DE102008013746A1 - Making moldings for recycling, using wastes arising from iron or steel production, adds water, cement, sand and additives and consolidates in mold - Google Patents

Abstract

Ferrous wastes are mixed with water and cement to form a starting material. This is consolidated and hardened, forming moldings which are recycled to the iron or steel production process. Before consolidation, the starting material is capable of being pumped. The starting material contains in addition, steelworks sand with a binder. The water content is adjusted to approximately 11% wt%, based on the quantity of residue. The sand composition, expressed as percentages by weight, is: CaO 30-45, SiO 230-45, Al 2O 35-15, MgO 4-17, S 0.5-1.5. Optionally, specified smaller quantities of iron, manganese, titanium dioxide, potassium oxide and sodium oxide may also be present. Approximately 10 wt% of cement is added, based on the dry weight of the residual waste. The initial strength of the cement is at least 10 MPa, preferably at least 30 MPa. The standard strength is 50 MPa or more. The cement quality is CEM III A 42.5Nor CEM I 52.5 R. About 5 wt% of sand is used, based on the dry mass of residual waste material. 3 wt% of binder is included. The starting material is placed in molds before consolidation and hardening. The residual waste comprises one or more of: coarse sludge from classification, oxide scale, fine sludge, especially from a sedimentation tank, millscale sinter, especially from settlement wells, separated iron or steel, fine iron, cast iron foundry dust, dust from dust removal plant following cast iron desulfurization, dust or sludge from galvanizing lines. The wastes are supplied in grain sizes up to 20 mm. An independent claim IS INCLUDED FOR the corresponding molding (or briquette).

Description

-The invention relates to a method for the return of in metallurgical residues such as dusts and muds from filter plants of steel mill dedusting and from the cleaning The water cycle system contained iron and steel in one Steel production process as well as one moldings For this Purpose derived from metallurgical residues will be produced.

at The production of iron and steel fall in the metallurgical plants size Quantities of residues, which for direct reuse in the converter are too fine (up to 20 mm). These are, for example, the following substances: coarse dust from classifiers, Fine Steel, Flämmzunder, Fine sludge from sedimentation tanks, roller sinter from settling wells, tinder from settling wells, sludge from chamber filter press, separation iron, Separation steel, each in grain size between 0 and 20 mm. In particular, significant amounts of filter dust fall that's a big one Proportion of recoverable iron and steel, for example about 60%, and usually mixed with water as so-called sludge is rinsed in the basin. Only a small part of the smelter can be processed in sintering plants and recycled, while the largest part is deposited.

Feinstahl and scouring scale are used today in sintering plants with other substances for use sintered in a blast furnace.

separation iron from desulfurization slag can after processing the torpedo car for Recycled become.

The Invention has for its object to show a way how the resulting Fe-containing residues are largely attributed to the production process can.

These Task is first by a method for the return of in skin residues contained iron and steel in a steel production process, wherein a starting material containing metallurgical residues, water and Cement is brought into a mold, compacted and cured.

The Starting material may be pumpable prior to compaction.

The Starting material may additionally granulated blast furnace slag and an adhesive.

It can be provided that a Water content of 5-15 Wt .-%, in particular 11 wt .-%, based on the Fe-containing metallurgical residues, is set.

The blastfurnace slag may have the following composition: CaO 30-45% by weight, SiO ₂ 30-45% by weight, Al ₂ O ₃ 5-15% by weight, MgO 4-17% by weight and S 0, 5-1.5 wt .-%. In addition, the blastfurnace slag may contain one or more of the following constituents: Fe 0.2-0.3% by weight, Mn 0.1-0.2% by weight, TiO ₂ 0.5-1.5% by weight. -%, K ₂ O 0.5-1.0 wt .-% and Na ₂ O 0.2-1.0 wt .-%.

Of the Cement can be added in an amount of 8 to 15% by weight, in particular 10 wt .-%, based on the dry mass of the slag, be included.

Of the Cement can have an initial strength of at least 20 MPa and in particular at least 30 MPa. The cement can be a standard strength of at least 40 MPa and in particular at least 50 MPa. The range of cement quality lies between CEM 42.5 and 52.5. The cement quality is preferably CEM 52.5 R.

