CN116813145B

CN116813145B - Mining wastewater recycling method

Info

Publication number: CN116813145B
Application number: CN202310990699.XA
Authority: CN
Inventors: 饶丽灵
Original assignee: Guardgreen Beijing Environment Technology Co ltd
Current assignee: Guardgreen Beijing Environment Technology Co ltd
Priority date: 2023-08-08
Filing date: 2023-08-08
Publication date: 2025-11-11
Anticipated expiration: 2043-08-08
Also published as: CN116813145A

Abstract

本发明提出了一种矿用废水的回收利用方法，该方法对矿用废水中的重金属离子和/或有毒害的金属离子，通过反应的方式配合一定的单元操作，使重金属和/或有毒害的金属离子被提取出来，得到包括所需阳离子和酸度的原料液，通过将原料液与必要的成分进行反应后，制备得到有机、无机相结合的具有协同增效性能的复合絮凝剂。采用上述方法不仅可以实现矿用废水的变废为宝式回收利用，且基本无废渣排放，废液几乎可以被全部回收再利用，为矿用废水的资源化利用提供的了新思路。This invention proposes a method for recycling mining wastewater. This method extracts heavy metal ions and/or toxic metal ions from mining wastewater through a reaction process combined with specific unit operations, yielding a raw material solution containing the desired cations and acidity. By reacting this raw material solution with necessary components, a composite flocculant with synergistic effects combining organic and inorganic components is prepared. This method not only achieves the transformation of mining wastewater into a valuable resource but also results in virtually no waste residue discharge, with almost all waste liquid being recycled and reused, providing a new approach to the resource utilization of mining wastewater.

Description

Mining wastewater recycling method

Technical Field

The invention relates to the technical field of waste water recycling, in particular to a recycling method of mining waste water.

Background

At present, a large amount of acid waste water is generated in mines, wherein the acid waste water mainly contains a small amount of non-extractable heavy metals, a large amount of base metals, calcium and magnesium ions, acid radicals and the like, and the waste water with particularly high content of metal elements can be subjected to temperature change to reduce the solubility so as to crystallize and precipitate, so that the recovery mode is achieved, and most of treatment methods adopt lime neutralization and then discharge treatment. Particularly copper or copper-containing mines, a large amount of copper is obtained by wet smelting, then acid leaching, extraction and electrodeposition, and a large amount of waste liquid is produced by the method, and contains a large amount of salts of elements such as copper, zinc, lead, cadmium, iron, aluminum, calcium, magnesium, arsenic and the like. At present, because the recovery value is low, the neutralization and the pollution removal are generally carried out by a lime method, and then the emission is carried out.

However, the treatment method has the following problems that 1, the waste slag contains a large amount of heavy metals, arsenic salt and other harmful substances, 2, the generated waste slag is large in amount and high in subsequent treatment cost, and 3, a large amount of lime is used in the treatment process, so that the cost is high.

Therefore, how to provide a treatment mode for mine waste water, especially copper mine waste water, so as to reduce the treatment cost, improve the treatment economic benefit and reduce the pollutant discharge, and the method becomes a technical problem to be solved urgently at present.

Disclosure of Invention

In view of the above, the invention provides a recycling method of mining wastewater, which aims to improve the recoverability of the mining wastewater and reduce the wastewater discharge.

The technical scheme of the invention is realized in such a way that the invention provides a mining wastewater recycling method, which comprises the following steps:

step one, removing oil in wastewater;

Step two, extracting and dezincification is carried out on the wastewater obtained in the step one by using an extraction liquid with an extraction function on zinc;

Thirdly, reacting sodium sulfide with part of heavy metals in the wastewater obtained in the second step to precipitate, and removing part of heavy metals through solid-liquid separation;

Fourthly, heating and preserving heat for reaction by using sodium sulfide and the wastewater obtained in the third step, and removing arsenic through solid-liquid separation;

Step five, regulating the pH value of the wastewater obtained in the step four to be less than 3 to obtain a raw material liquid;

And step six, reacting the raw material liquid with polysilicic acid, and aging to obtain the water treatment agent.

In some embodiments, a method of removing oil from wastewater includes filtering wastewater with a filtration system having a filtration accuracy of not less than 5 μm to remove oil from wastewater.

