DE2150677A1 - Process for the production of bricks from red mud - Google Patents

Description

$ e "5 brothers Giulini GmbH.

Ludwigshafen / Rh. ^Patient

"Process for the production of bricks from Rptschlamin" (Addition to patent application P 2 o63 o28.8)

The present invention relates to a method for manufacturing of bricks, in particular lightweight bricks made of red mud, in which the filter-moist Botschlamm before processing strongly binding organic or inorganic Substances are added to influence the consistency.

In the patent application P 2 o63 o28.8 it is already proposed to mix hot sludge with clay to keep its shape, to process bricks that are not blooming, u.zw. in such a way that the red mud is first brought to a humidity of 15 - 35 Wt .-%, preferably 2o - 25 wt .- Sf dried and then in an amount of 50-92% by weight, preferably 70-90 wt. Sf, based on the dry substance of the mixture, mixed with clay.

With this method, the raw mixture can be easily deformed and the bricks made from it also have a flawless quality Quality on. However, a disadvantage of this method is seen in the fact that it requires additional equipment is necessary for drying the red mud.

From "Ceramic Bulletin" ^ o [197Ij 3 it is also known To mechanically foam red mud mixed with clay, perlite and foaming agent and in this way into a Bring deformable consistency. Deformation in extrusion is not possible with this process. In addition, the strength values achieved are so low that the process is of no importance to industry.

3098 16/0454

It has now been found that the method according to the main application 2 o63 o28.0 improves in a simple manner can be that the filter-damp Rotscblornm Inorganic and / or organic substances that bind water can be added. The consistency of the red mud is through the addition of the water-binding agent surprisingly changed so that he without further measures - in particular without pre-drying - it can be mixed with clay in extrusion presses to form hollow bricks. the added amount of water-binding substances depends on Wasserbindevermb'gen 5 - 30 wt.%, Is however advantageous at 10-25% by weight. The water-binding substances can, for economic reasons, the red mud directly in the red claim removal facility, i.e. directly be added after filtration. The size of the added Particles should not exceed 4 mm, but advantageously a maximum of 2 mm. The particle size is not limited to the bottom.

In terms of inorganic substances, bentones, silica gels, clay gels, etc. come into consideration. As organic matter are cork, peat, sawdust, coal dust, paper and textile waste or mixtures of these substances with one another are preferred. In addition, ea is possible to largely dry off Add RotGchiamai as a vranr-binding substance.

P i The realization that despite the addition of water-binding organic and / or inorganic materials the production of fired bricks, in particular lightweight bricks, is possible. was completely surprising and unpredictable. An addition of these substances during manufacture of lightweight bricks or when used in conventional Ziorel

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raw materials is called namely by the brick industry considered technically useless. It will be in this ZueaTniaqjihariR to the German patent specification 1 126 3o2 referred to, according to which an addition of water-binding substances as a result of the sudden development of steam leads to the destruction of the bricks. For this reason it is also suggested that the raw material only add substances that absorb little or no water, e.g. foamed plastics with closed Pores. liotschlanm appears accordingly in his behavior to differ significantly from the properties of the raw materials commonly used in the brick and tile industry.

The still produced by the process according to the invention Stones have the following mechanical properties:

Bricks sub red mud according to the invention:

cht; J) .ruc> fci? Tipfcf: it

0.85 {/ or, ' ¹ 188 kp / cn ²

0 / jO '"? 50"

0.95 "302»

Seal f .: te ine after the German ο η! Potent: script 1 126 ⁷ , o? RauLigcwicht Drucki'e;? (Jgkeit 0.80 g / ciTi ^ 120 kp / cn * 0.95 "190"

In dcT · Großtechr- ischen lhr.zic-: has shown that with de :. ' Carrying out the- \ ^r ei l'nhron.s after tlor Urfinduiig despite the higher-v; n Warsercchaltes a perfect Verforriurif: nöglicli ict and aase- d ^ rüborhinpus also a very good GrÜKiitandfcptiglceii. ca-re: .cht is. Shrinkage or plotting was not observed either during drying or during firing. The bein Brer-nprozes-f? by burning out the

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The micropores created by organic substances enable the production of lightweight bricks. The resulting Combustion heat serves as an additional .energy source.

