阅读说明：本技术 一种提取湿法炼锌硫渣中单质硫的混合溶剂及其应用 (Mixed solvent for extracting elemental sulfur in wet-process zinc-smelting sulfur slag and application thereof ) 是由 曾纪斌 于 2019-09-10 设计创作，主要内容包括：本发明公开了一种提取湿法炼锌硫渣中单质硫的混合溶剂及其制备方法和应用。该混合溶剂质量比为m<Sub>四氯乙烯</Sub>:m<Sub>全氟辛烷(The invention discloses a mixed solvent for extracting elemental sulfur from wet-process zinc-smelting sulfur slag, and a preparation method and application thereof. The mass ratio of the mixed solvent is m Tetrachloroethylene :m Perfluorooctane And (5) =10: 0.6-2.4. The mixed solvent has the following advantages and effects: the mixed solvent is non-explosive, low in toxicity and not easy to volatilize, meets the requirement of safe production, has a metal salt extraction rate in the sulfur slag smaller than that of tetrachloroethylene, and can obtain elemental sulfur with higher purity. The solvent is used for extracting elemental sulfur in the wet-process zinc-smelting sulfur slag, so that the solvent is basically not lost in a closed container environment, and the solvent has a good industrial application prospect.)

1. Mixing method for extracting elemental sulfur from wet-process zinc smelting sulfur slagA solvent characterized by: the mixed solvent comprises tetrachloroethylene and perfluorooctane, and the mass ratio of the tetrachloroethylene to the perfluorooctane is m_{Tetrachloroethylene}: m_{Perfluorooctane}= 10 : 0.6~2.4。

2. The preparation method of the mixed solvent for extracting the elemental sulfur from the wet-process zinc smelting sulfur slag as claimed in claim 1, characterized by comprising the following steps: adding tetrachloroethylene into a closed container, heating to 65-75 ℃ in a gradient manner, adding perfluorooctane particles while stirring, and continuing to stir after the addition to obtain the mixed solvent.

3. The method of claim 2, wherein:

adding tetrachloroethylene into a stainless steel closed storage tank, heating to 70 ℃, wherein the heating speed is 10 ℃/min, then starting stirring, the stirring speed is 50-70rpm, slowly adding perfluorooctane particles of 50-150 meshes, continuing stirring at 50-70rpm for 1-3 h after the addition, and stopping stirring to obtain the mixed solvent.

4. The application of the mixed solvent for extracting elemental sulfur from the wet-process zinc-smelting sulfur slag according to claim 1 in the extraction of the elemental sulfur from the wet-process zinc-smelting sulfur slag is characterized in that: pumping the prepared mixed solvent into a closed extraction tank, starting stirring, feeding the mixed solvent into the zinc hydrometallurgy sulfur slag, enabling the mixed solvent and the zinc hydrometallurgy sulfur slag to be in stirring contact for 10-30 min, pumping the mixed solvent into a filter tank, filtering the mixed solvent while the mixed solvent is hot, heating the mixed solvent to 110-130 ℃, emptying filter residues, and enabling the filtered filtrate to enter a low-temperature crystallization tank at the temperature of 60-80 ℃ to obtain elemental sulfur.

5. Use according to claim 4, characterized in that: recovering the mixed solvent for recycling; and (5) filtering and recovering the supernatant for recycling.

6. Use according to claim 4, characterized in that: the mass ratio of the wet-process zinc smelting sulfur slag to the mixed solvent is m_{Wet zinc smelting sulfur slag}: m_{Mixed solvent}=1:8~9。

7. Use according to claim 4, characterized in that: sealing the extraction tank and the filter tank and keeping the temperature in the middle to 90 ℃; the wet zinc-smelting sulfur slag is 200 meshes, the water content is 15-25%, and the feeding is spiral feeding.

8. Use according to claim 4, characterized in that: the filter screen for hot filtration is 300 meshes.

Technical Field

The invention belongs to the field of circular economy, relates to a mixed solvent for extracting elemental sulfur in sulfur slag, and preparation and application thereof, and particularly relates to a mixed solvent for extracting elemental sulfur in wet-process zinc-smelting sulfur slag, and preparation and application thereof.

