DE1025150B - Process for the production of heavy metals from their sulphides - Google Patents

Description

GERMAN

The traditional way of large-scale processing of sulfidic metal ores or concentrates produced from poorer ores by flotation and / or descent separation especially sulphidic ores or concentrates of Cu, Ni 5 and Pb, is the roasting reaction process. It exists in that the sulphidic starting materials, possibly after previous partial disarmament, in one Flame, shaft or electric furnace are fused into a higher concentrate called stone, the accompanying metals, especially iron, preferentially go into the slag, while that to be extracted Heavy metal, ζ. B. copper, enriched as a double sulfide in the stone. The stone produced in this way is then blow in a converter with side nozzles, d. i.e., air is blown through which the Sulfur from the melt is burned to sulfur dioxide.

This way of working has the advantage of enriching the metal to be extracted in the stone before this is given to the converter, so that valuable converter space is saved will. Since the advent of modern flotation and sink separation methods for the enrichment of poor people Ores, however, this detour via the Steinher position is no longer absolutely necessary, since in the modern concentrates or other metallurgical byproducts raw materials are available whose content of heavy metal to be extracted is not significantly lower, and often even higher than in a classic stone. For example, copper stones with 20% Cu are often processed while on the other hand there are concentrates with 30% Cu. Lead ore concentrates with 80% Pb are also available today already available.

The aim of the invention is to improve on what has been customary up to now. Method of heavy metal extraction in such a way that the sulfidic raw material is directly applied to finished metal, e.g. B. blister copper, is fused. The possibility of direct blowing of raw concentrates in the converter, ie a kind of combination of raw melting in the furnace with blowing work has already been considered, but with the proviso that such a method of operation does not lead to any advantages, but only disadvantages, above all that a richer, non-settable slag is obtained. In the end, this concern is justified as long as conventional blowing is used, which requires the blowing air duorch nozzles to be injected directly into the molten sulphide bath. The resulting swirling of the bath prevents a sharp separation of the layers in molten metal, possibly a method of production
of heavy metals from their sulphides

Applicant:

Metallgesellschaft Aktiengesellschaft,
Frankfurt / M., Reuterweg 14

Dipl.-Ing. Carl-August Maelzer, Frankfurt / M.,
has been named as the inventor

Intermediate layer of stone and overlying slag, so that the latter becomes too rich. In addition, as the sulfur content decreases, the heat content of the bath decreases far more than that which is lost. SO ₂ corresponds, since the nitrogen ballast of the blown air causes additional cooling so that in the final stages of the process the temperature required to maintain it is not reached. For this reason, too, poor slag cannot be obtained in this way.

According to the invention, these disadvantages are eliminated by using, instead of air, oxygen or oxygen-enriched air which is not injected into the molten bath but is only blown onto the surface of the molten sulfidic material. When using high-percentage oxygen, in contrast to working with air, the diffusion and reaction rate is sufficient even without direct blowing in to be able to complete the process in a technically economical manner, and it is also avoided that the reaction occurs before it complete termination due to excessive heat dissipation through the nitrogen ballast freezes. The temperature of at least HOO ⁰ C, preferably 120 ¹ to 1300 ° C and above, necessary for fusing to metal, can rather be maintained until the process is complete.

709 907/334

3 4

By inflating according to the invention in place. Embodiment 1

During the injection, turbulence flows in the bath are melt-blown by means of oxygen in the

completely excluded and a sharp layer- discontinuous; Operation in a melting pear separation allows, so that a slag accumulates

poor enough to be deposed. 5 A melting bulb is placed vertically and from

In the procedure according to the invention, for example above, with the copper concentrates to be processed

When Cu ₂ S is blown to form Cu, the sulphidic type and the. for slagging the

Metal formed on the surface due to its secondary metals required slag formers for example

higher specific gravity to the bottom so that it is half filled. Then she becomes tight with a

is protected from further attack by oxygen, closed hood-shaped cover

and the surface of the melt always remains the sen. This hood is broken in three places,

Reactive to oxygen. in fact

In the case of direct fusing according to the invention,,, _v ,,, ,, ". ,.

τ, *. ι, ι · -U --U- ii -u ^a ) through a rotary valve for introduction

of metals can, as with the classical '-. . ". , °

" _T,. ,,. , j ... -urn ·, fresh concentrate,

Procedure, at least intermediate also a 15, *,,. ,,. , ". .... ... _r . _.

Form stone phase, which due to their specific ^b ) J " ^{rch an} *.

Weight between the top floating lead1 ^ ^{de * oxygen blower pipe} up to the

Schladienphase and the metal phase resting below, I would like to

is located. This stone phase is not off ^c> by a Abzugsoffnung to Abfuhrung

pierced and settled in continuous work ao resulting SO ₂ gases to \ erwertungsanlage

continuously in slag and metal, both removed (gas cleaning - sulfuric acid) or to the chimney

be pulled, or \ 'disappears with periodic stone.

