阅读说明：本技术 一种黑色页岩铀钒矿的浸出方法 (Leaching method of black shale uranium vanadium ore ) 是由 贾秀敏 向秋林 陈天宝 刘会武 刘忠臣 黄永 师留印 李培佑 于 2020-11-27 设计创作，主要内容包括：本发明涉及铀矿水冶技领域,尤其涉及一种黑色页岩铀钒矿的浸出方法。浸出方法,包括以下步骤：将黑色页岩铀钒矿样品进行破碎研磨,加水和硫酸混合均匀；对混合物进行熟化,得到熟化后物料；在所述熟化后物料中加入水或者稀硫酸,控制液体与固体的体积质量比,加入铁抑制剂以及中和剂,调整pH值至1～3,80～100℃下进行浸出处理；将所述浸出处理后的矿浆进行真空过滤,得到浸出液和滤饼；所述滤饼采用稀硫酸3～10段逆流洗涤,第一段洗水并入浸出液中。该方法实现了黑色页岩型铀钒矿的酸法浸出,在保证铀、钒浸出率的条件下,降低了浸出液中剩余酸浓度,抑制了杂质元素铁的溶出,可有效降低后续分离回收过程的试剂消耗。(The invention relates to the technical field of uranium ore hydrometallurgy, in particular to a leaching method of black shale uranium vanadium ore. A leaching process comprising the steps of: crushing and grinding a black shale uranium vanadium ore sample, adding water and sulfuric acid, and uniformly mixing; curing the mixture to obtain a cured material; adding water or dilute sulfuric acid into the cured material, controlling the volume mass ratio of liquid to solid, adding an iron inhibitor and a neutralizer, adjusting the pH value to 1-3, and leaching at 80-100 ℃; vacuum filtering the ore pulp after the leaching treatment to obtain a leaching solution and a filter cake; and the filter cake is subjected to counter-current washing by using 3-10 sections of dilute sulfuric acid, and the first section of washing water is merged into the leaching solution. The method realizes acid leaching of black shale type uranium vanadium ore, reduces the concentration of residual acid in the leaching solution, inhibits the dissolution of impurity element iron and can effectively reduce the reagent consumption in the subsequent separation and recovery process under the condition of ensuring the leaching rate of uranium and vanadium.)

1. The leaching method of the black shale uranium vanadium ore is characterized by comprising the following steps:

step S1: crushing and grinding a black shale uranium vanadium ore sample, adding water and sulfuric acid, and uniformly mixing to obtain a mixture;

step S2: curing the mixture to obtain a cured material;

step S3: adding water or dilute sulfuric acid into the cured material, controlling the volume mass ratio of liquid to solid, adding an iron inhibitor and a neutralizer, adjusting the pH value to 1-3, and leaching at 80-100 ℃;

step S4: vacuum filtering the ore pulp after the leaching treatment to obtain a leaching solution and a filter cake;

and the filter cake is subjected to counter-current washing by using 3-10 sections of dilute sulfuric acid, and the first section of washing water is merged into the leaching solution.

2. The leaching method of black shale uranium vanadium ore according to claim 1, wherein in the step S1, the addition amount of water is 0-30 wt% of the mass of the black shale uranium vanadium ore sample; the addition amount of the sulfuric acid is 1-100 wt% of the mass of the black shale uranium vanadium ore sample.

3. The leaching method of black shale uranium vanadium ore according to claim 1, wherein in the step S2, the temperature of the aging is 20 ℃ to 300 ℃, and the time of the aging is 0.5 to 100 hours.

4. The leaching method of black shale uranium vanadium ore according to claim 1, wherein in the step S3, the volume mass ratio of liquid to solid is controlled to be 0.3-10.

5. The method for leaching black shale uranium vanadium ore according to claim 1, wherein in the step S3, the time of the leaching treatment is 0.5 to 10 hours.

6. The method for leaching black shale uranium vanadium ore according to claim 1, wherein in the step S3, an iron inhibitor and a neutralizer are added to adjust the pH value to 1-2.

7. The method for leaching black shale uranium vanadium ore according to any one of claims 1 to 6, wherein the iron inhibitor is a sodium salt, an ammonium salt or a potassium salt.

8. The leaching method of black shale uranium vanadium ore according to any one of claims 1 to 6, wherein the neutralizer is calcium oxide, calcium hydroxide, calcium carbonate, sodium hydroxide, potassium carbonate or sodium carbonate.

