阅读说明：本技术 基于硫化矿物表面原位快速成膜的矿物氧化产酸抑制方法 (Mineral oxidation acid production inhibition method based on in-situ rapid film formation on surface of sulfurized mineral ) 是由 王潇男 郑洁琰 范丽俊 张道勇 潘响亮 于 2021-07-09 设计创作，主要内容包括：本发明公开了一种基于硫化矿物表面原位快速成膜的矿物氧化产酸抑制方法,包括在目标硫化矿物表面先后均匀喷涂第一疏水性膜溶液和第二疏水性膜溶液,使目标硫化矿物表面原位形成疏水性双层钝化膜,有效抑制目标硫化矿物氧化产酸。该方法能在黄铁矿、磁黄铁矿和砷黄铁矿等硫化矿物表面快速原位形成疏水性双层钝化膜,利用疏水性双层膜的隔绝作用,避免水分、空气和微生物与硫化矿物表面的接触,从而抑制硫化矿物在微生物、空气和水分等作用下的氧化作用,能从源头上根除酸性矿山废水产生的方法。本发明在尾矿库、尾矿渣堆场环境中可以快速、原位生成疏水性双层钝化膜,从源头上根除酸性矿山废水的产生,对于尾矿治理和环境保护具有重要意义。(The invention discloses a mineral oxidation acid production inhibition method based on in-situ rapid film formation on a sulfide mineral surface. The method can rapidly form a hydrophobic double-layer passive film on the surface of the pyrite, pyrrhotite, arsenopyrite and other sulfide minerals in situ, and avoids the contact of water, air and microorganisms with the surface of the sulfide minerals by utilizing the isolation effect of the hydrophobic double-layer film, so that the oxidation of the sulfide minerals under the action of the microorganisms, the air, the water and the like is inhibited, and the generation of acid mine wastewater can be eradicated from the source. The method can rapidly generate the hydrophobic double-layer passive film in situ in the environment of a tailing pond and a tailing slag storage yard, eradicates the generation of acid mine wastewater from the source, and has important significance for tailing treatment and environmental protection.)

1. A mineral oxidation acid production inhibition method based on in-situ rapid film formation on the surface of sulfide minerals is characterized by comprising the following steps: the first hydrophobic film solution and the second hydrophobic film solution are uniformly sprayed on the surface of the target sulfurized mineral in sequence, so that a hydrophobic double-layer passivation film is formed on the surface of the target sulfurized mineral in situ, and the target sulfurized mineral is effectively inhibited from being oxidized to generate acid;

the preparation method of the first hydrophobic membrane solution is as follows: uniformly mixing sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, limestone powder and acrylate copolymer emulsion, and then adjusting the pH value to 6.3-8.0 to obtain a first mixed solution; fully stirring the first mixed solution to fully react, and diluting to obtain a first hydrophobic membrane solution;

the second hydrophobic film solution is prepared as follows: modifying micro-nano silicon dioxide particles by using a first aqueous solution containing octadecyl dimethyl trimethoxy siloxane propyl ammonium chloride or N, N-dimethyl-N-dodecyl aminopropyl trimethoxy silane ammonium chloride to obtain modified silicon dioxide particles; modifying the modified silica particles by using a second aqueous solution containing cyclohexane and SEBS under an ultrasonic condition to obtain a first mixed product; and adding the acrylate copolymer emulsion into the first mixed product, and uniformly mixing to obtain a second hydrophobic membrane solution.

2. The method for inhibiting oxidative acidogenesis of minerals according to claim 1, wherein the sulfide minerals comprise one or more of pyrite, pyrrhotite and arsenopyrite, wherein the particle size of the pyrite is preferably 20 μm to 5cm, the particle size of the pyrrhotite is preferably 50 μm to 3cm, and the particle size of the arsenopyrite is preferably 15 μm to 2 cm.

