RU2108167C1 - Method of selective flotation of pentlandite in alkali medium from materials containing pyrrhotine sulfides - Google Patents

Abstract

FIELD: chemistry. SUBSTANCE: method includes treatment of material pulp with pyrrhotine depressor, conditioning with sulfhydryl collector and foaming agent, introduction of organic sulfur-containing additive and separation of pentlandite into foam product - selective nickel concentrate. Organic sulfur-containing additive is used in the form of oil-soluble sulfonic acids and/or salts of sulfonic acids - oil-soluble sulfonates of alkali-earth metals which are supplied in the form of detergent-dispersion additives to base lubricating oils or in composition with commercial oil products containing them, including their combination with used automobile oils. Flotation of pyrrhotine sulfides is suppressed by use of modifiers of depressing action, such as calcium hydroxide, alkali salts of dithiocarbamic acid, carbamide-formaldehyde resin. EFFECT: higher efficiency. 6 cl, 1 tbl

Description

 The invention relates to mineral processing by flotation, in particular to selective flotation separation of pentlandite from materials containing pyrrhotite sulfides, and can be used in flotation concentration of pyrrhotite-containing copper-nickel ores and intermediate products.

 A known method for the selective flotation of pentlandite from nickel-pyrrhotite intermediate obtained by beneficiation of sulphide copper-nickel ores, including treating the pulp of the intermediate with lime, which depresses the pyrrhotite flotation, conditioning the pulp with butyl xanthate and blowing agent in an alkaline medium and isolating pentlandite into a separate foam product nickel concentrate (Technological instruction for ore dressing at Talnakhsky concentrator - TI 0401.14.39-11-65-85. Introduction period from 01 .01.86 - MCM USSR, Soyuznikel, NMMC, Norilsk, 1985, p. 111-112).

 The disadvantage of this method is the relatively low selection of the process: the extraction of nickel in the concentrate of the same name does not exceed 62-65% with a nickel content of not more than 7.5-7.8%. An increase in the yield of nickel concentrate, for example, by increasing the consumption of xanthate or increasing the flotation time, can increase the target nickel recovery to 70-75%, however, the nickel content in the concentrate drops sharply to 5.5-6.0% as a result of dilution with pyrrhotite.

где R - алкилен;
R¹ - алкилен;
R² - водород, метил или этил;
М - щелочной металл или аммоний.A known method of beneficiation of sulfide ores containing molybdenite, pentlandite and sulfide minerals of the iron group (pyrrhotite, troilite, pyrite), comprising pretreating the pulp of the starting material with an organic depressor of iron-nickel minerals from the group of dithiocarbamates, followed by flotation of molybdenite, in which pentlandite and iron sulfides are obtained chamber product. In this case, alkali and ammonium salts of di (carboxyalkyl) dithiocarbamates of the formula are used as an organic depressant

where R is alkylene;
R ¹ is alkylene;
R ² is hydrogen, methyl or ethyl;
M is an alkali metal or ammonium.

 Pentlandite is isolated from an iron-nickel chamber product into a selective concentrate by known enrichment methods (US Pat. No. 4,702,821, 4 B 05 D 1/14, 1987).

 A disadvantage of the known method is that the regime of collective suppression of flotation of pentlandite and sulfide iron minerals used in it, based on the use of a strong organic depressor from the dithiocarbamate group, significantly complicates the subsequent isolation of pentlandite by flotation into a selective concentrate. The latter is due to the fact that the collective depression of minerals minimizes the natural difference in their flotation activity. In this case, for selective flotation of pentlandite, the surface of which is coated with an organic depressant film, a special selective activation is required, which preserves the iron minerals in a hydrophilic (depressed) state. Existing methods of activating minerals after they are suppressed by a strong organic depressant are very expensive, and, moreover, none of them provides a sufficiently high extraction of the target component in the foam product.

 Another serious disadvantage of this method is the increased consumption of an organic depressant when used in the collective depression mode of pentladite and iron sulfides. According to literature, the optimal consumption of reagent depressants of the dithiocarbamate group in this mode reaches 2700-5000 g / t ore (US patent N 4,554,068, CL 03 D 1/02 1984. US patent N 4702821, CL B 03 D 1 / 14, 1985). Since all reagents based on derivatives of dithiocarbamic acid are extremely expensive (from 3000 S / t and above), the application of the known method is economically justified only for the processing of molybdenum ores, where this method allows you to replace the expensive and environmentally dangerous inorganic depressant - sodium sulfide.

 A known method of beneficiation of sulphide copper-nickel ores, including selective flotation of nickel minerals, mainly pentlandite, from an intermediate product containing nickel minerals, pyrrhotite and gangue components. In the known method, industrial product pulp is treated with an organic pyrrhotite depressor, conditioned in an alkaline medium at pH 10.5 with a sulfhydryl collector and a blowing agent, after which pentlandite is isolated by flotation into a selective nickel concentrate. At the same time, an alkaline salt of dithiocarbamic acid, sodium dimethyldithiocarbamate (carbamate MN), in an amount excluding the suppression of flotation of pentlandite (Rybas VV, Ivanov VA, Volkov VI, etc.) is used as an organic pyrrhotine depressant. Effective technology development selective flotation of copper-nickel ores. Non-ferrous metals, 1995, N 6, pp. 37-39).

 An important advantage of this method is the ability to obtain high-quality nickel concentrate containing 13% nickel (36% pentlandite) with a mass fraction of pyrrhotite sulfides of 44%. This is ensured by an effective depression of the flotation of pyrrhotins, which sharply limits their transition to a foam product and reduces the dilution of the mineral mass of pentlandite with structurally free grains of pyrrhotite sulfides.

 The disadvantage of this method is the relatively low extraction of Nickel, cobalt and noble metals in the target product of enrichment - selective Nickel concentrate, industrial tests conducted on copper-Nickel pyrrhotite ores of the Norilsk Combine, showed that when using dimethyldithiocarbamate (reagent DIDK) as a depressor pyrrhotite the chamber product of nickel flotation passes,%: nickel 37; platinum 44; palladium 30; rhodium 76; ruthenium 71; gold 42; silver 46. Nickel-pyrrhotite concentrate (NPK) is isolated from the nickel flotation chamber product, which is further divided into pyrrhotite concentrate (PC) and nickel “head” and common enrichment tails (tails + low-nickel pyrrhotite product). At the same time, 13% of nickel and 10% of the amount of platinum metals are discharged into the dump with common tailings.

