CN105063383B

CN105063383B - Ion type rare earth in-situ leaching method process improved by activated ionized water and microbial acid

Info

Publication number: CN105063383B
Application number: CN201510594645.7A
Authority: CN
Inventors: 朱上翔; 徐海双; 曾文威
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-09-18
Filing date: 2015-09-18
Publication date: 2020-07-03
Anticipated expiration: 2035-09-18
Also published as: CN105063383A

Abstract

The invention discloses a formula and a process for improving an extraction liquid and a precipitator of the existing ionic rare earth in-situ leaching mining method, wherein microbial acid is used as an extractant of a leaching process instead of ammonium sulfate; activated ionized water is used as a precipitator of the mother liquor after leaching instead of oxalic acid. The strong alkaline water generated by preparing the activated ion water is used as a neutralizer, the sewage generated in the process of the process is purified and used for reproducing the microbial acid and electrolyzing again, and the sewage is recycled, so that zero discharge of the sewage is realized.

Description

Ion type rare earth in-situ leaching method process improved by activated ionized water and microbial acid

Technical Field

The invention relates to a rare earth mining technology, in particular to a new technology for improving an ionic rare earth in-situ leaching method by using activated ionic water and microbial acid.

Background

Rare earth is composed of 15 elements in lanthanide series of the periodic table of chemical elements plus the other two elements related to the 15 elements, and the total number of the 17 elements is as follows: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), yttrium (Y), and scandium (Sc). Rare earth (RE or R) for short.

The rare earth has wide application and is extremely important, is an industrial vitamin and is widely applied to the metallurgical industry, the petrochemical industry, the glass ceramic industry, new materials, agriculture and military top weapon manufacturing industry. China is the world with the most rare earth resources. The ionic rare earth ore is firstly discovered in south China in 70 years in China, and belongs to medium and heavy rare earth ore. The heavy rare earth in China accounts for more than 70% of the total weight of the heavy rare earth in the world. Is a valuable and precious mineral resource wealth bestowed by nature to China. Heavy rare earths, for the most part of the ionic type. The mining process is different from light rare earth. Since the 80 s, a great deal of research work is carried out in the mining industry of China, and a lot of new processes and new technologies are created in the aspect of mining ionic rare earth, which is the top of the world. The short time is 30 years, and the four-stage updating is carried out. Currently, the fourth generation, most advanced in-situ leaching process is mainly used. Due to the adoption of the advanced process, the heavy rare earth mining industry is greatly improved. The leaching rate of the rare earth is improved to over 95 percent from about 85 percent of the initial leaching rate, and the utilization rate of the rare earth resources is improved from 30 to 50 percentUp to over 75%. Greatly reduces the consumption of extractant (electrolyte) and greatly improves the quality of products. However, things always have two aspects, positive and negative. There are still many disadvantages in advanced in situ leaching processes. For this reason, we first know the specific links and chemicals used in the current process for mining ionic rare earths. Find out what problem it has, so as to develop a method for improving the process, find better preparation, overcome the disadvantages in the existing process. The in-situ leaching mining process is closely related to the characteristics of the ionic rare earth ore. 80-90% of the heavy rare earth is adsorbed on rare earth minerals such as kaolin, hydromica and the like in an ionic state. The rare earth cation adsorbed on clay mineral is insoluble in water or ethanol, but in strong electrolyte such as NaCl, NH₄Cl、(NH₄)₂SO₄When the ion exchange can occur in the solution and enter the solution, and meanwhile, the reversible reaction is realized. Hitherto, the treatment of mine leach liquors has mainly used a large amount of ammonium sulphate as an extractant or dissolver and oxalic acid as a precipitant. FIG. 1 is a process flow of a currently used in situ leaching process. It can be seen that ammonium sulfate and oxalic acid are the most important, most commonly used chemicals for the process. They are the source of destroying the ecological environment, polluting water sources and poisoning the health of workers.

Disclosure of Invention

The invention aims to further improve the in-situ leaching method of the ionic rare earth mining process, in particular to improve the chemical preparation for generating leaching liquor, the oxalic acid preparation for the precipitation stage, further optimize the whole process used at present, increase the reclaimed water recycling process beneficial to environmental protection, treat and recycle the supernatant in the process and realize zero discharge of sewage.