Background

With the increasing exhaustion of non-ferrous metal mineral resources, some low-grade sulphide ores must be treated by a hydrometallurgical process. The method for recovering sulfur in leaching residues of zinc hydrometallurgy mainly comprises a flotation method, a vacuum distillation method, a high-pressure decantation method, a thermal filtration method, a flotation method, an amine sulfide method, a granulation screening method, a furfural sulfur extraction method, a solvent method and the like (Lizhenhua, experimental research on recovery of elemental sulfur from leaching residues of zinc blende by oxygen pressure acid leaching, university of Kunming theory of technology, Master's paper, 2008). The flotation method does not need complex equipment, can treat ore pulp containing a large amount of unreacted sulfides, and is widely applied to industrial production at present, and has the defects that the recycled sulfur has low taste and can only play a role in enrichment; the cost for recovering the elemental sulfur by the vacuum distillation method is highThe preparation requirement is complex, and the industrialization is difficult to realize; the sulfur recovered by adopting the decantation method has low quality because the unreacted metal sulfide is also melted in the sulfur, and the sulfur is partially oxidized by oxygen in the air, so the recovery rate is influenced to a certain extent; the hot filtration method has the defects that the required equipment is complicated, and the residual sulfur in the filter residue is more; the flotation method does not need complex equipment, can process ore pulp containing a large amount of unreacted sulfides, and has the defects that the grade of the recovered sulfur is low, and only the sulfur enrichment effect can be realized, and in addition, some valuable metals are also included in the sulfur enrichment; the disadvantage of the amine sulfide method is that the noble metal is soluble in polysulfide to generate complex, which results in the loss of noble metal, the recovered sulfur contains a large amount of sulfide and has low purity, so the process condition must be strictly controlled to improve the recovery rate; the furfural sulfur extraction method is still in the laboratory research stage at present; the principle of the granulation screening method is that S is contained⁰After the materials are heated and quenched, elemental sulfur forms sulfur granules with larger granules, and then screening and recycling are carried out, so that the process is difficult to master, and the quality of the obtained sulfur is not high; the organic solvent method is to utilize the law that the solubility of the element sulfur in the organic solvent changes with the temperature, dissolve the element sulfur from the sulfur-containing material, after making the element sulfur separate from material, extract sulfur from the organic phase, the organic solvent that can dissolve the element sulfur is many in variety, mainly there are carbon disulfide, kerosene, methylbenzene, xylene, carbon tetrachloride, etc., the advantage of this method is that the recovery rate of sulfur is high, the purity is high, the organic solvent can be reused; the disadvantages are that the organic solvent is easy to volatilize and the requirement on the sealing property of the equipment is high.

Chinese patent (publication No. CN104195344A) discloses a method for recovering sulfur, lead, zinc and silver by ultrasonic strengthening of oxygen-enriched direct leaching slag of zinc concentrate or lead-zinc mixed ore: taking tetrachloroethylene or trichloroethylene as a solvent, carrying out ultrasonic wave strengthening on the zinc concentrate or lead-zinc mixed ore oxygen-enriched direct leaching slag pretreated by drying, grinding and screening to extract elemental sulfur in the slag, carrying out heat preservation and filtration, naturally cooling and forcibly cooling the filtrate, then filtering to obtain a sulfur product, and returning the regenerated sulfur extracting agent to the sulfur extraction process; the zinc, lead and silver in the filter residue are enriched, the filter residue can be directly sent to a lead system to recover the zinc, lead and silver, or the filter residue is sent to the lead system to recover the lead and silver after the zinc is leached and recovered, and the zinc-containing filtrate is returned to the direct leaching system.