The method according to the invention can be a nuisance Waste product of aluminum production an economic one Recycling and thus avoiding environmental pollution. -

The subject matter of the invention will now be explained in greater detail on the basis of the examples below.

Example 1:

On a rotary vacuum filter, 200 kg of moist red mud with 39-6 % water content were filtered per minute. The red sludge was transported away in a screw conveyor. I.

In this snail were the red mud per minute JO kg of waste cork flour added. In transit of 15 ml length and a residence time of 1 -1 ^ 5 min. a good mixing of the two components occurred and the mixture became more crumbly, easily transportable Form discharged from the screw.

50 tons of this material were then intimately mixed with 7.5 tons of clay, added to an extruder and there deformed to form brick blanks under a pressure of 8 atmospheres. The hollow parts were dried in a tunnel dryer at a temperature of 45 ° C. within 24 hours. A deformity was not observed here. With a Re stw ^ sr; ergeh old ^ of ^1%, the Fo RINL in jvo were placed in a ring furnace and fired for 20 hours at a temperature of 980-1000 ⁰ C. Abplatzui> r c ⁵ n • or Schwuridriese came here not auf.Die fired bricks had a Rohwielite of 0.92 kg / dm and a compressive strength of 258 kg / cm '. "

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Example 2t ■

In the screw conveyor described in Example 1, 20 kg were completely removed from the 200 kg of wet sludge per minute; Dried Rotachlamm added. On the conveyance route was
an intimate mixture of both substances is achieved and that
Mixture in a crumbly consistency from the snail from j

carried. . ^■:;

.25 tons of this material were mixed with 5 ^ + tons of waste clay; and in an extruder at a pressure of 9 atmospheres

Deformed brick blanks. The drying was done in one;

Tunnel dryer at a temperature of 52 ⁰ C -within i

22 hours carried out, with also crack-free, good loading - ^:

permanent briquettes were obtained. ,

The raw bricks were made with a residual moisture content of 3 %
placed in a ring furnace and 20 hours in a
Fired at a temperature of 1000 - 102C ⁰ O. The product was
free of shrinkage cracks and flaking. The burned '
Bricks had a gross density of 1.25 kg / dm and a.! Compressive strength of 510 kg / cm. · _!

Example g;

In the conveyor screw ~ according to Example 1: 200 kg of moist red sludge per minute were Q kg finer
Fly ash offset. On the way of transport were then
both materials mixed well and the mixture in more granular
Structure removed from the screw.

25 tons of this mixture were mixed with 4 tons of clay and

dimensionally stable in the extrusion press at 8.5 atmospheric pressure

Brick blanks deformed. The blanks were in one

steam-cooked commer dryers within 15 hours, with one

Temperature of 60 ° C, crack-free on one; Rc: humidity from

1,2 /.- dried off. With the subsequent B.-and in one

Rirjofen, whose internal temperature was 1000 - 'λ> 20 ° C,

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No cracks or flaking were found. The test of the fired bricks showed an Eohwichte of 1.08 kg / dur and a compressive strength of 387 kg / cm.

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Claims (7)

Claims M) _y Seduction to make bricks from red mud gejnäi. ;; -. Patent application P 2 o6J o28.8, characterized in that the filter-moist red mud "what binding inorganic and / or organic substances are added before mixing with clay. 2) Method according to claim 1, characterized in that the filter-free red mud 5-30% by weight, in particular 10-25% by weight, water-binding substances are added. 3) Method according to claims 1 and 2, characterized in that that the water-binding substances have a maximum particle size of 4 mm, preferably 2 mm, exhibit. Ί-) Method according to claims 1 bin 3i characterized j that the wascerbinäenden substances directly after filtration in the RotEchlanim removal facility Exercise must be networked. 5) Method according to claims 1 to 4, characterized in that that bentone, pebbles {;; ele, clay gels. and / or largely dried off as water-binding substances Red sludge can be used. 6) Method according to claims 1 to 4, 'characterized in that that cork, peat, Sawdust, coal dust, paper and / or textile waste gf ^ sets vjerden. 7) Verfnhi'cn according to claims 1-6, characterized in that that al r water binding substances mixtures of organic and inorganic substances: are used. BATH ORIGINAL 3098 16/0454