RU2514351C1 - Concentration of nonferrous metal ores - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to concentration of minerals and can be used to increase the yield of valuable products, particularly, zinc and lead, by flotation. Proposed method comprises flotation, processing of pulp-bearing solution by pulse discharges and precipitation of solid phase. Processing of pulp-bearing solution is carried out by pulsed high-voltage discharges of specific energy of 8.6-11.2 kJ/dm³ fed directly into pipeline communicating flotation machine with settle-thickener. Action of pulsed high-voltage discharges is brought about provided that: R/R_o=10.4 where: R is the radius of efficient wave effects; R_o is the spacing between electrodes and R.

EFFECT: higher intensity and rate of deposition of disperse particles from foam after flotation.

2 cl, 3 dwg, 1 tbl

Description

The invention relates to processes for the concentration of mineral ores and can be used to increase the completeness of the extraction of valuable products, in particular zinc and lead, by flotation.

There is a method of cleaning and sterilizing liquid or gaseous media by treating them with pulsed high voltage discharges generating UV radiation (RF patent No. 2326820, C02F 1/467, 06/20/2008).

When a sliding high-voltage discharge occurs on the surface of a water jet, the jet is crushed into tiny droplets, while active particles are formed in the water droplets and in the stream of the medium being cleaned under the influence of hard UV radiation. Purification and sterilization of the treated media is carried out as a result of the complex effect on the organic and biological pollutants of UV radiation and active radical particles. The direct effect of UV radiation leads to the rapid death of bacteria and viruses and causes the destruction of organic pollution molecules.

However, the performance when using this method will be low, because water is supplied for cleaning with a fine stream. The hollow configuration of the electrodes creates a risk of clogging of the tube to form a thin water stream, which makes the electrodes used unsuitable. In addition, additional equipment is required for the process, which leads to an increase in capital costs.

Closest to the claimed technical solution according to the technical nature and the technical result achieved is a method of beneficiation of sulfide siderite-containing ores (RF patent No. 2123885, B03B 7/00, 12/27/1998). Pretreatment of sulfide siderite-containing ores is carried out in a pulp by electric explosion at a specific energy of 50-150 kJ / dm ³ . Then the pulp is subjected to magnetic separation and flotation. Under certain modes of electric blasting, due to the whole complex of discharge and post-discharge phenomena, siderite contained in the initial ore decomposes completely and passes into a strongly magnetic form.

The described method is adopted as a prototype of the invention.

The disadvantages of the prototype:

- high energy costs compared with the proposed method (50-150 kJ / dm ³ );

- the need for additional equipment in the form of a contact vat, in which the electrode system is located and electric explosion treatment is carried out;

- the need for additional safety measures due to the use of high energy impacts.

An object of the present invention is to increase the intensity and rate of deposition of dispersed particles from the foam after flotation machines and to improve the quality of the purified solution.

This is achieved by the fact that in the proposed method of enrichment of non-ferrous metal ores, including flotation, preliminary treatment of the pulp-containing solution with high-voltage pulsed discharges and further precipitation of the solid phase, according to the invention, the preliminary processing of the pulp-containing solution is carried out with high-voltage pulsed discharges with a specific energy of 8.6-11.2 kJ / dm ³ , which are fed directly to the pipeline connecting the flotation machine with the settler-thickener.

Impulse high-voltage discharges are subject to

R / R _o = 10.4,

where R is the radius of the effective action of the waves;

R _o is the distance between the electrodes and R.

In this case, a pulsed high-voltage discharge occurs directly in the pipeline connecting the flotation machine with the settler-thickener, without using any intermediate additional capacities such as a contact vat.

The essence of the proposed method is as follows. As a result of flotation, a concentrated product and a pulp-containing solution are obtained. Further, the solution through the pipeline enters the settler-thickener. The solution is treated with pulsed high-voltage discharges directly in the pipeline. This allows the process to be carried out in a continuous hydrodynamic mode, unlike the prototype, where electric blasting is carried out in a stationary mode, in a contact vat with the electrode system.

The wave front formed by pulsed high-voltage discharges brings the medium to a complex stress state with the active participation of both compression waves, which depend on the energy parameters of the pulse and tensile waves, on which the geometric characteristics of the technological unit depend - the distance between the electrodes R _o and the radius of the effective action of the waves R . By experiment, it was proved that the radii are related by the ratio R / R _o = 10.4. As can be seen from the graph shown in Figure 1, the pressure maximum at the front of the direct wave (P _m1 ) increases nonlinearly with increasing specific processing energy, and the maximum pressure of the reflected wave (P _m2 ) stabilizes at energies of 8.6-11.2 kJ / dm ³ . The study of the effect of the density of the medium on the resulting pressure showed that with an increase in density to ρ = 1.26 g / cm ³ , which corresponds to pulp density T: W = 1: 3, an increase in the pressure of the shock wave is observed, and with the ratio R / R _o > 10.4, the pressure begins to fall, the coagulation of dispersed particles worsens.

Therefore, the practical use of shock waves in a pulsed high-voltage discharge is most effective at R / R _o = 10.4. This allows us to determine the optimal R.

