阅读说明：本技术 一种碱浸液中钼铼酸根选择性浮选分离的方法 (Method for selective flotation separation of molybdenum-rhenium acid radicals in alkali immersion liquid ) 是由 韩桂洪 刘兵兵 黄艳芳 王文娟 苏胜鹏 杨淑珍 薛毓斌 于 2019-11-07 设计创作，主要内容包括：本发明公开了一种碱浸液中钼铼酸根选择性浮选分离的方法,该方法是将含钼酸根和铼酸根的碱性浸出液调节pH值至7.1～12,再加入由三乙烯四胺、四乙烯五胺、甲基紫10B及椰油酰胺丙基甜菜碱组成的有机物改性活性炭捕收剂及表面活性剂,充气浮选,泡沫产品为富铼组分,余液为富钼溶液。该方法对钼铼的选择性分离效果好,工艺流程简单、成本低,特别适用于铼含量低、钼含量高的碱性浸出液中铼和钼的分离。(The invention discloses a method for selective flotation and separation of molybdenum-rhenium acid radicals in alkaline leaching solution, which comprises the steps of adjusting the pH value of alkaline leaching solution containing molybdenum acid radicals and rhenate radicals to 7.1-12, adding an organic modified activated carbon collecting agent and a surfactant, wherein the organic modified activated carbon collecting agent and the surfactant consist of triethylene tetramine, tetraethylene pentamine, methyl violet 10B and cocamidopropyl betaine, and performing air flotation, wherein a foam product is a rhenium-rich component, and the residual solution is a molybdenum-rich solution. The method has good selective separation effect on molybdenum and rhenium, simple process flow and low cost, and is particularly suitable for separating rhenium and molybdenum from alkaline leachate with low rhenium content and high molybdenum content.)

1. A method for selective flotation separation of molybdenum-rhenium acid radicals in alkali immersion liquid is characterized by comprising the following steps: adjusting the pH value of alkaline leachate containing molybdate radicals and rhenate radicals to 7.1-12, adding a modified activated carbon collecting agent and a surfactant, and performing air flotation, wherein a foam product is a rhenium-rich component, and the residual liquid is a molybdenum-rich solution;

the modified active carbon collector is prepared by the following method: finely grinding activated carbon particles to a micro-nano level, dispersing the activated carbon particles into water, adding a composite organic matter consisting of triethylene tetramine, tetraethylene pentamine, methyl violet 10B and cocamidopropyl betaine into the water, stirring for reaction, and filtering, washing and drying a reaction mixture to obtain the modified activated carbon collecting agent.

2. The method for selective flotation separation of molybdenum-rhenate in alkaline leaching solution according to claim 1, characterized in that: the composite organic matter comprises triethylene tetramine, tetraethylenepentamine, methyl violet 10B and cocamidopropyl betaine according to the mass ratio: 10-20: 20-30: 20-40: 10-20.

3. The method for selective flotation separation of molybdenum-rhenate in alkaline leach solution according to claim 1 or 2, characterized in that: the mass ratio of the activated carbon particles to the composite organic matter is 1: 0.1-1: 0.5.

4. The method for selective flotation separation of molybdenum-rhenate in alkaline leaching solution according to claim 1, characterized in that: the concentration of the activated carbon particles in water is 10 g/L-50 g/L.

5. The method for selective flotation separation of molybdenum-rhenate in alkaline leaching solution according to claim 1, characterized in that: the stirring reaction is carried out for 0.5-3 h at the temperature of not higher than 50 ℃.

6. The method for selective flotation separation of molybdenum-rhenate in alkaline leaching solution according to claim 1, characterized in that: the concentration of molybdate ions in the alkaline leaching solution containing molybdate ions and rhenate ions is 10 mg/L-30 g/L, and the concentration of rhenate ions is 5 mg/L-5 g/L.

7. The method for selective flotation separation of molybdenum-rhenate in alkaline leaching solution according to claim 1, characterized in that: the granularity of the modified active carbon collector meets the condition that the mass percentage of the modified active carbon collector is 100 percent and the specific surface area is not less than 500m ²/g。

8. The method for selective flotation separation of molybdenum-rhenate in alkaline leach solution according to claim 1, 6 or 7, wherein: the adding amount of the modified active carbon collector in the alkaline leaching solution containing molybdate radical and rhenate radical is 50 mg/L-20 g/L.

