DE1533070A1 - Process for the processing of metal-containing fine dust - Google Patents

Description

DUISBURG COPPER HUT "1533070

Duisburg, November k, 1966 Process for the processing of metal-containing fine dusts.

The inventive method relates to the work-up of metal-containing fine dusts or precipitated sludges by reduction and volatilization of those that are volatile at the reduction temperature Non-ferrous metals in a shaft furnace.

It is known that lead and zinc can be obtained from ores, which contain more lead than zinc, by reduction with coke in a shaft furnace. To do this, the charge is preheated _; the zinc condenses in liquid form and the lead at the bottom of the furnace is also tapped off in liquid form with the copper. The sulphidic ore is roasted beforehand by sintering and the sintered product is impregnated with flux. The gloss is preheated to 500-750 ° C _5, the carbon-containing reducing material is preheated to 800-1000 ° C and the wind required for shaft furnace operation is preheated to -800 ° C (DAS 1 027 879, US 3,231,370). This method has the disadvantage; that the raw materials to be processed must be sintered and preheated.

The process according to the invention for processing metal-containing fine dusts or F al Is chi amines by reducing and volatilizing the non-ferrous metals volatile at the reduction temperature in a shaft furnace does not have the disadvantages mentioned above with finely divided solid reducing agents in a Vorrichtungj for example, a mixer, mixed and adjusted to a moisture content which is typical for the particular grain spectrum and optimally _s to the drying in the shaft furnace sufficient for the furnace transition lumpiness and hardness to ensure "Subsequently, the stückiggemachten dusts melted in a known manner reducing.

To separate them into their metal content, they are reacted at a temperature such that _{f c,} for example, be recovered as zinc and lead sublimate, copper as stone and iron, optionally after addition of Flußmittelnr, slagged *

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It would now found that the several tested dusts require different and specific moisture for the processing in the shaft _furnace. Which depends on the respective grain composition, in such a _s that the required minimum and at the same time optimum wet the lower actual, the greater the fine-grain fraction (less than 60, u) of the dust isc If this moisture is not present, the tubers formed during mixing disintegrate again to dust when dried in the oven; which disrupts the oven operation. Of course, the humidity of the dust to be processed can be greater. However, the higher moisture content has no advantages and only requires unnecessary energy for drying. _F can also be Fällschlämme processed by the inventive method which is added to the necessary moisture adjustment particulate matter?

For tuber formation, a certain grain fineness and a corresponding proportion are required, which are largely independent of the chemical composition _P

It has been found that ₅ sufficient for the furnace transition optimal lumpiness and hardness are achieved when the moisture content is measured so that it for dusts having a particle size distribution of 100% less than 60 / u 13-23%. preferably 17 % -, at 60 % below 6o, u 17-27% _; preferably 21% _t and 20% under 60, and 33 - 45% ₅ is preferably 39% ₃ beträgt- all areas between two adjacent ones of said values can be determined by linear interpolation _c It was further _found that only those dusts are according to the invention processed can have a sufficient fines content, preferably at least 20 % below 60 / U ₁

There were Hocliofengicht dusts of the following chemical (I) and granulometric (II) composition processed

I. Zn 10 - 28 %

Pb 2 - 5 %

Fe 5 - 33 %

Cl 0.1 - 5.0 %

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II.

2 , 5 well = 0, 2 - 19th 1 , 25 mm = 0, 2 - 22 O , 125 mm = 0, 3 - 3 O , 063 mm = o _s 1 - 3 O , 045 mm = o, 8th - 10 O , 025 mm = 2 - 21st O , 025 mm = 6 - 8th O mpi = 13 - 22 <0 mm ■ 19 - 64

The dusts were provided with the necessary reducing agents and fluxes in a mixer and soaked accordingly and after weighing on a belt scale, evenly distributed over the cross-section of the shaft through an adjustable rotary duct (inlet opening).

When processing in the shaft furnace, the chlorides and in the dust go together with the zinc and lead partly also possibly existing silver in the sublimate *

The sublimates collected in a fabric filter showed the following metal contents.

Zn = 50 - 75% Pb = 8 - 16 %

The slag produced contained 0.3-0.58 % Zn or 0.12-0.25 % Pb, ie 2-3 % of the zinc or lead from the first run. She was tapped continuously. In addition to zinc and lead, the slag contained an average of 21.3% FeO; 33.2% SiO ₃ ; 24.2 5 CaO; 9.00 9 ^A l ₂ ° 3 ^{and 3; /} * " ^Mg0 · ^The small amounts of copper were found together with small amounts of iron at the bottom of the crucible.

With higher contents of copper, as in other dusts occurs. can do this with the help of sulfur in copper stone converted, withdrawn with the slag and separated from it due to the different density.

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The following are 2 examples from processed blast furnace light dusts listed for those with a certain grain composition the minimum moisture content is specified?

example 1

For processing dust with 28 % zinc content and 5 % lead content of the following grain composition

2 , 0 mm = 0c2 1 mm = 0; 2 O _S 25 mm = 0 _; 3 O , 125 mm = O ₅ I. O ; O63 mm = 0.8 O _t o45 mm = 3.9 O .025 mm = 8 _: 5 O , 025 mm = 21.8 O mm = 64.2

a minimum moisture content of 15 c 6 % was required <-

Example 2

The processing of a dust with 20 _r 2 % Zn and k _% 7% lead content of the grain composition

4 mm = 19-, 0 % 2 mm = 21.3 % 1 mm = 12 γ, 4% O ₅ 5 mm = 2j8% 0 "25 mm = 3 % 0.125 mm = 1.2 % O _t O63 now = 1 _S 9 % O _t o45 mm = 6.3% 0.025 mm = 13 _S 6% _<O; O25 mm = l8 ₅ 5 %

required a minimum of 24.5% "

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Claims (1)

153307G Claim 1 Process for the processing of metal-containing fine dusts or precipitation sludge by reducing and volatilizing the Reduction temperature of volatile non-ferrous metals in a shaft furnace, characterized in; that the dusts and / or felling sludge together with finely divided, solid reducing agents in a device, e.g. a mixer, and mixes to a moisture content which is typical and optimal for the respective grain spectrum in order to be able to use the Shaft furnace to ensure sufficient lumpiness and hardness for the furnace passage, and then reducing in a known manner melts. Claim 2 Process according to claim I _5, characterized in that the moisture is so dimensioned that it is suitable for dusts and sludges with a particle size distribution of 100 % below 60 / u 13-23%, preferably 17%, at 60 % below 60, u 17-27 %, and at 20 % below 60, u 33 - 45% _5, preferably 39%, is ₅ and all areas between two neighboring values are linearly interpolated = Claim 3 Process according to claims 1 and 2 _5, characterized in that only those dusts are suitable which have an adequate fine fraction; preferably at least 20 % below 6o, u » claim k Method according to claims 1 - 3s characterized! that the lump-made fine dusts or * Fällachlämrae to separate their metal contents are implemented at such a temperature that volatile NB metals are obtained as sublimate, non-liquid ones as metal or stone and iron predominantly, possibly after the addition of fluxes, as slag. 009830/0241