CN115821063A - Method for purifying magnesium from serpentine - Google Patents

Abstract

The invention belongs to the technical field of magnesium ore treatment, and in particular relates to a method for purifying magnesium from serpentine. The method for purifying magnesium from serpentine provided by the invention comprises the following steps: (1) carrying out acid leaching after grinding the serpentine, and filtering to obtain a leachate; (2) adding Neutralizing agent, after solid-liquid separation, neutralized liquid is obtained; (3) the neutralized liquid obtained in the step (2) is passed into an ion exchange resin adsorption system for adsorption treatment, to obtain adsorbed resin and adsorbed high-magnesium solution. The method can not only separate iron, aluminum, and chromium in the leach solution, but also effectively realize the separation of nickel, cobalt, manganese and magnesium in the leach solution, and realize the deep purification of the high-magnesium solution.

Description

A method for purifying magnesium from serpentine

technical field

The invention belongs to the technical field of magnesium ore treatment, and in particular relates to a method for purifying magnesium from serpentine.

Background technique

Magnesium is one of the lightest structural metal materials, and has the advantages of high specific strength and specific stiffness, good damping and machinability, and easy recycling. Magnesium alloys are used in the automobile industry at home and abroad to reduce weight, save energy, reduce pollution and improve the environment. Compared with plastics, magnesium alloy has light weight, high specific strength, good vibration damping, good thermal fatigue performance, not easy to age, good thermal conductivity, strong electromagnetic shielding ability, very good die-casting process performance, especially easy to recycle It is a new generation of high-performance structural materials that can replace steel, aluminum alloys and engineering plastics.

Serpentine is the alteration product of olivine. It is a general term for a hydrous magnesium-rich silicate mineral. Its general formula is Mg ₃ Si ₂ O ₅ (OH) ₄ , and its structure is silicon-oxygen tetrahedron and hydrogen-oxygen It is a 1:1 layered silicate mineral composed of magnesium octahedra. Serpentine ore contains more than 34% of silicon dioxide, more than 36% of magnesium oxide, more than 8% of iron oxide, and about 0.7% of calcium oxide and other small components. It is a very valuable mineral. Mineral resources, in which the content of magnesium oxide and silicon dioxide exceeds 1/3 of the total weight of the ore. If these serpentines can be properly treated, not only can the problem of waste accumulation be solved, but also magnesium metal with a wide range of uses can be obtained. wait.

Contents of the invention

The present invention is based on the inventor's discovery and recognition of the following facts and problems:

The existing patent application CN113548683A discloses a method of using serpentine to prepare magnesium-based and silicon-based materials without waste. The magnesium and silicon are initially separated by acid leaching, and the magnesium-containing filtrate is crystallized, redissolved, Precipitation and other operations to obtain high-grade magnesium-based materials.

Existing patent application CN114686702A proposes a method for purifying magnesium in one pot of serpentine atmospheric sulfuric acid leaching solution. The leaching solution of serpentine sulfuric acid atmospheric acid leaching is subjected to one-pot three-stage reaction treatment, followed by solid-liquid separation to obtain purified magnesium solution.

In the existing technology, magnesium metal is prepared by treating serpentine with acid leaching. After acid leaching, magnesium and other metals enter the leaching solution, and a neutralizing agent is added to adjust the pH. Most of the iron, aluminum, and chromium can be separated, but It is difficult to realize the separation of nickel, cobalt and manganese, which will affect the purity of the product when used in the preparation of subsequent magnesium products.

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, the embodiment of the present invention proposes a method for purifying magnesium from serpentine, which can effectively separate nickel, cobalt, manganese and magnesium in serpentine leaching solution, and realize deep purification of high-magnesium solution.

A kind of method for purifying magnesium from serpentine of the embodiment of the present invention, comprises the following steps:

(1) Carry out acid leaching after serpentine is ground, filter to obtain leachate;

(2) adding a neutralizing agent in the leachate obtained in the step (1), and obtaining a neutralized liquid after solid-liquid separation;

(3) Pass the neutralized liquid obtained in the step (2) into an ion-exchange resin adsorption system for adsorption treatment to obtain an adsorbed resin and an adsorbed high-magnesium solution.

