RU2286397C1 - Method for processing of magnesium production slime-salt wastes - Google Patents

Abstract

FIELD: non-ferrous metallurgy and alloys, in particular, processing of foundry conversion wastes in production of commercial magnesium and its alloys.

SUBSTANCE: method involves crushing and separating into fractions by sowing; initially subjecting slime wastes to crushing into 0-100 mm sized fraction, then into 0-30 mm sized fraction, followed by sowing into 0-1 mm, 1-3 mm, 3-10 mm and 10-30 mm sized fractions; subjecting 3-10 mm sized fraction to crushing into 0-10 mm sized fraction, followed by sowing into 3-10 mm and 0-3 mm sized fractions; subjecting the latter to crushing in conjunction with 1-3 mm sized fraction into 0-3 mm sized fraction, followed by sowing into 0-1 mm and 1-3 mm sized fractions.

EFFECT: simplified method for extracting of metal phase from slime wastes of magnesium production, reduced losses of magnesium and complex processing of slime wastes of magnesium production for obtaining of commercial product.

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Description

The invention relates to the field of metallurgy of non-ferrous metals and alloys, in particular to the processing of foundry waste in the production of salable magnesium and its alloys.

In the production of magnesium and its alloys, metallurgical waste is formed, consisting of an oxide-salt matrix with droplets of the metal phase dispersed in it. The metal content in the mixture is 10-60%, depending on the type of metal and the technology for its preparation. The oxide content ranges from 10-30%, and the rest is made up of chlorides and fluorides of alkali and alkaline earth metals. To date, this magnesium-containing waste has been disposed of in solid waste storage facilities, as There is no industrially implemented method for processing this type of waste. The total mass of metal irretrievably lost is only several thousand tons per year in Russia, therefore, the extraction of magnesium from these wastes is an important economic task.

A known method of extracting magnesium from crucible residues foundry redistribution of magnesium production. To extract magnesium in this method, the entire mass of bottom residues is crushed, followed by separation into salt and metal fractions (Emly E.F. Fundamentals of the technology of production and processing of magnesium alloys, M .: Metallurgy, 1972, p.124-125).

The disadvantage of this method, as practice shows, is that a large dispersion of metal granules in fractions makes it difficult to isolate metal from crushing products. The metal yield does not exceed 40%.

Also known is a method for the integrated processing of foundry wastes for the production of magnesium alloys, which includes melting in a molten flux medium, separation into metal and bottom components by settling method, alloy extraction, additional processing of the bottom component with a dispersing reagent, mixing, cooling and solid separation into a metal fraction, which is used as a granular magnesium reagent, and the oxide-salt fraction, which is used as a mineralizer. Separation in solid form is carried out by the method of mechanical disintegration (RF Application No. 2003104029, IPC С 22 В 7/00, priority date 11.02.2003).

The disadvantage of this method is its complexity and high energy costs for sludge and aging the molten metal-salt mixture, increased consumption of salt flux, as well as the loss of magnesium metal.

As a prototype of the claimed method, a method for processing waste from titanium-magnesium production, mainly crucible residues of refining magnesium and its alloys, including melting, heating and mixing waste in flux, holding the melt for 1.5-2.5 and separating the resulting products (a .s. No. 1731848, IPC С 22 В 7/00, priority from 04/23/1992).

The main disadvantages of this method include its complexity, high energy costs for sedimentation and aging of the molten metal-salt mixture, increased consumption of salt flux, incomplete (85%) extraction of magnesium, the formation of a large amount of waste in the form of a depleted electrolyte mixture from magnesium metal (40-80% of the total amount of processed metal-salt mixture).

The invention solves the problem of simplifying the method of extracting the metal phase from the slurry waste of magnesium production, reduce losses of magnesium metal, the integrated processing of sludge and salt waste of magnesium production with the receipt of marketable products: magnesium metal, magnesium granules, mineralizers, deicing preparations and flux for the production of ferroalloys.

