metal onto the one below Sture is open, as well as end walls, in one of aenen, in its upper one Part of an arrangement for the evacuation of steam of the admixtures to the condensation screens is, wherein the successively arranged baskets with respect to each other at an angle of 180 ° are turned so that the Steam the admixtures in Aen roofed steps (through never mentioned openings) in the opposite direction step out.

The above-mentioned embodiment of the invention shows a the most favorable constructive Ausrührungsrormen aer stages of the distillation column.

This ensures a continuous separation of the condensation zones volatile additions to be removed with consideration of the reduction their concentration in the liquid refined material from stage to stage in the amount of Distillation column, which intensifies the distillation process and the quality of the refining metal elevated.

According to a further embodiment of the invention, it is characterized the apparatus for the continuous refining of metals through out, aaB never drainage surfaces aer the mentioned long sides of the baskets are formed in terms of length, with the floor area of each basket that connects the dead drainage sides, one certain tendency towards the accumulation of metal in the area of the drain on the floor surface having.

This variant of the invention, in particular, shows an efficient one Constructive design of the ends and aerofoil surface of the step baskets The embodiment of the distiller according to the invention increases the evaporation surface and creates a better removal of impurities as well as mixing and heating through the entire mass of the liquid refined material.

According to the invention, other aer apparatus is advantageous continuous refining of metals by having the upper intake stage the distillation column aarsteller a four-walled basket, the outlet in the form of a in its bottom part longitudinally arranged row of holes for metal drainage below never on the receiving side of the horizontal step is formed.

This variant of the invention shows the most favorable constructive one Embodiment of the upper receiving stage of the distillation column.

This ensures accumulation and heating of the refined material and its uniform distribution over the entire surface of the longitudinal side of the receptacle the basket, the stage below and all subsequent stages of the distillation column, which in turn means a high quality of the refined material and complete @removing aer admixtures.

Another embodiment of the invention is particularly effective an efficient structural design and arrangement of the heater in the distillation column.

The heater is in the form of three three-phase circuits Rods executed, which are arranged along the longitudinal axis of the baskets such that the distances between each rod and peripheral points of the respective basket are about the same, and the bar spacings the distances mentioned at least by a factor of 1, which results in a uniform heat development from the center to the periphery of each stage of the distillation column and between the Rods of the heater, an even heating of the refined material, a more complete one Power delivery and a more intensive distilling off of harmful additions guaranteed.

Another special variant is designed for the same purpose the invention possible, the rational execution of the central rod of the heating in the form of a rod, the cross-section of which is the cross-sectional area of each the end rods by at least 1.2 times.

Another variant of the invention relates to the cheapest one Constructive design of the lower stage of the distillation column. she is in Form of a four-walled collecting basket with a drain wall and openings for the steam outlet of the admixtures carried out in three remaining side walls, with its bottom part contains a fine metal drain, which balances the chemical composition des isffiustmetalla the final removal of the attachments before the metal drain guaranteed.

There is finally another variant of the invention, the most favorable constructive execution form of the distillation screens with vertical beads shows what increases the rigidity of the screens and the condensation surface enlarged and thus the intensity and the completeness.

the ability to remove admixtures increases.

The following are objects and advantages of the present invention based on an example from a detailed description of the apparatus for the continuous refining of metals with reference to the description the accompanying drawings explained in more detail; Figure 1 shows a cross section through the apparatus according to the invention, FIG. 2 shows a longitudinal section through the same Apparatus, Fig. 3 the evaporation stage with an end wall, usually not shown in the apparatus in Figs. 1 and 2.

Contains the vacuum apparatus for continuous refining of metals a hermetically sealed water-cooled body 1 (see Figs. 1, 2), inside whose one distilling column is arranged, which consists of a receiving stage 2, several Evaporation stages 3 and a lower Samo stage 4 consists.

The steps in the form of elongated baskets are made of one carbon-based graphitized material executed. Via a graphed subset 5, the column is based on a butter placed in the lower part of the body 1 6th

Condensation screens 7 are attached outside the distillation column. To increase the degree of condensation, the condensation screens 7 are perforated with Executed checkerboard arrangement of the openings and point to increasing the mechanical stiffness and condensation surface vertical z. B. right-angled or semicircular beads in the entire height euf. These can be understood from the description Details are not shown in the drawing so that they are not unjustified gets complicated. The inner surface of the body also fulfills the role of the capacitor 4th

Above the intake level 2 there is a fall water pipe 8.

