CN110804703A

CN110804703A - Method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation

Info

Publication number: CN110804703A
Application number: CN201911141513.3A
Authority: CN
Inventors: 王俊峰; 唐林旺; 李海; 钟常明; 邱廷省
Original assignee: Buddhist Tzu Chi General Hospital
Current assignee: Jiangxi University of Science and Technology; Buddhist Tzu Chi General Hospital
Priority date: 2019-11-20
Filing date: 2019-11-20
Publication date: 2020-02-18

Abstract

The invention discloses a method for efficiently recovering extremely-low-concentration ionic rare earth, which comprises the following steps of ①, adding humic acid into distilled water according to a mass ratio of 1:500, stirring for 100-90 min at 200r/min, then placing the solution in a shaking table for vibration heating for 100-120min at 50 ℃, carrying out ultrasonic treatment on the solution for 80-90min after vibration is finished, filtering a 0.45-micron filter membrane to obtain a humic acid solution, ②, adding the prepared humic acid solution and the extremely-low-concentration rare earth ion-containing solution into the extremely-low-concentration rare earth ion-containing solution according to a volume ratio of 1:1, carrying out vibration reaction in a water bath constant temperature oscillator, standing for 20-24h by using filter paper, and ③, filtering the mixed solution which is fully standing to separate precipitates from a supernatant, thereby obtaining a rare earth precipitation enriched product.

Description

Method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation

Technical Field

The invention belongs to the field of mineral separation, and particularly relates to a method for cleaning, efficiently precipitating and enriching ionic rare earth with extremely low concentration by adopting humic acid.

Background

As a kind of unique important mineral resources in China, the ion-adsorption type rare earth (ionic rare earth for short) has the characteristics of complete distribution, high content of high-added-value elements, more high-tech application elements, high comprehensive utilization value and the like, and is concerned by the world. However, for a long time, a large amount of rare earth wastewater with low concentration and large volume is generated in the process of mining and extracting the ionic rare earth ore, the rare earth ion concentration in the wastewater is extremely low (the extremely low concentration referred to in the invention means that the rare earth concentration is not higher than 20mg/L, measured by REO), the requirement of the basic index (generally 1.0g/L and above) of industrial production cannot be met, and the ionic rare earth wastewater cannot be used as a direct raw material for production and use. The problems of environmental pollution, waste of rare earth resources and the like are easily caused.

The most common simple method for enriching and recovering the ionic rare earth solution with extremely low concentration is a precipitation method. The research on the precipitation method mainly focuses on the research and development of the precipitating agent. At present, most researches are carried out on oxalic acid organic precipitant, carbonate inorganic precipitant, magnesium salt inorganic precipitant and the like, and biological precipitant, particularly organic precipitant, is reported. Oxalic acid or ammonium bicarbonate is used as a precipitator to precipitate and separate free rare earth ions, and the precipitated product is subjected to deep processing, separation and purification to obtain a single rare earth product. However, the oxalic acid precipitation effect is good, the selectivity is high, the precipitate crystallization is good, but because the environmental protection requirement is increasingly strict, the disadvantage of the toxicity of oxalic acid and the like which are not friendly to the environment is increasingly shown, and a series of environmental problems are easily derived; the carbonate inorganic precipitant is used as a substitute of oxalic acid, has a lower precipitation effect than oxalic acid, has the defects of poor selectivity, incomplete crystallization, poor filterability of precipitate and the like, and limits further application. Therefore, the development of a new generation of clean and efficient precipitating agent, in particular to a technology for enriching and recovering ionic rare earth with extremely low concentration, is necessary.

Humic acid is a macromolecular organic substance widely existing in nature. Can be extracted from nature or artificially prepared. The modified phenolic hydroxyl-containing acrylic acid modified phenolic aldehyde resin contains various functional groups such as phenolic hydroxyl, carboxyl, alcoholic hydroxyl, hydroxyquinone, enol group, sulfonic group, amino, quinonyl and semiquinonyl, has the functions of hydrophilicity, faintly acid, surface activity, ion exchange and complexation, and the capabilities of catalysis, adsorption, buffering and the like, and has the characteristic of no pollution to the environment. However, few studies are currently conducted on the precipitation of rare earth solutions using humic acid, and particularly, ionic rare earth solutions with extremely low concentrations are rarely conducted.

