RU2845777C1 - Furnace for refining metallized zinc and aluminium wastes - Google Patents

Abstract

FIELD: furnaces.

SUBSTANCE: invention relates to processing of nonferrous metal wastes, particularly, to design of furnaces for processing fragmented zinc and aluminium wastes and can be used for processing hot zinc-plating wastes and fragmented aluminium wastes. Furnace includes a melt heating chamber, a chamber for mixing the melt with metallized wastes and reagents, well for installation of impeller, impeller for creation of liquid funnel connected by means of shaft with electric drive, chamber of slag sedimentation, wherein bottom section of chamber mixing the melt with metalized wastes and reagents is shaped to Archimedean spiral with its end extending into slag sedimentation chamber opening.

EFFECT: improving mixing quality of molten metal with reagents, improving the quality of the obtained metal, as well as reducing flux consumption at melting of aluminium chips.

2 cl, 3 dwg

Description

The invention relates to the processing of non-ferrous metal waste, in particular to the design of furnaces for processing fragmented zinc and aluminum waste, and can be used for processing hot-dip galvanizing waste and fragmented aluminum waste (aluminum shavings and crushed beverage cans).

Methods and a device are known for producing cast aluminum matrix composite materials based on aluminum and its alloys by mechanically mixing discrete ceramic fillers into aluminum melts (RU Patent No. 2186867, Class C22C 1/10, C22C 21/00, 10.08.2002; RU Utility Model No. 117439, Class C22C 1/10, 27.06.2012). The method consists of introducing filler powders into an aluminum melt superheated above the liquidus line by mixing the melt with stirrers of various shapes, ensuring its mixing with filler particles, including under the action of centrifugal forces, holding the suspension for degassing and subsequent casting. A device for producing cast aluminum matrix composite materials includes a furnace, a crucible with a melt, a stirrer with an impeller driven by an electric motor, and a dosing device for feeding filler.

A method for producing cast composite materials based on aluminum and a device for implementing it are known (patent KZ No. 23508, class C22C 1/10, C22C 21/00, 15.12.2010), including melting the matrix alloy, introducing a dispersed reinforcing phase, mixing the melt and then pouring the resulting suspension into a mold, wherein the loading of the matrix alloy and the dispersed phase into the melting furnace is carried out simultaneously, and heating and mixing of the charge is carried out in a vacuum, at a residual pressure of less than 10 mm Hg, and after mixing, an inert gas atmosphere is created in the system.

A method and device for producing cast composite materials based on aluminum are known (patent KZ No. 27170, Cl. C22C 1/10, C22C 21/00, 15.07.2013), including melting of the matrix alloy, introduction of a dispersed reinforcing phase, centrifugal mixing of the melt with an impeller, subsequent casting and crystallization, characterized by the use of a special mixing chamber, in the walls of which special slots are made, ensuring the circulation of the melt, which allows mixing of discrete filler in large volumes of melt. At the same time, due to the metered supply of discrete filler into the mixing chamber, its uniform mixing with the melt is ensured.

A furnace with a crucible installed therein, a mixing device with the possibility of moving along a vertical axis, including a chamber for mixing a melt with a discrete filler, an impeller installed with a gap inside the chamber, connected by means of a shaft to an electric drive, a reservoir for discrete material, connected to the mixing chamber by pipelines, in which the impeller has the shape of a cylinder, in the upper part turning into a cone; the mixing chamber along the vertical axis in the upper part has an opening for the input of the electric drive shaft, turning into a conical, and then into a cylindrical cavity, in which the impeller is located and the height of which corresponds to the height of the impeller; the chamber has a channel connected to a vertical pipeline, extending from the upper base of the chamber along the cylindrical surface of the cavity and connecting with it, wherein the channel does not reach the lower base of the chamber; the mixing chamber has a semi-cylindrical channel extending along the cylindrical surface of the cavity and connecting with it; the channel exits to the lower base of the chamber or through its side wall and has an angle of divergence with the channel of at least 180° in the direction of rotation of the impeller; the impeller has a blind axial hole extending from the lower base and two or more radial holes connecting the cylindrical surface of the impeller and the axial hole and made with an offset along the perimeter and along the height, the conical surface of the impeller is also connected by one or more holes to the axial hole; the vertical pipeline entering the mixing chamber has a pusher with a drive and is connected to the tank for discrete material by means of a horizontal or inclined pipeline with a pusher or auger.

A furnace for processing aluminum scrap is also known (patent SU 1263719 A1), which includes chambers for heating the melt and processing slag, a loading well, a well for installing a pump, partitions, movable valves and windows for metal flow, a chip heater. The disadvantages of the furnace include oxidation of the chips fed into the loading well under the heater with the formation of a compacted layer of chips, in which their oxidation occurs, leading to the formation of slag.