Chinese patent (publication No. CN104229745A) discloses an ultrasonic extraction method and a process for treating slag containing elemental sulfur, wherein the ultrasonic extraction method comprises the following steps: one or a mixture of more of tetrachloroethylene, trichloroethylene, toluene and xylene is used as a solvent to carry out ultrasonic extraction on the ore slag containing the elemental sulfur, the frequency of ultrasonic wave is 20-200KHz, and the sound intensity is 2.0-50w/cm²。

However, the two patents need to use ultrasound, the requirement of industrial production equipment is complex, the ultrasound easily causes the local temperature of the organic solvent (tetrachloroethylene or trichloroethylene) to be too high to cause explosion, and the solvent is seriously volatilized, so that the two patents are not suitable for industrial application. Therefore, there is a need for improvements in the prior art.

Disclosure of Invention

The invention aims to provide a mixed solvent for extracting elemental sulfur from wet-process zinc-smelting sulfur slag.

The technical scheme provided by the invention is as follows: a mixed solvent for extracting elemental sulfur from wet-process zinc-smelting sulfur slag comprises tetrachloroethylene and perfluorooctane, wherein the mass ratio of tetrachloroethylene to perfluorooctane is m_{Tetrachloroethylene}:m_{Perfluorooctane}＝10:0.6～2.4。

The invention also provides a preparation method of the mixed solvent for extracting the elemental sulfur in the wet-process zinc-smelting sulfur slag, which is characterized by comprising the following steps of: adding tetrachloroethylene into a closed container, heating to 65-75 ℃ in a gradient manner, adding perfluorooctane particles while stirring, and continuing to stir after the addition to obtain the mixed solvent.

In a more specific embodiment, tetrachloroethylene is added into a stainless steel closed storage tank, the temperature is raised to 70 ℃, the temperature raising speed is 10 ℃/min, then stirring is started, the stirring speed is 50-70rpm, perfluorooctane particles with 50-150 meshes are slowly added, stirring is continued at 50-70rpm for 1-3 h after the addition is finished, and then stirring is stopped, so that the mixed solvent is obtained.

The invention also provides application of the mixed solvent for extracting the elemental sulfur in the wet-process zinc-smelting sulfur slag in the extraction of the elemental sulfur in the wet-process zinc-smelting sulfur slag, which is characterized in that the prepared mixed solvent is pumped into a closed extraction tank, stirring is started, then the feed is fed into the wet-process zinc-smelting sulfur slag, the mixed solvent and the wet-process zinc-smelting sulfur slag are stirred and contacted for 10-30 min, then the mixed solvent and the wet-process zinc-smelting sulfur slag are pumped into a filter tank, then the mixed solvent is filtered when the mixed solvent is hot, the temperature is raised to 110 plus 130 ℃ after the filtering, filter residues are emptied, and the filtered filtrate enters a low-temperature crystallization.

In a preferred mode, the mixed solvent is recovered and reused; and (5) filtering and recovering the supernatant for recycling.

Preferably, the mass ratio of the zinc hydrometallurgy sulfur slag to the mixed solvent is m_{Wet zinc smelting sulfur slag}:m_{Mixed solvent}＝1:8～9。

In a preferable mode, the extraction tank and the filter tank are kept at 90 ℃ in a closed manner in the process; the wet zinc-smelting sulfur slag is 200 meshes, the water content is 15-25%, and the feeding is spiral feeding. Wherein the hot filtering screen is 300 meshes.

In a specific embodiment, the application of the mixed solvent in the recovery of elemental sulfur in the zinc hydrometallurgy sulfur slag comprises the following specific steps:

