DE2059299A1 - Method of removing antimony from copper or copper sulfide - Google Patents

Description

tockholm / Sweden

Process for removing antimony from copper or Copper sulfide

The present invention relates to a method of removal of antimony from copper or copper sulfide or copper or materials containing copper sulphide,

iiei the production of high quality copper, e.g. copper for electrical purposes, one must go through an electrolytic refining stage use to obtain the necessary degree of purity. Anodes are used in this electrolysis a copper content of 9a.0 to 93.5 ^ Gu at 2.0 to 0.5 $ various impurities, Ue contribute to the greatest l'eil the electrolysis itself insulates bsw. be eliminated, Lfm to be able to carry out an otrörena-free electrolysis

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it does not matter what impurities in the anode copper are contained or in what amount they are present. The limits are very narrow for certain impurities, for others, on the other hand, the tolerance is greater.

It is therefore necessary to pretreat the anode copper in such a way that the permitted limit contents are not exceeded will.

Antimony is a metal that affects the quality of electrolytic copper has a particularly detrimental effect, and one strives to get down to a content of at most 1 g / t, ii'all the anode copper too high antimony content, e.g. more than 350 g / t, the electrolysis produces a floating or floating sludge of antimony, arsenic, and in certain cases of bismuth, which the copper cathode in such a way can contaminate that the tolerance limits for antimony in the electrolytic copper are exceeded, thereby reducing the copper quality is endangered. Furthermore, this floating sludge can cause growths on the cathode, which between The anode and cathode lead to short circuits and can thus result in a reduced current yield.

Antimony cannot usually be removed from the antimony-containing copper raw material by enrichment because the Most of the copper deposits containing antimony contain antimony chemically bound to copper. Excessive antimony digests by means of enrichment processes results in too large a copper flow rate to be carried out economically to be able to. About the antimony content in the copper product to reduce, one is currently on the selection of raw material with low antimony content or on different rivets Processes relying on only a limited iYnfcim gea batten. A large number of ore deposits that would not be processed for the time being economically would not be processed nt be available for the production of quality copper,

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■ λ υ in which more effective antimony removal methods are developed could.

According to the. Now the commonly used technique is the copper before the electrolytic refining of a Yorraffinatioti including a majority of metallurgis rather treatment stages, like ^ oste, stone or crude smelting and conversion, subject. Each stage can be used to a certain degree to remove antimony. 'When roasting takes place it is caused by the volatilization of antimony, although the expulsion takes about 20% of the total amount of antimony.

With the addition of slag images, the osted material becomes common -ilisiuiioxyd, melted, being a slag and so-called raw stone practically the entire incoming amount of copper contain.

Jeim melting the copper roast, usually stone or The antimony content is distributed between the slag and the rough stone phases. This distribution is noteworthy to influence, for example by changing the slag composition or the amount of slag is not economically feasible.

after the black phase has been deposited, the Raw stone in molten form is transferred to a converter, where it is filled with air or with oxygen-enriched air Formation of essentially copper metal, sulfur dioxide and kioenoxides is oxidized. The iron oxides are simultaneously slagged by adding quartz sand.

The relatively lengthy oxidation treatment in the converter is an effective copper refining method in itself, but in terms of it is "in many cases not sufficient for removing antimony."

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There are several proposals for reducing the antimony content in the product obtained by the converter treatment (Raw copper or blister copper) have been made, including Treatment methods with a solid or liquid slag. For example, it has been the main ingredient in alkali (soda) proposed a refining slag, thereby producing antimony oxides dissolve more easily in the slag, which leads to a somewhat improved refining effect. Treatment with Alkali is well known and widely used. The treatment of raw copper or blister copper with OaO has also been proposed, as described, for example, in German patent specification 1,137,223. The refining methods mentioned have the disadvantage that the ijffekt primarily from one direct contact between the phase surfaces Uetallbad-Schlakkenbad and / or solid slag is dependent. Even if in the known process there is a metallurgical equilibrium Indicating good refining effects are great practical Difficulties in achieving the required reaction speed.

According to the invention, these difficulties are eliminated by that the molten copper sulfide or Ijipfer with oxidizable Iron or oxidizable iron compounds are added, which are soluble in molten copper or caper sulfide ™ and have a low content of antimony, and that subsequently the dissolved iron by partial oxidation, preferably using air or oxygen enriched air, in the usual way from the melt is removed or isolated. Examples of suitable oxidizable iron compounds are magnetic gravel and pyrite. These are expediently added in pelletized .Forts.