3. The method for inhibiting mineral oxidative acidogenesis as claimed in claim 1, wherein the spraying speed is 25-150 m²/h。

4. The method for inhibiting acid production by mineral oxidation according to claim 1, wherein 35 to 285gL^-1Sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, 50-270 g L^-1Limestone powder and 15-180 g L^-1The acrylate copolymerization emulsion is mixed according to the volume ratio of 1-3: 0.2-2: 0.1-1, and then the pH is adjusted to 6.3-8.0 to obtain the first mixed solution.

5. The method for inhibiting mineral oxidative acidogenesis according to claim 1, wherein the stirring temperature of the first mixed solution is 25-40 ℃, the stirring speed is 150-230 rpm, and the stirring time is 30-90 min.

6. The method for inhibiting oxidative acidogenesis of minerals according to claim 1, wherein the well-stirred first mixed solution is diluted with water in a volume ratio of 1:1 to 1: 15.

7. The method for inhibiting acid production by mineral oxidation according to claim 1, wherein the micro-nano-scale particles having a particle size of 5nm to 2 μm are usedPlacing the silicon dioxide particles in the first aqueous solution, and oscillating for 5-45 min at the temperature of 25-50 ℃ and the rotating speed of 130-200 rpm so as to modify the micro-nano silicon dioxide particles; wherein the modification mixing ratio of the first aqueous solution and the micro-nano silicon dioxide particles is 20-100 g L^-1。

8. The method for inhibiting oxidative acidogenesis of minerals according to claim 7, wherein the concentration of octadecyl dimethyl trimethylsiloxy ammonium chloride or N, N-dimethyl-N-dodecylaminopropyltrimethoxysilane ammonium chloride in the first aqueous solution is 15 to 180g L^-1。

9. The method for inhibiting oxidative acidogenesis of minerals according to claim 1, wherein cyclohexane and 0.50 to 40g L are added^-1Mixing the SEBS in a volume ratio of 10-20: 1-10 to obtain a second aqueous solution; 50-300 g L under the ultrasonic condition of 60-300W^-1The modified silica particles are modified for 5-30 min to obtain a first mixed product.

10. The method for inhibiting acid production by mineral oxidation according to claim 1, wherein 0.5 to 80g L is added to the first mixed product in a volume ratio of 1 to 3:1 to 2^-1And uniformly mixing the acrylic ester copolymer emulsion to obtain a second hydrophobic membrane solution.

Technical Field

The invention relates to a mineral oxidation acid production inhibition method based on in-situ rapid film formation on the surface of sulfide minerals, belonging to the technical field of tailing treatment.

Background

Acid Mine Drainage (AMD) is produced under natural conditions from ores and tailings ponds accumulated during mining. Most of metal mines in China are primary sulfide deposits (pyrite, pyrrhotite, arsenopyrite and the like), and acidic mine wastewater is easily formed by a large amount of abandoned sulfide minerals and tailings under the actions of weathering, leaching and the like, because the sulfide minerals are exposed to the environment and are easily oxidized under the action of water, oxygen and microorganisms. The pH of the acidic mine wastewater is extremely low, the contents of sulfate and heavy metal ions (Cd, Cu, Mn, Pb, Zn and As) are high, the surrounding environment is seriously damaged, and the acidic mine wastewater problem is troubled by local residents after the mine is closed for decades. A very important aspect in the treatment and restoration process of acid mine wastewater is to develop source control and treatment, isolate sulfide minerals as much as possible, and avoid oxidation reaction caused by air, water and microorganisms.