The invention relates to two environment-friendly alternative preparations of an ionic rare earth leaching process and a specific solution of a sewage recovery process, which comprise the following steps:

1. ammonium sulfate was replaced by the biological acid extract we cultured. First, a thorough understanding of why ammonium sulfate is the current choice in the in situ leaching industry? What does ammonium sulfate work? As mentioned above, the ionic rare earth is mostly positive ion, adsorbed on the surface of clay mineral such as kaolinite, muscovite, etc., and these rare earth cations with exchange state can be exchanged when they encounter cations with larger exchange potential, and the chemical reaction is expressed by the following formula:

m.nRE (clay mineral)⁺³+3nA⁺→

[ Clay mineral ] m3nA⁺+nRE⁺³

When ammonium sulfate is used as the leaching solution, the exchange mechanism is as follows:

in order to improve the efficiency, it is desirable to add an acidic ion H + to the ammonium sulfate solution, and the extraction leachate is acidic at a pH of 4 to 5.

In the early development of this process, various electrolyte solutions have been proposed as leachants for ion-adsorbed rare earth ores as long as they do not form poorly soluble compounds with rare earth. For example, hydrochloric acid, sulfuric acid, ammonium sulfate, ammonium chloride, sodium (potassium) chloride, sodium carbonate, and the like. But the source of sodium salt and ammonium salt is convenient and the price is low. Therefore, common salt or ammonium sulfate solution is used as the leaching agent. Later, ammonium sulfate (and sometimes ammonium carbonate) was used only because of the corrosive nature of common salt. The electrolyte of the leaching solution is prepared until now.

Can the ammonium sulfate solution be replaced with other harmless chemical solutions? Is entirely possible. We note that the major component is ammonium (NH)₄) Or Na and Cl. Acidic (containing H)⁺Ions) are of course also important constituents. As long as two are satisfied: firstly, rare earth is combined with ions to synthesize water-insoluble salt; second, there are stronger cations with greater exchange potential. Meeting these two requirements, the ionic rare earth will be replaced from the attached clay minerals such as kaolin, hydromica, etc. Ammonium sulfate is not necessarily used. We have studied a lactic acid-like form of microorganism produced under anaerobic conditionsThe product acid is quite in line with the condition of replacing ammonium sulfate. The biological acid contains hydrogen ions, has a suitable hydrogen ion concentration, has a pH of 3-5, and contains trace sodium, amino acids, lactic acid, and other organic components including NH₄And the like.

Through experiments, the biological acid liquid with the acidity of about 3 is cultured. The test using this biological acid instead of ammonium sulfate was very successful. The extraction rate is higher than that of using ammonium sulfate. Most importantly, the acid is safe and does not risk being inadvertently stuck in the mouth, as is done with Sichuan pickles. It may be referred to as a green lixiviant.

2. A small amount of auxiliary agent is added into the acidic ionized water after water electrolysis to replace oxalic acid. Oxalic acid is well known as an organic acid: a weak acid; high-concentration oxalic acid causes environmental pollution and is harmful to human health, and an environment-friendly substitute should be sought. Similarly, we first know what role oxalic acid plays in promoting the precipitation of leached rare earth mother liquor? As shown in FIG. 1, after the rare earth ore body is topped with ammonium sulfate or other leaching agent according to a certain operation method for a certain period of time, the rare earth (generally rare earth oxide) attached with ionic type can be dissolved in water to obtain rare earth mother liquor, which is collected and stored in a mother liquor sedimentation tank. The next step is to separate the rare earth oxide from the mother liquor. To select a suitable precipitant, the chemical activity of the rare earth element should be understood. Especially to know under what ph conditions it will form a precipitate. It is known from electrochemistry that certain trace elements, such as potassium, sulfur and molybdenum, are alkaline-loving and acid-aversive elements which are least active and precipitate in an acidic environment, i.e., at a PH of 3.0 (strongly acidic). Most of the seventeen rare earths are positive ion elements, and the active magnitude of the elements is similar to that of cobalt, potassium, sulfur and the like. Therefore, an electrolyte which generates strong acidity should be selected as a precipitant of the rare earth mother liquor. At present, oxalic acid or ammonium bicarbonate is mainly selected in the collection process of ionic rare earth ores in south China. The cost of the ammonium carbonate precipitation is low,

