RU2432405C1 - Procedure for manganese ore complex processing - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: lime or limestone are added to charge containing manganese ore and coke for obtaining slag of basicity as high, as 2.8 and charge is melted. Upon melting produced melt is refined by introduction of carbonates, chlorides and fluorides of alkali and/or alkali-earth metals or their mixtures and treated with ultra-sound of frequency equal to 18-21 kHz with separation of ferro-manganese and slag. Separated slag is cooled. Bi-water gypsum at amount of 4-6% of slag weight is added into slag which is milled to size as big, as 320 cm2/g and cement is produced. ^ EFFECT: raised efficiency of manganese ore processing with production of ferro-manganese and utilisation of slag for production of cement. ^ 1 tbl, 1 ex

Description

The invention relates to metallurgy, namely to the production of manganese alloys.

A known method of smelting high-carbon ferromanganese in electric furnaces [1. Pp. 250-265] and in blast furnaces. The essence of the method is to melt a mixture containing coke, limestone, dolomite, manganese ores. The phosphorus content in concentrates is 0.35% or more. The phosphorus content in the smelted ferromanganese reaches 0.35-0.60%. At the same time, when melting, slag with a basicity of (CaO / SiO ₂ ) of 1.09-1.25 is obtained. To improve the quality of the metal, it is desirable to use refining slag with a basicity of 2.8. The specified slag is stored in dumps. The disadvantage of these methods is the low quality of ferromanganese, high losses of manganese with slag (4.6-12.8%).

Also known is the flux-free method of smelting ferromanganese, the essence of which is the smelting of the alloy without the addition of fluxes [1. P.263-265]. The disadvantage of this method: low quality metal, large losses of manganese with dump slag (62%). The quality of the metal sharply decreases when carbonate and silicate manganese ores are used in the mixture, while the amount of slag and the loss of manganese with slag increase.

The closest analogue to the purpose and combination of essential features is patent RU 2347835 C2 (IPC C22C 33/04, 07/27/2008) [2], which discloses a method for complex processing of manganese ores, including melting a charge containing manganese ore and coke, to obtain slag and ferromanganese. In this case, rich low-phosphorous ore and high-phosphorous ore are used.

The disadvantage of this method is the low quality of ferromanganese 0.35% phosphorus. As a result, it is necessary to use rich manganese ore with a low phosphorus content (g / mp = 0.0021). In Russia, low-phosphorous manganese ores are absent. The second disadvantage of this method is that slag is not used.

The problem solved by the invention is to improve the quality of the alloys, to reduce the loss of manganese with dump slag, the efficient use of slag.

The technical result obtained by carrying out the invention is to improve the quality of the alloy by refining using carbonates, chlorides, fluorides of alkali and alkaline earth metals as reagents, reducing the loss of manganese with slag, using slag for the manufacture of cement by selecting the composition of the charge for smelting alloys.

To achieve the technical result provided by the invention, a method for complex processing of manganese ores is used, including the smelting of manganese alloys, characterized in that lime or limestone is added to the mixture before smelting to form slag with a basicity of not less than 2.8, after melting, the obtained melt is refined by introducing carbonates, chlorides and fluorides of alkali and / or alkaline earth metals or mixtures thereof and sonication with a frequency of 18-21 kHz with separation of ferromanganese and slag, department nny slag is cooled, it dihydrate gypsum in an amount of 4-6% by weight of the slag and grinding is carried out to a particle size of not less than 320 cm ² / g to obtain cement.

The essence of the claimed invention lies in the fact that to date, manganese oxide ores are practically processed. There was a need for the use of carbonate and silicate manganese ores. Carbonate and silicate ores are among the hardly refractory and contain an increased amount of phosphorus and mineral impurities. Rational processing technologies for these ores are not known. In the present invention, it is recommended to process and use the rock-forming minerals contained in the ore by co-smelting the mixture with the addition of a slag-forming component of limestone or lime to obtain highly basic slag with a basicity of not less than 2.8. Slag with a basicity of 2.8, crushed to a particle size of at least 320 cm ² / g, have astringent properties. It is proposed in the invention to separate slag after smelting the alloy and use it for cement production by co-grinding with the addition of two-water gypsum.

It is known that when smelting metal, slag metal remains in the slag. The use of ultrasonic treatment of molten slag and metal makes it possible to transfer the kings of alloys to ferromanganese and increase the yield of useful material. The solution to this problem is achieved by treating the melt with ultrasound at a frequency of 18-21 kHz.

In the smelting of manganese alloys, phosphorus from ore is almost completely converted into metal. It is proposed to refine the alloys using carbonates, fluorides, chlorides of alkali or alkaline earth metals. These reagents can be introduced into the metal by blowing with inert gases, oxygen, or packed reagents or metal containers with reagents can be introduced into the melt using a bar.