9. The method for selective flotation separation of molybdenum-rhenate in alkaline leaching solution according to claim 1, characterized in that: the surfactant is at least one of cetyl trimethyl ammonium bromide, potassium lauryl sulfate and polyoxyethylene fatty alcohol ether.

10. The method for selective flotation separation of molybdenum-rhenate in alkaline leaching solution according to claim 1 or 9, characterized in that: the addition amount of the surfactant in the alkaline leaching solution containing molybdate radicals and rhenate radicals is 20-100 mg/L.

Technical Field

The invention relates to a method for separating molybdenum-rhenium acid radicals in alkali leaching solution, in particular to a method for selectively and efficiently separating molybdenum and rhenium from alkali leaching solution by using a precipitation flotation method, and belongs to the technical field of separation of similar elements in wet metallurgy.

Background

Molybdenum and rhenium are respectively rare refractory metals and rare dispersion metals and are strategic metals which are extremely important and scarce, but the molybdenum and rhenium are extremely poor in resources, and the abundance of the molybdenum in nature is 1 multiplied by 10 ^-4(%), the abundance of rhenium was only 1 × 10 ^-7(％)。

The application of molybdenum in the steel industry is the first place, accounting for about 80% of the total molybdenum consumption, and the second place is in the chemical field, accounting for about 10%. In addition, molybdenum is also used in the fields of electrical and electronic technology, medicine, agriculture, and the like, and accounts for about 10% of the total consumption amount. Molybdenum is the most consumed in the steel field, mainly for the production of alloy steels (about 43% of molybdenum in the total consumed steel), stainless steels (about 23%), tool steels and high speed steels (about 8%), cast irons and rolls (about 6%). Molybdenum as an alloying element of steel has the following advantages: the strength and the toughness of the steel are improved; the corrosion resistance of the steel in acid-base solution and liquid metal is improved; the wear resistance of the steel is improved; improving hardenability, weldability and heat resistance of steel.

Rhenium is a rare refractory metal, has good plasticity, mechanical property and creep resistance, also has good wear resistance and corrosion resistance, and can keep good chemical inertness to most fuel gases except oxygen. Rhenium and its alloys are widely used in the fields of aerospace, electronics, petrochemical industry, etc. The high-temperature alloy is the largest consumption field of rhenium, which accounts for about 80% of the total consumption of rhenium, and the catalyst is the second largest consumption field of rhenium. As an alloy additive element, rhenium can greatly improve and enhance the performance of the alloy. Rhenium can form a series of alloys with various metals such as tungsten, molybdenum, platinum, nickel, thorium, iron, copper and the like, wherein rhenium-tungsten, rhenium-molybdenum and rhenium-nickel series high-temperature alloys are the most important alloys of rhenium and are widely applied to the industrial departments of aerospace, electronics and the like.

Rhenium is a very rare and dispersed element, mainly present in molybdenite. The high-pressure oxygen decomposition treatment of molybdenite under alkaline conditions is a method for effectively extracting molybdenum and rhenium from molybdenite. The main process conditions of the reaction process are as follows: the temperature is 130-200 ℃, the total pressure is 2.0-2.5 MPa, the reaction time is 3-7 h, and the consumption of NaOH is 1.0-1.03 times of the theoretical amount. Compared with the high-pressure oxygen decomposition process under the acidic condition, the high-pressure oxygen decomposition under the alkaline condition has high metal recovery rate, the leaching rate of molybdenum and rhenium is as high as 95-99%, and the corrosion of a reaction medium to equipment is small. The molybdenum and rhenium entering the immersion liquid can enter the next treatment procedure after being separated and purified. The existing separation method of molybdenum and rhenium in solution mainly comprises a chemical precipitation method, an ion exchange method and a solvent extraction method.

Chemical precipitation method: the common precipitation method of calcium molybdate and potassium perrhenate is used for molybdenum-rhenium pickle liquor, and calcium salt and potassium salt are added into the pickle liquor step by utilizing the solubility difference of calcium salt and potassium salt of molybdic acid and rhenic acid (the solubility of calcium molybdate is less than that of calcium rhenium and the solubility of potassium perrhenate is low) at normal temperature, so that the separation of molybdenum and rhenium is realized. Because the content of molybdenum in the pickle liquor is high, calcium chloride is added into the pickle liquor to precipitate and separate calcium molybdate, then rhenium-rich solution (the rhenium content is about 0.1g/L) after molybdenum recovery is evaporated and concentrated until the rhenium content reaches 10-30 g/L, and excessive potassium chloride is added to separate and recover rhenium. The precipitation method of calcium molybdate and potassium perrhenate has the following problems: the solubility of calcium molybdate is still as high as 0.34g/L at room temperature, the method is suitable for treating high-concentration molybdenum-rhenium immersion liquid, the selective separation effect on low-concentration immersion liquid is poor, repeated evaporation and concentration are needed, the process flow is long, and the efficiency is low.