A furnace for refining hard zinc is known (patent RU 206008 U1), which includes a well with a pump, melting chambers and chambers for separating slag from metal, metal pipeline troughs, windows for melt flow, melt settling chambers and is equipped with a chamber for forming a liquid funnel excited by a flow of melt entering through a curved trough located in the upper part of the funnel-forming chamber, and an opening for draining the melt is located in its lower part. A disadvantage of this furnace is the significant evaporation of flux (ammonium chloride) when loading it into the melt funnel, which has a large surface.

The objective of the present invention is to improve the quality of the resulting metal in zinc and non-metallic inclusions in aluminum alloys, and to reduce the consumption of fluxes when melting aluminum chips.

The technical result achieved by the claimed invention consists in improving the quality of mixing the melt with reagents and improving the quality of the resulting metal, as well as reducing the consumption of flux when melting aluminum chips.

The technical result is achieved by the fact that the furnace for refining metallized waste of zinc and aluminum includes a chamber for heating the melt, a chamber for mixing the melt with metallized waste and reagents, a well for installing an impeller, an impeller for creating a liquid funnel connected by means of a shaft to an electric drive, a slag settling chamber. In this case, the lower part of the well in the chamber for mixing the melt with metallized waste and reagents is made in the form of an Archimedes spiral with its end exiting into the window of the slag settling chamber.

In a preferred embodiment, the impeller for creating a liquid funnel is made with blades inclined to the vertical axis and equally spaced from each other.

Fig. 1 shows the proposed furnace, where 1 - heating chambers; 2 - slag settling chamber; 3 - impeller for creating a liquid funnel in the melt and moving it through the furnace chambers; 4 - well; 5 - window for melt flow from the heating chamber into the well of the melt mixing chamber with metallized waste and reagents; 6 - window for transferring melt from the melt mixing chamber with metallized waste and reagents into the slag settling chamber; 7 - window for transferring melt from the slag settling chamber to the heating chamber; 8 - openings in the heating chamber for installing fuel burners; 9 - openings for removing combustion products from the heating chamber; 10 - direction of the circulating melt flow; 12 - partition between the melt mixing chamber and the slag settling chamber.

Fig. 2 shows a photograph of a section after remelting aluminum chips in a rotary furnace with a flux consumption of 20% of the weight of the loaded A1 chips.

Fig. 3 shows a photograph of a section of aluminum melted in the proposed melting-refining furnace with a flux consumption of 4% of the weight of the loaded A1 chips.

The proposed furnace for melting and refining metallized zinc and aluminum waste operates as follows.

The melt heated in the heating chamber 1 enters the well of the melt mixing chamber with metallized waste and reagents. During the rotation of the impeller, the metallized waste (chips) mixed with fluxes in the well is mixed with the melt, which enters the slag settling chamber via the Archimedes spiral.

Loading fragmented non-ferrous metal waste and fluxes into the impeller operating area results in their mixing with the melt flow, melting of metal fragmented waste, adsorption of oxides by fluxes with slag formation, removal of the melt and slag mixture into the slag settling chamber, where the slags float, and the melt enters the heating chamber for heating and after heating enters the impeller operating area, where metallized waste and fluxes are continuously or periodically supplied. In this case, making the lower part of the well of the melt mixing chamber with metallized waste and reagents in the form of an Archimedes spiral improves the mixing of the melt with metallized waste (chips) in a mixture with fluxes in the lower part of the well and ensures uniform distribution of fluxes in the melt, which confirms the achievement of the declared technical result.

As can be seen from the photographs of the sections presented in Fig. 2 of aluminum alloys during the melting of aluminum chips in the proposed furnace, the number and size of pores in the metal and their dimensions are significantly smaller than during the melting of chips in the furnace according to patent SU 1263719 A1.

In addition, the consumption of fluxes in obtaining metal smelted in the proposed furnace is reduced, and the metal extraction is increased by 3% during comparative smelting of dry separated chips in the proposed furnace for processing aluminum scrap.

Claims (2)

1. A furnace for refining metallized zinc and aluminum waste, comprising a melt heating chamber, a chamber for mixing the melt with metallized waste and reagents, a well for installing an impeller, an impeller for creating a liquid funnel connected by means of a shaft to an electric drive, a slag settling chamber, wherein the lower part of the well in the chamber for mixing the melt with metallized waste and reagents is made in the form of an Archimedes spiral with its end exiting into the window of the slag settling chamber. 2. A furnace for refining metallized zinc and aluminum waste according to paragraph 1, characterized in that the impeller for creating a liquid funnel is made with blades inclined to the vertical axis and equidistant from each other.