Advantages and technical effects brought by the method for purifying magnesium from serpentine in the embodiments of the present invention, 1. In the embodiments of the present invention, a neutralizing agent is added to the leachate, and iron, aluminum, and chromium are precipitated by adjusting the pH of the leachate. 2. In the embodiment of the present invention, the effective separation of nickel, cobalt, manganese and magnesium can be realized by the ion exchange resin adsorption system, and the deep purification of the high-magnesium solution is realized; 3. In the embodiment of the present invention, the The method is simple and easy to operate, and is convenient for popularization and application in industrial production.

In some embodiments, in the step (1), the acid used in the pickling is any one of sulfuric acid and hydrochloric acid.

In some embodiments, in the step (2), the neutralizing agent includes at least one of sodium hydroxide, milk of lime, and magnesium oxide emulsion, and the addition amount of the neutralizing agent is to adjust the pH of the leachate 3 to 5 shall prevail.

In some embodiments, in the step (3), the ion exchange resin is IDA resin.

In some embodiments, the adsorption system is a single-column or multi-column series system.

In some embodiments, the column passing rate of the adsorption treatment is 1-3BV/h.

In some embodiments, in the step (3), dilute acid is passed into the adsorbed resin to wash the co-adsorbed magnesium to obtain the washed resin and magnesium-rich washed liquid. Preferably, the magnesium-rich After washing, the liquid is returned to step (1) for acid leaching.

In some embodiments, the dilute acid includes 15-20 g/L sulfuric acid or 10-15 g/L hydrochloric acid.

In some embodiments, high acid is introduced into the washed resin to desorb nickel, cobalt and manganese to obtain a mixed solution of the desorbed resin and nickel, cobalt and manganese.

In some embodiments, the high acid includes sulfuric acid with a concentration of not lower than 50 g/L or hydrochloric acid with a concentration of not lower than 37 g/L.

Detailed ways

Embodiments of the present invention are described in detail below, and the embodiments are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

A kind of method for purifying magnesium from serpentine of the embodiment of the present invention, comprises the following steps:

(1) Carry out acid leaching after serpentine is ground, filter to obtain leachate;

(2) adding a neutralizing agent in the leachate obtained in the step (1), and obtaining a neutralized liquid after solid-liquid separation;

(3) Pass the neutralized liquid obtained in the step (2) into an ion-exchange resin adsorption system for adsorption treatment to obtain an adsorbed resin and an adsorbed high-magnesium solution.

In the method for purifying magnesium from serpentine in the embodiment of the present invention, a neutralizing agent is added to the leachate, and by adjusting the pH of the leachate, iron, aluminum, and chromium are precipitated and then effectively separated; nickel can be realized through an ion-exchange resin adsorption system. , Cobalt, manganese and magnesium can be effectively separated to realize the deep purification of high-magnesium solution; the method is simple and easy to operate, and is convenient for popularization and application in industrial production.

In some embodiments, preferably, in the step (1), the acid used in the pickling is any one of sulfuric acid and hydrochloric acid. Further preferably, when the acid is hydrochloric acid, magnesium sulfate and barium chloride are sequentially added to the high-magnesium solution after adsorption, and solid-liquid separation is performed to obtain a deeply purified magnesium solution; wherein, magnesium sulfate is added in equimolar proportions according to the calcium ion content, Barium chloride was added equimolarly according to the sulfate ion content. The use of hydrochloric acid or sulfuric acid in the embodiments of the present invention can fully dissolve the metal in the serpentine, which is conducive to improving the purity of magnesium; when the acid used is hydrochloric acid, adding magnesium sulfate and barium chloride in turn can precipitate and remove the liquid phase respectively. Calcium and sulfate radicals in the solution to obtain a deeply purified magnesium solution.

