RU2499633C1 - Flotation of sulfur pyrrhotite-pyrite ores of ferrous and nonferrous metals - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to flotation of sulfur pyrrhotite-pyrite ores containing valuable components: copper, zinc and noble metals. Method of flotation of copper-zinc-pyrrhotite-pyrite ore comprises crushing in subcalcareous medium, conditioning by collectors and foam makers, copper flotation with production of "copper head", collective copper-zinc flotation with production of collective concentrate containing copper minerals and natural activated black jack, tails of collective copper-zinc flotation are conditioned by copper sulfate. Black jack is activated by lime and collector to perform selective flotation to extract black jack to zinc concentrate to produce pyrrhotite-pyrite-bearings final tailings. Composition "М-ТФ" composed of the mix of isobutyl dithiophosphate and thionourethane is used as collectors at the following molar ratio of components: isobutyl dithioohosphate:thionourethane of 20:40 to 60:80%, fed in combination with butyl xanthate as follows, in flotation cycles: copper cycle - "М-ТФ" composition is used, collective cycle - 3-4 wt % of "М-ТФ" and 0:1 wt % of butyl xanthate are used, zinc cycle - combination of 0:1 wt % of "М-ТФ" and 3-4 wt % of butyl xanthate.

EFFECT: higher yield of copper and zinc sulphides in commercial concentrates and that of zinc concentrate, reduced floatability of pyrrhotite-pyrite in all process operations.

2 cl, 1 tbl

Description

The invention relates to the field of flotation concentration of pyrite pyrrhotite-pyrite ores containing valuable components:

copper, zinc and noble metals.

Known methods of ore dressing, in which copper-zinc-pyrite ore is ground and classified in a highly alkaline environment; then the pulp is conditioned with modifying reagents, a collector and a foaming agent, the copper head is floated at a low collector flow rate and doflotation of inactive sphalerite from the tails of the collective cycle is carried out. In foreign practice, to use the natural floatability of zinc minerals and other sulfides, a wide range of sulfhydryl collectors are used in different flotation cycles: ethyl and isopropyl xanthate, dithiocarbamates, mercaptobenzothiazoles and other collectors. [A.A. Abramov. The technology of enrichment of non-ferrous metal ores. M .: Nedra, 1983, 190 pp.]. The disadvantage of using a combination of xanthates with different lengths of a hydrocarbon radical and a combination of xanthates with other sulfhydryl ionogenic collectors is the increased flotation activity of iron sulfides over all flotation cycles, which makes it difficult to obtain the required technological parameters both in the quality of copper and zinc concentrates and in the recovery of copper and zinc in appropriate concentrates.

It is known to use a combination of butyl xanthate with dialkyldithiophosphates, nonionic sulfhydryl collectors [Theory and technology of ore flotation / O.S. Bogdanov, II Maksimov, A.K. Podnek, N.A. Yanis. - M .: Subsoil. - 1980. - P.88-94].

However, as applied to pyrrhotite-pyrite copper-zinc ore, which has a very fine intergrowth of all mineral components: pyrrhotite, pyrite, non-ferrous metal sulfides and mineral associations of precious metals, the use of butyl xanthate, a combination of butyl xanthate and dithiophosphates, butyl xanthate and mass thionocarbamate fractions of butyl xanthate does not allow to obtain the required technological indicators for sulfides of copper, sphalerite, gold. The high flotation activity of pyrite and pyrrhotite is associated with a significant mass fraction of these minerals in the ore (up to 80-90% of the total), high oxidizability of pyrrhotite and butyl xanthate in the presence of pyrite and pyrrhotite, which leads to the formation of dixanthogenide. The primary fixation of the ionic form of butyl xanthate on the surface of iron sulfides, the co-adsorption of the molecular form of sulfhydryl collectors leads to a significant increase in the flotation activity of pyrite and pyrrhotite, despite the stringent conditions for the suppression of iron sulfides.

The use of a highly alkaline calcareous medium for suppressing pyrite and pyrrhotite simultaneously suppresses the flotation of gold, reduces the flotation ability of chalcopyrite and vice versa increases the flotation activity of sphalerite, which leads to the loss of non-ferrous and precious metals. Prolonged aeration in a calcareous medium is a fairly well-known technique for suppressing flotation of pyrrhotite. On the other hand, prolonged aeration in a calcareous medium increases the flotation activity of pyrite. These contradictions in the flotation behavior of pyrrhotite, pyrite and non-ferrous and precious metal minerals do not allow achieving the required technological parameters.

