SU1082848A1 - Method for preparing agglomeration batch - Google Patents

Abstract

A method for preparing the agglomeration alloy, including mixing sulphide concentrates with return and lime and pelletizing of the resulting mixture, extracts minus 1 mm, crushed to minus 1 mm, and minimizes the productivity of the sintering mill, returning the minus 1 mm to the production of the sludge concentrate. and then directed to mixing with the remaining components of the mixture.

Description

The invention relates to the agglomeration of metallurgical raw materials and can be used in preparing the charge for sintering at non-ferrous metallurgy sinter plants. A method is known for preparing the sintering mixture of sulphide concentrates, which includes mixing them with a significant number of turns of the agglomerate (return), the proportion of which in the charge is up to 50 up to 300% by weight of concentrate L. Due to the high content of returns in these mixtures, its granulometric composition has a significant impact on the performance of aglomain. Particular attention is paid to the regulation of the size of the return on the upper limit. Most often, it is shot to the size of minus 6-10 mm. Closest to the present invention is a method for preparing a charge for sintering sulphide copper-nickel concentrate, in which, in addition to return, lime 2 is mixed with the concentrate. A disadvantage of the known methods of preparation of the charge is that it does not regulate the content in the return of the fine fraction. In addition, the process of agglomeration also adversely affects the increase in the content in the return fraction minus 1-2 mm. The purpose of the invention is to increase the productivity of the sintering machine. This goal is achieved by the fact that according to the method of preparing the sintering mixture, which includes mixing sulphide concentrates with return and lime and pelletizing of the mixed charge, a fine fraction of minus 1 mm is recovered from the return before mixing, then crushed to a grain size, and then sent to mixing with other components of the charge. The exclusion from the return of the fraction minus 1 mm and its crushing to a large concentration of concentrate makes it possible to improve the chargeability of the charge and, as a consequence, to increase the gas permeability of the charge and the specific productivity of the sinter machine. Under pr1m1.1 conditions, at the Research Institute of Sulfide Honey (1 nickel coccerate, gotsgrzhti and return of fines, minus 1 mm fluctuates within 6-15%. In Table 1 Example 1) the content of the fraction minus 1 mm in return is given on the performance of sintering machines during sintering the mixture, prepared by a known method. In this case, a mixture consisting of nickel concentrate, the composition of which is given in Table 1, is sintered in a laboratory bowl installation with a grid area of 0.1 m. 2, return and lime at a ratio of 100: 150: 3 .. The sulfur content in the charge is 16.0%, the fraction minus 1 mm in the return is 6-15% and the humidity is 7.2%, which corresponds to the usual industrial mixtures. Before sintering, the mixture is thoroughly mixed, pelletized in a granulator and loaded into a bowl with a layer height of 170 mm (40 kg weight). Before ignition of the charge, the gas permeability of the cold layer is determined by the amount of air drawn through it at a vacuum of 500 mm of water, and after ignition, the gas permeability of the layer during sintering is determined by the amount of suction gases. Sintering is carried out at a vacuum of 1000 mm of water. Art. From example 1 it follows that an increase in the fraction content minus 1 mm in return from 6 to 15% is accompanied by a decrease in the gas permeability of the charge and sharply worsens all agglomeration indicators. The implementation of the method is shown in Examples X2 and 3 (Table 3). The preparation of the charge in these examples differs from Example 1 only in that a fraction of the minus 1 mm fraction is recovered from the return, it is distorted about the size of the concentrate (80% minus 44 microns) and is mixed into the concentrate used in the preparation of the mixture. In example 2, the initial return contains 15% of the fraction minus 1 mm. An increase in the fraction of the regrind part of this fraction of return to the charge makes it possible to significantly improve all indicators of agglimeration. So, with the complete withdrawal from the return of the entire fraction minus 1 mm for additional measurement, the productivity of the sinter is 42.5% and sulfur burning 50.5% (example 2, experiment 4). In example 3, in contrast to example 2, the content of the fraction minus 1 mm in the initial return is 10%.

And in this case, an increase in the share of the regrind part of the second fraction of return in the charge is also accompanied by an improvement in all indicators of the sintering process, however, their relative increase is smaller than in Example 2.

The given examples show that the use of the proposed method in the practice of sintering plants will be the more effective, the higher the content of fines minus 1 mm in return. A: The expected economic output will amount to 0.174 rubles per ton of sinter.

Table 1

6 8

0.162

1.02 0.145 0.93 0.132

10 15 0.83 0.085 0.53

5.20 3.15 40.3 27.30 8.55 2.20 2., 70

4430

3750 3080 4300 3030 4230 2120 3220

table 2

Content%

2.15

ij. fi II and C a 3

Claims (1)

METHOD FOR PREPARING AN AGLOMERATION MIXTURE, including mixing sulfide concentrates with return and lime and pelletizing the resulting mixture, which means that, in order to increase the performance of the sinter machine, a minus 1 mm fraction is separated from the return before mixing, grind to concentrate size , and then sent for mixing with the remaining components of the mixture.