In some embodiments, the filtration system comprises a combination of one or more of a cloth bag filter, a precision filter, an ultrafiltration membrane, a microfiltration membrane, and a nanofiltration membrane.

In some embodiments, the extraction liquid having an extraction function for zinc comprises at least one of an organic phosphorus-based extraction liquid and an amine-based extraction liquid, and the solvent of the extraction liquid comprises at least one of kerosene and ethanol.

In some embodiments, the organophosphorus extract is a tributyl phosphate solution.

In some embodiments, the amine extract is trioctylmethyl ammonium chloride solution.

In some embodiments, in step three, the mass ratio of sodium sulfide to heavy metals contained in the wastewater obtained in step two is (1-5): 1.

In some embodiments, in the fourth step, the mass ratio of sodium sulfide to arsenic in the wastewater obtained in the third step is (1-5): 1, wherein the temperature of the heating and heat-preserving reaction is 40-60 ℃, and the time of the heat-preserving reaction is 30-60min.

In some embodiments, in the third step, sodium sulfide reacts with heavy metal ions such as copper ions, zinc ions, lead ions and the like in the wastewater to generate corresponding metal sulfide precipitates, and the removal and separation of the heavy metal ions are realized by a solid-liquid separation mode.

In some embodiments, in the fourth step, sodium sulfide reacts with the wastewater obtained in the third step under heating to form sulfide precipitate of arsenic, and the arsenic is removed by solid-liquid separation.

In some embodiments, after adjusting the pH, further comprising adding an oxidizing agent comprising at least one of hydrogen peroxide, sodium hypochlorite, and sodium chlorate. The mass ratio of the oxidant to the wastewater is (8-12) 1000.

In some embodiments, the oxidizing agent is capable of oxidizing ferrous ions in the wastewater to ferric ions, which hydrolyze to form flocculated components of hydroxide.

In some embodiments, after adjusting the pH, further comprising evaporating and concentrating the wastewater by a factor of 2-4.

In the above embodiment, after concentration treatment, the concentration of effective ions can be increased, and the effect of the prepared water treatment agent can be improved.

In some embodiments, before or after adjusting the pH, further comprising, supplemental addition of at least one of an iron salt, an aluminum salt, a magnesium salt, and a borate.

In the above embodiment, whether to add the water in a supplementary manner, and the type and amount of the supplementary addition may be determined according to the concentration of the corresponding ions contained in the treated wastewater in actual production, and adjusted according to the concentration requirements of each ion in the flocculant for water treatment.

In some embodiments, the feedstock solution and polysilicic acid are reacted by adding an organic polymer solution, the organic polymer being an organic amine-based macromolecular polymer, the solvent of the organic polymer solution being acetic acid.

In the above embodiments, the organic polymer may be PAM or chitosan.

In the above embodiment, the ratio of the raw material liquid to the polysilicic acid is 1000 (1-100).

In some embodiments, the ratio of feedstock to organic polymer is (1000): (0-10).

In some embodiments, the reaction time is from 0.5 to 2 hours and the aging time is not less than 24 hours.

Compared with the prior art, the mining wastewater recycling method has the following beneficial effects:

(1) The mining wastewater recycling method can recycle various metals in the mining wastewater, thereby creating economic value;

(2) In the mining wastewater recovery method, besides a certain waste residue generated by the precipitation reaction of sodium sulfide on arsenic, the waste residue is hardly generated, and compared with the traditional lime method, the landfill cost of waste residue treatment is greatly reduced;

(3) The recovery method can lead the main part of the mining wastewater to be completely recovered and utilized, thereby greatly reducing the discharge of the wastewater and the treatment cost of the wastewater;

(4) Meanwhile, the recovery method changes the mining waste water into valuable, and after a series of treatment processes for removing toxic and harmful components such as heavy metals, the waste water becomes a flocculant which can be used for water treatment, and the performance of the flocculant is far higher than that of the traditional flocculant, so that pollutants such as COD, total phosphorus and the like of sewage can be removed more thoroughly, the cost performance is higher, and the cost is lower because the source of the raw materials is waste liquid, thereby being beneficial to reducing the pollution control cost of enterprises and reducing the pollution control burden of society.