где R - алкил;
R¹ - СН₂ - СН = СН₂ При этом аллиловые эфиры применяют в смеси с аэрофлотами в виде мелкодисперсных эмульсий при соотношении компонентов от 0,02:1 до 0,25: 1 (Щербаков В.А., Моисеева Р.И., Гурвич С.М.и др. Получение и флотационное испытание смесей аэрофлотов с S-эфирами дитиокислот фосфора (Труды ин-та "Гинцветмет" Совершенствование технологии обогащения руд цветных металлов на основе оптимизации реагентных режимов флотации. М., 1986, с. 75-81 - прототип). Использование аллиловых эфиров диакилдитиофосфорных кислот при разделении никель-пирротиновых материалов улучшает флотируемость пентландита, что снижает потери ценных компонентов с отвальными хвостами обогащения без ухудшения качества никелевого концентрата. Недостатком известного способа является сравнительно низкий уровень извлечения пекнтландита и ассоциированных с ним платиновых металлов в никелевый концентрат, особенно при флотации легкошламующихся руд, тонкоизмельченных материалов и высокодисперсных носообразованных сульфидов. Это обусловлено тем, что предложенная комбинация реагентов, включающая смесь аллиловых эфиров и аэрофлота, не только не обеспечивает флотацию тонких сульфидоносных шламов (менее 20 мкм), но, более того, осложняет ее в результате дестабилизирующего влияния на процесс флокулообразования.The closest to the proposed method for the totality of the characteristics and the achieved result is a method of beneficiation of sulfide copper-nickel ores, including selective flotation of pentlandite from pulp of a pyrrhotite-containing intermediate. At the same time, the industrial product pulp is treated with a pyrrhotine depressant, conditioned in an alkaline medium at pH 10-10.5 with a sulfhydryl collector and a blowing agent, an organic sulfur-containing reagent is added to increase the flotation activity of copper-nickel minerals, and pentlandite is isolated by selective flotation in a selective nickel concentrate. As an organic sulfur-containing reagent in the known method using allyl esters of dialkyl dithiophosphoric acids corresponding to the General formula

where R is alkyl;
R ¹ - CH ₂ - CH = CH ₂ In this case, allyl ethers are used in a mixture with aeroflot in the form of finely dispersed emulsions with a ratio of components from 0.02: 1 to 0.25: 1 (Shcherbakov V.A., Moiseeva R.I. , Gurvich S.M. et al. Obtaining and flotation testing of mixtures of aeroflot with S-esters of phosphorus dithioacids (Proceedings of Gintsvetmet Institute. Improving the technology of enrichment of non-ferrous metals based on optimization of reagent flotation regimes. M., 1986, p. 75 -81 - prototype.) The use of allyl esters of diacyldithiophosphoric acids in the separation of nickel-pyrrhotite materials fishing improves the flotability of pentlandite, which reduces the loss of valuable components with waste tailings without impairing the quality of nickel concentrate. The disadvantage of this method is the relatively low level of extraction of pecntlandite and its associated platinum metals in nickel concentrate, especially when flotation of easily sludge ores, finely ground materials and highly dispersed nosoobrazovannyh sulfides. This is due to the fact that the proposed combination of reagents, including a mixture of allyl ethers and aeroflot, not only does not provide the flotation of thin sulfide-bearing sludges (less than 20 μm), but, moreover, complicates it as a result of a destabilizing effect on the flocculation process.

 Another disadvantage of this method is its low efficiency in the flotation of aggregates. The use of the known method in the enrichment process of coarsely ground mineral raw materials with a high content of particle size classes plus 44 microns or in the presence of coarse dispersed polymineral formations of secondary origin, for example sulfide-containing flocs in the nickel flotation feed, causes increased losses of non-ferrous and noble metals with tailings. The need for deeper grinding of the initial ore significantly increases energy costs in the cycle of its pulp preparation and increases dust removal during subsequent pyrometallurgical processing of the obtained concentrates.

 In addition, increasing the completeness of the target extraction of non-ferrous and noble metals in the known method is achieved by expensive methods - increasing the consumption of sulfhydryl collector and the transition to the use of xanthates with a longer length of the hydrocarbon radical (amidole, hexyl), which is inevitably accompanied by a decrease in the selection rate of the process and, as a result, deterioration in the quality of nickel concentrate.

 The objective of the invention is to increase the extraction of pentlandite and its associated non-ferrous and noble metals in selective nickel concentrate, as well as to reduce the specific consumption of sulfhydryl collector by increasing the difference in flotation rates of pentlandite and pyrrhotin sulfides.

 The essence of the invention lies in the fact that in the method of selective flotation of pentlandite, carried out in an alkaline medium from materials containing pyrrhotite sulfides, including treating the pulp of the material with a pyrrhotite depressant, conditioning with a sulfhydryl collector and blowing agent, introducing an organic sulfur-containing additive and isolating pentlandite in a foam product, selective nickel the concentrate according to the invention, oil-soluble sulfonic acids and / or sulfates are used as an organic sulfur-containing additive oxides - oil-soluble sulfonates of alkaline earth metals.

 Another difference of the method is that petroleum-based oil-soluble alkaline earth metal sulfonates are used in the form of detergent dispersing additives to base lubricating oils or as part of marketable petroleum products containing them.

 A further difference is that the oil-soluble, oil-soluble alkaline earth metal sulfonates are used in used automobile oils.

 Another difference of the method lies in the fact that calcium hydroxide is used as a pyrrhotine depressant in a weight ratio of sulfhydryl collector, organic sulfur-containing additive and calcium hydroxide from 1: 0,0003: 2 to 1: 0,0035: 25.

 Another difference of the method is that alkali salts of dithiocarbamic acid are used as a pyrrhotine depressant with a weight ratio of sulfhydryl collector, organic sulfur-containing additive and alkali salt of dithiocarbamic acid from 1: 0.0001: 0.5 to 1: 0.0015: 10.

 The last difference is that a urea-formaldehyde resin is used as a pyrrhotine depressant with a weight ratio of sulfhydryl collector, organic sulfur-containing additive and urea-formaldehyde resin from 1: 0,0002: 6 to 1: 0.003: 14.