Ion exchange method: is a method for separating molybdenum and rhenium based on the difference of selective effects of the resin on molybdenum and rhenium ions. The molybdenum and rhenium can be separated in both acidic and basic media using anion exchange resins. In acidic medium, using MoO ₄ ^2-And ReO ₄ ^-The difference of the ionic valence and the form of the molybdenum and the rhenium are separated by using anion exchange resin in a proper acidity range. In alkaline medium, molybdenum and rhenium are both present in anionic form, utilizing ReO ₄ ^-The affinity with resin is far greater than that of MoO ₄ ^2-And OH ^-Property of (2) alsoCan realize the separation of molybdenum and rhenium. The commonly used resin comprises macroporous anion exchange resin, trialkylamine extraction resin and the like, and the molybdenum-rhenium separation effect is good. The main problems and difficulties of the ion exchange method are as follows: the process flow is long, the ion exchange resin is expensive, easy to be poisoned and sensitive to pH and temperature.

Solvent extraction method: is a method for separating ions by utilizing different partition characteristics of the ions in two immiscible phases (organic solvent and water). The rhenium extraction is carried out by using a plurality of extracting agents such as amine, ketone, phosphine and quaternary ammonium salt extracting agents. Amine extractant on MoO ₄ ^2-、ReO ₄ ^-The method has good extraction effect, for example, after molybdenum and rhenium are extracted by N235, the molybdenum and rhenium-rich organic phase can be subjected to back extraction by ammonia water, molybdenum in the back extraction solution is recovered by acid precipitation, rhenium is adsorbed and recovered by 201 strong-base anion resin, and the recovery rates of molybdenum and rhenium are respectively 95% and 87%. The ketone extractant does not need a subsequent back extraction process, has remarkable advantages of extracting rhenium in an alkaline medium, but has relatively low extraction capacity (about 80 percent), for example, methyl ethyl ketone has a good selective extraction effect on rhenium, hardly extracts molybdenum, and can relatively effectively separate molybdenum and rhenium. The phosphine extractant has the characteristics of low acidity, high selectivity, easy back extraction and the like, but has smaller extraction capacity and separation coefficient. The solvent extraction method has the advantages of simple operation, strong selectivity, good separation effect and continuous operation, but the extractant is expensive, the solvent loss is more in the extraction process, and a third phase is easy to form.

The method for separating molybdenum and rhenium from the alkaline leaching solution cannot simply continue to use the method for separating molybdenum and rhenium from the acidic solution. If the method for separating the molybdenum and the rhenium acid radicals in the acidic solution is adopted, a large amount of acidic reagents are consumed for acid-base neutralization to reach the required pH value range, so that the reagent consumption is large and the cost is high. However, in the prior art, the method for separating the molybdenum-rhenium acid radicals in the alkali immersion liquid has poor selectivity to the molybdenum-rhenium acid radicals, high cost and complex flow, so that the research on the high-efficiency separation technology for the selectivity of the molybdenum-rhenium acid radicals in the alkali immersion liquid has very important significance for the green sustainable development of the molybdenum industry in China.

Disclosure of Invention

Aiming at the problems of poor selectivity, high cost and complex flow in the separation of molybdenum-rhenium acid radicals in alkaline solution in the prior art, the invention aims to provide a method for efficiently and selectively separating molybdenum-rhenium in alkaline leachate by a flotation method.

In order to achieve the technical purpose, the invention provides a method for selectively floating and separating molybdenum-rhenium acid radicals in alkali leaching solution, which comprises the steps of adjusting the pH value of the alkali leaching solution containing the molybdenum acid radicals and rhenate radicals to 7.1-12, adding a modified activated carbon collecting agent and a surfactant, and performing air flotation, wherein a foam product is a rhenium-rich component, and the residual solution is a molybdenum-rich solution; the modified active carbon collector is prepared by the following method: finely grinding activated carbon particles to a micro-nano level, dispersing the activated carbon particles into water, adding a composite organic matter consisting of triethylene tetramine, tetraethylene pentamine, methyl violet 10B and cocamidopropyl betaine into the water, stirring for reaction, and filtering, washing and drying a reaction mixture to obtain the modified activated carbon collecting agent.