Of the granulated blast furnace slag can be added in an amount of from 2 to 8% by weight, in particular 5% by weight, be included.

The Adhesive is preferably sugar cane molasses and / or sugar beet molasses, expediently Diluted 1: 1 with water, and may be added in an amount of from 2 to 5% by weight, in particular 3% by weight, based on the dry mass of the sludge, be included.

The The object of the invention is further achieved by a shaped body for Repatriation of in metallurgical residues contained iron and steel in a steel production process, wherein the molded body Hut residues and cement. The molding can additionally granulated blast furnace slag and an adhesive.

The Composition of the blast furnace sand as well as the addition amounts of cement and adhesive can the Correspond to statements made above regarding the process.

It may be provided with respect to the method and the molding that the metallurgical residues include one or more of the following: Gross dust Classifiers, fine steel, scourers, Fine sludge from sedimentation tanks, roller sinter from settling wells, tinder from settling wells, sludge from chamber filter press, separation iron, each in grain between 0 and 20 mm.

following become two preferred embodiments of the invention explained.

The huts resulting from the production of steel as filter dust mixed with water Sludge has a water content of about 7 wt .-% and a grain size of 0 to 20 mm and has a proportion of about 60 wt .-% (based on the dry matter) of usable iron. The slag is treated with about 10% by weight (all aggregate quantities are based on the dry matter of the slag) CEM 42.5-52.5 grade cement, 5% by weight slag sand and 3% by weight of a 1: 1 mixture from sugar cane molasses or sugar beet molasses and water mixed to a starting material, compressed and / or pressed and then cured. The added sugar beet or cane molasses has as adhesive the task of holding the moldings immediately after compression or compression in the still moist, uncured state, so that they do not disintegrate before curing.

Of the Total sugar content of sugar beet molasses (Neat) is about 47% or more, the dry matter content 76 to 79% and the Water content less than 28%. Sugarcane molasses as a residual product sugar cane sugar production contains approx. 28 to 30% water, approx. 45% total sugar and approx. 17% organic non-sugars.

The Molasses with the above composition is first used in the relationship 1: 1 mixed with water before the mixture is then in said Proportion of 3 wt .-% is added.

All Components are thoroughly mixed and to moldings pressed or compacted, for example, cubic blocks with different Edge length. The pressed ones or compacted body harden at room or ambient temperature, for example at temperatures between 5 ° C and 30 ° C, within from one to three days, preferably within 48 hours. Thereafter, they have sufficient strength to be returned to a steel production process. Here are the moldings a molten steel added or filled in torpedoes, in which they melt, so that contained iron and steel can be recovered directly.

Of the slammed cement has as a binder the task of the molding to give necessary strength, so that this at the later addition in molten Steel does not burst open prematurely, but only at temperatures about 900 ° C melts. For this purpose, the cement used comprises 95 to 100% Portland cement clinker and has an initial strength (2 days) of at least 10 MPa and a standard strength (28 days) of at least 42.5 MPa.

Portland cement of quality CEM I 52.5 R is preferably used, with a standard compression strength EM 196 of 40 MPa (2 days) and 70 MPa (28 days), and with the following mechanical data: specific surface 5335 cm ² / g, water requirement 29, 8% by mass, solidification - beginning of 131 mm, room stability 0 mm. Chemical analysis: loss on ignition 2.48, insoluble residue 0.67, SiO ₂ 21.66, Al ₂ O ₃ 5.17, Fe ₂ O ₃ 2.87, CaO 66.3, MgO 0.83, SO ₃ 2, 5, Na ₂ O 0.25, K ₂ O 0.41, Na ₂ O (equivalent) 0.52, chloride 0.05, C ₃ S 60.3, C ₂ S 16.6, C ₃ A 8, 8 and C ₄ AF 8.7 (each in% by mass). The lime standard is 94.0.

at the embodiment of the invention described above the starting material introduced into molds, compacted and then cured. The Compaction can be due to vibration at small geometric shapes take place, for example on a vibrating table or by so-called Vibrators.

at large-scale forms the compaction takes place by means of rollers or vibrating plates. This compression occurs statically and / or dynamically.

