RU2427529C1 - Method of extracting elementary sulphur from sulphur-containing materials - Google Patents

Abstract

FIELD: chemistry. ^ SUBSTANCE: method relates to chemistry and nonferrous metallurgy. The method involves treating starting sulphur-containing material with an extractant-solvent in form of turpentine to transfer sulphur into the solution while stirring at temperature 50-70C. The obtained pulp is filtered and the extraction solution is cooled to temperature not higher than 30C. The starting sulphur-containing material used can be sludge cake from leaching copper-zinc concentrates or anode sludge from electrolysis of sulphide alloys of nonferrous metals. The process can be realised in a closed volume. ^ EFFECT: efficient method of extracting elementary sulphur from solid sulphur-containing materials. ^ 3 cl, 2 dwg, 1 ex

Description

The invention relates to the field of chemistry, in particular, to methods for extracting elemental sulfur from solid sulfur-containing materials formed during hydrometallurgical processes of non-ferrous metallurgy.

A known method for the extraction of elemental sulfur by processing sulfur-sulfide concentrate released during sulfuric acid autoclave-oxidative leaching. The method consists in the fact that the aqueous pulp of the starting material is treated with a hydrophilizer reagent, at a temperature that ensures the melting of sulfur, preferably at 120-130 ° C, the resulting pulp is cooled and floated to produce sulfur and sulfide concentrates. The following alkaline compounds are used as hydrophilizing elements: sodium sulfide, caustic soda, lime, or a mixture thereof (Goryachkin V.I. et al. Hydrometallurgical processing of copper-nickel concentrates based on autoclave oxidative leaching, hydrometallurgy, autoclave leaching, sorption, extraction. Edited by B.N. Laskorin, Moscow: Nauka, 1976, p. 55-57).

The disadvantage of this method is that the use of lime during processing introduces sulfur emulsion stabilizers into the process, which prevent the coalescence of sulfur droplets, complicating their reformation during collisions and reducing the degree of separation of sulfur and sulfides. As a result, selectivity worsens during subsequent flotation and the quality of the resulting sulfur and sulfide concentrates decreases. The bulk of the sulfur in the sulfur concentrate (70-90%) is represented by the fineness class less than 44 microns. Subsequent melting of such a highly dispersed material is extremely unstable.

A known method of sulfur recovery by disintegration of the pulp of the source sulfur-sulfide material at a temperature above the melting point of elemental sulfur for 60 minutes in the presence of a calcium hydrophilizer reagent, in which a surfactant is added to reduce the negative effect of sulfur emulsion stabilizers. As a reagent, lime with additives of petroleum products in the amount of 0.5-3.0 kg per ton of solid feedstock is used. Next, the product is subjected to flotation with the supply of kerosene and blowing agent. Conditioned sulfuric concentrate with a sulfur content of more than 70% is fed to sulfur smelting, and sulfide concentrate with a sulfur content of not more than 5% is processed by pyrometallurgical methods (USSR Author's Certificate No. 1303549, MKI С01В 17/027, publ. 15.04.87. Bull. No. 14 )

The disadvantage of this method is that the effectiveness of reagents as destabilizers of sulfuric emulsions is insufficient and does not allow to obtain high-quality concentrates. Autoclave smelting of sulfur from concentrates with a reduced elemental sulfur content is complicated by the formation of a multiple emulsion, which reduces the quality of marketable sulfur and sharply increases the cost of processing tailings. In addition, the organic surfactants used in the process have negative side effects, reduce the grade of sulfur, causing the need for additional purification from organic impurities.

A known method of extracting elemental sulfur from a solid residue from oxidation under pressure in the processing of ores or concentrates containing non-ferrous and noble metals, with the receipt of the residue with a low content of elemental sulfur. Sulfur recovery is carried out by foam flotation of a solid residue from oxidation under pressure to obtain a rich flotacin sulfur concentrate and sulfur-depleted flotation tailings, followed by extraction of sulfur from a flotacin concentrate with a suitable extractant. In this case, the extraction is carried out at a temperature of 90-150 ° C, and kerosene and tetrachlorethylene are used as the extractant (Application for invention of the Russian Federation No. 98100309, IPC ⁶ C22B 3/08, C22B 15/00, C22B 19/00, C22B 23/00, publ. 10/27/1999 - prototype).

The method is characterized by multi-stage technological operations, the need to use sophisticated equipment, low quality of the resulting product, associated with difficulties in separating the sulfide part from the extractant. Moreover, the cost of reagents, the complexity of their regeneration, toxicity, fire and explosion hazard reduce the production capabilities of the method.

