SU1008259A1 - Binding additive for iron ore material - Google Patents

Abstract

CONNECTING ADDITIVE FOR COMBUSTION OF IRON ORE MATERIAL I, including bentonite and soda, characterized in that, in order to improve the quality of pellets and reduce the consumption of bentonite and soda, it additionally contains concentrate and tails from the enrichment of red mud at the following ratio of ingredients: -1.0 Soda Red concentrate 10 -65 sludge Tails from enrichment of red CO 5 -25 sludge Bentonite Else

Description

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The invention relates to metallurgy. hygiene, in particular to the technique of obtaining pellets.

At present, bentonite is used as a binding additive for the production of iron ore pellets.

The closest to the technical essence and the achieved results is a binding additive for the work of iron ore material f, in which, in order to improve the binding properties of bentonite and reduce the consumption of soda, the binding additive for the work of iron ore concentrate 5 contains polymethacrylamide of the type mets in the following ratio of ingredients Dents,%: Soda 5-1 Polymethacrylamide. Metas type 0.5-0.1 Bentonite Else. The disadvantages of this composition are the addition of soda, negatively affecting the durability of the meta-iilic structures of the factory of pellets and lining of the blast furnace shaft, high consumption of deficient bentonite (about UJ. Technically difficult task is to evenly distribute this amount of bentonite in the mass of the wet concentrate. The purpose of the invention is to improve the quality of the pellets and reduce the consumption of bentonite. I This goal is achieved by the fact that the binder additive for the casting iron ore material, including bentonite and soda, additionally contains concentrate and tailings from the enrichment of alumina red sludge in the following ratio of ingredients: soda 0.5-1 red concentrate was 10-65, tailings of red sludge 5-25i bentonite the rest. iron content in the pellets when replacing part of the bentonite by the concentrate of red mud. At the same time, there is no deterioration in the strength properties of the pellets. The essence of the proposed additive is as follows. The best component from the red mud, in terms of the content

leach in pellets is a concentrate with (O-iron and 2-5% silica against k-5% and 50-60%, respectively, in bentonite. However, low

in the chewing properties of the concentrate is not

provide equal strength to the pellets, since the concentrate has a higher particle size. Tailings from the enrichment of red mud are

is a mixture of the largest fractions. Thin fractions have high surviving properties within specified limits with concentrate,

PRI me R. The additive for the clogging of iron ore material is based on the red mud of the Nikolaev alumina refinery with reference to the use of finely ground magnetite concentrates in the pelletizing factories. The concentrate of red mud contains,%: Fe 5,3; Fe20 77.6G 8.5; Si02 2.1; CaO 0.58; loss on ignition (SPT) 8.5- In the tailings from the enrichment: Fe 18.3. In the original red mud,%: Fe 35, SiOo 5.8. In bentonite and clays,%: Fe 5.0 - 10.0, SiOj 55.0-65.0. For comparison, pelletizing additives are prepared and tested in laboratory conditions for comparable pro-; totype and counterparts. The pellets are obtained from Lebedinsky concentrates. Investigation of the pelletizing process and carried out according to the method of variable moistening and dusting. The pellets are obtained in a drum 0 bOOx x 200 mm, intended for carrying out periodic experiments with small (2.0-3.0 kg) weights of the material. Experiments on obtaining pellets are carried out at the frequency of rotation of the drum. 3 OBIN. To pelletize the mixture, water is pumped into the drum in a thin stream from a measured glass vessel. Small granules (grain) of 53 mm in size are prefabricated. In the drum, the grain is evenly powdered with fine grain material. The moistening and dusting operations are repeated until pellets of a given size are formed (10-20 mm). Palletizing is carried out for 5 minutes. The quality assessment of raw pellets is made by their mechanical strength, crush resistance, (kg / s) and impact resistance (the number of drops from a height of 500 mm). Pellet firing studies are carried out in a 5 cm long tubular electric furnace with a pellet duration in the zone of constant temperature from 5 to 15 mi. Raw pellets with a diameter of It mm are loaded into the quartz tube of the apparatus. After heating the furnace to a predetermined temperature, the tube with pellets is introduced into the oven and advances at a predetermined speed, which ensures the gradual heating of the pellets and the specified duration of their exposure during firing with subsequent cooling. Such a firing mode in a tubular silicon furnace allows to simulate approximately the temperature zones of the firing conveyor machine and conduct comparative studies to determine the influence of various technological factors on the quality of the calcined material. The test results are given in. the table. 7100 The limits of use of KOHueHtpara and tailings from the enrichment of red mud, listed in the table, are due to the following: the addition of less than 10 concentrate from red mud slightly increases the iron content in the pellets, the addition of more than b5 concentrate leads to a deterioration of the strength properties of the pellets due to the low effective properties of the concentrate . The optimal amount of injected concentrate / v6o, and the maximum effect is obtained both in the increase in iron and in the strength of the pellets, the addition of less than 5% of the fine fraction of red sludge needles does not contribute to an improvement in the earthing properties and, as a result, the strength of the pellets and the addition of more 25% of the tails slightly increases the strength, and does not contribute to a significant increase in the iron content in the pellets. The optimum amount of tailings added to the additive is 20%. The tests show that the quality of the pellets is improved by increasing the iron content when replacing part of bentonite with red concentrate, bentonite costs are reduced, the productivity of the blast furnace is increased by increasing the iron content of the pellets, coke costs are reduced for blast furnace smelting due to the increased iron content in the pellets. The practical implementation of the binding additive in pellet factories is not associated with additional capital investment.

Claims (1)

A BINDING ADDITIVE FOR RIPPING IRON MATERIAL, including bentonite and soda, characterized in that, in order to improve the quality of the pellets and reduce the consumption of bentonite and soda, it additionally contains concentrate and tails from the enrichment of red mud in the following dietes: Soda Red mud concentrate Tails from enrichment of red mud Bentonite ratio ingre 0.5-1.0 10 -65 5 -25 Else SU. „1008259> 5-1 0.5-0.1 The rest. of this composition