In an alternative embodiment The invention eliminates the components slag sand and adhesive, d. H. the starting material contains slag sludge and cement. Here, the starting material is preferably pumpable, so that it can be pumped into molds.

The Compaction in this case by external or internal vibrators (vibrating bottles).

Claims (21)

A process for producing a shaped body for recycling steel and iron contained in metallurgical residues into a steel production process, characterized in that a raw material containing Fe-containing metallurgical residues, water and cement is formed, compacted and cured. Method according to claim 1, characterized in that that this Starting material before compression is pumpable. Method according to claim 1, characterized in that that this Additional material granulated blast furnace slag and an adhesive. Method according to claim 3, characterized the existence Water content of 5-15 Wt .-%, in particular 11 wt .-%, based on the metallurgical residues, is set. Process according to Claim 3 or 4, characterized in that granulated blastfurnace slag is used having the following composition: CaO 30-45% by weight, SiO ₂ 30-45% by weight, Al ₂ O ₃ 5-15% by weight, MgO 4-17 wt% and S 0.5-1.5 wt%; and optionally with one or more of the following constituents: Fe 0.2-0.3 wt%, Mn 0.1-0.2 wt%, TiO ₂ 0.5-1.5 wt% , K ₂ O 0.5-1.0 wt .-% and Na ₂ O 0.2-1.0 wt .-%. Method according to one of the preceding claims, characterized characterized in that Cement in an addition amount of 8-15 wt .-%, in particular 10 Wt .-%, based on the dry mass of the metallurgical residues, is included. Method according to one of the preceding claims, characterized characterized in that Cement an initial strength of at least 10 MPa and in particular at least 30 MPa. Method according to one of the preceding claims, characterized characterized in that Cement a standard strength of at least 10 MPa and in particular at least 50 MPa. Method according to one of the preceding claims, characterized characterized in that cement quality CEM 42.5-52.5 R is. Method according to one of the preceding claims, if based on claim 3, characterized in that blast furnace slag in an addition of 2-8 Wt .-%, in particular 5 wt .-%, based on the dry mass of Hut residues is used. Method according to one of the preceding claims, if based on claim 3, characterized in that as Adhesive sugar cane and / or beet molasses is used. The method of claim 11 when dependent on claim 3, characterized in that the molasses with water in the ratio 2: 1 to 1: 2, especially 1: 1, diluted becomes. Method according to one of the preceding claims, if based on claim 3, characterized in that the adhesive in an addition of 2-5 Wt .-%, in particular 3 wt .-%, based on the dry matter of the metallurgical residues, is used. moldings for the return of in metallurgical residues contained iron and steel in a steel production process, by characterized in that moldings Hut residues and cement. moldings according to claim 14, characterized in that the shaped body slag sand and an adhesive contains. Shaped body according to claim 15, characterized in that the blastfurnace slag has the following composition: CaO 30-45% by weight, SiO ₂ 30-45% by weight, Al ₂ O ₃ 5-15% by weight, MgO 4-17 Wt% and S 0.5-1.5 wt%; and optionally with one or more of the following constituents: Fe 0.2-0.3 wt%, Mn 0.1-0.2 wt%, TiO ₂ 0.5-1.5 wt% , K ₂ O 0.5-1.0 wt .-% and Na ₂ O 0.2-1.0 wt .-%. moldings according to one of the claims 14 to 16, characterized in that cement in an added amount from 8 to 15 wt .-%, in particular 10 wt .-%, based on the dry matter the metallurgical residues, is included. moldings according to one of the claims 15 to 17, characterized in that granulated slag in an added amount from 2 to 8 wt .-%, in particular 5 wt .-%, based on the dry matter the metallurgical residues, is included. moldings according to one of the claims 15 to 18, characterized in that adhesive in an added amount from 2 to 5 wt .-%, in particular 3 wt .-%, based on the dry mass the metallurgical residues, is included. moldings according to one of the claims 15 to 19, characterized in that the adhesive is sugar cane and / or sugar beet molasses is. Process or molding according to one of the preceding Claims, characterized in that the Hut residues include one or more of the following: Gross dust Classifiers, fine steel, scourers, Fine sludge from sedimentation tanks, roller sinter from settling wells, tinder from settling wells, sludge from chamber filter press, separation iron, each in grain up to 20 mm.