In some embodiments, preferably, in the step (2), the neutralizing agent includes at least one of sodium hydroxide, milk of lime, and magnesium oxide emulsion, and the addition amount of the neutralizing agent is such that the leachate Adjust the pH to 3-5. In the embodiment of the present invention, adding an alkaline neutralizing agent to the leaching solution can cause iron, aluminum, and chromium to form precipitates and separate them out. The addition amount of the neutralizing agent is further preferred, which is conducive to fully removing iron, aluminum, and chromium, and does not leave the leaching solution. Introduce new impurity elements.

In some embodiments, preferably, in the step (3), the ion exchange resin is IDA resin. Further preferably, the adsorption system is a single-column or multi-column series system. More preferably, the column passing rate of the adsorption treatment is 1-3BV/h. In the embodiment of the present invention, the kind of ion-exchange resin is preferred, which is conducive to the selective adsorption of nickel, cobalt, and manganese in the liquid after neutralization, and further limits the rate of adsorption through the column, and then makes the nickel, cobalt, and manganese Adsorption is carried out more fully, effective separation from magnesium is realized, and the purity of magnesium solution is further improved.

In some embodiments, preferably, in the step (3), dilute acid is introduced into the adsorbed resin to wash the co-adsorbed magnesium to obtain the washed resin and magnesium-rich washed liquid. Preferably, the After the magnesium-rich washing, the solution is returned to step (1) for acid leaching. Further preferably, the dilute acid includes 15-20 g/L sulfuric acid or 10-15 g/L hydrochloric acid. In the embodiment of the present invention, the magnesium adsorbed in the adsorbed resin is washed with dilute acid to obtain a magnesium-rich washed liquid, and the magnesium-rich washed liquid is returned to step (1) for acid leaching treatment, which can increase the recovery rate of magnesium at 95%.

In some embodiments, preferably, a high acid is introduced into the washed resin to desorb nickel, cobalt and manganese to obtain a mixed solution of the desorbed resin and nickel, cobalt and manganese. Further preferably, the high acid includes sulfuric acid with a concentration not lower than 50 g/L or hydrochloric acid with a concentration not lower than 37 g/L. In the embodiment of the present invention, high acid is used to desorb the resin after washing, so that nickel, cobalt and manganese are desorbed from the resin, and the nickel, cobalt and manganese are recovered.

In some embodiments, preferably, a neutralizing agent is added to the mixed solution of nickel, cobalt and manganese for precipitation or extraction and separation for recycling respectively. Further preferably, soft water is passed into the resin after the desorption for washing. In the embodiment of the present invention, nickel, cobalt, and manganese are recycled to increase the utilization value of serpentine. In addition, the desorbed resin is washed with soft water, and the residual acid can be returned to the adsorption process in step (2) for repeated use, which reduces the cost of industrial production.

The present invention will be described in detail below in conjunction with specific embodiments.

Example 1

(1) Serpentine is leached with hydrochloric acid after ore grinding, and the leachate composition is as shown in Table 1 below:

Table 1. Composition of serpentine sulfuric acid leaching solution (mg/L)

Mg co mn Ni Ca Fe Al Cr 55514 32.62 134.95 266.02 3497.5 4523 3306 2189

(2) Add magnesium oxide emulsion to the obtained leaching solution, adjust pH=4.2, make iron, aluminum, chromium form precipitation, obtain neutralized liquid after solid-liquid separation, and the composition of neutralized liquid is shown in Table 2 below.

Table 2. Neutralized solution composition (mg/L)

Mg co mn Ni Ca 55510 32.62 134.95 266.02 3497.5

(3) Pass the neutralized liquid into a 3-stage series-connected IDA ion exchange resin adsorption system, the rate of adsorption through the column is 1BV/h, remove nickel, cobalt, manganese, etc., and obtain a high-magnesium solution after adsorption, and a high-magnesium solution after adsorption The ingredients are shown in Table 3 below.