Studies have established that with a decrease in the frequency of ultrasound below 18 kHz, the necessary extraction of metal kings from slag into the alloy is not achieved. An increase in the ultrasound frequency of more than 21 kHz does not increase the extraction of metal from slag into the alloy. The optimal mode is the processing of the melt by ultrasound at a frequency of 18-21 kHz for 13 minutes. An increase in the duration of exposure to ultrasound more than 13 minutes is not rational (table).

Example. Ferromanganese was obtained in a three-phase electric furnace with a capacity of 10,000 kVA. A rectangular bathtub measuring 7.6 × 2.9 meters. The electrodes are self-baking with a diameter of 1 m. The depth of the bath is 2.1 m. The electrodes are arranged in a row at a distance of 2.2 meters between the axes. Melting was carried out by a continuous process with the immersion of the electrodes in the charge of 1.2-1.4 meters.

For the experiment, highly phosphorous lump ore of the Mazul deposit was used. The composition of galosh: manganese lump ore; the size of the pieces is 90-140 mm - 300 kg, pressed iron shavings - 15 kg, coke from OJSC Kuznetsk Metallurgical Plant, limestone of the Mazulsky deposit. Limestone was added to the mixture before melting to form a slag with a density of 2.2. Electricity consumption amounted to 4800 kW × h per 1 ton of ferromanganese. At the end of the smelting, metal and slag were discharged into the ladle, after which a refining mixture was introduced into it. For refining, a mixture of NaCl 50% (by mass), Na ₂ CO ₃ - 50% were used. The refining mixture was packaged in metal bags made of thin iron sheet. Bags were introduced into the melt with metal rods. The slag melt was sonicated at a frequency of 21 kHz for 13 minutes. After that, the slag was poured into slag, cooled and crushed in a hammer mill, mixed with two-water gypsum and grinded to a particle size of 350 cm ² / g. Studies have established that the specified method obtained cement grade M500.

In experiment 2, a mixture of the composition (kilogram per 1 ton of ferromanganese) was used for melting: manganese ore - 3100, coke - 600, lime - 3500, steel shavings - 190.

A mixture of composition was used for refining: NaCl - 40%, Na ₂ CO ₃ - 40%, NaF - 20%. The amount of the mixture is 3% by weight of ferromanganese.

In experiments 1, 2, the same results were obtained on the quality of ferromanganese and on the quality of cement, which is of practical interest for production with the possibility of slag utilization.

The main factor in increasing the efficiency of processing manganese ores is the full use of manganese ores, namely the use of rock-forming minerals (silicates, feldspars) containing calcium, magnesium, silica, oxide iron for smelting raw materials from these components for the production of cement (clinker). The present invention allows the full use of manganese ore to obtain ferromanganese and cement.

Ultrasonic treatment of the melt under various melting conditions The frequency of ultrasound, kHz The duration of sonication, minutes The amount of slag from the mass of metal,% Slag basicity CaO / SiO ₂ The amount of gypsum in the slag,% The amount of refining mixture,% The metal content in the slag, wt.% 13 6 eighteen 13 13 fifteen 13 23 fifteen eighteen 6 eleven eighteen 13 four eighteen 23 four 21 6 6 21 13 four 21 23 four 27 6 four 27 13 four 27 23 four 10 5 10 2,8 four 3 four fifteen fifteen 5 2,8 5 3 four 21 13 13 2,8 6 3 four eighteen 10 fifteen one 5 3 four 21 13 twenty 2 5 3 four 21 13 twenty 2,8 5 four 21 13 twenty 2.5 5 3 four 12 13 twenty 5 one 5 21 13 twenty 5 1,5 7 25 13 twenty 2,8 5 2.5 3

Continuation of table 1 13 twenty 2,8 5 3 four 13 twenty 2,8 5 3 6 13 twenty 2,8 5 3 7.9 13 twenty 6 3 Optimal conditions 21kHz 13 twenty 2,8 5 3 four

Information sources

1. Gasik M.I., Lyakishev N.P., Emlin B.I. Theory and technology for the production of ferroalloys. M., "Metallurgy", 1988, p. 783.

2. Patent RU 2347835 C2 (IPC C22C 33/04, July 27, 2008).

Claims (1)

A method of complex processing of manganese ores, including melting a charge containing manganese ore and coke, characterized in that lime or limestone are added to the charge before smelting to form slag with a basicity of not less than 2.8, after smelting, the obtained melt is refined by introducing carbonates, chlorides and alkali and / or alkaline earth metal fluorides or mixtures thereof and sonication with a frequency equal to 18-21 kHz, with the separation of ferromanganese and slag, the separated slag is cooled, two-water gypsum is added to it in a col amount equal to 4-6% by weight of the slag, and grinding is carried out to a particle size equal to at least 320 cm ² / g to obtain cement.