Method for preparing high-purity silicon dioxide from laterite-nickel ore acid leaching residues

Abstract

The invention provides a method for preparing high-purity silicon dioxide from laterite-nickel ore acid leaching residues. The method comprises the following steps: (1) dissolving the acid leaching residues and a soluble alkali solution for reaction to obtain a sodium silicate solution; (2) introducing CO2 gas into the sodium silicate solution, and carrying out secondary carbonization separation to obtain crude SiO2 precipitate; and (3) carrying out H2SO4 acid pickling, water washing and solid-liquid separation on the crude SiO2 precipitate, and drying and roasting the separated solid phase to obtain the high-purity silicon dioxide. The method for preparing the high-purity silicon dioxide from the laterite-nickel ore acid leaching residues is simple in technological process, low in raw material price, low in synthesis cost, simple and feasible in synthesis process in industry and low in energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of recycling, and in particular to a method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue. Background Art

[0002] Acid leaching residue is the tailings left after nickel is extracted from laterite nickel ore by acid leaching. The main components are SiO2 and so on. Entering the 21st century, with the development of stainless steel, special steel, power batteries and other fields, the demand for nickel has increased significantly. Especially in the field of new energy, since nickel can increase the energy density of batteries, high nickel content in power batteries has become an industry trend. In order to meet the world's demand for nickel resources, the mining of laterite nickel ore will increase year by year. After the acid treatment of laterite nickel ore to extract nickel elements, a large amount of acid leaching residue is discharged. If these acid leaching residues are not fully utilized, new waste will be formed. Therefore, strengthening the utilization of acid leaching residue will be a common issue faced by countries around the world. The main component of laterite nickel ore acid leaching residue is SiO2, which accounts for more than 65%, and has extremely high resource value in the utilization of silicon resources. At present, a large amount of laterite nickel ore slag is mainly stored in open-air piles, which not only occupies valuable land, but also pollutes the surrounding environment and groundwater. Therefore, it is of great strategic significance to explore efficient extraction processes and develop new silicon products. Summary of the invention

[0003] In view of the above technical problems, the present invention proposes a method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides a method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue, comprising the following steps: (1) reacting the acid leaching residue of laterite nickel ore with a soluble alkali solution to obtain a sodium silicate solution; (2) introducing CO2 gas into the sodium silicate solution to perform carbonization separation to obtain crude SiO2 precipitate; (3) The crude SiO2 precipitate is acid-washed with H2SO4, washed with water, and separated into solid and liquid. The separated solid phase is then dried and calcined to obtain high-purity silicon dioxide.

[0005] Furthermore, in step (1), the laterite nickel ore acid leaching residue comprises silicon ions, aluminum ions, magnesium ions and iron ions; the mass percentage of the silicon ions is 62% to 73%, the mass percentage of the aluminum ions is 2% to 4%, the mass percentage of the magnesium ions is 8% to 16%, and the mass percentage of the iron ions is 2% to 8%; Preferably, the mass percentage of the silicon ions is 64% to 71%, the mass percentage of the aluminum ions is 2.3% to 3.5%, the mass percentage of the magnesium ions is 10% to 14%, and the mass percentage of the iron ions is 3% to 7%.

[0006] Furthermore, the soluble alkaline solution in step (1) includes at least one of sodium hydroxide and potassium hydroxide, and the mass percentage of the soluble alkaline solution is 5% to 30%. Preferably, the mass percentage of the soluble alkaline solution is 10-25%.

[0007] Furthermore, in the step (1), the dissolution reaction temperature is 60-90° C., and the concentration of the sodium hydroxide solution is 5-30%; Preferably, the dissolution reaction temperature in step (1) is 65-85°C.

[0008] Furthermore, in step (2), the carbonization temperature is 60 to 90° C., and the carbonization time is 1 to 3 hours.

[0009] Furthermore, in step (2), the carbonization is performed twice, the pH of the first carbonization is 10.8-13.5, and the pH of the second carbonization is 8.5-9.5.

[0010] Furthermore, in step (3), the concentration of H2SO4 is 0.1 to 0.3 mol / L.

[0011] Furthermore, the drying temperature in step (3) is 100-110°C.

[0012] Furthermore, in step (3), the calcination temperature is 300-500° C. and the calcination time is 1-3 hours.

[0013] The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue of the present invention has a simple process flow, low raw material price, low synthesis cost, simple and easy synthesis process in industry, and low energy consumption. The silicon dioxide material synthesized by the method of the present invention has high purity and is a raw material for manufacturing glass, quartz glass, water glass, optical fiber, important parts of the electronic industry, optical instruments, handicrafts and refractory materials.