Table 3. Liquid components after adsorption (mg/L)

Mg co mn Ni Ca 55503 <0.1 <0.1 <0.1 3495

(4) Add magnesium sulfate in an equimolar amount to the calcium ion in the high-magnesium solution after adsorption, then add barium chloride in an equimolar amount to the sulfate ion, respectively precipitate and remove calcium and sulfate in the liquid phase to obtain a deep purification Magnesium liquid, the composition of deeply purified magnesium liquid is shown in Table 4 below.

Table 4. Deeply purified magnesium liquid composition (mg/L)

Mg co mn Ni Ca 54518 <0.1 <0.1 <0.1 <0.1

(5) After the adsorption, the resin is passed into 10g/L dilute hydrochloric acid to wash the co-adsorbed magnesium to obtain the washed resin and the magnesium-rich washing liquid. The composition of the magnesium-rich washing liquid is shown in Table 5 below, and return to step (1) Serpentine Stone acid leaching process.

Table 5. Magnesium-rich liquid components after washing (mg/L)

Mg co mn Ni Ca 35 8 12 3 <0.1

(6) Pass into the hydrochloric acid of 40g/L in the resin after washing and carry out desorption, obtain the mixed solution of resin and nickel, cobalt, manganese after desorption, the composition of nickel, cobalt, manganese mixed solution is as shown in table 6 below.

Table 6. Mixed solution components of nickel, cobalt and manganese (mg/L)

co mn Ni 301 1220 2538

(7) Pass soft water into the resolved resin to wash away the residual acid, and return to the adsorption process for repeated use.

(8) The mixed solution of nickel, cobalt and manganese is extracted by P204 and P507 in sequence, and recycled after separation.

In this embodiment, the calculated recovery rate of magnesium is 98.2%, the recovery rate of Ni is 98.1%, the recovery rate of Co is 99.0%, and the recovery rate of Mn is 95.4%.

Example 2

The operation procedure of this embodiment is the same as that of Example 1, the only difference is that what is used in step (3) is a single-column adsorption system, the rate of adsorption through the column is 3BV/h, and nickel, cobalt, manganese, etc. are removed by adsorption to obtain adsorption After the high magnesium solution, the composition of the high magnesium solution after adsorption is shown in Table 7 below.

Table 7. Liquid components after adsorption (mg/L)

Mg co mn Ni Ca 55481 <0.1 <0.1 <0.1 3276

In this embodiment, the calculated recovery rate of magnesium is 99.9%, the recovery rate of Ni is 96%, the recovery rate of Co is 97%, and the recovery rate of Mn is 84%.

Example 3

The operation procedure of this embodiment is the same as that of Example 1, except that in step (5), the diluted hydrochloric acid of 15g/L is passed into the adsorbed resin to wash the co-adsorbed magnesium to obtain the washed resin and magnesium-enriched washed magnesium. liquid, the composition of the liquid after magnesium-rich washing is shown in Table 8 below, and returns to step (1) serpentine acid leaching process.

Table 8. Magnesium-rich liquid components after washing (mg/L)

Mg co mn Ni Ca 67 18 44 25 <0.1

In this embodiment, the calculated recovery rate of magnesium is 97.3%, the recovery rate of Ni is 97%, the recovery rate of Co is 98%, and the recovery rate of Mn is 88%.

Example 4

The operation steps of this embodiment are the same as those of Example 1, except that in step (5), the diluted hydrochloric acid of 25g/L is passed into the adsorbed resin to wash the co-adsorbed magnesium to obtain the washed resin and the magnesium-enriched washed resin. The composition of the magnesium-rich washing solution is shown in Table 9 below, and the magnesium-rich washing solution returns to step (1) serpentine acid leaching process.

Table 9. Magnesium-rich liquid components after washing (mg/L)

Mg co mn Ni Ca 542 43 85 34 <0.1

In this embodiment, the calculated recovery rate of magnesium is 95%, the recovery rate of Ni is 60%, the recovery rate of Co is 58%, and the recovery rate of Mn is 43%.