Try un ^ ^T! n ~ ^T '"' ionunfpi ⁴ φ Ζ'όο ^ τ -it"»r," -it the copper converter - C4: f -. oigebsu, «ai3 Hi \ . .. ^ ug from Antimony eua Kupferi ~ ■"'<. . ipfer ^ ('ir "~ ^ * ->" T ^ uall in the \ ^% : · -.4, ":: ydation of

* ' QU g 7, ' CL-. '

jiisen in the rough stone and metal melt. When converting of raw copper stone containing antimony, the greater part of the antimony content leaves the copper and is in the To find converter slag. Through phase studies of the solidifying converter slag, e.g. in microprobes, found that antimony is present in oxidized form and together with other components forms minerals with a spinel structure. These minerals are essentially iron oxides, like magnetite, trivalent iron being partially substituted by trivalent antimony. A general The formula of the converter slag (magnetite spinel) is:

(i'e (II), Zn, Ou) 0 '· (Ee (III), Al, 3b) ₂ O _{7) J}

with both copper and antimony in lower concentrations available.

In samples of converter slag with varying magnetite contents, the antiriron content was determined and some results are given in the table below:

Magnetite content Antimony content

11.2 0.10

21.3 0.19 46.7 0.55

This confirms the assumption that a strong chemical bond exists between iron and antimony in an oxidized form. If one studies the course of the copper conversion closely, one gets that the speed of the anti-riot flyover of s copper raw stone or copper metal in the Sohlaoke functional a direct connection with the egg oxidation in the rough stone or has copper.

When the melt is oxidized, it becomes iron practically completely oxidized before significant amounts of ι copper are oxidized. In sulphurous environments, i.e. when

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the Haffinatioti Ια llohsteinschmelzen are carried out: nl ι., Sulphide sulfur is oxidized simultaneously with iron and Reduces the rate of slag formation "with a constant supply of oxidizing agent. The oxidized iron comes after oxidation to the surface and also contains; refined antimony. The iron oxide gets through either mechanical scraping from the copper melt surface or after Slag formation with silica by decanting in liquid l'Orm away.

The refining process described, in which iron or iron compounds with a low antimony content are fed to the refining system, is expediently carried out in connection with the copper conversion and in a copper converter; it can of course also be carried out in other types of furnace, e.g. flame furnace or rotary furnace. Iron scrap, iron-copper scrap, iron sulfides or copper pebbles can expediently come into consideration as antimony-free or essentially antimony-free iron additives. However, scrap iron is most effective, while pebbles are less effective. When using Eisensohrott and iron sulphide which K _o is extended nvertierungsdauer without the copper production is increased.

Air oxygen or air enriched with oxygen is expediently used as the oxidizing agent. The oxygen is preferably supplied under the bath surface either with the aid of blow openings or with a lance.

The invention is explained in more detail using the following example.

example

In a copper coaverter which has been coated with Robstein containing 35 $ copper and 0.14 $ antimony, the copper sulphide naota from the Robstein vase gives 0.04 $ antimony. To the

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AntiMJon content. continue to degrade, became granulated I''eS added in. An amount equal to $ 6 of the amount of copper, and after the oxidation, the amount of FeS added to FeO and Fe, O. was the antimony content of the finished blown copper dropped to $ 0.02. Other batches with the same incoming material, exposed to the same treatment but without additives contained 0.055-0.040 $ Sb after blow molding. In another experiment, copper sulfide was used with a rough stone of low copper and low antimony in treated with the same converter. The copper sulfide batch, say 150 t, was treated with 10 t of raw stone. The antimony content in the finished blown copper was $ 0.06 0.03 / '' reduced. Without the addition of rough stone with low Copper content, the antimony content after Pertigbasen was $ 0.045.

The example shows that the method according to the invention enables a significant reduction in the antimony content in the copper produced, and that such a reduction it allows material richer in antimony to be used without the risk of deteriorating the quality of the product can be worked up by the antimony content.

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Claims (1)

Claims 1. Procedure sau removing antimony from copper or Copper sulfide, characterized in that molten swab π ulf id. or copper with oxidizable iron or oxidizable iron compounds are added, which are soluble in molten swab or copper sulfide and have a low content of antimony, and that subsequently the dissolved iron is isolated from the melt by partial oxidation, such that Antimony is oxidized and bound to iron oxide at the same time which is a separate phase insoluble in the melt. 2. The method na oh claim 1, characterized in that Iron in the form of metallic iron, e.g. B. scrap iron, is added. 3. The method according to claim 1, characterized in that Iron is added in eggs i'Orm of iron-copper-scrap. 4. / experience according to claim 1, characterized in that .li-'ion in the i'or'Ji of iron sulfides, z.'ß. Pyrite, Jiagnet- ψ gravel, is added. '■': ■ . Method according to claim 1, characterized in that ■ .'jisen in. c'nr ^ o rm of copper pebbles, preferably copper con-3cnt;. "it, r; u _L. (" octzh v; ird. C, Ζ ei:: "'■. Ijrr.ii nrr, oh claim 4 or _ ~, characterized in that the sulfides are pelletized before the addition. 7. '/ erfr, Uren according to one of claims 1 to G _5, characterized in that the method is in a copper! "Converter by' ο i.'i - '' nrt. 109827/0922 B ORIGINAL : J. Process according to claim I, da'I uran characterized in that the oxidation using atmospheric oxygen or with oxygen enriched air takes place. BATH ORIGINAL 109827/0922