The surface passivation method is a novel source control method for acid mine wastewater. And applying a passivating agent to the surface of the mine to form an inert film on the surface of the mineral through a series of chemical reactions, so that the contact of oxygen and water with the mineral is hindered, and the generation of acid mine wastewater is inhibited. The current research is mainly focused on the passivation methods of organic matters such as silane, the microcapsule passivation method including the phosphate passivation method and the organic acid passivation method, and the carrier-microcapsule passivation method. For example, chinese patent CN202011565100.0 discloses a method and apparatus for passivating heavy metals in tailings by gas-solid phase sulfidation crystallization microcapsule, which mainly uses reducing sulfur-containing gas as a gaseous sulfidation/passivating agent, eliminates the risk of autoxidation inside the tailings particles through sulfidation reduction crystallization, and realizes sulfidation crystallization and microcapsule wrapping passivation in the same reaction equipment through reaction condition regulation and control based on the difference that reducing content is in the reaction products of gas, metal oxide and sulfide under aerobic and anaerobic conditions. However, the method has complicated operation conditions and general passivation effect.

Therefore, it is highly desirable to provide a method for inhibiting acid production by mineral oxidation based on in-situ rapid film formation on the surface of sulfide minerals, thereby eradicating the generation of acidic mine wastewater from the source.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a mineral oxidation acid production inhibition method based on in-situ rapid film formation on the surface of a sulfurized mineral. The method can rapidly form a hydrophobic double-layer passive film on the surface of the pyrite, pyrrhotite, arsenopyrite and other sulfide minerals in situ, and avoids the contact of water, air and microorganisms with the surface of the sulfide minerals by utilizing the isolation effect of the hydrophobic double-layer film, so that the oxidation of the sulfide minerals under the action of the microorganisms, the air, the water and the like is inhibited, and the generation of acid mine wastewater can be eradicated from the source. The method can rapidly generate the hydrophobic double-layer passive film in situ in the environment of a tailing pond and a tailing slag storage yard, eradicates the generation of acid mine wastewater from the source, and has important significance for tailing treatment and environmental protection.

The invention adopts the following specific technical scheme:

the invention provides a mineral oxidation acid production inhibition method based on in-situ rapid film formation on the surface of sulfide minerals, which comprises the following steps: the first hydrophobic film solution and the second hydrophobic film solution are uniformly sprayed on the surface of the target sulfurized mineral in sequence, so that a hydrophobic double-layer passivation film is formed on the surface of the target sulfurized mineral in situ, and the target sulfurized mineral is effectively inhibited from being oxidized to generate acid;

the preparation method of the first hydrophobic membrane solution is as follows: uniformly mixing sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, limestone powder and acrylate copolymer emulsion, and then adjusting the pH value to 6.3-8.0 to obtain a first mixed solution; fully stirring the first mixed solution to fully react, and diluting to obtain a first hydrophobic membrane solution;

the second hydrophobic film solution is prepared as follows: modifying micro-nano silicon dioxide particles by using a first aqueous solution containing octadecyl dimethyl trimethoxy siloxane propyl ammonium chloride or N, N-dimethyl-N-dodecyl aminopropyl trimethoxy silane ammonium chloride to obtain modified silicon dioxide particles; modifying the modified silica particles by using a second aqueous solution containing cyclohexane and SEBS under an ultrasonic condition to obtain a first mixed product; and adding the acrylate copolymer emulsion into the first mixed product, and uniformly mixing to obtain a second hydrophobic membrane solution.

Preferably, the sulphide minerals comprise one or more of pyrite, pyrrhotite and arsenopyrite. Among them, the particle size of pyrite is preferably 20 μm to 5cm, the particle size of pyrrhotite is preferably 50 μm to 3cm, and the particle size of arsenopyrite is preferably 15 μm to 2 cm. The particle size selection is to consider that most of mineral particles existing in the environment are large in size and mainly take mineral particles of millimeter level and above, so that the invention selects pyrite, pyrrhotite and arsenopyrite particles of micron level to millimeter level for experiments, and the corresponding effect is verified.

Preferably, the spraying speed is 25-150 m²/h。

Preferably, 35 to 285g L^-1Sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, 50-270 g L^-1Limestone powder and 15-180 g L^-1The acrylate copolymerization emulsion is mixed according to the volume ratio of 1-3: 0.2-2: 0.1-1, and then the pH is adjusted to 6.3-8.0 to obtain the first mixed solution.