 The effectiveness of the use of oil-soluble oil-soluble sulfonic acids and their salts in the selective flotation cycle of pentlandite is due to the peculiarities of its separation from pyrrhotite sulfides.

 Both shared minerals: both pentlandite and pyrrhotite, have natural hydrophobicity (Mitrofanov S.I. Selective flotation. - M .: Gosizdat, 1966). Therefore, to suppress the flotation of one of them (pyrrhotite), special techniques are used based on the selective inhibition of the flotation rate of pyrrhotine sulfides and limiting the flotation time of pentlandite. The separation efficiency is higher, the greater the achieved difference in the flotation rates of the shared minerals.

It was experimentally established that the use of only one of these methods, in particular suppressing the flotation of pyrrhotins by introducing a depressant reagent into the pulp, does not provide optimal process conditions. For example, when using “soft” depressants (lime) or small expenses of “strong” (KFS, DMDK), a significant amount of pyrrhotins goes into nickel concentrate, which worsens its quality and reduces the TEC of the metallurgical redistribution. On the other hand, the “severe” depression of pyrrhotite flotation, achieved by using increased costs of such reagents as KFS, DMDK, etc., provides high-quality nickel concentrate, but a significant amount of pentlandite and the metals associated with it remain in the chamber product (tails) nickel flotation. The latter is due to two factors - the polydispersity of the material and its structural features:
- a part of pentlandite in the initial nutrition is represented by hard-to-particle size classes - sludge minus 20 microns;
- a significant mass of pentlandite is not in a free state, but in the form of splices with pyrrhotite.

 Therefore, the flotation rates of pentlandite and pyrrhotite are not constant, and depending on the size and structure of the grain of the mineral vary in some areas. These areas overlap to one degree or another, since the flotation rate of slimy pentlandite particles and its large intergrowths with other minerals is comparable with the flotation rate of pyrrhotite of optimal flotation size. The stronger the overlapping regions of speed variation, the more difficult it is to separate pentlandite from pyrrhotite sulfides.

 Mineralogical and optical analyzes of the composition of the products of selective flotation of pentlandite (DMDK pyrrhotine depressor) in the scheme of beneficiation of pyrrhotite copper-nickel ore of Norilsk Combine JSC showed the following.

 In nickel-pyrrhotite concentrate (a product of enrichment of nickel flotation tailings), pentlandite is free by 34 rel.%, While by 19.5 rel.% - in the class of more than 45 microns and by 38.9 rel.% - in the class of less than 45 microns from corresponding containing it in these classes. The bulk of pentlandite splices (95% of their total number) are in classes of more than 20 μm, while 33, O rel.% Of splices are open type.

 In the general enrichment tailings, pentlandite is only 1! 4 rel.% Free, while all free grains are in the class of less than 20 μm, of which 69% are in the class of minus 10 μm. A large proportion of intergrowths - 78 rel.% Of their total number, is in the size classes plus 20 microns, of which 4% - in the classes plus 45 microns. At the same time, 88.5% of the total content of intergrowths in this class is accounted for by intergrowths of pentlandite with pyrrhotite, the rest (intergrowths of the triple type) pentlandite + chalcopyrite + pyrrhotite.

 Thus, the mass fraction of free pentlandite grains in thin classes (minus 20 microns) of the nickel flotation chamber product is on average 80%. It follows that the use of a reagent that selectively enhances the flotation activity of fine pentlandite particles allows one to increase the mass fraction of nickel in the concentrate of the same name by 0.4 wt.% While increasing the extraction of non-ferrous and noble metals. Along with this, it is necessary to increase the difference in the flotation rates of minerals (to reduce the overlapping region of the regions of their variation) so that when flotation of free grains of pentlandite pyrrhotite is not taken into concentrate.

 In order to increase the selectivity of flotation of pentlandite, the authors propose a double differentiated effect on the difference in flotation rates of shared minerals, including depression of pyrrhotite and simultaneous selective activation of pentlandite. This is achieved by a combination of antagonistic reagents — a pyrrhotite flotation depressant and pentlandite flotation activator — whose congruent ratio ensures high target recovery of valuable metals without impairing the quality of nickel concentrate.

 As a reagent that improves the flotation activity of pentlandite, the invention provides oil-soluble oil-soluble sulfonic acids and their salts, oil-soluble alkaline earth metal sulfonates. According to the results of kinetic experiments, these compounds not only significantly increase the flotation rate of small classes of free pentlandite, but also simultaneously increase the floatability of partially depressed pentlandite + pyrrhotite aggregates with a high content of open pentlandite. This shows that the actions of the depressor and activator must be strictly balanced; otherwise, either pentlandite-rich splices will pass into the chamber product, or splices with a high content of pyrrhotins will be extracted into the nickel concentrate. The mass ratio of these reagents is one of the main factors determining the flotation of pentlandite. It depends on a number of process parameters: structural-mineralogical and dispersion-flotation characteristics of the initial flotation feed, the type of pyrrhotite depressant used, the conditions of the products obtained, the aeration characteristics of the equipment, etc. The specific ratio of the reagents is selected empirically, varying their costs depending on a given composition of nickel concentrate and extracting valuable components into it.

 Sulfonic acids are sulfonation products of alkyl aromatic hydrocarbons of petroleum or synthetic origin. In industrial conditions, oleum, concentrated sulfuric anhydride (gaseous or liquid) and air-gas mixtures containing 7-8 vol.% Sulfuric anhydride are used as a sulfonating agent (Kuliev A.M. Chemistry and technology of additives to oils and fuels. - L .: Chemistry, 1985, pp. 66-71).

 The main method for producing sulfonates is to neutralize the saponification of) sulfonic acids with oxides or hydroxides of alkali and alkaline earth metals. Depending on the nature of the feedstock, sulfonates, like sulfonic acids, are divided into petroleum and synthetic.

 The solubility of sulfonic acids and sulfonates in solvents of different polarity depends on the molecular weight of the feedstock. In this regard, they are divided into 3 groups: water-soluble ("green") - soluble in water and insoluble in petroleum oil; oil-soluble ("red") - soluble in oil and insoluble in water; water-oil soluble, occupying an intermediate position between "green" and "red" and dissolving in both polar and hydrocarbon solvents (Sadikhov KI, Agaev AN Sulfonate additives to lubricating oils. Baku, 1982, p. 6- 7, Halperin AE Production of additives to motor and transmission oils. - M .: Chemistry, 1974, p. 86-87).

