RU2623851C1 - Method for flotation separating minerals of heavy metals - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method uses a selective collector M-TF, which is a mixture of dithiophosphate and thionocarbamate with a variable ratio of dithiophosphate and thionocarbamate depending on the proportion of pyrite and pyrrhotite in the sulphide ore, on the ratios of copper sulfides and sphalerite varieties in a collective concentrate and selective flotation operations. In the samples studied, copper sulfides are represented by primary and secondary minerals, as well as minerals from the group of faded ores. In the method for the flotation separating minerals of pyrrhotite-pyrite-containing ores as a collector, a combination of butyl xanthate and M-TF reagent is used at variable fraction ratio of the M-TF collector components in various flotation cycles.

EFFECT: decreasing the flotation of pyrite, pyrrhotite, increasing the flotation activity of the main minerals of copper - chalcopyrite, bornite and creating conditions for active flotation of tennantite, as well as mineral associations of gold.

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Description

The invention relates to the field of flotation concentration of copper, copper-zinc, polymetallic, lead-containing and other non-ferrous ores.

The greatest difficulties for the flotation separation of copper, zinc and lead sulfides are caused by secondary copper sulfides, faded ore minerals - tennantite and tetrahedrite, naturally activated sphalerite, highly ferrous sphalerite-marmatite, corroded and colomorphic pyrite species, multiphase pyrrhotite, brittle and easily friable cerrusite. Moreover, in the absence of “hard depressants”, selective collectors and when using lime, sulfide minerals acquire almost equal flotation properties. The problem of separation of sulfides is complicated by an uneven finely dispersed interspersion, a wide range of sizes from nanoscale free grains to polymineral intergrowth associations and aggregate formations, the opening of which during grinding occurs with a time interval in a certain natural sequence and with different contents of newly formed free and ready to flotation ones that are easily difficult to float and easily difficult to suppress other minerals.

The application of the selective flotation method has been developed for ores with a homogeneous material composition.

A known method of flotation, in which the pulp after grinding and classification is floated with collectors of DMDK (dimethyldithiocarbamate) in combination with xanthate [Ostrozhnaya E.E., Khramtsova I.N. On the combined use of dialkyldithiocarbamate and butyl xanthate in the flotation of pyrrhotite-containing ores // Non-ferrous metals, 1999, No. 5, p. 14-15].

A method is known in which crushed polymetallic, copper-molybdenum, copper-zinc ores are floated by collectors of the Beraflot 3026 series (a mixture of dialkyldithiophosphate and dialkyl sulfide in a different ratio) to obtain a collective sulfide concentrate in which the minerals of copper, molybdenum, zinc, lead are extracted partially pyrite and precious metals [Chanturia V.A., Nedosekina T.V., Mantsevich M.I. et al. The effect of dimethyldithiocarbamate on the interaction of pyrrhotite with butyl xanthate // Non-ferrous metals, 2002, No. 10, p. 19-21].

Known methods of flotation of non-ferrous metal ores containing gold and silver, one of which is used as collectors xanthates, dithiophosphates, mercaptans [Fishman MA and others. The practice of enrichment of ores of non-ferrous and noble metals. M .: Nedra, 1967, p. 23-32].

The known method [A.S. USSR No. 306679, class B03D 1/02, 1969], in which aliphatic esters of nicotinic acid are used.

The known method [A.S. USSR No. 547685, cl. B03D 1/02, 1976], in which xanthate mixtures and organic oil distillation fractions are used.

The known method [Ignatkina V.A., Bocharov V.A., Milovich F.O. and other new approaches to the study of the mechanism of action of sulfhydryl collectors during flotation of sulfides // Collection of materials of the Congress of enrichment of the CIS countries, 2015, M .: MISiS, Outotec, t. II, p. 475-482], in which diisobutyl dithiophosphinate alone or in combination with xanthates exhibits high reactivity comparable to xanthates, but has less selectivity compared to dithiophosphates.