Disclosure of Invention

Aiming at the defects existing in the research of the current rare earth precipitator, the invention adopts organic matter-humic acid with wide sources as the precipitator, and utilizes a clean and efficient precipitator to carry out efficient enrichment and separation on rare earth ions with extremely low concentration based on the concept of waste recycling, thereby achieving the purpose of waste recycling, reducing the production cost, achieving the efficient unification of environmental benefits and economic benefits, and promoting the progress of ecological construction and sustainable development.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for enriching the ionic rare earth with extremely low concentration by adopting humic acid precipitation comprises the following steps:

s1, preparing a humic acid solution;

s2, precipitating and enriching rare earth ions with extremely low concentration;

s3, preparing rare earth precipitation enriched products.

Preferably, the specific method of S1 is as follows: adding humic acid (analytically pure) into distilled water according to the mass ratio of 1:500, stirring for 100-.

Preferably, the specific method of S2 is as follows: adding the humic acid solution prepared by S1 and the rare earth ion solution with extremely low concentration into the rare earth ion solution with extremely low concentration according to the volume ratio of 1:1, carrying out oscillation reaction in a water bath constant temperature oscillator, and standing for 20-24 h.

Preferably, the specific method of S3 is as follows: and (4) filtering the fully-standing mixed liquid filter paper of the reaction container in the step S2 to separate the precipitate from the supernatant. The filtrate (supernatant) is returned to S1 for reuse, and the finally obtained precipitate is the rare earth precipitation enriched product.

Preferably, the reaction control conditions are shaken in a water bath constant temperature shaker in S2: about 55 ℃, 100r/min, and the reaction time is 50-60 min.

The solution containing the rare earth ions with extremely low concentration is rare earth tailing wastewater, residual rare earth leacheate, wastewater generated in the rare earth processing and smelting process and the like, the content of the rare earth ions is less than or equal to 20mg/L in terms of REO.

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

1. the clean and efficient precipitator prepared by the humic acid can efficiently enrich the ionic rare earth with extremely low concentration, can achieve the purpose of efficiently recycling wastes, has the characteristics of wide sources, low cost, environmental friendliness, high efficiency and stability,

2. the obtained precipitate is detected by an X-ray fluorescence spectrometer and a single-channel scanning inductively coupled plasma sand-jet spectrometer, so that the method can effectively separate the rare earth elements from the precipitate in the ionic rare earth solution with extremely low concentration, has high action efficiency and simple operation, and realizes the efficient recovery of the rare earth with extremely low concentration.

3. Based on the concept of waste recycling, the rare earth ions in the ionic rare earth solution with extremely low concentration are precipitated and enriched, so that the aim of recycling waste resources is fulfilled, the production cost is reduced, the high-efficiency unification of environmental benefits and economic benefits is realized, and the social ecological construction and sustainable development are promoted.

Detailed Description

s1, preparing a humic acid solution, wherein the specific method is as follows:

adding humic acid (analytically pure) into distilled water according to the mass ratio of 1:500, stirring for 100-.

S2, precipitating and enriching rare earth ions with extremely low concentration, and the specific method is as follows:

adding the humic acid solution prepared by S1 and a solution containing rare earth ions with extremely low concentration (rare earth tailing wastewater, residual rare earth leacheate, wastewater generated in the rare earth processing and smelting process and the like, wherein the content of the rare earth ions is 20 ≦ mg/L, calculated by REO) into the solution containing the rare earth ions with extremely low concentration according to the volume ratio of 1:1, carrying out oscillation reaction in a water bath constant temperature oscillator (the control conditions are about 55 ℃, 100r/min and the reaction time is 50-60min), and standing for 20-24 h;

s3, preparing a rare earth precipitation enriched product, wherein the specific method comprises the following steps:

and (4) filtering the fully-standing mixed liquid filter paper of the reaction container in the step S2 to separate the precipitate from the supernatant. The filtrate is returned to S1 for reuse, and the finally obtained precipitate is the rare earth precipitation enriched product.