The specified problem is solved as follows.

A method for processing sludge-salt waste from magnesium production, including separation, that is, a well-known and common sign with the prototype, has new features: separation is carried out by sieving, and sludge waste is first crushed to a fraction of 0-100 mm, then to a fraction of 0-30 mm followed by sieving it into fractions of 0-1 mm, 1-3 mm, 3-10 mm and 10-30 mm, while the fraction of 3-10 mm is subjected to crushing 0-10 mm, followed by its sieving to fractions of 3-10 mm and 0-3 mm, which is subjected to crushing together with a fraction of 1-3 mm to a fraction of 0-3 mm with subsequent sieving to fractions 0-1 mm and 1-3 mm.

It is thanks to such operations and their specific sequence that the task can be solved.

The drawing shows a structural diagram of a crushing and screening complex, which implements the claimed method.

The crushing and screening complex consists of a jaw crusher 1 of medium crushing successively connected by vehicles, crushing to a fraction of 0-100 mm, a hammer crusher 2 of medium crushing, crushing to a fraction of 0-30 mm, a rotary screen 3 having three grids with different sizes cells sieving into fractions 0-1 mm, 1-3 mm, 3-10 mm and 10-30 mm, hammer mill 4, crushing to fractions 0-10 mm, rotary screen 5 having two grids with different mesh sizes, sifting on a fraction of 0-3 mm and 3-10 mm, a disintegrator 6, crushing into a fraction of 1-3 mm and finishing the fraction of 0-3 mm to a fraction of 0-3 mm, a rotary screen 7 having two grids with different mesh sizes, performing sieving on fractions 0-1 mm and 1-3 mm.

As a result of the proposed method for processing sludge salt waste from magnesium production, the following commodity products are obtained: sludge-electrolyte mixture with a grinding size of 0-1 mm, which is used by oil industry workers as a mineralizer or metallurgists as a flux for melting ferroalloys, for example ferrovanadium; metal granules of magnesium or magnesium alloys 1-3 mm, which are used for desulfurization of cast iron and steel; granules of 3-10 mm and kings of 10-30 mm are suitable for remelting into compact metal ingots.

Thus, the implementation of the method of processing sludge salt waste from the production of magnesium under crushing and sieving conditions allows us to completely recycle these wastes into commercial products.

An example implementation of the method.

For the processing of sludge salt waste into marketable products, 1000 kg of metal-containing oxide salt waste was taken in the form of granules of a fraction of 0-100 mm, containing, wt.%:

Mg, Al, Zn fifty MgO twenty MgCl ₂ , KCl, NaCl thirty

As a result of crushing and sieving according to the proposed method, 500 kg of the metal phase were obtained in the crushing and screening complex, consisting of 300 kg of the 1-3 mm fraction, 120 kg of the 3-10 mm fraction and 80 kg of the 10-30 mm fraction, as well as 500 kg sludge-electrolyte mixture fraction 0-1 mm All products obtained from the processing of sludge-salt mixture were sent to consumers.

Claims (1)

A method of processing sludge-salt waste from the production of magnesium, including fractionation into commercial products, characterized in that the separation is carried out by sieving, while the sludge-salt waste is first crushed to a fraction of 0-100 mm, then to a fraction of 0-30 mm, followed by sieving into fractions 0-1 mm, 1-3 mm, 3-10 mm and 10-30 mm, and the fraction of 3-10 mm is subjected to crushing to a fraction of 0-10 mm, followed by sieving to fractions of 3-10 mm and 0-3 mm, which subjected to crushing together with a fraction of 1-3 mm to a fraction of 0-3 mm, followed by sieving to a fraction 0-1 mm and 1-3 mm to obtain marketable products: sludge-electrolyte mixture used as a mineralizer or as a flux for melting ferroalloys, and metal granules of magnesium or magnesium alloys used for desulfurization of cast iron and steel.