m.nRE (clay mineral)⁺³+3nA⁺→

[ Clay mineral ] m3nA⁺+nRE⁺³

Can the ammonium sulfate solution be replaced with other harmless chemical solutions? Is entirely possible. We note that the major component is ammonium (NH)₄) Or Na and Cl. Acidic (containing H)⁺Ions) are of course also important constituents. As long as two are satisfied: firstly, rare earth is combined with ions to synthesize water-insoluble salt; second, there are stronger cations with greater exchange potential. Meeting the two requirements, the ion rare earth can be replaced from the attached clay minerals such as kaolin, hydromica and the likeTo do so. Ammonium sulfate is not necessarily used. We have studied a lactic acid-like biological acid produced by microorganisms under anaerobic conditions, which is well in line with the ammonium sulfate replacement condition. The biological acid contains hydrogen ions, has a suitable hydrogen ion concentration, has a pH of 3-5, and contains trace sodium, amino acids, lactic acid, and other organic components including NH₄And the like.

2. A small amount of auxiliary agent is added into the acidic ionized water after water electrolysis to replace oxalic acid. Oxalic acid is well known as an organic acid: a weak acid; high-concentration oxalic acid causes environmental pollution and is harmful to human health, and an environment-friendly substitute should be sought. Similarly, we first know what role oxalic acid plays in promoting the precipitation of leached rare earth mother liquor? As shown in FIG. 1, after the rare earth ore body is topped with ammonium sulfate or other leaching agent according to a certain operation method for a certain period of time, the rare earth (generally rare earth oxide) attached with ionic type can be dissolved in water to obtain rare earth mother liquor, which is collected and stored in a mother liquor sedimentation tank. The next step is to separate the rare earth oxide from the mother liquor. To select a suitable precipitant, the chemical activity of the rare earth element should be understood. Especially to know under what ph conditions it will form a precipitate. It is known from electrochemistry that certain trace elements, such as potassium, sulfur and molybdenum, are alkaline-loving and acid-aversive elements which are least active and precipitate in an acidic environment, i.e., at a PH of 3.0 (strongly acidic). Most of the seventeen rare earths are positive ion elements, and the active magnitude of the elements is similar to that of cobalt, potassium, sulfur and the like. Therefore, an electrolyte which generates strong acidity should be selected as a precipitant of the rare earth mother liquor. At present, oxalic acid or ammonium bicarbonate is mainly selected in the collection process of ionic rare earth ores in south China. The precipitation with ammonium carbonate is low in cost, but generates silica, alumina and the likeThe precipitate, most rare earth mining companies, was oxalic acid chosen as the precipitant. When oxalic acid is used as precipitant, only the needed rare earth oxide is separated out, but the two metal oxides of silicon and aluminum are not precipitated and mixed into the rare earth composite oxide. Oxalic acid is dissolved in water to form an oxalic acid solution, which is an organic acid, and the weight percentage or concentration of the oxalic acid solute component is 4 to 8(g/L) in terms of weight, according to the current practical use. The pH of this liquid oxalic acid is about 1.5. This indicates that oxalic acid provides a large amount of hydrogen ions H⁺. In addition, since acid radicals are organic substances or elements such as carbon, hydrogen, and oxygen, it is necessary to select substances having a function similar to oxalate in consideration of what kind of substances are used instead of oxalic acid, and a combination of these substances is also possible. The invention provides a scheme that two substances (activated ionized water and oxalic acid cultured by biological bacteria) replace oxalic acid to be used as a precipitating agent. The second method, the project of preparing biological oxalic acid by using the biological bacterium aspergillus niger culture solution is cooperating with bioengineering experts and is in a test stage. The structure of the biological oxalic acid is basically the same as that of organic oxalic acid, and the biological oxalic acid is prepared by using a biological enzyme method in different places, so that the toxicity is reduced, and the biological oxalic acid is safer. It is expected that the precipitation of the rare earth mother liquor by oxalic acid prepared by the biological enzyme should be the same or similar. Therefore, the replacement of the current oxalic acid by it is basically suspensionless. But the toxicity of the biological oxalic acid is lower than that of the organic oxalic acid, and the use of the biological oxalic acid cannot cause the damage to the natural environment. The invention emphatically discloses a method for replacing oxalic acid by activated ionized water and an effect after the use. The idea is that under certain conditions, oxalic acid is not always discarded completely, because the acid radical has obvious and important function and is difficult to replace by inorganic salt. If the amount of oxalic acid can be reduced, for example, by 10% -40%, the oxalic acid-substituted precipitant is also good. The activated ionized water is electrolyzed functional water with better performance and stronger function, which is obtained by adding certain auxiliary agents into environment-friendly strong acid (pH is less than 2) and strong base (pH is more than 11) obtained by the inventor by an electrolysis method, and is called ionized activated water, and comprises alkaline ionized activated water and acidic ionized activated water. Has been successfully applied to industrial ion washingCleaning clothes and linen; the degreasing, derusting and dewaxing process is applied to the plated parts in the electroplating industry; the pesticide is applied to agricultural plant growth promoters and alternative pesticides, and can kill bacteria and deinsectize; is applied to daily life and cleaning and disinfection of hospitals, etc. The invention provides a method for replacing or partially replacing oxalic acid by strongly acidic activated ionized water, which comprises the following steps: (1) salt or hydrochloric acid is used as an auxiliary agent to form brine or dilute hydrochloric acid electrolyte. Electrolyzing water to obtain H⁺The pH value of the acidic electrolyzed water with high ion concentration is less than 2, the oxidation-reduction potential (ORP) is more than 1100mv, and the activated ionized water is small molecular group hexagonal water.