[0014] The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue of the present invention has the following advantages: first, silicon is recovered from laterite nickel ore acid leaching residue as raw material, which provides a new idea for the treatment of laterite nickel ore acid leaching residue. Second, the laterite nickel ore acid leaching residue is used as raw material to efficiently utilize silicon dioxide in the acid leaching residue, avoid secondary pollution of tailings, and realize the rational use of resources. Third, NaOH solution is used to extract silicon from the acid leaching residue, with mild reaction conditions, low energy consumption and low processing cost. Fourth, CO2 gas is used to produce silicon dioxide from sodium carbide silicate solution, which is simple to operate and effectively discharges impurity elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a process flow chart of a method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue. DETAILED DESCRIPTION

[0016] See also Figure 1 The present invention provides a method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue, comprising the following steps: (1) reacting the acid leaching residue of laterite nickel ore with a soluble alkali solution to obtain a sodium silicate solution; (2) introducing CO2 gas into the sodium silicate solution to perform carbonization separation to obtain crude SiO2 precipitate; (3) The crude SiO2 precipitate is acid-washed with H2SO4, washed with water, and separated into solid and liquid. The separated solid phase is then dried and calcined to obtain high-purity silicon dioxide.

[0017] Furthermore, the mass percentage of silicon ions in step (1) is preferably 62% to 73%, further preferably 64% to 71%, and more preferably 66% to 70%; the mass percentage of aluminum ions is preferably 2% to 4%, further preferably 2.3% to 3.5%, and more preferably 2.5% to 3.3%; the concentration of magnesium ions is preferably 8% to 16%, further preferably 10% to 14%, and more preferably 11% to 13%; the concentration of iron ions is preferably 2% to 8%, further preferably 3% to 7%, and more preferably 4% to 6%.

[0018] In the present invention, soluble alkali solution is used to dissolve laterite nickel ore acid leaching residue, and the mass fraction of the alkali solution is preferably 5% to 30%, more preferably 10 to 25%, and more preferably 15 to 20%; the alkali solution preferably comprises one or more of sodium hydroxide solution and potassium hydroxide solution.

[0019] In the present invention, the dissolution reaction temperature in step (1) is preferably 60 to 90°C, more preferably 65 to 85°C, and even more preferably 70 to 80°C.

[0020] Experimental parameters Mass fraction of silicon in slag / % Mass fraction of alkali solution / % Dissolving temperature / ℃ Alkali soluble silicon yield / % 1 62 5 60 58.12% 2 64 10 65 72.33% 3 66 15 80 92.18% In the present invention, the carbonization reaction temperature in step (2) is preferably 60-90°C, more preferably 65-85°C, more preferably 70-80°C; the carbonization time is preferably 1-3h, more preferably 1.5-2.8h, more preferably 1.8-2.5h.

[0021] In the present invention, the pH of the first carbonization in step (2) is preferably 10.8-13.5, more preferably 12.0-13.0, more preferably 12.3-12.8; the pH of the second carbonization is preferably 8.5-9.5, more preferably 8.7-9.4, more preferably 8.8-9.3.

[0022] Experimental parameters Carbonization temperature / ℃ Carbonization time / h First carbonization pH Second carbonization pH Purity of crude silica / % 1 60 1.0 13.5 9.5 84.86% 2 65 1.5 13.0 9.4 88.93% 3 80 2.0 12.5 8.8 92.18% In the present invention, the H2SO4 in step (3) is preferably 0.1-0.3 mol / L, more preferably 0.13-0.28 mol / L, and even more preferably 0.15-0.26 mol / L.

[0023] In the present invention, the drying temperature in step (3) is preferably 100-110°C, more preferably 102-108°C, and even more preferably 103-107°C.

[0024] In the present invention, the calcination temperature in step (3) is preferably 300-500°C, more preferably 350-450°C, more preferably 380-420°C; the calcination time is preferably 1-3h, more preferably 1.5-2.5h, more preferably 1.8-2.3h.

[0025] Experimental parameters <![CDATA[H2SO4 concentration / mol / L]]> Drying temperature / ℃ Calcination temperature / ℃ Calcination time / h Silica purity / % 1 0.1 100 300 1.0 92.88% 2 0.15 103 350 1.5 93.42% 3 0.2 105 400 2.0 95.56% The reaction principle of the method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue of the present invention is analyzed as follows: A: SiO2+2OH - →SiO3 2- +H2O B: SiO3 2- +CO2→CO3 2- +SiO2 Example

[0026] A certain amount of acid leaching residue was mixed with 15% sodium hydroxide solution at a solid-liquid ratio of 1:2, and dissolved at 80°C for 1 hour to obtain a sodium silicate solution; at a temperature of 80°C, CO2 gas was introduced into the sodium silicate solution while stirring, and the CO2 ventilation rate was 20mL / min. The pH value during the first carbonization separation was adjusted to 13 to remove impurity elements in the solution. After the first carbonization separation was completed, the pH value during the second carbonization separation was adjusted to 9.0. The crude SiO2 precipitate was obtained by stirring for 1 hour; the crude SiO2 precipitate was mixed with 0.15mol / L dilute sulfuric acid solution at a solid-liquid ratio of 1:3 for dissolution reaction for 0.5h. After the reaction was completed, it was filtered while hot and rinsed with pure water until the pH was close to neutral to obtain a filter cake, which was dried at 100°C for 1 hour, calcined at 350°C for 1 hour, and cooled to obtain silicon dioxide with a purity of 93.42%. Example