 The use of water- and water-oil-soluble sulfo compounds as activating reagents in the flotation of sulfide materials is ineffective (L. Shubov and other Flotation reagents. Handbook, 1990, p. 17). In addition, some representatives of the group of "green" sulfonates exhibit strong depressing properties in relation to the flotation of sulfides of heavy non-ferrous metals. So, for example, sulfonates, which form the basis of chromium azo dyes, are used as a depressant in the flotation of copper-zinc ores (ed. Certificate of the USSR N 1058137, class B 03 D 1/02, 1982), and lignosulfonates obtained as a by-product of production cellulose is a potent non-selective depressant of sulfides of copper, nickel and cobalt (Mantsevich M.I., Malinsky R.A., Scherbakov V.A. et al. / Non-ferrous metals, 1983, N 1 - p. 77-79).

 Oil-soluble sulfonic acids in their properties differ significantly from water- and water-oil-soluble analogues. They are obtained only from heavy petroleum distillates having a molecular weight of at least 400 cu Commodity sulfo compounds of this group are obtained on the basis of oil distillates that have undergone selective purification and dewaxing, that is, from AC-6, DS-8 oils, as well as from residual selectively purified MS-20 oil, its fractions, or a mixture of distillate oils with MS-20 ( Shekhter .N., Crane S.Z.Surfactants from petroleum feedstocks. - M.: Chemistry, 1971, p. 13).

 Of the various groups of aromatic hydrocarbons (light, medium and heavy), light hydrocarbons are the most suitable for producing oil-soluble sulfonic acids and their salts - mono- and bicyclic alkylaromatic hydrocarbons with long paraffinic or naphthenic chains (C and above), which have a high viscosity index. Multicore (polycyclic) aromatic hydrocarbons with short side chains give “green” (oil-soluble) sulfonic acids upon sulfonation (Halperin AE Production of additives, 1974, p. 87. Kuliev AM Chemistry and technology of additives, 1985, p. 69 )

 Oil-soluble sulfonates are obtained by neutralizing “red” sulfonic acids with hydroxides of alkaline earth metals - calcium, magnesium, barium and strontium. Sulfonates of this group have found wide application as detergent-dispersing detergents for engine oils, designed to reduce the formation of carbon deposits on parts of internal combustion engines (Sadikhov K.I. et al. Sulfonate additives, 1982, p. 7).

 In the process of creating the invention, it was found that, in contrast to water and water-oil-soluble sulfonic compounds, oil-soluble sulfonic acids and red alkaline earth metal sulfonates in an alkaline medium have the ability to selectively increase the flotation activity of pentlandite in the presence of all known types of pyrrhotite depressants. According to the accepted classification of flotation reagents, the sulfo compounds under consideration, according to the nature of the effect on the selection process of pentlandite, manifest themselves as modifiers of the activating effect (Shubov L.Ya., Ivankov SI, Shcheglova NK Flotation reagents in the processes of mineral processing. Reference, in 2 books under the editorship of Kondratieva L.V., Moscow: Nedra, 1990, book 1, p. 5-26).

 An analysis of the scientific, technical and patent literature shows that the technological properties of sulfonic acids and their sulfosalts are determined not so much by the nature of the functional group, by the nature of the feedstock, but by the structure and molecular weight of the hydrocarbon radical, the spatial orientation of the sulfo group in the molecule of these compounds, and the valence state of the metal attached to the functional group. A clear illustration of this fact is a comparison of the properties of the water-soluble salt of lignosulfonic acids and the oil-soluble salt of petroleum sulfonic acids: the first sharply inhibits the flotation of sulfides, the second acts in the exact opposite.

 The studies revealed a correlation between the effectiveness of the collective action of oil-soluble sulfo compounds and their molecular weight. With an increase in the molecular weight of sulfonic acids and sulfonates, that is, with an increase in the number of carbon atoms in the alkyl chain, along with an increase in their solubility in petroleum oils and an improvement in detergent-dispersant properties (Sadykhov K.I. et al. Sulfonate additives, 1982, p. 6 ), the collective activity of “red” sulfo compounds is noticeably enhanced.

 It was experimentally established that the use of oil-soluble sulfonic acids and alkaline earth metal sulfonates in combination with a sulfohydryl collector and a depressant of the indicated combination of reagents on the selectivity of pentlandite flotation turns out to be much larger than might be expected with their additive action.

 The effect of selective activation of pentlandite in this process is apparently due to the displacement of depressor ions from its surface due to more energy-efficient sorption of oil-soluble sulfo compounds and the formation of hydrophobic coatings (substrates) at these sites, which ensure effective and durable fixation of the sulfhydryl collector. For intergrowths with a high surface content of pentlagdite, the activation effect of sulfo compounds overlaps the effect of the hydrophilizing effect of a depressor sorbed by exposed areas of pyrrhotine sulfides. Thus, the resulting hydrophobicity of the surface of a polymineral particle and, therefore, the probability of its transition into a foam product is determined by the ratio of activating, depressing and collective effects. The balance of these effects is achieved by the associated regulation of the costs of the collector, depressor and sulfur-containing additives.

 Studies of the selective flotation of pentlandite from a wide range of pyrrhotite-containing materials, carried out at various cost ratios of the indicated combination of reagents, showed that, with an independent change in the consumption of “red” sulfonic acids and sulfonates, the process indicators are noticeably inferior to the prototype.

According to experimental data, the range of optimal ratios of reagents depends on the type of pyrrhotin sulfide depressant used. Regardless of the nature and chemical-mineralogical composition of the enriched pentlandite-containing raw materials, the best flotation performance is achieved with the following weight ratios of sulfhydryl collector, oil-soluble sulfo compound and pyrrhotine depressant:
when using calcium hydroxide as a depressant of pyrrhotite, from 1: 0,0003: 2 to 1: 0,0035: 25, respectively;
when using the alkali salt of dithiocarbamic acid as a depressant of pyrrhotite from 1: 0.0001: 0.5 to 1: 0.0015: 10;
when using a urea-formaldehyde resin from 1: 0,0002: 6 to 1: 0,003: 14 as a pyrrhotine depressant.