The modified activated carbon collector provided by the invention is rich in a large number of active functional groups, can adsorb rhenate ions in an alkaline solution system at high selectivity and high efficiency, and shows absolute advantages in the separation process of rhenate and molybdate.

In a more preferable scheme, the weight ratio of triethylene tetramine, tetraethylene pentamine, methyl violet 10B and cocamidopropyl betaine in the composite organic matter is as follows: 10-20: 20-30: 20-40: 10-20.

In a more preferable scheme, the mass ratio of the activated carbon particles to the composite organic matter is 1: 0.1-1: 0.5.

In a more preferable embodiment, the concentration of the activated carbon particles in water is 10g/L to 50 g/L.

In a preferable scheme, the stirring reaction is carried out for 0.5-3 h at the temperature of not higher than 50 ℃. If the temperature is higher than 50 ℃, the reagent is denatured, and the modified activated carbon collector with better rhenium acid radical ion collection is difficult to obtain.

In a more preferable embodiment, the concentration of molybdate ions in the alkaline leach solution containing molybdate ions and rhenate ions is 10mg/L to 30g/L, and the concentration of rhenate ions is 5mg/L to 5 g/L.

In a preferable scheme, the granularity of the active carbon collector meets the condition that the mass percentage of the active carbon collector is 100% when the particle size is less than 5 microns, and the specific surface area is not less than 500m ²/g。

In a preferable scheme, the adding amount of the activated carbon collector in the alkaline leaching solution containing molybdate radicals and rhenate radicals is 50 mg/L-20 g/L.

More preferably, the surfactant is at least one of cetyl trimethyl ammonium bromide, potassium lauryl sulfate and polyoxyethylene fatty alcohol ether.

In a more preferable scheme, the addition amount of the surfactant in the alkaline leaching solution containing molybdate radicals and rhenate radicals is 20-100 mg/L.

In a preferred embodiment, the flotation froth product is acid washed to obtain a rhenium-rich solution. The acid washing solution may be at least one of hydrochloric acid, perchloric acid, and hypochlorous acid. The concentration of the acid washing solution is 1.01-2 mol/L. The rhenate absorbed by the modified active carbon collecting agent is easy to recover, and the rhenate solution can be obtained by directly adopting acid washing.

The preparation method of the modified activated carbon collector comprises the following steps: firstly, finely grinding activated carbon particles to a micro-nano level, dispersing the finely ground activated carbon particles in water, wherein the concentration of the activated carbon in the water solution is 10-50 g/L, and then adding a compound organic matter into the solution, wherein the compound organic matter comprises 10-20 parts by mass of triethylene tetramine, 20-30 parts by mass of tetraethylenepentamine, 20-40 parts by mass of methyl violet 10B and 10-20 parts by mass of cocamidopropyl betaine; the mass ratio of the activated carbon particles to the composite organic matter is 1: 0.1-1: 0.5; mechanically stirring for 0.5-3 h at the temperature of not higher than 50 ℃, and filtering, washing and drying to obtain the micro-nano modified active carbon collecting agent.

Compared with the prior art, the technical scheme of the invention has the beneficial effects that:

according to the technical scheme, the efficient selective separation of the molybdate radicals and the rhenate radicals in the alkaline solution is realized through a flotation separation method, the rhenate and molybdenum separation effect is good, the recovery rate is high, the operation is simple, and the method has obvious technical advantages compared with the traditional molybdenum-rhenium separation technology through an ion exchange method and a solvent extraction method.

According to the technical scheme, the special modified activated carbon is used as a collecting agent material to selectively adsorb rhenate in an alkaline solution system, the rhenate-loaded activated carbon has certain hydrophobicity, so that air bubble products can float upwards along with air bubbles under the action of a surfactant and the air bubbles to collect air bubble products to obtain activated carbon containing the rhenate, and rhenium is desorbed through an acid washing solution to respectively obtain solutions enriched in molybdenum and rhenium.

The micro-nano modified active carbon collector provided by the technical scheme of the invention is obtained by modifying organic functional groups, is rich in active functional groups such as amino groups and the like, can selectively adsorb rhenate ions in an alkaline system, and hardly adsorbs molybdate, so that enrichment and recovery of rhenium can be realized, rhenate adsorbed by the active carbon is easy to elute, rhenium is easy to recover, and the active carbon can be repeatedly used, so that the cost is reduced.

Detailed Description

The following examples are intended to further illustrate the present disclosure, but not to limit the scope of the invention.