9. The leaching method of black shale uranium vanadium ore according to claim 1, wherein the step S1: and crushing and grinding the black shale uranium vanadium ore sample until the granularity is less than-3 mm.

10. The method for leaching black shale uranium vanadium ore according to claim 1, wherein in the step S4: the washing ratio is 0.3 to 0.5.

Technical Field

The invention relates to the technical field of uranium ore hydrometallurgy, in particular to a leaching method of black shale uranium vanadium ore.

Background

Black shale is generally rich in organic matter and finely dispersed pyrite, siderite, and the like. In the black shale type uranium vanadium ore, uranium mostly exists in a dispersion state and an adsorption state, so that the black shale type uranium vanadium ore is easy to leach; most of vanadium exists in clay minerals such as micas, kaolinite and the like in a trivalent form, aluminum, titanium, iron and the like in silica octahedrons and alumina octahedrons are partially substituted, and vanadium existing in a similar form must destroy the lattice structure of the alumina octahedrons and oxidize the vanadium so as to be leachable. The leaching method of the uranium vanadium ore is greatly different according to the occurrence forms of uranium and vanadium. In the early stage, a sodium roasting process is adopted at home and abroad to treat uranium vanadium ore or single vanadium ore, but the process belongs to the processes of blank oxidizing roasting, calcifying roasting and the like which are eliminated due to serious environmental pollution, and the processes developed on the basis of the sodium roasting process have the problems of high energy consumption and unfavorable uranium leaching caused by high-temperature roasting, and are more suitable for treating vanadium ore without or with a small amount of uranium; the alkaline leaching process is suitable for the ores in which vanadium exists in an oxidation state; the acid leaching process has stronger adaptability than an alkaline leaching process and is environment-friendly, so that the acid leaching process is the most commonly adopted process in the current comprehensive recovery of uranium vanadium ore.

When the acid leaching process is adopted to treat black shale uranium vanadium ore, in order to destroy the mica structure and dissociate vanadium therein, a certain residual acid concentration needs to be ensured during conventional acid method agitation leaching, and the reaction generally needs to be carried out at high temperature, which can cause a large amount of impurity elements such as iron and aluminum in the ore to be dissolved out, increase reagent consumption and cause difficult metal separation. Taking vanadium recovery as an example, a cation extractant is generally adopted in a sulfuric acid system for extraction, and in order to ensure higher vanadium extraction rate, the pH value of a balanced water phase is generally controlled to be 1.5-2; in addition, the cationic extractant has higher extraction rate to the ferric iron, and the ferric iron is not easy to be back-extracted and is easy to accumulate in an organic phase, so that the capacity of the extractant is reduced and the iron content of a vanadium product exceeds the standard. Therefore, the pH and potential of the solution are generally adjusted before vanadium extraction, the pH of the raw material solution is adjusted to 2.5-3, and the potential is adjusted to-200 mV. The problems of excessive consumption of alkali and reducing agent, excessive consumption of reagents in the wastewater treatment process and the like in the vanadium recovery process can be caused by excessive concentration of residual acid and iron in the leaching solution; when the concentration of iron and iron is too high, even if a reducing agent is used for adjusting the potential, the iron is inevitably accumulated in an organic phase along with the extraction-back extraction process, and the iron of a vanadium product still exceeds the standard.

In order to reduce reagent consumption and ensure the quality of vanadium products, a leaching method of black shale uranium vanadium ore needs to be researched, and a leaching solution meeting the requirement of an extraction process is prepared under the condition of meeting the requirement of a leaching rate.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the leaching method of the black shale uranium vanadium ore is provided, so that the reagent consumption in the leaching and subsequent separation processes is reduced, and the quality of the vanadium product is ensured.

The invention provides a leaching method of black shale uranium vanadium ore, which comprises the following steps:

step S1: crushing and grinding a black shale uranium vanadium ore sample, adding water and sulfuric acid, and uniformly mixing to obtain a mixture;

step S2: curing the mixture to obtain a cured material;

step S3: adding water or dilute sulfuric acid into the cured material, controlling the volume mass ratio of liquid to solid, adding an iron inhibitor and a neutralizer, adjusting the pH value to 1-3, and leaching at 80-100 ℃;

step S4: vacuum filtering the ore pulp after the leaching treatment to obtain a leaching solution and a filter cake;

and the filter cake is subjected to counter-current washing by using 3-10 sections of dilute sulfuric acid, and the first section of washing water is merged into the leaching solution.

Preferably, in the step S1, the addition amount of the water is 0 to 30 wt% of the mass of the black shale uranium vanadium ore sample; the addition amount of the sulfuric acid is 1-100 wt% of the mass of the black shale uranium vanadium ore sample.