A known method of flotation of pyrite copper-zinc ore using a combination of dithiophosphates, thionocarbamates and butyl xanthate in a ratio of 3: 4.5: 1 for flotation of copper sulfides and sphalerite [V.A. Bocharov, V.A. Ignatkina et al. Method for flotation of copper-zinc-pyrite ore. Patent No. 2433866, registered November 20, 2011, application No. 2009141930. Priority dated 11/16/2009]. This method is only suitable for ores of uniform composition. Indicators are reduced in ore, in which the proportion of pyrrhotite in iron sulfides increases significantly.

The above methods are ineffective, since the collectors used in them also actively float many varieties of the main sulfide minerals of non-ferrous metals and iron. The collectors used, having high sorption ability, have insufficient selectivity with respect to iron sulfides - pyrite, pyrrhotite, sphalerite - and, in addition, do not create conditions for increasing the flotation activity of faded ore minerals - tennantite, and also do not take into account the features of sequential opening and flotation modifications of minerals - corroded pyrite, multiphase pyrrhotite, secondary copper minerals, high arsenic tennantite, easily oxidized in the process of destruction of mineral aggregates during grinding, in connection with which it is necessary to apply an intensive regime of sequential opening and rapid withdrawal from the grinding cycle to flotation, selecting a scheme for the selective dosing of collector combinations with different variable ratio of components in the combination of collectors in various flotation operations, and the regulation and stabilization of sulfide oxidation process is not optimized iron, tennantite and secondary copper minerals that activate the flotation of sphalerite, pyrite, pyrrhotite during the flotation of copper sulfides. Accepted in the mineral separation mode, the pH of the medium does not contribute to a decrease in the flotation activity of pyrite, pyrrhotite, and an increase in the floatability of copper minerals, especially tennantite, which is one of the reasons for the decrease in the quality of finished concentrates and the low floatability of tennantite.

As a prototype, a flotation method using isobutyl dithiophosphate and thionocarbamate compositions was adopted — the M-TF series reagent, which is a mixture of dithiophosphate and thionocarbamate in small ratios from 20-60% to 80-40%, respectively [V. Ignatkina, V. Bocharov. A., Puntsukova B.T. and others. Studies of the selective action of combinations of xanthate and dithiophosphate with thionocarbamates // FTPPRI, 2010, No. 3].

The combined use of M-TF and butyl xanthate provides high performance in collective flotation at a mass ratio of 3 ÷ 4: 0 ÷ 1, and in zinc flotation at a "mirror" ratio of 0 ÷ 4: 3 ÷ 4. A distinctive feature of the prototype from known methods is the use of certain molar ratios of the component of the selective collector M-TF in combination with butyl xanthate in the optimal ratio for each flotation cycle. The main disadvantage of the prototype is the wide concentration range of St. CaO - not lower than 800-1000 mg / l - and the absence of a specific dependence of the concentration of St. CaO and flotation varieties of sulfide mineral.

The technical result of the invention is to reduce the flotability of pyrite, pyrrhotite, while increasing the flotation activity of the main copper minerals - chalcopyrite, boron - and the creation of conditions for active flotation of tennantite, as well as mineral associations of gold.

The flotation method of refractory pyritic copper-zinc ores includes grinding and flotation with sulfhydryl collectors - xanthates - in combination with dithiophosphates and thionocarbamates in an alkaline medium to obtain a collective concentrate and its subsequent separation using sphalerite and iron sulfides, sodium sulfide, sulfate as depressants zinc and lime, characterized in that they carry out grinding with sequential disclosure of minerals and in inter-cycle operations of copper flotation as collectors are injected with an M-TF collector, which is a mixture of dithiophosphate and thionocarbamate with a composition ratio of dithiophosphate-thionocarbamate components 2: 1, in combination with butyl xanthate at a ratio of fractions of M-TF and xanthate 3 ÷ 4: 1 at pH values in the first copper flotation of 7 , 0-8.0. Collector M-TF is introduced into the collective copper-zinc flotation at a ratio of dithiophosphate-thionocarbamate fractions of 1: 1.5 in combination with butyl xanthate 1: 1 ÷ 2 at pH = 9.0-10.0. An M-TF collector is introduced into zinc ore flotation at a ratio of dithiophosphate and thionocarbate fractions of 1: 1.5 in combination with butyl xanthate at a ratio of 1: 2 ÷ 3 at pH> 10.0-11.0. The M-TF collector is introduced into the selection of the collective concentrate, in which the mass fraction of thionocarbamate and dithiophosphate is in the ratio of 1.5 ÷ 2: 1 at pH = 7.5-8.5.