The humic acid solution (with the concentration of 0.95g/L) prepared by the method is mixed with the leaching solution of certain ionic type rare earth mine from Gannan (wherein the concentration of the rare earth ions is 19.13mg/L in terms of REO). According to the technical scheme and the specific implementation steps, the rare earth precipitation enrichment (the mass fraction of the rare earth is 39.5 percent, calculated by REO) is obtained.

Taking a sample of the supernatant before and after mixing, and detecting the rare earth element concentration of the supernatant of the mixed solution by single-channel scanning inductively coupled plasma emission spectrum, wherein the specific results are shown in table 1:

TABLE 1 main index of precipitation Effect

The data in the table 1 are compared to find that the detected precipitation efficiency of the rare earth elements is basically over 84.03 percent after the ionic rare earth solution with the extremely low concentration is mixed with the humic acid solution, the precipitation effect is excellent and obvious, and the method fully indicates that the method for selecting the humic acid as the precipitator of the ionic rare earth leaching solution with the extremely low concentration is a green and environment-friendly method.

Taking the rare earth precipitation enriched product to carry out an X-ray fluorescence spectrometer, and the specific detection result is shown in table 2.

TABLE 2 elemental analysis results of rare earth precipitation enriched products

The data results in table 2 show that the precipitate contains a large amount of rare earth elements, and the method for precipitating and enriching the ionic rare earth with extremely low concentration is a green and environment-friendly method.

Some of the main instrumentation used in the examples are shown in Table 3.

Table 3 main equipment

FIG. 1 shows the effect of precipitation and enrichment of rare earth mine leaching solution of certain ionic type in Gannan (with rare earth ion concentration of 19.13mg/L in terms of REO), where series 1 is rare earth leachate and series 2 is mixed liquor supernatant.

Figure 2 shows the weight percentage of each element in the final rare earth precipitate concentrate.

The method has the advantages of high efficiency, good effect, environmental friendliness and the like when being used for precipitation and enrichment of the ionic rare earth leachate with extremely low concentration, achieves the purpose of resource utilization, and has important guiding significance for realizing organic unification of economic benefit, environmental benefit and social benefit.

Claims

1. A method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation is characterized by comprising the following steps:

s1, preparing humic acid solution

S2, precipitating and enriching rare earth ions with extremely low concentration

S3, preparing rare earth precipitation enriched products.

2. The method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation as claimed in claim 1, wherein the S1 is characterized by comprising the following specific steps: adding humic acid (analytically pure) into distilled water according to the mass ratio of 1:500, stirring for 100-.

3. The method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation as claimed in claims 1-2, characterized in that the S2 is implemented by the following specific method: adding the humic acid solution prepared by S1 and the rare earth ion solution with extremely low concentration into the rare earth ion solution with extremely low concentration according to the volume ratio of 1:1, carrying out oscillation reaction in a water bath constant temperature oscillator, and standing for 20-24 h.

4. The method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation as claimed in claims 1-3, characterized in that the S3 is implemented by the following specific method: and (4) filtering the fully-standing mixed liquid filter paper of the reaction container in the step S2 to separate the precipitate from the supernatant. The filtrate is returned to S1 for reuse, and the finally obtained precipitate is the rare earth precipitation enriched product.

5. The method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation as claimed in claims 1-4, wherein the reaction control conditions are vibrated in a water bath constant temperature oscillator in S2: about 55 ℃, 100r/min, and the reaction time is 50-60 min.

6. The method for enriching ionic rare earth with extremely low concentration by adopting humic acid precipitation as claimed in claims 1-5, wherein the solution containing the extremely low concentration rare earth ions is the waste water of rare earth tailings, residual rare earth leacheate, waste water generated in the rare earth processing and smelting process, and the content of the rare earth ions is less than or equal to 20mg/L in terms of REO.