Preferably, in the step S2, the curing temperature is 20 to 300 ℃, and the curing time is 0.5 to 100 hours.

Preferably, in the step S3, the volume-to-mass ratio of the liquid to the solid is controlled to be 0.3 to 10.

Preferably, in the step S3, the time of the leaching treatment is 0.5 to 10 hours.

Preferably, in the step S3, an iron inhibitor and a neutralizer are added to adjust the pH value to 1-2.

Preferably the iron inhibitor is a sodium, ammonium or potassium salt.

Preferably, the neutralizing agent is calcium oxide, calcium hydroxide, calcium carbonate, sodium hydroxide, potassium carbonate or sodium carbonate.

Preferably, the step S1: and crushing and grinding the black shale uranium vanadium ore sample until the granularity is less than-3 mm.

Preferably, in step S4: the washing ratio is 0.3 to 0.5.

Compared with the prior art, the leaching method of the black shale uranium vanadium ore can reduce the concentration of the residual acid from 40-50 g/L to below 5g/L under the condition of ensuring the leaching rate of uranium vanadium; the iron in the leaching solution can be reduced to below 5g/L from 30-40 g/L. The purposes of reducing the concentration of the leached residual acid and inhibiting the dissolution of iron are realized, and the consumption of raw materials is effectively reduced.

Drawings

Fig. 1 is a schematic flow chart of a leaching method of black shale uranium vanadium ore according to an embodiment of the present invention.

Detailed Description

For a further understanding of the invention, embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are included merely to further illustrate features and advantages of the invention, and are not intended to limit the invention.

The embodiment of the invention discloses a leaching method of black shale uranium vanadium ore, which comprises the following steps:

step S1: crushing and grinding a black shale uranium vanadium ore sample, adding water and sulfuric acid, and uniformly mixing to obtain a mixture;

step S2: curing the mixture to obtain a cured material;

step S3: adding water or dilute sulfuric acid into the cured material, controlling the volume mass ratio of liquid to solid, adding an iron inhibitor and a neutralizer, adjusting the pH value to 1-3, and leaching at 80-100 ℃;

step S4: vacuum filtering the ore pulp after the leaching treatment to obtain a leaching solution and a filter cake;

and the filter cake is subjected to counter-current washing by using 3-10 sections of dilute sulfuric acid, and the first section of washing water is merged into the leaching solution.

According to the invention, the leaching method of the black shale uranium vanadium ore is explained in detail as follows:

step S1: crushing and grinding a black shale uranium vanadium ore sample, adding water and sulfuric acid, and uniformly mixing to obtain a mixture;

crushing and grinding the mixture until the granularity is less than-3 mm;

the addition amount of the water is 0-30 wt% of the mass of the black shale uranium vanadium ore sample; the addition amount of the sulfuric acid is 1-100 wt% of the mass of the black shale uranium vanadium ore sample.

The concentration of the sulfuric acid in the present invention is not particularly limited, and may be a concentration known to those skilled in the art.

Step S2: curing the mixture to obtain a cured material;

the curing temperature is preferably 20-300 ℃, more preferably 80-100 ℃, and further preferably 90-95 ℃; the aging time is preferably 0.5 to 100 hours, more preferably 2 to 24 hours, and further preferably 24 hours or 2.5 hours.

Step S3: adding water or dilute sulfuric acid into the cured material, controlling the volume mass ratio of liquid to solid, adding an iron inhibitor and a neutralizer, adjusting the pH value to 1-3, and leaching at 80-100 ℃;

controlling the volume mass ratio of the liquid to the solid to be 0.3-10;

the leaching time is preferably 0.5-10 hours, and more preferably 1-6 hours;

adding an iron inhibitor and a neutralizer, and adjusting the pH value to 1-2.

The iron inhibitor is preferably a sodium salt, an ammonium salt or a potassium salt, more preferably sodium chloride, sodium sulfate, sodium carbonate, sodium phosphate, potassium chloride, potassium sulfate, potassium carbonate, potassium phosphate, ammonium chloride, ammonium sulfate, ammonium carbonate or ammonium phosphate.

The neutralizer is calcium oxide, calcium hydroxide, calcium carbonate, sodium hydroxide, potassium carbonate or sodium carbonate.

Step S4: vacuum filtering the ore pulp after the leaching treatment to obtain a leaching solution and a filter cake;

and the filter cake is subjected to counter-current washing by using 3-10 sections of dilute sulfuric acid, and the first section of washing water is merged into the leaching solution.