The technical result consists in the fact that the collector M-TF at pH = 7.2-7.5 is selectively adsorbed on free surface areas of copper sulfides, mineral forms of gold to a greater extent than on sphalerite, iron sulfides, and is fixed only on free areas surfaces of minerals not occupied by other compounds. In the subsequent supply with a lower consumption of a stronger collector - butyl xanthogenate - there are much less free areas for fixing it, and sorption requires a much longer contact in time, in which desorption of a weak collector is possible under the conditions of the hydrodynamic operating mode of the flotation apparatus. In this regard, conditioning with an optimal depression regime of suppressed minerals and an optimal concentration of depressed sulfide pulp ions and pH values should be short-term with active flotation of recoverable copper minerals for a short duration. In collective flotation, with an increase in pH (St. CaO) to the values necessary for the flotation of the bulk of copper sulfides and activation of sphalerite, a triple mixture of collectors is fed with an increase in the share of a strong collector, xanthogenate in combination.

The technical result is achieved, firstly, by using experimentally established optimal variable combinations and component ratios in the compositions of the M-TF collector with different molecular structures and their multipoint dosing in the operations of the technological scheme; secondly, by regulating various pH values (St. CaO) for flotation operations, while creating conditions for the stabilization and oxidation state of sulfide minerals, especially iron sulfides, maintaining the necessary optimal concentration of depressing ions to suppress the flotation of iron sulfides and sphalerite, activating the flotation of all copper sulfides in the separation of copper-zinc concentrate by pH values, the flow rate of the collector M-TF with a variable ratio of the proportions of components in different flotation cycles, the flow rate of depressants; thirdly, the organization of the sequential disclosure of splices of minerals and their modifications during grinding with the conclusion to flotation of free from spliced grains of varieties of minerals of optimal size in different operations.

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, образующихся при окислении пирита, в мельницу добавляют сульфат цинка и сульфид натрия при соотношении 3:1 в количестве 50-100 г/т суммарно; пенный продукт флотации является первым черновым медным концентратом, камерный продукт флотации поступает на вторую стадию измельчительного цикла для последующего раскрытия минералов меди и цинка от сростков с другими компонентами при крупности измельчения до 80-85% кл. -0,074 мм. Измельченную пульпу флотируют с выделением в пенный продукт коллективного медно-цинкового концентрата. Флотация проводится в известковой среде при pH=8,5-10,0 смесью дитиофосфата, тионокарбамата и бутилового ксантогената при соотношении 1:1,5:1÷2; пенный продукт поступает на флотационное разделение минералов меди и цинка по режиму предлагаемого способа. Из камерного продукта коллективной флотации после кондиционирования с известью при pH≥10-11 и сульфатом меди флотируют неактивированную разновидность сфалерита смесью собирателей бутилового ксантогената и М-ТФ при соотношении 2÷3:1 с выделением чернового цинкового концентрата.The essence of the proposed method for flotation separation of sulfide minerals of pyrite ore or concentrates is that polymineral pyrite ore of non-ferrous metals is ground with lime (pH = 7.2-7.5), classified according to the class -0.074 mm 55-75% with the return of sand to ore mill of the first stage and with the direction of the discharge fraction to the flotation of copper minerals freed from intergrowths (secondary copper sulfides, tennantite and partially primary minerals in free grains), as collectors in the grinding cycle and in the stadium w flotation at pH = 7-8 is dosed collector M-TP at a ratio of shares thionocarbamates dithiophosphate and 2: 1. To reduce the flotation activity of iron sulfides and sphalerite before feeding the collector mixture in order to avoid and stabilize the concentration of depressing ions S ^-2 ,