pumping a certain amount of prepared mixed solvent at 70 ℃ into a closed extraction tank (90 ℃), starting stirring at the speed of 60rpm, feeding a certain amount of 100-200-mesh zinc hydrometallurgy sulfur slag (the water content is 15-25 wt%, pre-drying is not needed, and spiral feeding plays a sealing role to prevent volatilization of the mixed solvent) through spiral feeding, stirring and contacting the mixed solvent and the zinc hydrometallurgy sulfur slag for 15-20 min, pumping into a filter tank (90 ℃), filtering while hot (a filter screen is 300 meshes), heating to 120 ℃ after filtering is finished, recovering the mixed solvent into a stainless steel closed storage tank, reusing, emptying filter residues and selling; and (3) allowing the filtered filtrate (high-temperature sulfur-containing mixed solvent) to enter a low-temperature crystallization tank (70 ℃), standing for 3h to obtain elemental sulfur, performing suction filtration on the supernatant to enter a stainless steel sealed storage tank, returning, heating the low-temperature crystallization tank to 120 ℃ after suction filtration, recovering the mixed solvent to the stainless steel sealed storage tank, returning, directly bagging the obtained elemental sulfur, and warehousing.

Wherein the mass ratio of the wet-process zinc smelting sulfur slag to the mixed solvent is m_{Wet zinc smelting sulfur slag}:m_{Mixed solvent}＝1:8～9。

The purity of the obtained elemental sulfur is more than 99.5 percent.

The filter residue does not contain a mixed solvent, and the moisture content is less than 8 wt%.

The upper layer of the stainless steel closed storage tank contains water extracted from the wet-process zinc-smelting sulfur slag, and the water can be discharged through a water outlet on the side wall of the stainless steel closed storage tank after reaching a certain amount.

The invention creatively utilizes the characteristics of the tetrachloroethylene and the perfluorooctane to compound the tetrachloroethylene and the perfluorooctane according to the similar compatibility principle. Specifically, tetrachloroethylene has a melting point of-22 ℃ and a boiling point of 121.2 ℃, and is moderately toxic, insoluble in water, soluble in absolute alcohol, and flammable; the perfluorooctane is a nontoxic and nonflammable inert liquid, has very good heat resistance, the decomposition temperature of over 800 ℃, good stability, and is degraded only by reacting with alkali metal at 400-500 ℃ to generate metal fluoride and carbon, wherein the melting point of the perfluorooctane is 65 ℃, and the boiling point of the perfluorooctane is 104 ℃. If the mixed solvent is compounded, the properties are stable, the mixed solvent is non-flammable, the toxicity is low, the mixed solvent is not easy to volatilize, the extraction rate of elemental sulfur in the wet-process zinc-smelting sulfur slag is higher than that of a single-component solvent, and the leaching of various metal salts can be reduced. Based on this, compared with the prior art, the invention has the following advantages and effects: the mixed solvent has the innovation points that the mixed solvent is non-explosive, low in toxicity and not easy to volatilize, and meets the requirement of safe production; and the extraction rate of the mixed solvent to the metal salt is less than that of tetrachloroethylene, so that the elemental sulfur with higher purity can be obtained. The solvent is used for extracting elemental sulfur in the wet-process zinc-smelting sulfur slag, so that the solvent is basically not lost in a closed container environment, and the solvent has a good industrial application prospect.

Drawings

FIG. 1 is a schematic diagram of the process of extracting elemental sulfur from wet-process zinc-smelting sulfur slag by using the mixed solvent of the invention.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Wherein the content of the first and second substances,

explosion prevention of the mixed solvent: the explosive gas environment is divided into a 0 area, a 1 area and a 2 area according to GB 3836. Wherein, the area 0 is a place where the explosive gas environment continuously appears or exists for a long time; zone 1 is a location where an explosive gas environment may occur during normal operation; zone 2 is a location where, during normal operation, an explosive gas environment is unlikely to occur, and if so, it also occurs infrequently and only for a short time.

Toxicity of the mixed solvent: testing the acute inhalation toxicity test of the mixed solvent according to GB/T21605-2008; testing the acute oral toxicity of the mixed solvent according to GB/T21603-;

volatility of the mixed solvent: according to the national standard GB/T8017 ASTM D323, the measurement is carried out by adopting an automatic saturated vapor pressure tester (Reid method);

the process of extracting elemental sulfur from the zinc hydrometallurgy sulfur slag by using the mixed solvent in the following embodiments is shown in fig. 1, and is described below by using specific examples.