Detailed Description

The following description of the embodiments of the present invention will clearly and fully describe the technical aspects of the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the invention belong. If the definitions set forth in this section are contrary to or otherwise inconsistent with the definitions set forth in the patents, patent applications, published patent applications and other publications incorporated herein by reference, the definitions set forth in this section are preferentially set forth in the definitions set forth herein.

The invention uses the characteristics of the constituent substances in the wet waste liquid, classifies and treats various elements in the waste liquid by taking the chemical properties of the elements in the waste liquid under different conditions and taking the conditions of conversion among different valence states of the elements into consideration, takes out toxic elements from the waste liquid, obtains cations and acidity required by the water treatment agent, and finally changes the waste liquid into partial raw materials of the novel composite water treatment agent, thereby realizing the recycling comprehensive utilization of changing waste into valuable.

The following examples use a waste liquid of a copper mine as a recycling raw material, and the waste liquid contains a large amount of copper, zinc, arsenic, lead, iron, aluminum, calcium, magnesium, sulfuric acid, and other components, and the specific components are as follows:

Copper content is more than or equal to 60mg/L

Zinc is more than or equal to 200mg/L

Lead 2-5mg/L

Iron 8-12g/L

Aluminium 2-5g/L

Calcium not less than 1000mg/L

Magnesium not less than 200mg/L

Arsenic is more than or equal to 60mg/L

Sulfuric acid not less than 15g/L

pH 1.2-1.5

Example 1

Filtering and degreasing 1L of the waste liquid of the copper mine by adopting a cloth bag filter with the filtering precision of 5 mu m, adding 250L of ethanol solution of tributyl phosphate with the mass concentration of 7% into the filtered waste liquid, carrying out liquid-liquid separation by adopting countercurrent extraction equipment, thereby obtaining waste liquid with most zinc ions removed, adding 10g of sodium sulfide into the waste liquid with a small amount of zinc ions remained, generating corresponding insoluble sulfide precipitate after copper, zinc and lead in the waste liquid are reacted, carrying out solid-liquid separation by adopting plate-frame filter pressing, and obtaining waste liquid with copper, zinc and lead removed, wherein the solid obtained by filter pressing can be used for copper recovery. Then adding 15g of sodium sulfide into the waste liquid, heating to 40 ℃, carrying out heat preservation reaction for 360min, carrying out solid-liquid separation through plate-frame filter pressing, wherein the solid is arsenic-containing waste residue, and the liquid is used as raw material liquid.

Adding hydrochloric acid into the separated raw material liquid, regulating the pH value to 3.0, taking 1L of the raw material liquid with the pH value regulated, adding 111g of polysilicic acid, stirring and reacting for 0.5h, and aging for 24h to obtain the water treatment agent.

Example 2

Filtering and degreasing 1L of the waste liquid of the copper mine by adopting a microfiltration membrane with the filtration precision of 5 mu m, adding 250L of kerosene solution of trioctyl methyl ammonium chloride with the mass concentration of 5% into the obtained filtered waste liquid, carrying out liquid-liquid separation by adopting countercurrent extraction equipment, thereby obtaining the waste liquid with most zinc ions removed, adding 12g of sodium sulfide into the waste liquid with a small amount of zinc ions remained, generating corresponding insoluble sulfide precipitate after copper, zinc and lead in the waste liquid are reacted, carrying out solid-liquid separation by plate-frame filter pressing, and obtaining the waste liquid with copper, zinc and lead removed, wherein the solid obtained by filter pressing can be used for copper recovery. Then adding 15g of sodium sulfide into the waste liquid, heating to 50 ℃, carrying out heat preservation reaction for 50min, carrying out solid-liquid separation through plate-frame filter pressing, wherein the solid is arsenic-containing waste residue, and the liquid is used as raw material liquid.

Adding hydrochloric acid into the separated raw material liquid, regulating the pH value to 2.9, taking 1L of the raw material liquid with the pH value regulated, adding 10L of hydrogen peroxide and 80g of polysilicic acid, stirring and reacting for 2 hours, and aging for 24 hours to obtain the water treatment agent.