The intake level 2 has a number of continuous drainage openings in the floor on, which are attached along a vertical longitudinal wall. The group level 4 has Below is a flow opening for the molten metal, an inclined wall for receiving it the melt, while in the upper part of the remaining vertical walls openings are trained.

Each lower evaporation stage 3 is with respect to the upper by one Turned angle from 1800. Pig. 3 shows these evaporation stages 3 (an end wall is not shown). The longitudinal wall "A" is inclined and its surface is smooth formed or has, as the drawing shows, longitudinal steps for area and surface enlargement metal film evaporation. The bottom of the evaporation stage rises towards it the overflow threshold. the Overflow threshold "B" is also with a smoother one Surface or, as the drawing shows, has longitudinal steps to the surface and surface enlargement of the metal film evaporation. The front wall of the evaporation stage has an opening "C" or several similar openings in its upper part to the directional The additions that evaporate as a result are released.

The second, not shown end wall of the step has no openings on.

The through holes "D" for the rods of the heater to pass through are in the bottom of the step either with the same cross-section, and with distances between them, the at least 1.2 times z. B. 2 times larger than a distance up to at any point of the step, or compared to the end holes is the Cross-sectional area of the central bore and the rod passing through it, as the drawing shows, at least 1, 2 times z. B. 2 times larger executed. A combination of the two mentioned chin variants can also be provided.

A pipe 9 for discharging the fine metal is connected to the lower stage at. A pipe 10 is used to discharge condensate to a water-cooled condenser box 11.

The interior of the body is evacuated via a nozzle 12, the is in communication with a vacuum system (not shown). To guarantee the evacuation of the entire volume of the support base 5 is perforated out.

The connection points of the parts of the body 1 as well as the points for Passage from the pipes 8, 9, 10 and 12 are sealed with vacuum seals 13.

The graphite rods of the heater 14 pass through all the evaporation plates and have contact assemblies 15 and 16 at the upper and lower ends.

The graphite rods of the heater are arranged in series; the middle one is for the uniform release of the heat output in the spaces between the heater with a compared to the end bars at least by 1, 2fa- <> and possibly are ches z. B. by twice the cross-section / also the interstices between the heater at least 1, 2 times (e.g. 2 times) larger than the distance from one every heater up to any point on the surrounding plate At the contact assemblies 15 and 16 are protruding from the body 1 after busses Power leads 17 output lines and 18 connected to the from one Three or three single-phase transformers can be switched on.

The lower ends of the rods of the heater 14 can be provided with connecting webs 19 can be connected in star. In this case, the power supply 18 is neutral. The latter circuit diagram of the rods of the heaters 14 is from the standpoint of reduction in number the openings to be sealed for the power supply lines in the lower part of the body 1 from structurally simpler and more preferred. The star connection scheme of the heater can also be carried out without a star point.

The places for the passage of the power supply lines 18 and 17 through the Body 1 have electrical insulation and vacuum seals 20. In order to increase the The contact assemblies 15 and 16 and the power supply lines are functional 17 and 18 run water-cooled. In addition, each power supply 18 is additional enclosed by a protective tube 21 (made of graphite or quartz) in order to prevent the Eliminate foreign matter and condensate vapor.

The vacuum apparatus for refining metals works as follows: Through the fall water pipe 8, the raw melt runs into the recording stage 2, from which it in the form of a wide thin film through the lower openings overflows onto the sloping wall of the evaporation stage 3 and is at the bottom of the stage accumulates; Depending on the accumulation, the melt flows over an open sill executed inclined below te wall on the sloping wall of the lying step and so on further down to the collecting stage 4, from which the fine metal flows down through the pipe 9.

The evaporating additions escape through a low, threshold-like Executed wall and openings in one of the end walls are on the screens 7 condenses and then flow into the lower part of the apparatus and further into Pipe 10 down. The admixtures flow from the pipe into the water-cooled condensate @ orkastea 11 and also in a collecting container.

Work stages 2, 3, 4 and stand 5 can be machined or in the form of fittings with dimensions that correspond to the dimensions of standard graphite blocks are carried out with the necessary processing allowances.