Preferably, the stirring temperature of the first mixed solution is 25-40 ℃, the stirring speed is 150-230 rpm, and the stirring time is 30-90 min.

Preferably, the well-stirred first mixed solution and water are diluted according to a volume ratio of 1: 1-1: 15.

Preferably, the micro-nano silicon dioxide particles with the particle size of 5 nm-2 microns are placed in the first aqueous solution, and are vibrated for 5-45 min at the temperature of 25-50 ℃ and the rotating speed of 130-200 rpm so as to carry out modification treatment on the micro-nano silicon dioxide particles; wherein the modification mixing ratio of the first aqueous solution and the micro-nano silicon dioxide particles is 20-100 g L^-1。

Further, the concentration of octadecyl dimethyl trimethyl siloxy propyl ammonium chloride or N, N-dimethyl-N-dodecyl aminopropyl trimethoxy silane ammonium chloride in the first aqueous solution is 15-180 g L^-1。

Preferably, cyclohexane and 0.50 to 40g L^-1Mixing the SEBS in a volume ratio of 10-20: 1-10 to obtain a second aqueous solution; 50-300 g L under the ultrasonic condition of 60-300W^-1The modified silica particles are modified for 5-30 min to obtain a first mixed product.

Preferably, 0.5-80 g L is added into the first mixed product according to the volume ratio of 1-3: 1-2^-1And uniformly mixing the acrylic ester copolymer emulsion to obtain a second hydrophobic membrane solution.

Compared with the prior art, the invention has the following beneficial effects:

(1) the raw material of the hydrophobic double-layer film used in the method has high cost performance, is easy to obtain and has less pollution; (2) the method can quickly form a film on the surface of pyrite, pyrrhotite, arsenopyrite and other sulfide minerals, and has good film forming effect; (3) the hydrophobic double-layer film generated in situ on the surface of the sulfide minerals such as pyrite, pyrrhotite, arsenopyrite and the like can effectively inhibit the oxidation of the sulfide minerals such as pyrite, pyrrhotite, arsenopyrite and the like, and is suitable for the anti-oxidation treatment of tailings in dry environments such as tailing ponds and the like.

Detailed Description

The invention will be further illustrated and described with reference to specific embodiments. The technical features of the embodiments of the present invention can be combined correspondingly without mutual conflict.

Example 1

(1) 50g L^-1Sodium dodecyl sulfate 120g L^-1And 70g L^-1The acrylic ester copolymer emulsion (available from Beijing Hongya construction materials Co., Ltd.) was prepared in accordance with the following ratio of 1: 1:1, and adjusting the pH to 7.6 to obtain a first mixed solution.

(2) Stirring the obtained first mixed solution at 40 ℃ and 180rpm for 30min, and diluting with tap water according to a volume ratio of 1:5 to obtain a first hydrophobic membrane solution. The first hydrophobic film solution is then added to the paint spray apparatus.

The dilution of the first hydrophobic film solution is based on a combination of cost control and the effect of the spray coating film formation, and the dilution is also advantageous for the spray coating operation.

(3) Uniformly spraying the first hydrophobic film solution on the surface of the pyrite with the particle size of 40 mu m by using a coating spraying device, wherein the spraying speed is 60m²And h, forming a hydrophobic bottom film on the surface of the pyrite firstly.

(4) To a concentration of 60g L^-1Octadecyl dimethyl trimethylsilylammonium chloride (QAS) as a first aqueous solution. The silica particles were immersed in the first aqueous solution at 40 ℃ and 150rpm for 20g L^-1Oscillating the silica particles (with the particle size of 500nm) for 5-45 min to fully utilize the first aqueous solution to modify the silica particles, wherein the prepared modified silica particles are marked as QAS @ SiO₂。

(5) Using cyclohexane and 20g L^-1The SEBS (a linear triblock copolymer with an ethylene-butene copolymer obtained by hydrogenation of polybutadiene as a middle elastic block) of (1) was prepared in a volume ratio of 10:10 to obtain a second aqueous solution. Under the ultrasonic condition of 60W, the mixture is subjected to 250g L^-1QAS @ SiO of₂Modifying for 10min to obtain a first mixed product.