In the countercurrent washing process, the washing ratio is preferably 0.3-0.5.

For further understanding of the present invention, the following examples are provided to illustrate the leaching method of black shale uranium vanadium ore according to the present invention, and the scope of the present invention is not limited by the following examples.

Example 1

Some black shale uranium vanadium ore contains 1.05% vanadium and 0.085% uranium, of which 82% of the vanadium is present in mica and the uranium is mainly present in adsorbed form. The black shale uranium vanadium ore is processed by the following steps:

(1) ore pretreatment: grinding ore to-60 mesh, adding 20 wt% (based on the mass of the raw ore) of sulfuric acid and 15 wt% (based on the mass of the raw ore) of water, and uniformly mixing;

(2) curing: sealing the mixed materials, and curing at 90 ℃ for 24 hours.

(3) Leaching: adding water into the cured material in the step (2), controlling the liquid-solid volume mass ratio to be 1, leaching at 96 ℃, adding 1.2 wt% of inhibitor sodium sulfate in the leaching process, adding calcium hydroxide to adjust the pH value to be 1.66 in the leaching process, adjusting the dosage of the calcium hydroxide to be 3.89 wt%, and leaching for 2 h.

(4) And (3) filtering: and (4) carrying out vacuum filtration on the ore pulp leached in the step (3) to obtain a leaching solution and a filter cake.

(5) Washing: the filter cake is washed by 3 sections of dilute sulphuric acid in a counter-current way, the washing ratio of a single section is 0.4, and the first section of washing water is merged into the leaching solution.

After the leaching by the method, the concentration of the residual acid in the leaching solution is 3.05g/L, the concentration of iron is 3.21g/L, and the leaching rates of uranium and vanadium are 94.5 percent and 76.8 percent respectively.

Comparative example 1

The same black shale uranium vanadium ore as in example 1 was used, containing 1.05% vanadium and 0.085% uranium, with 82% of the vanadium being present in the mica and the uranium being present mainly in adsorbed form. When the ore is treated by conventional agitation leaching, the acid dosage in the leaching process is 20%, the solid-to-volume mass ratio of the leaching solution is 1, the residual acid concentration of the leaching solution is 49.2g/L, the iron concentration is 35.1g/L, and the leaching rates of uranium and vanadium are 94.4% and 74.5% respectively.

Example 2

Some black shale uranium vanadium ore contains 0.946% of vanadium and 0.080% of uranium, wherein 88% of vanadium exists in mica, and uranium mainly exists in an adsorption form. The black shale uranium vanadium ore is processed by the following steps:

(1) ore pretreatment: grinding the ore to a particle size of-100 meshes, adding 12 wt% (based on the mass of the raw ore) of sulfuric acid and 18 wt% (based on the mass of the raw ore) of water, and uniformly mixing.

(2) Curing: after the materials are evenly mixed and sealed, the materials are cured for 2.5 hours at the temperature of 93 ℃.

(3) Leaching: adding water into the cured material in the step (2), controlling the liquid-solid volume mass ratio to be 1, leaching at 90 ℃, adding 1.5 wt% of inhibitor sodium sulfate (calculated by raw ore) in the leaching process, adding calcium carbonate to adjust the pH value to be 1.32 in the leaching process, adjusting the calcium carbonate consumption to be 4.10 wt% (calculated by raw ore), and leaching for 1 h.

(4) And (3) filtering: and (4) carrying out vacuum filtration on the ore pulp leached in the step (3) to obtain a leaching solution and a filter cake.

(5) Washing: the filter cake is washed by 4 sections of dilute sulphuric acid in a countercurrent way, the single-section washing ratio is 0.4, and the first section of washing water is merged into the leaching solution.

After the leaching by the method, the concentration of the residual acid in the leaching solution is 4.96g/L, the concentration of iron is 4.02g/L, and the leaching rates of uranium and vanadium are 93.9 percent and 72.1 percent respectively.

Comparative example 2

The same black shale uranium vanadium ore as in example 2, containing 0.946% vanadium, 0.080% uranium, with 88% of the vanadium present in the mica and the uranium mainly present in adsorbed form, was used. When the ore is treated by conventional agitation leaching, the acid dosage in the leaching process is 12%, the solid-to-volume mass ratio of the leaching solution is 1, the residual acid concentration of the leaching solution is 35.6g/L, the iron concentration is 21.8g/L, and the leaching rates of uranium and vanadium are 94.3% and 67.5% respectively.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.