 Outside of these ranges, the results of using the proposed method are sharply reduced. When the ratio of the reagents is lower than the lower limit, the quality of the nickel concentrate deteriorates compared with the prototype while increasing the effective consumption of sulfhydryl collector. When the ratio of the reagents is above the upper limit, the extraction of pentlandite in the nickel concentrate decreases, while it is diluted with pyrrhotite sulfides. In addition, with an increased consumption of oil-soluble sulfo compounds, difficulties arise in the separation of minerals in the cycle of subsequent pyrrhotite flotation and the problem of closed technological water circulation is aggravated.

In the proposed method, oil-soluble sulfonic acids can be used independently in the form of a refined concentrate or as part of a sulfonated oil product with an initial molecular weight of at least 400 units Heavy distillate oils, motor fuels for slow-moving parts (according to GOST 1667-68 of the grades DT and DM) can serve as raw materials for the production of “red” sulfonic acids; fuel oil diluted with fuel distillates, etc. In the conditions of metallurgical production for the sulfonation of hydrocarbon products, it is rational to use contact gases of plants for producing sulfuric acid (5-7 vol.% SO ₃ ) or "strong" process gases of melting units, for example, gases of the Vanyukov furnace, after catalytic oxidation of sulfur dioxide to SO ₃ .

 Oil-soluble sulfonates of alkaline earth metals are preferably used in the form of industrially produced detergent-dispersant additives for motor oils, for example, SB-3 (GOST 10534-78); PMS (calcium, GOST 12418-66); PMS (barium, TU 38101574-75); SK-3 (TU 39101111-71); S-300 (TU 38101444-74); DP-4 (TU 0257-003-013230476-94) and others. The table shows the results of flotation using two samples of sulfonate additives as a sulfur-containing organic additive: SB-3 and DP-4. Additive SB-3 (barium sulfonate) is a barium salt of sulfonic acids obtained by selective purification of diesel oil. Additive DP-4 is a concentrate of oil-soluble calcium sulfonates obtained on the basis of heavy oil distillate.

 In the proposed method, alkaline earth metal sulfonates can also be used as part of marketable petroleum products, for example, as part of motor oils (GOST 17479-72) used to lubricate internal combustion engines. Of these, group D oils are most preferred, for example M-8D; M-10D; M-20D and others containing up to 20% sulfonate additives.

 Given the high cost and scarcity of all types of motor oils in the proposed method, spent oil products of the IMO group (used motor oils used in accordance with OST 21046-86) containing an increased percentage of sulfonate additives can be used as a carrier of oil-soluble sulfonates.

где: R и R₁ - углеводородные радикалы;
М - К⁺ или Nа, применяемых для депрессии флотации пирротинсульфидов, наиболее доступным является диметилдитиокарбамат натрия (ДМДК), получаемый при взаимодействии аминов, сероуглерода и натриевой щелочи.Among the alkali salts of dithiocarbamic acid of the general formula

where: R and R ₁ are hydrocarbon radicals;
M - K ⁺ or Na, used for depression of flotation of pyrrhotine sulfides, the most accessible is sodium dimethyldithiocarbamate (DMDK), obtained by the interaction of amines, carbon disulfide and sodium alkali.

 Using the proposed method will provide the greatest effect in the selective flotation of "resistant" pentlandite-containing materials, characterized by an increased content of fine sludge, as well as in the flotation of coarse polymineral aggregates and large grains of recoverable minerals. Objects of this kind are refractory finely disseminated, easily slurry ores; sulphide ore dressing sludge; sulfide copper-nickel ores with fine intergrowth of pentlandite and pyrrhotite sulfides and other materials.

 Information on the use of petroleum oil-soluble sulfonic acids and / or petroleum oil-soluble sulfonates of alkaline earth metals in the selective flotation of pentlandite in an alkaline medium from materials containing pyrrhotite sulfides has not been identified in the study of patent and scientific literature.

 It is known to use oil-soluble sulfonic acids and / or their salts, alkaline earth metal sulfonates, when they are in a mass ratio with a sulfhydryl collector (0.005-0.10: 1 for collective flotation of sulfides in acidic and neutral media from polymetallic iron-containing materials (Application for RF Patent N 95110951 / 03, CL B 03 D 1/02, positive decision of 16. O1.97) However, this feature is not identical to the proposed one, since collective flotation processes in which naturally hydrophobic minerals (heavy sulfides metals and elemental sulfur) are separated from purely hydrophilic components (hydrated iron oxides, aluminosilicates, silica, sulfates, etc.), significantly differ from selective flotation processes. In the latter case, two (or more) hydrophobic minerals are separated and the process is based on differences in rates flotation of shared components, while the necessary degree of process selection is achieved through the use of a depressant reagent. The total result of the action of an organic sulfur-containing additive and the depressant reagent used cannot be predicted in advance. It was also established that, in the case of collective flotation, oil-soluble sulfo compounds play the role of an additional collector, while in selective flotation the same sulfo compounds play the role of an activating modifier that eliminates the excessive effect of the depressant reagent and promotes efficient and durable sorption of the sulfhydryl collector on the surface of the recoverable mineral (pentlandite). Thus, the combination of conditions inherent in the known method of collective flotation, including the combination and ratio of the reagents used, are significantly different from the proposed method.

 Selective flotation methods are also known in which water-soluble sulfur-containing compounds are used as process modifiers; thiourea, cellulose sulfate, cellulose ethanesulfonate, cellulose sulfite liquor, lignosulfonates, carbosulfite, as well as polymers of vinyl or allyl sulfonic acids and / or their salts (Shubov L.Ya., Ivankov S.I. Shcheglova N.K. Flotation reagents in mineral processing processes. - M .: Nedra, 1990, book 1, pp. 23-26, 327). All of these reagents are modifiers (regulators) of the depressing effect. Their addition to the pentlandite flotation process dramatically reduces the extraction of nickel in the concentrate of the same name.

где R = C_nН_2n-1,
n = O - 4,
три(сульфометил)амин типа

где Х - Н - металл или его соли
и др. аналоги (там же, с. 315-340). Использование модификаторов данной группы в процессе селективной флотации пентландита не обеспечивает положительного эффекта.It is known to use water-soluble sulfur-containing activating modifiers in the flotation of non-sulfide ores. These include compounds of the type

where R = C _n H _2n-1 ,
n = O - 4,
tri (sulfomethyl) amine type

where X - H is a metal or its salts
and other analogues (ibid., pp. 315-340). The use of modifiers of this group in the process of selective flotation of pentlandite does not provide a positive effect.