Example 5

The operation procedure of this embodiment is the same as that of Example 1, and the difference is that step (5) is cancelled, and the hydrochloric acid of 40g/L is directly passed into the resin after adsorption for desorption, and the mixture of resin and nickel, cobalt and manganese is obtained after desorption. Solution, the composition of the mixed solution of nickel, cobalt and manganese is shown in Table 10 below.

Table 10. Mixed solution components of nickel, cobalt and manganese (mg/L)

co mn Ni Mg 301 1220 2538 1304

In this embodiment, the calculated recovery rate of magnesium is 73%, the recovery rate of Ni is 98.1%, the recovery rate of Co is 99.0%, and the recovery rate of Mn is 95.4%.

Comparative example 1

The comparative example is the same as in Example 1, except that the resin in the ion-exchange resin used in step (3) is an anion resin, and nickel, cobalt, manganese, etc. are removed to obtain a high-magnesium solution after adsorption. The composition of the post-high magnesium solution is shown in Table 11 below.

Table 11. Liquid components after adsorption (mg/L)

Mg co mn Ni Ca 55510 32.62 134.95 266.02 3497.5

In this comparative example, the anion resin was used as the ion exchange resin, and the nickel, cobalt, manganese and magnesium in the neutralization solution could not be separated, and the deep purification of the high magnesium solution could not be realized.

As used herein, the terms "one embodiment," "some embodiments," "example," "specific examples," or "some examples" mean specific features, structures, materials, or features described in connection with the embodiment or example. A feature is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the above-mentioned embodiments have been shown and described, it can be understood that the above-mentioned embodiments are exemplary, and should not be construed as limitations on the present invention. Changes, modifications, substitutions and variations made by those skilled in the art to the above-mentioned embodiments All within the protection scope of the present invention.

Claims (10)

1. a method for purifying magnesium from serpentine, is characterized in that, comprises the following steps: (1) Carry out acid leaching after serpentine is ground, filter to obtain leachate; (2) adding a neutralizing agent in the leachate obtained in the step (1), and obtaining a neutralized liquid after solid-liquid separation; (3) Pass the neutralized liquid obtained in the step (2) into an ion-exchange resin adsorption system for adsorption treatment to obtain an adsorbed resin and an adsorbed high-magnesium solution. 2. the method for purifying magnesium from serpentine according to claim 1, is characterized in that, in described step (1), the acid that described pickling adopts is any one in sulfuric acid and hydrochloric acid. 3. the method for serpentine purified magnesium according to claim 1, is characterized in that, in described step (2), described neutralizer comprises at least one in sodium hydroxide, milk of lime, magnesium oxide emulsion , the addition amount of the neutralizing agent is based on adjusting the pH of the leachate to 3-5. 4. the method for serpentine purified magnesium according to claim 1, is characterized in that, in described step (3), described ion exchange resin is IDA resin. 5. The method for purifying magnesium from serpentine according to claim 1 or 4, characterized in that, the adsorption system is a single column or a multi-column series system. 6. The method for purifying magnesium from serpentine according to claim 1 or 4, characterized in that, the column passing rate of the adsorption treatment is 1-3BV/h. 7. according to the method for the described serpentine magnesium of claim 1 or 4, it is characterized in that, in the described step (3), in the resin after described adsorption, pass into the magnesium that dilute acid washing co-adsorbs, obtains The washed resin and magnesium-rich washed liquid, preferably, the magnesium-rich washed liquid is returned to step (1) for acid leaching. 8. The method for purifying magnesium from serpentine according to claim 7, wherein the dilute acid comprises 15-20g/L sulfuric acid or 10-15g/L hydrochloric acid. 9. according to the method for claim 7 or 8 described serpentine purified magnesiums, it is characterized in that, in the resin after described washing, pass into high-acid desorption nickel, cobalt, manganese, obtain resin and nickel, cobalt, manganese after desorption Manganese mixed solution. 10. The method for purifying magnesium from serpentine according to claim 9, wherein the high acid comprises sulfuric acid with a concentration not lower than 50 g/L or hydrochloric acid with a concentration not lower than 37 g/L.