In the strong acid electrolytic water, a certain amount of oxalic acid is directly added, and the added amount is less than half of the current ion rare earth mining dosage. Stirring ionized water and a small amount of oxalic acid uniformly to obtain acidic activated ionized water, storing in a container made of acid-resistant material in a dark place, and sealing, temporarily storing for later use.

When in use, the acid activated ionized water prepared above is directly added into the leaching mother liquor collected in the in-situ ore leaching process according to a certain proportion, the mixture is uniformly stirred, a large amount of white flocculate appears after the mixture is kept stand for about 20 minutes, and the white flocculate is quickly precipitated at the bottom of the mother liquor pool. Removing supernatant, filtering, removing impurities to obtain wet rare earth oxide, squeezing, and calcining to obtain mixed rare earth oxide product. The acidic supernatant is not discharged immediately, and the obtained strongly alkaline ionized water can be neutralized when preparing electrolyzed water (salt is used as an auxiliary agent). After being filtered and purified, the waste water is recycled. The reuse water can be used for culturing the biological acid; or electrolyzing again to prepare activated electrolyzed water. The steps are repeated in this way and are recycled. Only after long-term repeated cyclic utilization, when the impurities exceed a certain limit, the impurities are discharged after reaching the standard after being treated by environment-friendly water. Is not only environment-friendly, but also economical. The recovery rate of rare earth is higher than that of oxalic acid. FIG. 2 is a process flow of extracting mixed rare earth oxide by a microbial acid-activated ion water system.

Drawings

FIG. 1, the process flow of extracting mixed rare earth oxide by ammonium sulfate-oxalic acid system

FIG. 2, the process flow of extracting mixed rare earth oxide by microorganism acid-activated ion water system

Detailed Description

Example [1 ]: examples of culturing microbial acids

An ore leaching agent for ion rare earth leaching, which has a typical culture medium formula as follows:

culture process and conditions, parameters

The current (time)	Temperature (. degree.C.)	Change of pH value	Remarks for note
				7, month, 16, day 14: 00	30	6.4 (Start)
7, month, 17, day 9: 30	303	5.6	The turbidity of the medium begins to increase and surface colonies form
				7, month, 18, day 15: 20	30	5.1	------
7 month, 19 days 10: 00	29	4.6	------
				7 month, 19 days 14: 00	29	3.1	Terminating the fermentation