The technical result of the invention is to increase the dissolution efficiency and simplify the process of extracting elemental sulfur into a marketable product in the form of an extraction element.

The specified technical result is achieved by the fact that in the method for extracting elemental sulfur from sulfur-containing materials, comprising treating the initial sulfur-containing material with solvent extractant with the conversion of sulfur into solution, according to the invention, the sulfur-containing material is treated with turpentine at a temperature of 50-70 ° C with stirring, the resulting pulp is filtered, and the extraction solution is cooled to a temperature of not more than 30 ° C.

At the same time, leaching cakes of copper-zinc concentrates or anode slimes of electrolysis of sulfide alloys of non-ferrous metals are used as the initial sulfur-containing material, and the extraction process is carried out in a closed volume.

As follows from figure 1, the solubility of sulfur in turpentine increases with increasing temperature. Therefore, it is possible to release sulfur from the liquid phase when the system is cooled to a temperature of not more than 30 ° C.

The method is as follows.

The sulfur-containing solid product is treated with turpentine with stirring at a temperature of 50-70 ° C. Then the pulp is filtered and the extraction solution is cooled to a temperature of not more than 30 ° C. The process must be carried out at a temperature of 50-70 ° C. At higher temperatures, turpentine is degraded, and at low temperatures, turpentine's sulfur capacity decreases. In comparison with the known tetrachlorethylene turpentine is highly selective for sulfur. After saturation of turpentine in elemental sulfur, the solution is cooled, while the solubility of sulfur in turpentine is reduced. Upon cooling, sulfur is separated from the extractant (turpentine) and separated on the filter, and the remaining extraction solution is recycled to the beginning of the process.

Examples of the method

Example 1. The processing of cake from oxidative sulfuric acid leaching was carried out according to the scheme shown in figure 2. The leaching cakes of copper-zinc concentrate contained ~ 20% of the sum of Cu, Fe, Co. The main phase components of the material were elemental sulfur, sulfates of copper, zinc and iron. The total sulfur content varied from 23.3 to 66.6%, including elemental sulfur from 12.6 to 48.2%. Cake was treated with turpentine at a ratio of W: T = 4: 1 and a temperature of 50 ° C. Used gum and hydrolysis turpentine. The process was carried out in an experimental setup consisting of a thermostatically controlled beaker, a stirrer for mixing cake with extractant, and a water-cooled suction filter. The extraction was carried out for 15 minutes, then the pulp was filtered, the solution was cooled to 20 ° C and filtered. Elemental sulfur was isolated on the filter. The sulfur recovery results are shown in the table.

Table
The results of the extraction of sulfur from cake The total sulfur content in cake,% The content of elemental sulfur,% The content of sulfate sulfur,% The recovery of elemental sulfur,% one 28.3 12.6 15.7 99.6% 2 43,2 31,2 12.0 99.7% 3 66.6 48,2 18,4 99.8%

Example 2. Sulfur sulfide slurry (a mixture of sulfides of copper and nickel with elemental sulfur) of the electrolysis of copper-Nickel matte, containing,%: 2,55 Cu; 9.71 Ni; Fe 0.22; 80.0 S; 0.24 Co was leached in turpentine for 10 minutes at 70 ° C. Leaching was carried out on a thermostatic unit consisting of a glass, a mixer for mixing sludge with an extractant, and a water-cooled suction filter.

The ratio of W: T (turpentine: sludge) was 10: 1. After cooling the extractant to 30 ° C and filtering the solution, elemental sulfur was isolated. Sulfur recovery from sludge was 90.8%. The slurry after treatment with turpentine contained%: 11.3 Cu; 39.42 Ni; 2.09 Fe; 36.4 S; 1.04 Co.

The proposed method for the extraction of elemental sulfur has the following advantages:

- lack of alkali in the solvent system;

- simplicity and technological process in industrial use;

- higher dissolution efficiency.

Claims (3)

1. The method of extracting elemental sulfur from sulfur-containing materials, comprising treating the starting sulfur-containing material with solvent extractant with the conversion of sulfur into a solution, characterized in that the starting material is treated with turpentine at a temperature of 50-70 ° C with stirring, the resulting pulp is filtered, and the extraction solution is cooled to a temperature of no more than 30 ° C. 2. The method according to claim 1, characterized in that the leaching cakes of copper-zinc concentrates or the anode slimes of the electrolysis of sulfide alloys of non-ferrous metals are used as the source of sulfur-containing material. 3. The method according to claim 1, characterized in that the processing of the source material is carried out in a closed volume.

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