Example 3

And (3) filtering and degreasing 1L of the waste liquid of the copper mine by adopting a microfiltration membrane with the filtration precision of 5 mu m, adding 300L of kerosene solution with the mass concentration of 5% of trioctyl methyl ammonium chloride into the obtained filtered waste liquid, carrying out liquid-liquid separation by adopting countercurrent extraction equipment, thereby obtaining the waste liquid with most zinc ions removed, adding 10g of sodium sulfide into the waste liquid with a small amount of zinc ions remained, generating corresponding insoluble sulfide precipitate after the reaction of copper, zinc and lead in the waste liquid, and carrying out solid-liquid separation by plate-frame filter pressing to obtain the waste liquid with copper, zinc and lead removed, wherein the solid obtained by filter pressing can be used for copper recovery. Then adding 20g of sodium sulfide into the waste liquid, heating to 50 ℃, carrying out heat preservation reaction for 40min, carrying out solid-liquid separation through plate-frame filter pressing, wherein the solid is arsenic-containing waste residue, and the liquid is used as raw material liquid.

Adding hydrochloric acid into the separated raw material liquid, regulating the pH value to 3.0, taking 1L of the raw material liquid with the pH value regulated, adding 10L of hydrogen peroxide for oxidation reaction, evaporating the raw material liquid to concentrate the raw material liquid to 2 times of concentration, adding 100g of polysilicic acid, stirring and reacting for 2 hours, and ageing for 24 hours to obtain the water treatment agent.

Example 4

And (3) filtering and degreasing 1L of the waste liquid of the copper mine by adopting a microfiltration membrane with the filtration precision of 5 mu m, adding 250L of kerosene solution with the mass concentration of 5% of trioctyl methyl ammonium chloride into the obtained filtered waste liquid, carrying out liquid-liquid separation by adopting countercurrent extraction equipment, thereby obtaining the waste liquid with most zinc ions removed, adding 8g of sodium sulfide into the waste liquid with a small amount of zinc ions remained, generating corresponding insoluble sulfide precipitate after the reaction of copper, zinc and lead in the waste liquid, and carrying out solid-liquid separation by plate-frame filter pressing to obtain the waste liquid with copper, zinc and lead removed, wherein the solid obtained by filter pressing can be used for copper recovery. Then adding 12g of sodium sulfide into the waste liquid, heating to 60 ℃, carrying out heat preservation reaction for 40min, carrying out solid-liquid separation through plate-frame filter pressing, wherein the solid is arsenic-containing waste residue, and the liquid is used as raw material liquid.

Adding hydrochloric acid into the separated raw material liquid, regulating the pH value to 3.0, taking 1L of the raw material liquid with the pH value regulated, adding 16g of ferric chloride and 13g of aluminum chloride in a supplementary manner, adding 8L of hydrogen peroxide for oxidation reaction, evaporating the raw material liquid to concentrate the raw material liquid to 2 times of concentration, adding 85g of polysilicic acid, stirring for reaction for 2 hours, and aging for 24 hours to obtain the water treatment agent.

Example 5

Filtering and degreasing 1L of the waste liquid of the copper mine by adopting a microfiltration membrane with the filtration precision of 5 mu m, adding 300L of kerosene solution with the mass concentration of 5% of trioctyl methyl ammonium chloride into the obtained filtered waste liquid, carrying out liquid-liquid separation by adopting countercurrent extraction equipment, thereby obtaining the waste liquid with most zinc ions removed, adding 15g of sodium sulfide into the waste liquid with a small amount of zinc ions remained, generating corresponding insoluble sulfide precipitate after copper, zinc and lead in the waste liquid are reacted, carrying out solid-liquid separation by plate-frame filter pressing, and obtaining the waste liquid with copper, zinc and lead removed, wherein the solid obtained by filter pressing can be used for copper recovery. Then adding 12g of sodium sulfide into the waste liquid, heating to 55 ℃, carrying out heat preservation reaction for 60min, carrying out solid-liquid separation through plate-frame filter pressing, wherein the solid is arsenic-containing waste residue, and the liquid is used as raw material liquid.