The above is a mineral leaching agent obtained by culturing 1% of self-prepared lactic acid bacteria stock solution for 3 days (72 hours) at the beginning of the development stage, and the pH value is changed from the initial 6.4 to 3.1. Can be used as mineral leaching and top pouring liquid for in-situ ion rare earth mining. The formula can be further optimized according to the specific conditions of the soil around the ion rare earth ore. The optimal culture temperature is selected, and the growth period is shortened (the requirement is less than 18 hours) so as to meet the requirement of large-scale industrial production. The fungus in the lactic acid-like seed stock solution is anaerobic, and aeration is not needed during culture. The process is simple, the dosage proportion of the seed stock solution is small, and the seed water obtained by people can be purified by utilizing a bioengineering method so as to meet the requirement of large-scale industrialized production. Since too high acidity is not required as a dissolving agent (or extractant) for leaching. For example, pH is 4-5, while the pH of the leachant cultured from the strain can reach around 3. In actual use, dilution is required. The dilution multiple is 10-100 times. That is, if 5000 tons of leachate are required to be poured into the rare earth slime every day in the in-situ leaching mining, only 50 tons to 500 tons of concentrate need to be cultured. This creates good conditions for large-scale production in the field environment. At present, we are completing the work of strain purification. After the culture fermentation process is completed, the culture fermentation process can be greatly accelerated, and the aim that the culture period is less than 18 hours can be achieved. (this technique will be disclosed in addition.)

Example [2] improved Process of activating Ionic Water as a precipitating agent instead of oxalic acid

Firstly, summarizing: acid, alkali mixed ionized water and acidic ionized water with salt content of 1 per mill and 5 per mill are respectively used as stock solutions, and oxalic acid is added as an auxiliary agent to form 19# rare earth acidic precipitator.

Secondly, preparing acidic ionized water with salt content of 1 per mill and acid-base mixed ionized water, wherein the specific operation data is as follows:

A. q total 12.15L/Min 729L/H

(1) Q acid 10.4L/Min 621L/H, acidic ionized water pH2.9

(2) Q is 1.7L/Min is 102L/H, and alkaline ionized water PH is 11.4

(3) Q acid + Q base Q acid-base mixed ion water, its PH8.8

B. (1) pH2.9 acidic ionized water/liter +4.5 g/liter oxalic acid-pH 1.4 acidic ionized water (note 19# -1)

(2) PH8.8 acid-base mixed ionized water/liter +4.5 g/liter oxalic acid ═ PH1.5 acidic ionized water (note 19# -2)

Thirdly, preparing acidic ionized water with salt content of 5 per mill and acid-base mixed ionized water, wherein the specific operation data is as follows:

A. q total is 7.24L/Min 434.4L/H

(1) Q acid 3L/Min 180L/H, acidic ionized water PH2.1

(2) Q is 4L/Min 240L/H, and pH is 11.3

(3) Q acid + Q base Q acid-base mixed ion water, the PH of which is 9.3

B. (1) pH2.1 acidic ionized water/liter +4.5 g/liter oxalic acid-pH 1.4 acidic ionized water (note 19# -3)

(2) PH9.3 acid-base mixed ionized water/liter +4.5 g/liter oxalic acid ═ PH1.5 acidic ionized water (note 19# -4)

Fourthly, preparing oxalic acid solution with pH1.5 which is tap water/liter and 8 g/liter of oxalic acid

Fifthly, comparing the precipitated rare earth mother liquor:

the rare earth mother liquor 150ML +45ML19# -1 reacts violently, and the rare earth precipitation aging time is 30 minutes;

the rare earth mother liquor 150ML +45ML19# -2 reacts violently, and the rare earth precipitation aging time is 30 minutes;

the rare earth mother liquor 150ML +45ML19# -3 reacts violently, and the rare earth precipitation aging time is 30 minutes;

the rare earth mother liquor 150ML +45ML19# -4 reacts violently, and the rare earth precipitation aging time is 30 minutes;

the rare earth mother liquor 150ML +45MLPH is 1.5 oxalic acid solution, the reaction is violent, and the rare earth precipitation and aging time is 3 hours. The precipitation speed is improved by 6 times, and the oxalic acid amount is reduced by 55 percent.

Sixthly, conclusion:

the precipitation reaction in the step (five) can obtain: under the same condition, the reaction effect of the 19# -1, 2, 3 and 4 series ionized water and the rare earth mother liquor is equivalent to that of the oxalic acid solution, the precipitation and aging time of the ionized water is shortened by 2.5 hours, the cost of the oxalic acid is saved by 30-40%, and the economic benefit is considerable.

Example [3 ]: examples of new processes for the in situ extraction of pure oxalic acid and biogenic acid-substituted thiamine with activated ionized water. By using the formula and the process, the ionic rare earth ore in some northern Guangdong is subjected to a primary extraction comparison experiment. The results of this experiment are disclosed hereinafter. Among them, there are several shorthand notations to be explained in advance: HOH means activation.