(6) To the first product mixture was added 20g L in a 2:1 ratio^-1Propylene of (2)And (3) uniformly mixing the acid ester copolymer emulsion (purchased from building materials Co., Ltd., Hongya, Beijing) to obtain a second hydrophobic membrane solution. Uniformly spraying the second hydrophobic film solution on the surface of the pyrite on which the hydrophobic bottom film is formed by using a coating spraying device, wherein the spraying speed is 60m²And h, forming a hydrophobic upper layer film on the hydrophobic bottom film, thereby forming a hydrophobic double-layer film on the surface of the pyrite.

To verify the inhibitory effect of the in situ generated hydrophobic bilayer membrane on pyrite oxidation, the following operations were performed: the pyrite (40 μm) without film formation and the pyrite with film formation in the example were respectively left standing for 60d in an outdoor open air environment, and the passivation rate of the pyrite was measured by using a hydrogen peroxide oxidation method at different times. As a result, the hydrophobic double-layer passivation film generated on the surface of the pyrite (40 mu m) is found to improve the passivation rate of the pyrite by 81.5%.

Example 2

(1) 50g L^-1Sodium dodecylbenzenesulfonate, 120g L^-1And 70g L^-1The acrylic ester copolymer emulsion (available from Beijing Hongya construction materials Co., Ltd.) was prepared in accordance with the following ratio of 1: 0.2: 0.1, and adjusting the pH value to 6.9 to obtain a first mixed solution.

(2) Stirring the obtained first mixed solution at 40 ℃ and 180rpm for 30min, and diluting with tap water according to a volume ratio of 1:15 to obtain a first hydrophobic membrane solution. The first hydrophobic film solution is then added to the paint spray apparatus.

(3) Uniformly spraying the first hydrophobic film solution on the surface of the pyrrhotite with the particle size of 1cm by using a coating spraying device at the spraying speed of 25m²I.e. first forming a hydrophobic bottom film on the surface of pyrrhotite.

(4) To a concentration of 60g L^-1Octadecyl dimethyl trimethylsilylammonium chloride (QAS) as a first aqueous solution. The silica particles were immersed in the first aqueous solution at 40 ℃ and 150rpm for 20g L^-1The silicon dioxide particles (the particle size is 300nm) are oscillated for 5-45 min to fully utilize the first aqueous solution to modify the silicon dioxide particles, and the modified silicon dioxide particles are preparedSilica particles are designated QAS @ SiO₂。

(5) Using cyclohexane and 20g L^-1The SEBS (a linear triblock copolymer with an ethylene-butene copolymer obtained by hydrogenation of polybutadiene as a middle elastic block) was prepared in a volume ratio of 10:1 to obtain a second aqueous solution. 50g L pairs under 100W ultrasonic conditions^-1QAS @ SiO of₂Modifying for 10min to obtain a first mixed product.

(6) To the first product mixture was added 20g L in a ratio of 1:1^-1The acrylic ester copolymer emulsion (purchased from Beijing Hongya construction materials Co., Ltd.) is mixed uniformly to obtain a second hydrophobic membrane solution. Uniformly spraying the second hydrophobic film solution on the surface of the pyrrhotite on which the hydrophobic bottom film is formed by using a coating spraying device, wherein the spraying speed is 25m²And h, forming a hydrophobic upper layer film on the hydrophobic bottom film, thereby forming a hydrophobic double-layer film on the surface of the pyrrhotite.

