RU2452781C1 - Method of processing metal-containing sludge from operating sludge collector of general circulation water supply system at metallurgical works - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: proposed method comprises drying the material to air-dry state, grinding it and sizing performed in steps. First, metal-containing sledge is screened to fraction of particle size exceeding 0.08 mm represented by quartz feldspar product with total content of iron lower than 5 wt % used as raw stock for construction materials. Then, remaining fraction of 0-0.08 mm-class with total metal content over 50 wt % used as metallurgical stock may be subjected to magnetic separation to extract magnetic fraction with metal content over 57 wt % and nonmagnetic fraction with total iron content approximating to 50 wt %.

EFFECT: commercial raw stock for metallurgy and production of construction materials.

Description

The invention relates to the field of metallurgy and can be used for the processing of metal-containing sludge waste.

A known method of processing metal-containing waste from wet cleaning systems for technological dust and gas emissions, including drying, crushing, separation into magnetic and non-magnetic components, mixing magnetic components and pressing [1]. The method involves the use of additional components - slaked lime and water glass as a binder. A device that implements the known method contains a filter system, a sludge loading system, a sludge receiving system, water and oil collection, a sludge preparation system for pressing.

The reasons that impede the achievement of the following technical result when using the known method include the fact that the known invention involves the use of slurries of the current output. In addition, when using the known method, the non-magnetic fraction of the sludge remains waste.

There is also a method of processing metal-containing waste from dry cleaning systems for technological dust and gas emissions, including selective selection by fractions, gravity concentration and magnetic separation [2]. The flue gas capture products are processed and the magnetic separation is carried out in stages: in the first stage, weakly magnetic, in the second, highly gradient and in the third, magnetic separation in a traveling field. According to this method, a strong magnetic fraction is sent to metallurgical raw materials, a weakly magnetic fraction is sent to hydrometallurgical extraction of rare earth and other valuable elements, and a non-magnetic fraction is sent to raw materials to obtain building materials.

The reasons that impede the achievement of the following technical result when using the known method include the fact that the method involves the use of waste current output. In addition, when using the known method, a complex multi-stage magnetic separation scheme and the associated high capital costs are used.

Closer in technical essence to the claimed invention, adopted as a prototype, is a method for removing and processing metallurgical sludge from an existing storage device, including feeding slurry in the form of pulp from metallurgical equipment through pressure pipelines to a sludge collector, pumping out, dewatering the sludge and preparing it for use in sintering, blast furnace charge or shipment to consumers [3]. The method allows to utilize sludge with an iron content of up to 35 wt.% From the sintering sludge sump and to eliminate the need for the construction of new sumps, to reduce the cost of the main products, to extend the preparation of the second stage of the alluvium map.

The reasons that impede the achievement of the technical result indicated below when using the known method include the fact that the method involves the use of relatively separated sludge fractions of a relatively constant composition from the local workshop circulating system with its own sewage treatment and treatment facilities, which narrows the direction of sludge utilization in the future .

The technical result of the invention is the creation of a method for processing metal-containing sludge from the existing sludge collector of the general recycling water supply system of metallurgical production to produce dispersed raw materials of different fractions that are commercially significant for the metallurgical and building materials industries.

The technical result of the proposed method is achieved by the fact that the processed metal-containing sludge with a moisture content of 20 to 24 wt.% From the active sludge collector of the general recycling water supply system of metallurgical production is first dried to an air-dry state, the material pelletized during drying is subjected to grinding, then the product is fractionally separated by size classes.

The essence of the method lies in the fact that fractional separation includes sieving the material on a sieve No. 008 to obtain a fraction of the class with a particle size of more than 0.08 mm, represented by a quartz-feldspar product with an iron content of less than 5% by weight, which is a ready-made raw material for building materials materials, and a fraction of class 0 ... 0.08 mm with an iron content of more than 50 wt.% total, which is a ready-made metallurgical raw material for use in sintering, blast furnace charge, is subjected to magnetic separation if necessary and release the magnetic fraction represented primarily magnetite with total iron content of over 57 wt.%, and the remainder of the non-magnetic fraction with a content of iron components of total iron to 50 wt.%.

The analysis of the prior art by the applicant, including a search by patents and scientific and technical sources of information and identification of sources containing information about analogues of the claimed invention, allowed to establish that the applicant did not find an analogue characterized by features identical to all the essential features of the claimed invention. The definition from the list of identified analogues of the prototype as the closest in the set of essential features of the analogue made it possible to identify the set of essential distinguishing features in relation to the applicant's technical result in the claimed claims.

An example of a specific use. The sludge selected from the map of the active sludge collector of the general circulating water supply system was subjected to processing, with a total iron content of 29.45 wt.% And a total other metal content of 1.165 wt.%. The sludge was dried to an air-dry state, the material pelletized during drying was subjected to control grinding, and the resulting product was sieved on a No. 008 sieve. In a fraction of class 0 ... 0.08 mm, iron concentration occurs:

Component The degree of extraction of the component from its total content in the sludge,%: fraction of class 0 ... 0.08 mm sieve residue total iron 92.38 7.62 manganese 60.17 39.83 copper 60.05 39.95 cadmium 48.06 51.94 nickel 58.08 41.92 lead 57.26 42.74 zinc 55.33 44.67 common chrome 79.78 20.22

The purification of the fraction of particle size class 0 ... 0.08 mm by magnetic separation made it possible to obtain a total iron content of 57.78 wt.% In the magnetic fraction. This product in terms of iron content may be a finished raw material for the metallurgical industry. Non-magnetic fraction with a residual iron content of total 48.84 wt.% Also meets the technical conditions for metallurgical raw materials. No significant redistribution of other metals between the magnetic and non-magnetic fractions was found.

It is also positive that the fraction of the class with a particle size of more than 0.08 mm with an iron content of less than 5 wt.%, Represented by a quartz-feldspar product, meets the technical conditions for raw materials for building materials.

The process is simple in hardware design and can be carried out on the basis of the main production.

The advantage of the proposed method is that the processing of sludge will provide the possibility of organizing the operation of the sludge collector as an intermediate tank for storing the solid phase of sludge effluent in a closed circuit using existing capacities.

Information sources

1. Patent RU No. 2217510, cl. MKI ⁷ C22B 1 / 00.1 / 243, B03B 9/06, publ. November 27, 2003, BI No. 33.

2. Patent RU No. 2086679, cl. MKI ⁶ C22B 7/00, publ. 08/10/1997, BI No. 22.

3. Patent RU No. 2139360, cl. MKI ⁶ C22B 1/00, publ. 10.10.1999 g, BI No. 28.

Claims (1)

A method of processing metal-containing sludge from the existing sludge collector of the general system of recycled water supply of metallurgical production, including drying the material to an air-dry state, grinding it and fractional separation, which is carried out stepwise, and first the metal-containing sludge is sieved to obtain a class fraction with a particle size of more than 0.08 mm, represented by a quartz-feldspar product with a total iron content of less than 5 wt.%, used as raw material for building materials, and then the remaining fraction of the class 0-0.08 mm with an iron content of more than 50 wt.% total, used as metallurgical raw material, if necessary, is subjected to magnetic separation with the release of a magnetic fraction with an iron content of more than 57 wt.% and non-magnetic fraction with a total iron content of up to 50 wt.%.