 Thus, the proposed method fully meets the criterion of "inventive step".

 The method is as follows.

 The pulp of the initial pentlandite-pyrrhotite material is subjected to preliminary alkaline treatment with a pyrrhotite sulfide depressor, conditioned with a sulfhydryl collector and a blowing agent, oil-soluble sulfonic acids and / or salts of their alkaline earth metals are introduced and floated to isolate pentlandite into a selective nickel concentrate foam product. Pyrrhotine sulfides and gangue components remain in the chamber product, which is the nickel flotation tailings.

 Depending on the technological structure of the processing and metallurgical complex, the characteristics of the genesis and chemical-mineralogical composition of the raw materials; texture and structural features, the proximity of the flotation properties of the shared minerals; oxidation state; fortresses; isomorphism; the ratio of useful components; the nature of the accompanying rock and other mineral and technological factors, lime, alkali salts of dithiocarbamic acid, urea-formaldehyde resin, as well as other selective depressants of pyrrhotite and their various combinations can be used as a depressor of pyrrhotite sulfides.

 As the sulfhydryl collector, various xanthates (butyl, amyl, hexyl, isobutyl, isopropyl), aeroflot (dialkyl or diaryldithiophosphates) and their various combinations can be used. Due to the fact that oil-soluble sulfo compounds and their products are characterized by a high viscosity index, the proposed method provides for the mixing of sulfonic compounds (acids, alkaline earth salts) with organic diluents. As diluents, low-boiling oil distillates (gasoline, kerosene, diesel fuel), natural gas condensate and products of its distillation, as well as mixtures of distillate and residual oil products, for example, motor and liquid fuel boiler fuels, can be used. The choice of diluent is determined by the specific conditions of the enrichment process and its availability. Sulfo compounds, their mixtures with a diluent, as well as sulfa-containing oil products are used in the form of aqueous emulsions, which greatly enhances the effectiveness of their activating effect.

The costs of the reagents introduced into the pulp — a sulfhydryl collector, an oil-soluble sulfo compound, and a pyrrhotine depressant — depend on the type of the latter and correspond to the following mass ratios, respectively:
when pyrrhotite is depressed by calcium hydroxide from 1: 0,0003: 2 to 1: 0,0035: 25;
when pyrrhotite is depressed with the alkaline salt of dithiocarbamic acid from 1: 0.0001: 0.5 to 1: 0015: 10;
when pyrrhotite is depressed with a urea-formaldehyde resin from 1: 0,0002: 6 to 1: 0,003: 14.

 Depending on the characteristics of flotation, the supply of sulfonic compounds can be concentrated and fractional, simultaneous with the supply of sulfhydryl collector and another. The amount of reagents introduced into the pulp in each case is selected experimentally, focusing on the quality of the resulting selective nickel concentrate and tails.

 The nickel concentrate obtained as a result of flotation is sent to pyrometallurgical processing. Pyrrhotite (nickel-pyrrhotite) concentrate processed by autoclave-hydrometallurgical technology and dump tailings are separated from the chamber product of the nickel cycle by flotation. It is possible to process the nickel flotation chamber product in a three-product scheme, in which nickel-pyrrhotite concentrate, low-nickel pyrrhotite product and tails are obtained. The last two are combined and sent to storage and tailing.

 Flotation products are subjected to volumetric and weight measurements, tested and analyzed. Based on the results of analyzes and measurements, the material balance of the process is calculated.

 The proposed method is described in specific examples, and its result is shown in the table.

 The experiments were carried out on an industrial pulp, which is a chamber product of copper flotation, obtained in the enrichment cycle of copper-nickel pyrrhotite-containing ore at the PSC of JSC Norilsk Combine. Product composition,%: nickel 2.81-2.84, copper 1.26-1.27, cobalt O, 139-O, 141, iron 43.9-44.3, sulfur 25.1-25.5, pentlandite 8.6-8.7, chalcopyrite 3.6-3.7, pyrrhotite 53.8-54.0, magnetite 4.7-4.8, rock 28.9-29.1, total platinum metals (Pt + Pd + Ph) 8.85-8.97 g / t. The source ore was pre-ground to 83% grade minus 44 microns.

 Example 1 (experiment 1 of the table) - implementation of the prototype method.

A sample of copper flotation tails was loaded into a laboratory flotation machine of a mechanical type with a capacity of 1, О dm ³ and treated with lime (6O% CaO _act ) with stirring without aeration at a flow rate of 14 ° g / t for 1O min. Then, a mixture of dibutyl dithiophosphoric allyl ester (DBFE) and dibutyl dithiophosphate (DBP) was introduced into the pulp at a ratio of O, O9, respectively: 1. Consumption of DBFE 1.5 g / t; DBP 27.5 g / t. The pulp was conditioned with stirring for 5 minutes, after which the product was aerated for 1 minute and conditioned for 1 minute with fractionally charged 7O g / t butyl xanthate and 40 g / t T-8O blowing agent. The pulp treated with reagents was subjected to selective flotation at a pH of 1O, 4 and an air flow rate of 1 dm ³ / min • dm ^{3 of} pulp, releasing pentlandite into a foam product - selective nickel concentrate. The flotation time was 30 minutes.

 The efficiency of the reagent flotation regime was evaluated by the chemical composition of the products obtained, the level of extraction of valuable metals in nickel concentrate, and the consumption of sulfhydryl collector.

 The results of the experiment are shown in the table. Extraction of valuable metals in nickel concentrate amounted to,%: nickel 62.4; copper 74.9; the amount of platinum metals is 58.5. Nickel concentrate contains: nickel 7.21%; copper 3.90%; the amount of platinum metals is 21.40 g / t.

 Example 2 (experiment 2 tables) - the proposed method.

The composition of the feed and equipment are the same as in Example 1. The difference is that the weighed tailings of copper flotation were initially treated with lime (60% CaO _act ) at a rate of 1400 g / t for 10 min, after which the pulp was conditioned without aeration butyl xanthate and T-80 blowing agent at their rates of 60 g / t and 40 g / t, respectively, for 1 min. A pre-prepared aqueous emulsion of a 5% solution of oil-soluble sulfonic acids in gas-condensate diesel fuel of the FGD brand was introduced into the treated pulp and mixed without aeration for 5 minutes. The mass ratio of butyl xanthate, oil-soluble sulfonic acids and calcium hydroxide was 1: 0.002: 14. The flotation parameters are the same as in example 1.

