SU1574660A1 - Method of preparing briquettes from oxide nickel-containing materials - Google Patents

Abstract

The invention relates to the agglomeration of fine-grained raw materials prior to subsequent metallurgical processing, in particular, to methods of briquetting charges based on nickel-containing materials. The purpose of the invention is to increase the yield of suitable briquettes by increasing their mechanical strength. Preparation of briquettes from nickel oxide-containing materials is carried out by pressing a mixture of ore, dust of shaft furnaces in an amount of up to 15% by weight of the ore, reducing sulphidizing additives and a binder in the form of technical lignosulfonates. At the same time, the dust of the shaft furnaces is cooled to 60–85 ° C, moistened with stirring with an aqueous solution of technical lignosulfonates, introduced in an amount of 8–10% of the mass of dust, and briquetting is carried out at a pressing pressure of 300–400 MPa. 2 tab.

Description

The invention relates to methods for the agglomeration of fine-grained raw materials prior to subsequent metallurgical processing, in particular, to methods of briquetting charges based on nickel-containing materials.

The purpose of the invention is to increase the yield by increasing their mechanical strength.

Silica is used as starting materials.

nickel ore (with a content, wt.%: nickel 1.27; cobalt 0, b5; iron (III) oxide 24.19; silica 39.5; magnesium oxide 6.4; aluminum oxide 8.9; calcium oxide 1 , 9) a size class of 0, -2 mm, pyrite (with a content of 28, 5 wt.% Iron (total) 30.3 wt.% Sulfur (total) of the same size, and also dust of shaft furnaces - scrubber (wt. % nickel 1.48; cobalt 0.44; iron 29.48; silicon dioxide 35.68; magnesium oxide 5.94; oxide

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aluminum 7.82; carbon 5.63 with a particle size of 0.92 mm) and cyclone (wt.%: nickel 1.47; cobalt 0.46; iron 20.95; silica 34.80; magnesium oxide 6.30; aluminum oxide 10.5; carbon 7.21) size 0.21 mm).

The ratio in briquettes of ore, pyrite, dust is 80:10:10 (%). moreover, the scrubber and cyclone dust is taken in a ratio of 2: 1 (share) J which corresponds to the dust output in practice (in the mine smelting of briquettes), the moisture content of the charge is maintained at 13-14%. .

The binding substance is technical lignosulfonate (LST) - waste of the Kama pulp and paper mill. Lignosulfonate contains up to 50% moisture, 8.5% ash wt.%: Fe203 1.5-7.4; AljO-j 0.8-1.5; Na40 2.0-2.5; CaO 2.5-2.8; MgO up to 10, S03 - 24-35.5) and is a sodium-sodium salt of lignosulfonic acids. Heat of combustion LST 9300 kJ / kg,

The briquetting of the charge is carried out on a PGPr hydraulic press (PWaxc 4 t) at a specific pressure of 250-450 MPa.

The resulting briquettes are tablet-shaped with a diameter of 30 mm with a maximum height of 17-19 mm. In tests of briquettes for mechanical strength, the compressive and drop resistances from a height of 1 m are determined on a concrete slab. The quality of briquettes is judged by the number of drops before splitting and the number of pieces that are formed during the destruction of briquettes over 10 mm in size. The maximum number of drops is 30.

The results of the first series of experiments in comparison with the prototype are summarized in table 1. The data presented are averaged over several dimensions. The discrepancy in parallel experiments does not exceed ± 10%.

According to the proposed method, before wetting, the dust is heated in a muffle furnace to the required temperature, then it is moistened with a solution of lignosulfonate resin with stirring and the ore and pyrite are metered into the mixture. In the base case (experiments 1, 2), the ore, pyrite, and dust are blended without a binder and then moistened with a solution of lignosulfonates.

The data in table 1, indicate that the briquettes, obtained by the proposed method, I have

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higher rates of mechanical strength and lower values of indicators of the total consumption of the binder in comparison with the known method with the addition of the binder directly to the briquette.

The positive effect of the proposed method is found while maintaining the temperature of the dust at the level of the consumption of binder 8-10% of the mass of dust. At a reduced binder consumption (experiment 3), the required strength of the briquette for dropping is not achieved. The excess (in excess of the recommended amount) of the binder (test 11), as well as relatively low (test 5) and high (test 9) dust temperatures give similar results on the mechanical strength of the briquettes, which are lower than the proposed method (tests 4.6 , 7,8,10).,

According to the proposed method, there is no sintering (sticking) of the particles of the briquetted charge with the matrix and punch, because of the Czech method in the known method (experiments 1, 2), the yield of finished briquettes does not exceed 98%.

In the second series of experiments (Table 2), a parameter is tested, the briquetting pressure. The binder consumption is set at 9% of the dust mass, the dust temperature is maintained at 70 ° C. It was established that at a pressure of less than 300 MPa (experiment 12), the strength of the briquette for dropping is substantially (35%) lower than the maximum reached. In the pressure range of 300-400 MPa (experiments 13, 14, 7), the dependence of the strength on pressure is close to linear. Increasing the pressure above 400 MPa (test 15) does not give an increase in strength.

The use of the proposed method for producing briquettes, in comparison with the known method, allows stabilizing the smelting process, reducing the cost of coke and increasing the extraction of nickel into matte.

Claims (2)

Invention Formula The method of preparing briquettes from nickel oxide materials, including pressing materials from a mixture of ore, dust of shaft furnaces in an amount of up to 15% by weight of ore, reducing-sulphidizing additives and a binder in the form of technical lignosulphonates, of which and , in order to increase the yield of suitable briquettes by increasing their mechanical strength, the dust of shaft furnaces is cooled to 60-85 ° C, moistened with stirring with an aqueous solution of technical lignosulfonates, introduced in an amount of 8-10% by weight Or, and briquetting is carried out at a pressing pressure of 300-400 MPa. Table t Note. In all cases, when dropping tests, the number of pieces larger than 10 mm that were formed during the destruction of briquettes was equal to 2. Pressing pressure of 350 MPa. Briquettes are poorly removed from the matrix, the surface is uneven, with defects. Briquettes are even and smooth, and they are easily removed from the matrix. The briquettes are even, smooth, and are removed spontaneously. Table 2