In order to verify the inhibition effect of the in-situ generated hydrophobic double-layer film on pyrrhotite oxidation, the following operations were carried out: the pyrrhotite (1cm) without film formation and the pyrrhotite (1cm) with film formation in the embodiment are respectively kept still for 60d in an outdoor open environment, and the passivation rate of the pyrrhotite is measured by sampling at different times by using a hydrogen peroxide oxidation method. As a result, the hydrophobic double-layer passivation film generated on the surface of pyrrhotite (1cm) is found to improve the passivation rate of pyrrhotite by 56.4%.

Example 3

(1) 50g L^-1Sodium dodecyl sulfate 120g L^-1And 70g L^-1Acrylate copolymer emulsion (available from beijing macroasia construction materials ltd) according to 3: 2:1, and adjusting the pH to 8.0 to obtain a first mixed solution.

(2) Stirring the obtained first mixed solution at 40 ℃ and 180rpm for 30min, and diluting with tap water according to a volume ratio of 1:1 to obtain a first hydrophobic membrane solution. The first hydrophobic film solution is then added to the paint spray apparatus.

(3) Uniformly spraying the first hydrophobic film solution on the granules by using a coating spraying deviceSpraying arsenic pyrite surface with diameter of 1mm at a speed of 150m²I.e. first forming a hydrophobic primary film on the surface of arsenopyrite.

(4) To a concentration of 60g L^-1As a first aqueous solution, N-dimethyl-N-dodecylaminopropyltrimethoxysilane ammonium chloride (DDATAC). The silica particles were immersed in the first aqueous solution at 40 ℃ and 150rpm for 20g L^-1Oscillating the silicon dioxide particles (the particle size is 300nm) for 5-45 min to fully utilize the first aqueous solution to modify the silicon dioxide particles, and marking the prepared modified silicon dioxide particles as DDATAC @ SiO₂。

(5) Using cyclohexane and 20g L^-1The SEBS (a linear triblock copolymer with an ethylene-butene copolymer obtained by hydrogenation of polybutadiene as a middle elastomeric block) of (A) was prepared in a volume ratio of 20:10 to obtain a second aqueous solution. Under 100W ultrasonic condition, the ultrasonic probe is used for treating 300g L^-1DDATAC @ SiO₂Modifying for 20min to obtain a first mixed product.

(6) To the first mixed product was added 20g L in a 3:2 ratio^-1The acrylic ester copolymer emulsion (purchased from Beijing Hongya construction materials Co., Ltd.) is mixed uniformly to obtain a second hydrophobic membrane solution. Uniformly spraying the second hydrophobic film solution on the surface of the arsenopyrite with the hydrophobic bottom film by using a coating spraying device at a spraying speed of 150m²And h, forming a hydrophobic upper layer film on the hydrophobic bottom film, thereby forming a hydrophobic double-layer film on the surface of the arsenic pyrite.

To verify the inhibition of the oxidation of arsenopyrite by the in situ generated hydrophobic bilayer membrane, the following operations were performed: the arsenopyrite (1mm) without film formation and the arsenopyrite (1mm) with film formation in the embodiment are respectively kept still for 60 days in an outdoor open environment, and the passivation rate of the arsenopyrite is measured by sampling at different times by using a hydrogen peroxide oxidation method. As a result, the hydrophobic double-layer passivation film generated on the surface of arsenopyrite (1mm) is found to improve the passivation rate of arsenopyrite by 72.5%.

At present, the existing methods for forming films on mineral surfaces are all that mineral particles are added into film forming liquid in a laboratory and stirred to form films, and the practicability is very low. The method is characterized in that a large amount of experimental groping is carried out on the film forming material and the specific parameter setting thereof, the optimal process parameter is finally obtained, the film can be rapidly formed on the surface of the mineral in situ, the method can be well applied to the surface in situ passivation of minerals such as pyrite, pyrrhotite, arsenopyrite and the like, the acid production process by oxidation of the minerals is inhibited, the generation of acid mine wastewater can be eradicated from the source, and the method has important significance for tailing treatment and environmental protection.

The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, the technical scheme obtained by adopting the mode of equivalent replacement or equivalent transformation is within the protection scope of the invention.