Adding hydrochloric acid into the separated raw material liquid, regulating the pH value to 3.0, taking 1L of the raw material liquid with the pH value regulated, adding 30g of ferric chloride and 13g of aluminum chloride in a supplementary manner, adding 12L of hydrogen peroxide for oxidation reaction, evaporating the raw material liquid to concentrate the raw material liquid to 2 times of concentration, adding 11g of polysilicic acid, and 1g of PAM acetic acid solution with the concentration of 1ppm, stirring and reacting for 2 hours, and aging for 24 hours to obtain the water treatment agent.

The water treatment agents prepared in examples 1 to 5 were each subjected to metal ion content detection, the total amount of metal ions was calculated from the concentration, and the change value was calculated by comparing with the total amount of metal ions in the waste liquid before treatment. Change value= (total amount of metal ions in water treatment agent-total amount of metal ions in waste liquid before treatment)/total amount of metal ions in waste liquid before treatment is 100%. The specific data are as follows:

the data show that the heavy metal in the mining wastewater can be effectively removed by adopting the recycling method, and the solid waste generated after the heavy metal is removed is very little.

Comparative example 1

Adopting an aqueous solution of polyaluminium chloride as a water treatment agent, wherein the mass concentration of the polyaluminium chloride is 20%;

Comparative example 2

The ferric chloride aqueous solution is used as a water treatment agent, and the mass concentration of the ferric chloride is 20%.

The water treatment agents obtained in the above examples and comparative examples were used for treating a certain domestic wastewater, and the COD values before and after treatment and the solid contents before and after treatment were detected, respectively, to obtain the following table data:

The data show that the recovery and utilization method of the invention is adopted to recover and treat the mining wastewater, and the mining wastewater shows good water treatment effect when being transferred to water treatment, and has better treatment effect compared with the conventional polyaluminum chloride and ferric chloride flocculating agent.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1. A method for recycling and utilizing mining wastewater, characterized by comprising the following steps:

Step 1: Use a filtration system with a filtration degree of not less than 5μm to filter the wastewater to remove oil. The specific composition of the wastewater is as follows: copper ≥60mg/L, zinc ≥200mg/L, lead 2-5mg/L, iron 8-12g/L, aluminum 2-5g/L, calcium ≥1000mg/L, magnesium ≥200mg/L, arsenic ≥60mg/L, sulfuric acid ≥15g/L, pH 1.2-1.5;

Step 2: Extract the wastewater obtained in Step 1 with an extractant that has the function of extracting zinc to remove zinc. The extractant that has the function of extracting zinc is a tributyl phosphate solution or a trioctylmethylammonium chloride solution. The solvent of the extractant includes at least one of kerosene and ethanol.

Step 3: React sodium sulfide with some of the heavy metals in the wastewater obtained in Step 2 to precipitate them, and remove some of the heavy metals by solid-liquid separation. The mass ratio of sodium sulfide to heavy metals in the wastewater obtained in Step 2 is (1-5):1.

Step 4: Heat and keep warm the wastewater obtained in Step 3 with sodium sulfide to remove arsenic through solid-liquid separation. The mass ratio of sodium sulfide to arsenic in the wastewater obtained in Step 3 is (1-5):1. The heating temperature is 40-60℃ and the holding time is 30-60min.

Step 5: Adjust the pH of the wastewater obtained in Step 4 to less than 3, add an oxidant to obtain a raw material solution. The oxidant includes at least one of hydrogen peroxide, sodium hypochlorite and sodium chlorate. The mass ratio of the oxidant to the wastewater is (8-12):1000.

Step 6: The raw material solution, polysilicic acid, and organic polymer solution are reacted and aged to obtain a water treatment agent. The reaction time is 0.5-2 hours, and the aging time is not less than 24 hours. The organic polymer is an organic amine macromolecular polymer, and the solvent of the organic polymer solution is acetic acid.

2. The method for recycling mining wastewater as described in claim 1, characterized in that, in step five, after adjusting the pH, the wastewater is further evaporated and concentrated, with a concentration factor of 2-4 times.

3. The method for recycling mining wastewater as described in claim 1, characterized in that, in step five, before or after adjusting the pH, at least one of iron salt, aluminum salt, magnesium salt, and borate is added.