In the method of flotation of gold ore, the results are obtained using composite mixtures of aeroflot prepared on the basis of normal butyl alcohol and alcohol fraction of fusel oil in a ratio of 1: 1. [Tropman EP, Tusunboyev N.K. and others. Proceedings of the conference Metallurgy XXI, Almaty, 2006, 125-130 p.].

Dithiophosphates have a lower collective ability, compared with xanthates, iron disulfides are much weaker. Dithiophosphates are the most difficult to oxidize sulfhydryl collectors. However, weak collective properties do not allow the use of dithiophosphates on their own with the achievement of high technological parameters at reasonable costs, so they are used in combination with xanthates. In addition, increased consumption of dithiophosphates can lead to the formation of abundant hard-to-break foam and the mechanical removal of depressed minerals into the foam.

A known method of selective flotation of copper-zinc-pyrite ore, in which the collectors use a combination of weak sulfhydryl collectors - isobutyl dithiophosphate and isopropyl-O-methyl-N-thionocarbamate and butyl xanthate in a ratio of 3: 4.5: 1 for flotation of copper sulfides and sphalerite into collective concentrate [V. A. Bocharov, V. A. Ignatkina et al. Method for flotation of copper-zinc-pyrite ore. Patent No. 2433866 is registered on November 20, 2011. Application No. 2009141930. Priority: 11.16.2009]. However, the use of this collector composition gives good results only for pyrite ores of a relatively constant and uniform composition. Pyrrhotite-pyrite copper-zinc ores have a more complex mineral and phase composition, and with the composition of collectors used, it is necessary to take into account the technological properties of all mineral components, and especially the quantitative and phase composition of pyrrhotite and pyrite, their particle size distribution and crystal structure features. The problem is greatly complicated when iron sulfides are represented by pyrrhotite and pyrite at a ratio of 2: 1 or 1: 1.

The closest in terms of collective and flotation ability with respect to pyrrhotite and pyrite, copper and zinc sulfides, noble metals is the flotation method, which includes a combination of butyl, isopropyl xanthates and butyl or other aeroflot, which was used and is used at enrichment plants of the Ural region. However, the use of this combination of collectors also does not provide high rates of selective flotation of pyrite copper-zinc ores for the same reasons as the above methods [A. A. Abramov. The technology of enrichment of non-ferrous metal ores. M .: Nedra, 1983, p.191]. According to the noted method, flotation is carried out in several stages. First, they flotate copper minerals in the form of a “copper head”, then collectively flotate the minerals of copper and naturally activated sphalerite, and then flotate sphalerite with weak natural activity with the addition of copper sulfate; zinc flotation concentrate can be sent to the main zinc flotation of the collective concentrate separation cycle or to rough zinc concentrate. In all flotation techniques, a composition of weak sulfhydryl collectors is used as the collector. Collective concentrate selection includes: desorption of the collector with sodium sulfide and activated carbon, depression of zinc minerals with zinc sulfate, conditioning with a collector composition and xanthate, copper-pyrite flotation to produce foam copper concentrate and zinc concentrate with a chamber product. One of the disadvantages of this method can be noted that butyl xanthate provides a stable non-selective extraction of all sulfide minerals with worse quality concentrates in comparison with the proposed method - the use of a composition of several weak selective sulfhydryl collectors in combination with a stronger butyl xanthate in an optimal ratio in different flotation cycles . When using only butyl xanthate, it is not possible to selectively separate zinc into a high-quality zinc concentrate in the ore cycle after collective flotation, due to the high flotability of pyrrhotite and pyrite.

The objectives of the claimed invention are to reduce the flotability of pyrrhotite and pyrite, the selective concentration of the bulk of the copper sulfides in the first copper concentrate, the remaining copper sulfides and activated sphalerite in the collective copper-zinc concentrate, and the subsequent extraction of unactivated sphalerite in the zinc concentrate in the ore cycle from the chamber product collective flotation.

In this case, the following technological results are achieved - the volume of circulating flotation load is reduced and the losses of zinc and copper with tailings are reduced, as well as the loss of copper and zinc in the corresponding finished concentrates.