The extract of petroleum oil-soluble sulfonic acids used in the experiment was obtained by a known method (Schekhter Yu.N., Krein SZ, Teterina LN Oil-soluble surfactants. - M .: Chemistry, 1978, p. 96-116) sulfonation of diesel oil M-II with gaseous sulfur trioxide. For sulfonation, industrial contact gas of the Norilsk MMC Copper Plant was used, containing, vol.%: SO ₃ 4-5, SO ₂ O, 5-O, 6; O ₂ 10-15; the rest is nitrogen. The extract contained about 90% red sulfonic acids.

 The results of the experiment are presented in the table. The combination of sulfhydryl collector, sulfonic acids and calcium hydroxide at a selected ratio of their costs ensured a high level of target extraction of non-ferrous and noble metals for this process,%: nickel 67.5; copper 79.3; the amount of platinum metals is 63.4. At the same time, the quality of nickel concentrate in comparison with the prototype did not deteriorate, the content of valuable metals in it was: nickel 7.27%; copper 3.83%; the amount of platinum metals is 21.62 g / t.

 Example 3 (experiment 4 tables) - the proposed method.

 The starting food, equipment, and enrichment conditions for the material are the same as in Example 2. The difference is that barium sulfonate extract was used as the oil-soluble sulfo compound.

 The consumption of butyl xanthate was 55 g / t solid in the feed; the mass ratio of xanthate, barium sulfonates and calcium hydroxide is 1: 0.0035: 25, respectively.

 The extract of oil-soluble barium sulfonates was isolated from the SB-3 grade sulfonate additive (GOST 10534-78) by chromatographic method. The work was carried out according to the standard methodology used for analysis in the sulfonate additives of the mass fraction of the active substance (Clause 3 of GOST 10534-78 "Sulfonate additive SB-3"). The calculated amount of the obtained extract (mass fraction of the active substance 90%) was mixed with diluent-gas condensate diesel fuel brand "FGD" in a ratio of 1:20, respectively. The mixture was introduced into the pulp in the form of an aqueous emulsion obtained in a special agitator.

 At the same time, the extraction of valuable metals in nickel concentrate amounted to,%: nickel 68.2; copper 80.1; the amount of platinum metals is 64.2. The quality of the concentrate obtained indicates a high level of process selection; the concentrate contained: nickel 7.26%; copper 3.82%; the amount of platinum metals is 21.58 g / t.

 Example 4 (experiment 10 of the table) - the implementation of the prototype method.

 similar nutrition, equipment and conditions of flotation concentration of the material are the same as in example 1.

 The only difference is that the alkali salt of dithiocarbamic acid, sodium dimethyldithiocarbamate (DMDK), introduced into the pulp in the amount of 550 g / t solid in nutrition was used as a pyrrhotine depressant. The consumption of butyl xanthate was 140 g / t, BDE 6.2 g / t, DBP 68.5 g / t (ratio of DBFE: DBP = 0.09: 1).

 Pentlandite flotation was carried out in an alkaline medium at pH 10.2. The alkalinity of the pulp was provided by the addition of lime, which in this process (in combination with DMDK) mainly played the role of a medium regulator.

 Extraction of valuable metals in selective nickel concentrate amounted to,%: nickel 64.7; copper 58.1; the amount of platinum metals is 67.9. The composition of the obtained concentrate,%: nickel 12.66%; copper 5.12%; the amount of platinum metals is 42.47 g / t.

 Example 5 (experiment II of the table) - the proposed method.

 The feed, equipment and conditions of flotation concentration of the material are the same as in example 4.

 The only difference is that an oil-soluble sulfo compound was additionally introduced into the pulp, which was used as calcium sulfonates in the detergent-dispersing sulfonate additive of the DP-4 grade according to TU 0257-003-13230476-94 (mass fraction of active substance 26%). The consumption of the additive was 0.34 g / t, which corresponded to the consumption of calcium sulfonates of 0.088 g / t of solid pulp. A selected aliquot of the additive was mixed with a diluent (diesel DTN fuel) in a ratio of 1:20 and a 5% aqueous emulsion was prepared from the mixture. Butyl xanthate with a flow rate of 110 g / t was used as sulfhydryl collector, and DMDK reagent added in an amount of 550 g / t was used as a pyrrhotine depressant. The reagents were introduced into the pulp one at a time: initially DMDK, then xanthate and only 2 minutes after the conditioning of the pulp with xanthate began - the emulsion of the additive DP-4. The mass ratio of xanthate, calcium sulfonates and DMDC was 1: 0,0008: 5.

 Pentlandite flotation was carried out at a pulp pH of 9.8 using technical lime as a medium regulator.

 In this experiment, a rich nickel concentrate with a nickel content of 13.10% was obtained; copper 5.31%; amounts of platinum metals 43.80 g / t. The concentrate is recovered,%: nickel 69.7; copper 63.2; the amount of platinum metals is 73.9.

 Example 6 (experiment 17 of the table) - the implementation of the prototype method.

 The experimental conditions, including the initial power, equipment, the pulp preparation mode of the material and the selective flotation mode are the same as in example 1.

 The experience is that a urea-formaldehyde resin (CFS) with a flow rate of 800 g / t solid feed was used as a pyrrhotine depressant. The consumption of butyl xanthate was 100 g / t; DBFE 4.5 g / t. DBP 48.2 g / t (ratio of DBFE: DBP = 0.093: 1). The amount of lime added (medium regulator) provided a pulp pH of 10.6.

 During the flotation of the material treated with the reagents, the nickel concentrate was recovered,%: nickel 58.5; copper 49.0; the amount of platinum metals is 61.2. The concentrate contains: nickel 11.46%; copper 4.32%; the amount of platinum metals is 37.87 g / t.

 Example 7 (experiment 18 of the table) - the proposed method.

 The experimental conditions are the same as in example 6.