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formed during the oxidation of pyrite, zinc sulfate and sodium sulfide are added to the mill at a ratio of 3: 1 in an amount of 50-100 g / t in total; the foam flotation product is the first crude copper concentrate, the chamber flotation product enters the second stage of the grinding cycle for the subsequent disclosure of copper and zinc minerals from splices with other components with a grinding size of up to 80-85% cells. -0.074 mm. The ground pulp is floated with the release of collective copper-zinc concentrate into the foam product. Flotation is carried out in a lime medium at pH = 8.5-10.0 with a mixture of dithiophosphate, thionocarbamate and butyl xanthate at a ratio of 1: 1.5: 1 ÷ 2; the foam product enters the flotation separation of copper and zinc minerals according to the regime of the proposed method. After conditioning the collective flotation product after conditioning with lime at pH≥10-11 and copper sulfate, an inactive sphalerite variety is floated with a mixture of collectors of butyl xanthate and M-TF at a ratio of 2 ÷ 3: 1 with the release of rough zinc concentrate.

From the collective concentrate after classification by cl. -0.074-90-95% and regrinding of the sand fraction float copper minerals with preliminary conditioning with sodium sulfide and zinc sulfate at a ratio of 1: 3 ÷ 4 at pH = 7.5-8.5, and M is metered as collectors in copper flotation TF with the ratio of the shares of thionocarbamate and dithiophosphate 1.5 ÷ 2: 1 to obtain the second blister copper concentrate in the foam product, and the chamber product is either blister zinc concentrate or the initial feed of zinc ore flotation. Rough copper and zinc concentrates are subjected to finishing operations according to well-known classical schemes and technological conditions.

The proposed method for the separation of pyrite polymetallic ores and non-ferrous metal concentrates was tested on technological ore samples of non-ferrous metal deposits of the Ural region. Tables 1, 2 show the results of collective flotation of pyrite copper-zinc ores with different pyrite contents and an impurity ratio of copper to zinc of 1: 1.5 ÷ 4 according to the mode in accordance with the claimed project of the invention.

Table 3 shows the results of the separation of the collective copper-zinc concentrate.

The above technological results show that the use of the distinguishing features of the invention allows, in comparison with the prototype, to obtain higher separation results both in the recovery of metals and in the quality of concentrates. Extraction of copper in copper concentrate is higher by 3.5%; and the extraction of zinc in zinc concentrate - by 7%; gold recovery in collective concentrate - by 12.5%.

Claims (1)

Method of flotation concentration of refractory pyritic copper-zinc ores, including grinding and flotation with sulfhydryl collectors - xanthates in combination with dithiophosphates and thionocarbamates in an alkaline medium to obtain a collective concentrate and its subsequent separation using sphalerite and iron sulfides, sodium sulfide, sulfate as depressants zinc and lime, characterized in that they carry out cyclic grinding with sequential disclosure of minerals and in the inter-cycle periods are carried out first the first copper flotation and M-TF collector is introduced as collectors, which is a mixture of dithiophosphate and thionocarbamate with a ratio of dithiophosphate-thionocarbamate components 2: 1, in combination with butyl xanthate at a ratio of M-TF and xanthate fractions 3 ÷ 4: 1 at values The pH in the first copper flotation is 7.0-8.0 to obtain the first crude copper concentrate, then the collector M-TF is introduced into the collective copper-zinc flotation at a ratio of dithiophosphate-thionocarbamate fractions of 1: 1.5 in combination with butyl xanthate atwith a ratio of 1: 1 ÷ 2 at pH = 9.0-10.0 with the release of collective copper-zinc concentrate, then the collector M-TF is introduced into the zinc flotation at a ratio of dithiophosphate and thionocarbate fractions 1: 1.5 in combination with butyl xanthate at ratio of 1: 2 ÷ 3 at pH> 10.0-11.0 with the release of rough zinc concentrate, then the collector M-TF is introduced into the selection of the collective concentrate, in which the mass fraction of thionocarbamate and dithiophosphate is in the ratio of 1.5 ÷ 2: 1 at pH = 7.5-8.5, to obtain a second crude copper concentrate.