HOH water is activated ion water generated after the assistant is added into the electrolyzed water. HOH acid: refers to active biological acids. The number definitions of the two extractants are given in the report:

HOH-XT-2014-NOC-18, 18# extractant, which is basically the mother liquor precipitant of activated acidic ionized water instead of oxalic acid.

HOH-XT-2014-BIO-019, which is called 19# extractant for short, essentially means that anaerobic biological acid is used for replacing ammonium sulfate as ion rare earth solvent-extract liquid in the ore leaching process. The conventional rare earth extractant is the extractant for leaching by using thiamine, and the mother liquor precipitator adopts oxalic acid.

Comparison experiment of HOH rare earth extractant and conventional rare earth extractant

1. Experimental conditions and purposes

A total of three experiments were performed. The experimental conditions, purpose, experimental procedure and number of each experiment for each group were as follows:

a first group: group number is I

The method comprises the following steps: putting the rare earth-containing ore soil into a funnel with filter paper, and pouring thiamine into the rare earth according to the proportion of 1: 1.5 to obtain mother liquor. Two experiments were then performed with different extractants.

I- (1): extracting with oxalic acid; i- (2) extracting with HOH extractant;

second group: group number II

The method comprises the following steps: putting the rare earth-containing ore soil into a funnel with filter paper, and pouring an HOH biochemical anaerobic bacteria acid extracting agent into the rare earth according to the proportion of 1: 1.5 to obtain a mother solution. Two experiments were then performed with different extractants.

II- (1): extracting with oxalic acid; II- (2) extracting with HOH extractant;

third group: group number is III.

The method comprises the following steps: the mother liquor which has been obtained (obtained by extraction with thiamine) is used. Two experiments were then performed with different extractants.

III- (1): extracting with oxalic acid; III- (2) extracting with HOH extractant;

purpose of experiment

The first group, HOH-19# extractant is tested to have equal extraction efficiency of oxalic acid; and comparing the consumption and the quantity of the obtained rare earth.

Second, HOH-18# extractant was tested to have equivalent extraction efficacy to thiamine; and comparing the consumption and the obtained mother liquor. Meanwhile, the effectiveness of the HOH-19# extractant for replacing oxalic acid is further verified.

2. Results and analysis of the experiments

With the help of BRUKER, a precise instrument company in the United states, in China Shanghai office, the dried 6 rare earth samples obtained by the experiment carried out by the company are subjected to element content analysis by using the most advanced metal element content analyzer of the company. The results are now set forth in the following table: (the number of the experiment is defined, see 'HOH rare earth extractant and conventional rare earth extractant contrast experiment-experimental condition and experimental purpose')

3. List of experimental results

Second, analysis

1. The first set of experiments: by comparing the contents of the rare earths La and Ce, it can be seen that:

(1) the HOH19# extractant can replace oxalic acid to extract rare earth minerals La and Ce from the mother liquor;

(2) the extraction effect of the HOH19# extractant is better than that of oxalic acid: the mass ratio of the rare earth La obtained by using HOH19# extractant to the La extracted by using oxalic acid as extractant is 140 percent, and the proportion of Ce is 120 percent;

(3) observing the mass of the elements Al2O3, SiO2 and s can see that: oxalic acid or HOH19# is used as the extractant, and the amount of the generated impurities is basically similar.

2. The second set of experiments: two purposes-firstly, compared with the first group of experimental results, the effect of replacing thiamine by HOH18# biological aerobic acid is tested;

the second objective was to further understand the effect of replacing oxalic acid with an extractant No. HOH19 #. By comparing the contents of rare earth La and Ce with the contents of impurities Al2O3, SiO2 and s, it can be seen that:

comparing the La and Ce contents obtained from the two groups of experiments under Nos. 578 and 576 and 579 and 577, it was found that the biological aerobic acid of HOH # 18 replaced thiamine surprisingly well. After the rare earth-containing mud is extracted by HOH18# to obtain mother liquor, the mother liquor is extracted by oxalic acid and HOH19# extractant respectively, and the amount of the obtained rare earth is greatly increased. Wherein the content of the first and second substances,

la increase was 2380/681 ═ 3.5 (oxalic acid) and 2283/957 ═ 2.39(HOH 19 #); ce increase factor is 22450/6302 ═ 3.56 (oxalic acid) and 36252/7629 ═ 4.75(HOH19 #);

further proves that the HOH19# extractant can replace oxalic acid to be used as the extractant, and sometimes the effect is even better than that of oxalic acid. When the HOH18# extractant and the HOH19# extractant are simultaneously applied, Al2O3 impurities are not contained in the obtained rare earth.