This goal is possible due to the use of reagents of the M-TF series, which are a composition of isobutyl dithiophosphate and thionocarbamates (isopropyl-O-methyl-N-thionocarbamate or isopropyl-O-ethyl-N-thionocarbamate Z-200) in a molar ratio of components - isobutyl dithiophosphate : thionocarbamate from 20-60 to 80-40%. This ratio provides a selective increase in the floatability of copper sulfides while maintaining a low flotation activity of iron sulfides and unactivated sphalerite. With the prevalence of pyrrhotite in pyrite ore (40-60% of the total sulfides), compared with pyrite (about 20% of the total sulfides), the optimal molar ratio of the components in the composition of isobutyl dithiophosphate and thionocarbamate was established. This ratio is determined by the fact that thionocarbamates are able to more actively form surface compounds with active Fe ²⁺ centers on pyrrhotite than on pyrite. The highest technological indicators in collective flotation are achieved when M-TF is used together with butyl xanthate at a mass ratio of 3-4: 0-1, and in the main zinc flotation, an inverse (“mirror”) mass ratio in combination of M-TF with butyl xanthate is required which corresponds to the range 0-1: 3-4. Copper flotation to obtain a copper-ready concentrate is carried out by the M-TF collector.

The essence of the claimed invention is as follows: sulfide copper-zinc pyrrhotite-pyrite ore is ground in a lime medium at a pH of 8.0-9.0 with the addition of sodium sulfide in the mill; to bind copper cations and sulfidization of oxidized minerals, then the pulp is classified according to the class of 74 microns. The ground pulp with a particle size of 80-85% of class minus 74 μm is conditioned sequentially with M-TF for the selective flotation of copper minerals into a “copper head” and in a certain mass ratio of M-TF with butyl xanthate in accordance with the required flotation activity of sulfides in flotation cycles :

the remaining sulfide minerals of copper and naturally activated sphalerite are floated in a collective concentrate. After that, the tails of collective flotation are conditioned with copper sulfate, lime, M-TF in combination with butyl xanthate in the optimal weight ratio and a foaming agent, then selective flotation is carried out with the release of sphalerite into a rough zinc concentrate and obtaining dump pyrrhotite and pyrite-containing tails. Use the following weight ratios in combination of collectors for flotation cycles: copper cycle - M-TF; collective cycle - M-TF: butyl xanthate 3-4: 0-1; copper selection cycle - M-TF; zinc cycle (ore) - M-TF: butyl xanthate 0-1: 3-4; zinc selection cycle - M-TF: butyl xanthate 3-4: 1. Reduction of flotation of pyrrhotite and pyrite is carried out by lime on flotation cycles at different pH and the use of selective collectors. Using reagent M-TF allows selective copper and collective flotation at a lower pH value (8-9) than with butyl xanthate (pH = 10.5-11.5), which allows to increase the extraction of copper sulfides, free gold and gold in open splices. The reagent M-TF allows for the prevalence of pyrrhotite in the ore (40-60%) to achieve a selective decrease in the flotability of pyrrhotite after prolonged aeration in a low alkaline calcareous medium (pH 8-9).

The invention achieves the following technological results:

- low flotability of pyrrhotite and pyrite in all technological operations;

- high and selective extraction of copper and zinc sulfides in commodity concentrates;

- the allocation of the bulk of the zinc concentrate immediately in ore flotation after collective copper-zinc flotation, which reduces the volume of technological operations in the separation of collective copper-zinc concentrate, reduces the pulp load on these and other operations, which ultimately reduces the total flotation front and reduce the circulation of sphalerite and iron sulfides with industrial products. Technological results are achieved through the use of a selective M-TF collector and a combination of collectors in a certain order of their dosing according to flotation cycles and the ratio with butyl xanthate.

A significant difference between the claimed invention and its advantage in comparison with the prototype and known technical solutions is that in the proposed method, the components of the selective collector M-TF (a mixture of dithiophosphate and thionocarbamate) are used in a specific molar ratio in combination with a strong collector of butyl xanthate in the optimal mass ratio for each flotation cycle, which allows selective flotation of the disclosed primary, secondary copper sulfides in the first copper flotation and the remaining sulfides copper ides and naturally activated sphalerite in collective flotation using a highly alkaline calcareous medium (at least 800-1000 mg / l St. CaO) and a combination of M-TF: butyl xanthate in a ratio of 0-1: 3-4, which allows selective flotation sphalerite in the finished zinc concentrate.