It can be seen that, if necessary, graphite blocks with different dimensions or fittings for producing the working stages of the distillation column from the apparatus In any case, compared to the levels of the known single-phase apparatuses the area of the graphite steps increases significantly, which increases the performance of the apparatus be effective. For the heater of the apparatus can, for. B. graphitized, 75, 100, 125, 150, 175, 200, 225, 250, 300 etc. up to 710 mm electrodes can be used. Compared to the existing single-phase prototypes, which have an output of 250 kVA, the apparatus according to the invention can, for. B. for an output of 750 kVA can be designed without any technical risk.

The apparatus can be used for fine metal extraction in the distillation process find extensive practical use. He can see, for example, tin refining to free them from lead and bismuth. Another powerful one The co-continuous zinc deposition from lead can be used.

The use of zinc to secrete precious metals from lead is known to cause contamination of lead with this metal. To a In order to obtain quality metal, it is necessary to remove zinc and lead. The vacuum process lead refining to free zinc and zinc refining from its impurities is based on the difference between the boiling temperatures of metals as well as on the Difference between the vapor pressures of zinc and lead.

For the rapid removal of zinc by distillation, the invention Apparatus provided all the necessary conditions: the melt lead has in the evaporation stages a large surface and flows in a broad, thin-layered jet of level to level above. The most effective film evaporation of the foreign substance vapor takes place here of refined goods instead.

Claims (8)

PATENT CLAIMS 1. Apparatus for the continuous refining of metals, the one Hermetically sealed, cooled body to be evacuated inside, in a distillation column is arranged with evaporation stages, the upper one where the melt of the refined material is fed continuously, which in turn over all stages to the outlet of the apparatus, an electric heater that flows through the evaporation stages perforated condensation screens to evaporate the metal impurities, which surround the steps, and contains a cooled condenser box, d a d u r c h g e k e n n n z e i c h n e t that the evaporation stages (3) in the amount of Distillation column from a group of graphite rods in a three-phase circuit switched electric heater (14) are penetrated, the stages (3) in such Form are designed that the melt of the refined material from the top Receiving stage (2) flows down to the lower stage (4) as a thin film. 2. Apparatus for continuously refining metals according to claim 1, that the evaporation stages (3) in the form of elongated baskets placed one on top of the other, the rods of the heater (14) Arranged along the longitudinal axis of the bottom part of the paint, each basket one Recording long side, which are used to create the metal drain on the mentioned bottom part is inclined, an opposite exit side, in the form of an overflow threshold for the overflow of metal on the underlying Stage is open, as well as having end walls, in one of which, in its upper one Part of an opening for the steam discharge of the admixtures attached to the condensation screens with the successively arranged baskets at an angle with respect to one another from 1800 are turned in such a way that the vapors of the admixtures in the neighboring Step out through the openings mentioned in the opposite direction. 3. Apparat sul continuous refining of metal according to claim 1 or 2, d a d u r c h g 0 k e n n -s e i c h n o t that the drainage areas of the mentioned longitudinal sides of the baskets are formed in a graduated length, the A certain floor area of each basket connecting the stepped drainage sides Opposition to the accumulation of metal in the area of the drain on the floor surface having. , 4. Apparatus for the continuous refining of metal len according to one of claims 1 to 3, d a d u r c h g e k e 1 fl t e i c h n o t that the the upper intake stage of the distillation column is a four-walled basket, whose drain in the form of a row of holes arranged lengthwise in its bottom part Metal drain is formed on the underneath took side of the lying step. 5. apparatus for continuous refining of metals after one of claims 1 to 4, that the heater contains three three-phase connected rods running along the longitudinal axis of the baskets are arranged so that the distances between each rod and peripheral Points of the respective basket are roughly the same, and the bar spacings are the ones mentioned Distances exceed at least 1.2 times. 6. Apparatus for continuous itaffinizing of s.etall after one of claims 1 to 4, d u r c h g e n n n z e i c h n e t that the central rod of the heater has a cross-section that is the cross-sectional area of each of the End bars by at least 1.2 times. 7. Apparatus for continuously refining metals after a of claims 2 to 6, d a d u r c h g e n n n z e i c h n e t that the lower Stage of the distillation column has a four-walled collecting basket with a waste wall and openings for the steam outlet of the admixtures in the three remaining side walls represents, with its bottom part containing a fine metal drain. 8. Apparatus for continuously refining metals after a of claims 1 to 7, d a d u r ch g e k e a a s e i c h n e t that the perforated Condensation screens that surround the baskets of the distillation column with vertical Corrugations are made, which increase the rigidity of the screens and the condensation surface enlarge. L e r s e i t e