And (4) conclusion: 1. the rare earth is extracted by adopting HOH18# and HOH19#, and the extraction rate is more than two times higher than that of the conventional method.

2. The process for collecting rare earth meets the requirement of environmental protection.

3. Through preliminary measurement and calculation, the cost is reduced by about half by adopting HOH series extracting agents.

From the above examples it can be seen that: the invention is a comprehensive optimization and improvement of the existing advanced process-ionic rare earth in-situ leaching mining method. The biological anaerobic lactic acid type liquid is used as extractant instead of ammonium sulfate, and the activated acidic ionized water is used as precipitant for leaching mother liquor instead of pure oxalic acid. The effect of the preliminary test shows that: the new process can meet the requirements of in-situ leaching mining, not only maintains the prior advantages of the advanced process, and has the characteristics of high extraction rate, high resource utilization rate, good product quality and the like, but also overcomes the defect that the prior large use of ammonium sulfate and concentrated oxalic acid causes damage to the environmental ecology, reduces the potential damage to engineering technicians and workers involved in mining, greatly reduces the production cost, recycles reclaimed water obtained after the neutralization and filtration treatment of wastewater, and has the possibility of realizing zero discharge of sewage. The economic benefit is also improved. Therefore, the ion adsorption type rare earth ore in-situ leaching mining method of the < activated ion water-microbial acid > system is a brand-new green and environment-friendly new process for collecting ion rare earth, and is expected to be comprehensively popularized and applied to the ion type rare earth mining industry with specific performance after further optimization and improvement.

The above embodiments are only for the purpose of disclosing the basic idea and the innovative point of the present invention, but the design concept of the present invention is not limited to these individual examples, and all insubstantial changes made to the basic concept of the present invention are actions infringing the scope of protection of the present invention.

Claims

1. The technique for improving the ionic rare earth in-situ leaching method by activating the ionized water and the microbial acid is characterized in that: replacing ammonium sulfate in the existing ionic rare earth in-situ leaching method with lactic acid generated by microorganisms under anaerobic conditions to serve as leaching solution; replacing oxalic acid as a precipitating agent in the leaching mother liquor with acidic activated ionized water; the produced sewage is neutralized by using the strong alkaline electrolyzed water obtained during water electrolysis as a neutralizing agent, and the filtered and clarified reclaimed water is returned to the extraction tank and the electrolytic bath for recycling, so that zero discharge of the sewage is realized.

2. The activated ionized water and microbial acid modified ionic rare earth in situ leaching process of claim 1, wherein: the microbial acid is obtained by culturing and fermenting anaerobic lactic acid bacteria stock solution in an incubator or a container with similar functions after preparing a culture medium, wherein the culture medium comprises the following formula components in percentage by weight:

the culture solution is fermented, the culture solution stops being fermented after the acidity reaches pH 3 after growing, the culture solution is cultured at a fixed speed, and the culture solution is diluted by 10-100 times in a high-level liquid pool before being used as an extracting agent of an in-situ leaching method to be filled into a liquid injection well, so that the pH value of the culture solution is 4-5.

3. The activated ionized water and microbial acid modified ionic rare earth in situ leaching process of claim 1, wherein: in the solution obtained by adding an auxiliary agent into strongly acidic water obtained by electrolyzing water, the pH value of the strongly acidic water is less than 2, the oxidation-reduction potential is more than 1100mv, the strongly acidic water is small molecular group hexagonal water, and the auxiliary agent is a small amount of oxalic acid, and the dosage of the auxiliary agent is less than half of the total amount of oxalic acid required by using oxalic acid as a precipitator at present.

4. The activated ionized water and microbial acid modified ionic rare earth in situ leaching process of claim 1, wherein: the strong alkaline ionized water obtained by the water electrolysis method has the pH value larger than 11 and is used as a neutralizer for treating acidic sewage generated after mother liquor precipitation, and the acidic sewage is used as recycled clean water for preparing microbial acid again and is electrolyzed again to obtain activated ionized water for recycling, so that zero discharge of sewage is realized.