[0027] A certain amount of acid leaching residue was mixed with 15% sodium hydroxide solution at a solid-liquid ratio of 1:3, and dissolved at 80°C for 2 hours to obtain a sodium silicate solution; at a temperature of 80°C, CO2 gas was introduced into the sodium silicate solution while stirring, and the CO2 ventilation rate was 20mL / min. The pH value during the first carbonization separation was adjusted to 12.6 to remove impurity elements in the solution. After the first carbonization separation was completed, the pH value during the second carbonization separation was adjusted to 9.0. The crude SiO2 precipitate was obtained by stirring for 1 hour; the crude SiO2 precipitate was mixed with 0.2mol / L dilute sulfuric acid solution at a solid-liquid ratio of 1:3 for dissolution reaction for 0.5h. After the reaction was completed, it was filtered while hot and rinsed with pure water until the pH was close to neutral to obtain a filter cake, which was dried at 105°C for 1h, calcined at 400°C for 2h, and cooled to obtain silicon dioxide with a purity of 95.56%. Example

[0028] A certain amount of acid leaching residue was mixed with 15% sodium hydroxide solution at a solid-liquid ratio of 1:3, and dissolved at 80°C for 2 hours to obtain a sodium silicate solution; at a temperature of 80°C, CO2 gas was introduced into the sodium silicate solution while stirring, and the CO2 ventilation rate was 20mL / min. The pH value during the first carbonization separation was adjusted to 12.3 to remove impurity elements in the solution. After the first carbonization separation was completed, the pH value during the second carbonization separation was adjusted to 8.8. The crude SiO2 precipitate was obtained by stirring for 1 hour; the crude SiO2 precipitate was mixed with 0.25mol / L dilute sulfuric acid solution at a solid-liquid ratio of 1:3 for dissolution reaction for 1 hour. After the reaction was completed, it was filtered while hot and rinsed with pure water until the pH was close to neutral to obtain a filter cake, which was dried at 105°C for 2 hours, and then calcined at 400°C for 2 hours. After cooling, silicon dioxide with a purity of 94.37% was obtained.

[0029] The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue of the present invention has a simple process flow, low raw material price, low synthesis cost, simple and easy synthesis process in industry, and low energy consumption. The silicon dioxide material synthesized by the method of the present invention has high purity and is a raw material for manufacturing glass, quartz glass, water glass, optical fiber, important parts of the electronic industry, optical instruments, handicrafts and refractory materials.

[0030] The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue of the present invention has the following advantages: first, silicon is recovered from laterite nickel ore acid leaching residue as raw material, which provides a new idea for the treatment of laterite nickel ore acid leaching residue. Second, the laterite nickel ore acid leaching residue is used as raw material to efficiently utilize silicon dioxide in the acid leaching residue, avoid secondary pollution of tailings, and realize the rational use of resources. Third, NaOH solution is used to extract silicon from the acid leaching residue, with mild reaction conditions, low energy consumption and low processing cost. Fourth, CO2 gas is used to produce silicon dioxide from sodium carbide silicate solution, which is simple to operate and effectively discharges impurity elements.

[0031] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not limited to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue, characterized in that: The steps include: (1) reacting the acid leaching residue of laterite nickel ore with a soluble alkali solution to obtain a sodium silicate solution; (2) introducing CO2 gas into the sodium silicate solution to perform carbonization separation to obtain crude SiO2 precipitate; (3) The crude SiO2 precipitate is acid-washed with H2SO4, washed with water, and separated into solid and liquid. The separated solid phase is then dried and calcined to obtain high-purity silicon dioxide.

2. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: In step (1), the laterite nickel ore acid leaching residue comprises silicon ions, aluminum ions, magnesium ions and iron ions; the mass percentage of the silicon ions is 62% to 73%, the mass percentage of the aluminum ions is 2% to 4%, the mass percentage of the magnesium ions is 8% to 16%, and the mass percentage of the iron ions is 2% to 8%; Preferably, the mass percentage of the silicon ions is 64% to 71%, the mass percentage of the aluminum ions is 2.3% to 3.5%, the mass percentage of the magnesium ions is 10% to 14%, and the mass percentage of the iron ions is 3% to 7%.

3. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: The soluble alkaline solution in step (1) includes at least one of sodium hydroxide and potassium hydroxide, and the mass percentage of the soluble alkaline solution is 5% to 30%. Preferably, the mass percentage of the soluble alkaline solution is 10-25%.

4. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: The dissolution reaction temperature in step (1) is 60-90° C., and the concentration of the sodium hydroxide solution is 5-30%; Preferably, the dissolution reaction temperature in step (1) is 65-85°C.

5. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: In the step (2), the carbonization temperature is 60 to 90° C. and the carbonization time is 1 to 3 hours.

6. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: In the step (2), the carbonization is performed twice, the pH of the first carbonization is 10.8-13.5, and the pH of the second carbonization is 8.5-9.

5.

7. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: In the step (3), the concentration of H2SO4 is 0.1 to 0.3 mol / L.

8. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: The drying temperature in step (3) is 100-110°C.

9. The method for preparing high-purity silicon dioxide from laterite nickel ore acid leaching residue according to claim 1, characterized in that: In the step (3), the calcination temperature is 300-500° C. and the calcination time is 1-3 hours.

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