 The difference lies only in the fact that when preparing the feed for selective pentlandite flotation, an oil-soluble sulfonic compound — red sulfonic acids — obtained by treating DT motor fuel according to GOST 1667-68 (molecular weight 450 cu) was additionally introduced into it gas. The method of sulfonation of motor fuel, the equipment and composition of the contact gas are similar to Example 2. The mass ratio of sulfonating agent in terms of sulfur trioxide to the processed product was 1: 25. The obtained sulfonic acids were introduced into the conditioning process as part of sulfonated fuel (mass fraction of active substance 20%). The product, taken in an amount of 0.64 g / t based on O, 128 g of sulfonic acids per 1 ton of solid feed pulp, was preliminarily mixed with a diluent — diesel FGD in a ratio of 1:10, after which the mixture was emulsified and added to the treated pulp. 2 minutes after the addition of sulfonic acids, butyl xanthate was introduced into the pulp in an amount of 80 g / t solid pulp. The mass ratio of xanthate, oil-soluble sulfonic acids and CFS in this example was 1: 0.0016: 10.

 Alkalinity of the pulp during flotation was regulated by the addition of lime, providing a pH of 10.4.

 In this experiment, the extraction of valuable metals in Nickel concentrate amounted to,%: Nickel 63.5; copper 56.2; the amount of platinum metals is 66.7. The concentrate contained: nickel 11.82%; copper 4.73%; the amount of platinum metals is 39.36 g / t.

 The table shows examples that differ in the nature of the sulfo compounds used and their organic diluent, the type of reagent depressant pyrrhotite, as well as the ratio of sulfhydryl collector, sulfo compounds and depressor pyrrhotite.

 According to the obtained experimental results (experiments 2-4, 7-9, 11-13, 16, 18-20), the proposed method provides high extraction of non-ferrous and platinum metals in selective nickel concentrate, regardless of the nature of the applied pyrrhotite depressor. At the same time, the quality of the nickel concentrate is improved and the consumption of the sulfhydryl reagent-collector is reduced.

 Comparison of the results of experiments 3,7-9, 11-13, 16, 18, 19 with the results of experiments 2, 4, 20 of the table shows that oil-soluble sulfonic compounds work equally well as part of marketable petroleum products (motor oils, dispersant-dispersant additives, sulfonated fuel), and in a free state - in the form of concentrated extracts of "red" sulfonic acids and alkaline earth metal sulfonates.

 From the point of view of the economics of the flotation process and the provision of consistently high technological results, the most rational is the use of sulfonate detergent-dispersant additives, which are distinguished by their availability, manufacturability and stability of the material composition. As diluents, it is preferable to use gas condensate and petroleum distillates or mixtures thereof.

 Analysis of the results shows that the use of the proposed method for the selective flotation of pentlandite from pyrrhotite-containing materials, in comparison with the prototype (op. 1, 10, 17), allows for an optimal ratio of sulfhydryl collector, oil-soluble sulfo compounds and pyrrhotine depressant to increase the recovery of nickel in nickel concentrate 5.0-5.3%; copper by 4.4-7.2%; the amount of platinum metals at 4.9-6.2%. At the same time, the consumption of sulfhydryl collector (xanthogenate) is reduced by 15-20% without reducing the quality of the resulting concentrate.

 The proposed method is most effective when using oil-soluble sulfo compounds in combination with a strong depressor of pyrrhotite, in particular with DMDC. This confirms the mechanism of the activation effect of sulfo compounds on the surface of pentlandite, which eliminates the excess inhibitory effect of even such powerful depressant reagents as alkaline salts of dithiocarbamic acid or acid salts of the product of the condensation of dicyandiamide with formaldehyde (DCS), etc., that are equal in strength to them.

 Blank experiments conducted with the addition of diluents without an oil-soluble sulfo compound, ceteris paribus, showed lower results than in the experiments according to the prototype method. This indicates an insignificant inherent effect of the diluent sulfo compounds on the performance of selective flotation.

Symbols and accepted abbreviations:
FGD - gas condensate diesel fraction (diluent of sulfonic compounds and products containing them);
SB-3 - brand of barium sulfonate additive;
DP-4 - a brand of calcium sulfonate additives;
MT - motor fuel of the DT brand according to GOST 1667-68 (diluent of sulfo compounds and raw materials for the production of oil-soluble sulfonic acids);
DTN - diesel oil of brand "Z" according to GOST 305-82 (diluent of sulfonic compounds and products containing them);
M-20D is a brand of motor oil according to GOST 17479-72 (contains 20% by weight of the sum of calcium and barium sulfonates);
MMO - used motor oils in accordance with GOST 21046-86 (contain 12 wt.% Oil-soluble barium calcium sulfonates);
DMDK - dimethyldithiocarbamate (pyrrhotine depressor);
KFS - urea-formaldehyde resin (pyrrhotine depressant);
tails - a chamber product of selective flotation of pentlandite;
DBFE - allyl dibutyl dithiophosphoric acid ester;
DBP - dibutyl dithiophosphate (butyl aeroflot) a

Claims (6)

 1. The method of selective flotation of pentlandite in an alkaline medium from materials containing pyrrhotin sulfides, including treating the pulp of the material with a pyrrhotite depressant, conditioning with a sulfhydryl collector and blowing agent, introducing an organic sulfur-containing additive and isolating pentlandite into a foam product - selective nickel concentrate, characterized in that as organic sulfur-containing additives use oil-soluble sulfonic acids and / or salts of sulfonic acids - oil-soluble alkaline earth sulfonates metals.  2. The method according to claim 1, characterized in that the organic oil-soluble sulfonates of alkaline earth metals are used in the form of detergent-dispersant additives to base lubricating oils or as part of marketable petroleum products containing them.  3. The method according to claim 1, characterized in that the organic oil-soluble alkaline earth metal sulfonates are used in the composition of used automobile oils.  4. The method according to one of claims 1 to 3, characterized in that calcium hydroxide is used as a pyrrhotine depressant in a weight ratio of sulfhydryl collector, organic sulfur-containing additive and calcium hydroxide from 1: 0,0003: 2 to 1: 0,0035: 25.  5. The method according to one of claims 1 to 3, characterized in that the alkali salts of dithiocarbamic acid are used as the pyrrhotine depressant at a weight ratio of the sulfhydryl collector of the organic sulfur-containing additive and the alkaline salt of dithiocarbamic acid from 1: 0.0001: 0.5 to 1 : 0.0015: 10.  6. The method according to one of claims 1 to 3, characterized in that a urea-formaldehyde resin is used as a pyrrhotine depressant with a weight ratio of sulfhydryl collector, organic sulfur-containing additive and urea-formaldehyde resin from 1: 0,0002: 6 to 1: 0.003: 14.

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