Thus, in contrast to the method adopted for the prototype, it is possible to determine the optimal diameter of the slurry pipeline, taking into account the calculated radius of the effective impact of the shock waves, in which the electric blasting will be carried out in the most efficient way.

With a ratio of T: W to 1: 3, the optimal distance R is 10-12.5 mm (Figure 2). Therefore, the optimal diameter of the slurry pipeline is 25 mm.

The impact of high-voltage pulsed discharges significantly reduces the electrokinetic potential of the particles. This is crucial in terms of coagulation of dispersed particles. From the diagram shown in Figure 3, it can be seen that the potential reaches a value (7–9 mV), significantly less than the limit of the coagulation threshold (30 mV), which improves the coagulation of particles and their subsequent deposition. It was experimentally established that the most intense coagulation and precipitation of particles is observed in the case of exposure to the solution before it is clarified by pulsed high-voltage discharges with a specific energy of 8.6-11.2 kJ / dm ³ (table).

Thus, under these conditions, the electrokinetic potential of particles due to the processing of a pulp-containing solution by high-voltage pulsed discharges at a specific energy of 8.6-11.2 kJ / dm ³ reaches a value of 7-9 mV, which leads to an acceleration of the deposition of dispersed particles.

With such processing energies, the completeness of extraction of valuable components is maximum, and the loss of product with clarified solution is minimal.

An example implementation of the method.

The initial sample contained,%: Pb - 4.07; Zn - 0.5; Cu 0.17; Fe - 27.5; SiO ₂ - 33.32; Al ₂ O ₃ - 2.96; CaO - 1.86; Mn - 1.66.

The required grinding fineness of 75% of class 0.074 was achieved by grinding in a laboratory core mill with a ratio of T: W: C = 1: 0.8: 4.8.

Sample weight - 250 g. Grinding time - 40 min. Flotation time - 10 min.

Flotation regime: soda (900 g / m, t = 1 _to m); sodium sulfide (30 g / m, t = 1 _to m); butyl xanthate (90 g / m, t = 2 _to m); pine oil (60 g / m, t = 1 _to m).

Flotation was carried out in a 1 liter flotation machine at a solid concentration of 25%. Water temperature - 18 ° С.

Next, the pulp-containing solution was subjected to treatment with pulsed discharges with energies from 3.4 to 16.5 kJ / dm ³ . The distance between the electrodes was 12.5 mm. In this case, the discharges were fed directly into the pipeline connecting the flotation machine with the settler-thickener. The diameter of the pipeline is 25 mm. Then the solution was sent to the thickener settler, where it was separated into solid and liquid phases under the action of gravity, and the settling efficiency was determined. The experimental results are shown in the table.

Table The dependence of the solids content in the clarified solution on the pulse energy of a high voltage discharge Specific discharge energy, kJ / dm ³ 0 3.4 6.0 8.6 9.2 11,2 13,4 16.5 The solids content in the clarified solution, mg / DM ³ 35 8 5 0.9 one 4.6 10 fifteen

Experimental data show that an increase in pulse energy of more than 8.6-11.2 kJ / dm ³ leads to overgrowth of particles, deterioration of their aggregation and subsequent deposition. The impact of a pulse with an energy of less than 8.6-11.2 kJ / dm ³ is not able to reduce the electrokinetic potential of a particle to a value below the limit of the coagulation threshold. As can be seen from the table, the solids content in the solution decreases from 35 g / l to 0.9 g / l. The efficiency of extraction of the solid phase from the pulp-containing solution is 97.4%.

The advantages of the proposed method in comparison with the prototype:

1) The solution is processed at significantly lower specific energies (8.6-11.2 kJ / dm ³ ), which leads to a reduction in energy costs;

2) Reducing the specific energy of the treatment allows to reduce the electrokinetic potential. As a result, coagulation of the dispersed particles improves. The solid content in the solution decreases from 35 g / l to 0.9 g / l. The efficiency of extraction of the solid phase from the pulp-containing solution is 97.4%.

3) Processing is carried out in a continuous hydrodynamic mode, in contrast to the prototype, where the use of additional equipment is necessary;

4) The optimal ratio of the distance between the electrodes R _o and the radius of the effective action of the waves R: R / R _o = 10.4, at which the use of shock waves with pulsed electric discharge is most effective, is determined.

5) The ability to determine the optimal diameter of the slurry pipeline.

Claims (2)

1. The method of enrichment of non-ferrous metal ores, including flotation, pre-treatment of the pulp-containing solution with high-voltage pulsed discharges and its further deposition, characterized in that the preliminary processing of the pulp-containing solution is carried out with high-voltage pulsed discharges with a specific energy of 8.6-11.2 kJ / dm ³ , which are fed directly into the pipeline connecting the flotation machine to the settler-thickener. 2. The method of beneficiation of non-ferrous metal ores according to claim 1, characterized in that the exposure to pulsed high-voltage discharges is carried out under the condition
R / R _o = 10.4,
where R is the radius of the effective action of the waves;
R _o is the distance between the electrodes and R.

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