A specific implementation of the methods was carried out on the following example in laboratory conditions on pyrite copper-zinc-pyrrhotine-pyrite ore. The ore is crushed in a calcareous medium for 22 minutes at a pH of 8.0–9.0 with the addition of sodium sulfide 50 g / t to bind copper cations formed during the oxidation of secondary sulfides; pulp is classified according to the class of 74 microns. The crushed ore with a particle size of 80-85% of the class minus 74 microns is conditioned sequentially with a composition of selective collectors supplied in a certain order and ratio: M-TF and butyl xanthate. At various mass ratios for flotation cycles: copper cycle - M-TF; collective cycle - 3: 1; copper selection cycle - M-TF; zinc cycle (ore) - 1: 3; zinc cycle selection - 3: 1. Adding a foaming agent, copper flotation is carried out to obtain a “copper head”, copper-zinc flotation to obtain a collective concentrate containing sulfide minerals of copper and naturally activated sphalerite; then the tails obtained after collective copper-zinc flotation are conditioned with copper sulfate, to activate sphalerite, with lime, to create a highly alkaline medium for suppressing pyrrhotite and pyrite, by the composition of M-TF collectors with butyl xanthate, a foaming agent, and selective flotation is carried out with the release of sphalerite into rough zinc concentrate and receiving dump pyrrhotite-pyrite-containing tailings.

The flotation results of copper-zinc-pyrotine-pyrite ore by the prototype method and the proposed method are shown in table 1.

Table 1 Laboratory Results Exit, % Content% Recovery% Note Cu Zn Cu Zn one Ore one hundred 1.74 3.65 100.0 100.0 The indicators of the proposed method - M-TF and butyl xanthate Copper Head Concentrate 3.8 25.00 3.46 54.6 3.6 Copper selection concentrate 4.0 13.89 3.25 31.7 3,5 Total copper concentrate 7.8 18.68 3.35 86.3 7.1 Zinc Concentrations in the Ore Cycle 5.2 0.70 52.08 2.1 74,2 Zinc concentrate selection 1,0 2.96 22.46 1.7 6.3 Total Zinc Concentrate 6.2 1.98 47.21 3.8 80.5 Tail tails 86.0 0.20 0.50 9.9 11.8 2 Ore 100.0 1.65 3.45 100.0 100.0 The performance of the prototype only with butyl xanthate Copper Head Concentrate 2,4 18.49 6.39 25.5 4.2 Copper selection concentrate 5,6 17.06 2,52 54.7 3.9 Total copper concentrate 8.0 17.49 4.10 80.2 8.1 Zinc concentrations in the ore cycle 2.6 2.88 50.12 4.3 35.7 Zinc concentrate selection 3.2 1.68 47.16 3,1 41.6 Total Zinc Concentrate 5.8 2.10 48.48 7.4 77.3 Tail tails 86.2 0.25 0.62 12,4 14.6

According to the proposed method, the increase in the extraction of metals in commercial selective concentrates was: copper - 6.1% and zinc - 3.2%.

Claims (2)

1. A method of flotation of copper-zinc-pyrrhotine-pyrite ore, including grinding in a slightly lime medium, conditioning with reagents - collectors and a foaming agent, copper flotation to obtain a copper head concentrate, collective copper-zinc flotation to obtain a collective concentrate containing copper minerals and naturally-activated sphalerite, the tails of collective copper-zinc flotation are conditioned with copper sulfate, to activate sphalerite, with lime and a collector, and selective flotation is carried out with pouring sphalerite into zinc concentrate and obtaining dump pyrrhotite-pyrite-containing tailings, characterized in that the collectors use the composition M-TF, which is a mixture of isobutyl dithiophosphate and thionocarbamates in the following molar ratio of components - isobutyl dithiophosphate: thionocarbamate from 60: from 20: 80%, supplied in combination with butyl xanthate as follows for flotation cycles: copper cycle — use M-TF, collective cycle — 3-4 mass fractions of M-TF and 0: 1 mass fraction are shared utilovogo xanthate, zinc cycle - 0 use a combination of: 1 part by weight and M-FFs 3-4 mass fraction butyl xanthate. 2. The method according to claim 1, characterized in that the thionocarbamates are isopropyl-O-methyl-N-thionocarbamate (ITC trademark) or isopropyl-O-ethyl-N-thionocarbamate (trademark Z-200).