Work completely in the course of the process. The surface of the concentrate to be treated

To carry out the process according to the invention, the oxidation is started with a Any melting furnace that has 25 initial ignition means (glowing coal, burning wood the introduction of oxygen and with oxygen or the like) partially covered. On this initial ignition, enriched Air allowed. The oxygen flow is now directed as a particularly advantageous mass, but has not become a known state of being in its surroundings through the combustion Technique belonging melting bulb with a single of the initial ignition means achieves a temperature that The opening has been shown to be sufficient around its transverse axis in both 3 ° to initially cover a small part of the con-directions can be rotated by at least 180 ° and heated to the ignition temperature in the center. Since the each position of its longitudinal axis can rotate freely because reaction - essentially the combustion of the Such a melting pear makes a particularly good separation. Sulfur - very exothermic in the stream of oxygen tion of the reaction products in metal and slag, it is sufficient to add more oxygen, enables. 35 to continue the oxidation of the copper concentrate

Use of oxygen or lead with oxygen. It arises from the amount of sulfidic enriched air for the fusion of sulfidic concentrates a mixture of sulfures and oxides. In addition to the above, concentrates also offer a The Sulfüre sink through the meanwhile schmelz series further advantages. Liquefied charge to the bottom of the

Since the work of compression of the blowing gas 40 melting pear is set, while the oxides react with the slag formers to 20% compared to normal blowing to form silicate slag, much smaller amounts of gas have to be compressed by the combustion of the sulphide and those than usual. You can also segregation of the copper-iron-sulphurous material, which is easier to store and regulate, so that it is possible to surface the melt in combustible material, which in its concentration and quantity is very strong equalize and encountered depending on the fresh concentrate. The concentrate is the requirements of the downstream H ₂ SO ₄ -An- by the rotary valve located in the hood, this was either constant quantities or a different one; suitable metering device in a constant SO ₀ concentration. The furnace introduced into the furnace and, due to the relatively high lower and more uniform amount of gas, can also be heated to 5 ° furnace temperature as well as the heat transfer due to its low volume in simple gas due to contact with the melt, cleaning systems cleaned so that also An advantage here is that the ignition is only caused by oxygen due to the lower construction costs. As the roasting gas inflate goes on. The gaseous prolich which has not been diluted by nitrogen in the reactions up to now is also possible. SO _{2 of} any purity at the same time with the 55 products are continuously removed. Recovered metal dusts in a single step. Since they are fed back into the melting pear. The heating of the nitrogen ballast is omitted, liquid reaction products can separate into slag and relatively low-sulfur starting materials directly and copper matte. From these, the slag is melted down onto metal, whereby to generate the reaction either by inclining the supply of the required heat, the combustion of the sulfur contained in the melting pear is tipped off or the sulfur contained in the batch is removed by tapping and, if necessary, a tapping hole. The copper stone verder accompanying metals, especially iron, is used. Um remains in the furnace and, if it still contains iron, will save on apparatus space and the further processing will be blown into copper sulphate and slag. After processing and cleaning of the roasting gas, the tipping of the residual slag, the copper can be processed according to a special embodiment of sulfur by blowing more oxygen, blowing with oxygen or with acid to copper and sulfur dioxide. The substance-enriched air under pressure, preferably sulfur dioxide, is discharged as above and that up to about 10 atm. take place. Copper tipped or tapped as above. By

The method is shown below with reference to two the possibility of rotating the furnace vessel Embodiments explained in more detail. 70 its axis results in the possibility of

Compensate for heat build-up within the refractory lining of the melting bulb by rotating it.

Embodiment 2

Melting process in a continuous process in a rotary kiln

A rotary kiln of conventional design is advantageously used as follows to carry out this process equipped: An oxygen supply pipe is installed at the lower end so that it is tight ends above the storage edge with slag discharge, which is also to be attached at the lower end. At the end of the task The furnace is equipped with a gas vent for the discharge of the resulting, high sulfur dioxide content Exhaust gases as well as a dosing device for the regulated application of the solids.

To carry out the process, the rotary kiln is partially equipped with an initial ignition device (glowing coal, burning wood or the like) filled and through; Supply of oxygen to this initial ignition agent burned. Due to the heat generated in this way, the lining of the furnace is converted to a brought to such a temperature that fed raw or pre-roasted copper concentrate in mixture with the slag formers required for the slagging of the 'iron and other secondary components' the heat transfer from the refractory lining has already been brought to the ignition temperature will. By further inflation, the introduced copper concentrate is partially oxidized by oxygen, so that oxides and sulphures result from them. The resulting sulphures are caused by the rotation of the The furnace is no longer lifted up, but collects on the furnace base and accumulates finally, covered by the continuously forming slag, behind the one at the lower end of the furnace attached storage ring or stowage d. The slag continually overflows, while the copper sulphur accumulates more and more behind the edge of the storage space. The copper sulphate should now be blown onto copper the supply of fresh concentrate with slag formers is interrupted and the The entire slag portion is drawn out of the furnace by overflowing the storage ring. That now before

Copper sulphide lying on the ground is converted in an exothermic reaction by further inflation of oxygen into metallic copper and sulfur dioxide. The metallic copper is made by parting from the storage ring also withdrawn from the furnace, while the resulting sulfur dioxide collects along with the other waste gases from the process, are appropriately cleaned and recycled will.

In contrast to the process of blowing in the melting pear, this process is practically continuous, because the flow of oxygen and thus the release of sulfur dioxide continuously from the furnace takes place regardless of whether this sulfur dioxide is now from the combustion of the sulfide too Sulfur or desulfur to metal takes place.

Claims (4)

Patent claims: 1. A process for the extraction of heavy metals from their sulfidic ores, concentrates or metallurgical by-products by blowing their sulfur content to SO ₂ , characterized in that oxygen or oxygen-enriched air is blown onto the reactive surface of the molten sulfidic material. 2. Procedure according to. Claim 1, characterized in that the for the oxygen treatment intended charging by external heating or by own reaction heat - z. B. by a roasting process - even before it is introduced into the areas intended for oxygen treatment The apparatus is preheated to such an extent that the oxygen supplied is ignited immediately he follows. 3. The method according to claim 1 and 2, characterized in that a for melting Lard pear is used. 4. The method according to claim 1 to 3, characterized in that the melting and blowing under pressure, preferably under pressure up to. ΙΟ ¹ atm., Takes place. Considered publications: V. Tafel, "Textbook of Metallurgy", Halle, 1951, vol. 1, p. 403.