阅读说明：本技术 一种用富硅黏土制备水玻璃联产金属盐结晶的方法 (Method for preparing water glass and co-producing metal salt crystals by using silicon-rich clay ) 是由 潘爱芳 马昱昭 孙悦 马润勇 于 2021-10-22 设计创作，主要内容包括：本发明涉及一种用富硅黏土制备水玻璃联产金属盐结晶的方法,通过酸碱联合分步溶出,可将富硅黏土中的硅分离提取,并转化为水玻璃产品,同时将铝铁等金属盐结晶。本发明方法具有工艺过程简单、对设备无特殊要求、能耗低、工艺参数可控性好、残渣剩余量小、成本低等优点,为富硅黏土的开发利用开辟了新的途径。(The invention relates to a method for preparing water glass and coproducing metal salt crystals by using silicon-rich clay, which can separate and extract silicon in the silicon-rich clay through acid-base combined step-by-step dissolution, convert the silicon into a water glass product and crystallize metal salts such as aluminum, iron and the like. The method has the advantages of simple process, no special requirement on equipment, low energy consumption, good controllability of process parameters, small residual amount of residues, low cost and the like, and opens up a new way for developing and utilizing the silicon-rich clay.)

1. A method for preparing water glass and co-producing metal salt crystals by using silicon-rich clay is characterized by comprising the following steps:

s1, crushing and grinding the silicon-rich clay to 100-400 meshes to obtain a silicon-rich clay powdery sample;

s2, mixing the silicon-rich clay powder sample obtained in the step S1 with a sulfuric acid solution, stirring for reaction, and filtering and separating to obtain an acid leaching solution and an acid leaching residue;

s3, adding the acid leaching residue obtained in the step S2 into a sodium hydroxide solution, stirring and mixing, and filtering to obtain water glass after stirring;

s4, concentrating the pickle liquor obtained in the step S2 to obtain aluminum iron metal salt crystals.

2. The method of claim 1, wherein in step S2, the concentration of sulfuric acid is 4 to 12 mol/L; the liquid-solid ratio of the sulfuric acid solution to the silicon-rich clay powder is preferably 5-10: 1.

3. The method of claim 1, wherein in step S2, the stirring reaction temperature is 80-200 ℃ and the stirring reaction time is 0.5-6 h.

4. The method of claim 1, wherein the sodium hydroxide solution has a mass concentration of preferably 10% to 40% in step S3.

5. The method of claim 1, wherein in the step S3, the solid-liquid mass ratio of the acid leaching residue to the sodium hydroxide solution is 1: 3.5-20.

6. The method according to claim 1, wherein in step S3, the solid-liquid mass ratio of the acid leaching residue to the sodium hydroxide solution is 1: 3.5-14.

7. The method of claim 1, wherein in step S3, the stirring temperature is 60-100 ℃ and the stirring time is 0.5-3 h.

8. The method of claim 1, further comprising the steps of:

s5, calcining the aluminum iron metal salt crystal, adding water into the calcined powder, stirring, filtering and separating to obtain iron oxide and aluminum sulfate solution;

s6, slowly adding alkali into the aluminum sulfate solution, and adjusting the pH value to obtain the aluminum hydroxide colloid flocculating constituent.

9. The method of claim 8, wherein in step S5, the calcination temperature is 490-520 ℃ and the calcination time is 15-30 min.

10. The method of claim 8, wherein in step S6, the alkali is sodium hydroxide, potassium hydroxide or ammonia water, and the addition of the alkali is stopped when the pH value is 5.5-7.

Technical Field

The invention relates to a method for preparing water glass and co-producing metal salt crystals by using silicon-rich clay, belonging to the technical field of metallurgy and mineral product utilization.

Background

Sodium silicate, commonly known as natron, is a water-soluble silicate, and its aqueous solution, commonly known as water glass, is an ore binder. Has a chemical formula of R₂O·nSiO₂In the formula, R₂O is alkali metal oxide, n is the ratio of the mole numbers of silicon dioxide and alkali metal oxide, and is called the water glass modulus.

The application of the water glass is very wide and almost extends to various departments of national economy. The silicon compound is used for manufacturing various silicate products such as silica gel, white carbon black, zeolite molecular sieve, sodium metasilicate pentahydrate, silica sol, layered silicon, instant powdery sodium silicate, potassium sodium silicate and the like in a chemical system, and is a basic raw material of the silicon compound. In economically developed countries, more than 50 deep processing series products using sodium silicate as raw material have been developed, and some of them have been used in the high, fine and sophisticated scientific fields; the water-soluble polymer is an indispensable raw material in detergents such as washing powder, soap and the like in the light industry, and is also a water softener and a settling agent; the product is used for manufacturing quick-drying cement, acid-proof cement waterproof oil, soil curing agent, refractory material and the like in the building industry; the silicon fertilizer can be produced in agriculture; in addition, the catalyst is used as a silicon-aluminum catalyst for petroleum catalytic cracking, a metal preservative, a food preservative, an adhesive and the like.

The water glass is prepared by calcining quartz sand and soda ash at 1300-1400 ℃ to generate solid, and dissolving the solid in high-temperature high-pressure water to obtain a solution water glass product. However, the cost of the raw material quartz sand is high, and the energy consumption required by high temperature of 1300-1400 ℃ is large, so that the cost for preparing the water glass is high, and how to provide a method for preparing the water glass which does not need high-temperature calcination and has low cost is a technical problem which needs to be solved urgently. The invention provides a novel method for preparing water glass from silicon-rich clay with lower raw material cost, and opens up a new way for utilizing the silicon-rich clay.

Disclosure of Invention

Technical problem to be solved

In order to solve the above problems in the prior art, the invention provides a method for preparing water glass and co-producing metal salt crystals by using silicon-rich clay, which separates and extracts silicon in the silicon-rich clay and converts the silicon into a water glass product, thereby realizing the utilization of extracting silicon from the silicon-rich clay.

(II) technical scheme

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

a method for preparing water glass and co-producing metal salt crystals by using silicon-rich clay comprises the following steps:

s1, crushing and grinding the silicon-rich clay to 100-400 meshes to obtain a silicon-rich clay powdery sample;

s2, mixing the silicon-rich clay powder sample obtained in the step S1 with a sulfuric acid solution, stirring for reaction, and filtering and separating to obtain an acid leaching solution and an acid leaching residue;

s3, adding the acid leaching residue obtained in the step S2 into a sodium hydroxide solution, stirring and mixing, and filtering to obtain water glass after stirring;

s4, concentrating the pickle liquor obtained in the step S2 to obtain aluminum iron metal salt crystals.

In the method, preferably, in the step S2, the concentration of the sulfuric acid is 4-12 mol/L; the liquid-solid ratio of the sulfuric acid solution to the silicon-rich clay powder is preferably 5-10: 1.

In the above method, preferably, in step S2, the stirring reaction temperature is 80 to 200 ℃, and the stirring reaction time is 0.5 to 6 hours.

Further preferably, the temperature of the stirring reaction is 80-180 ℃.

As described above, preferably, in step S3, the mass concentration of the sodium hydroxide solution is preferably 10% to 40%.

In the method, in step S3, the solid-liquid mass ratio of the acid leaching residue to the sodium hydroxide solution is preferably 1:3.5 to 20.

Further, preferably, the solid-liquid mass ratio of the acid leaching residue to the sodium hydroxide solution is 1: 3.5-14.

In the above method, in step S3, the stirring temperature is preferably 60 to 100 ℃, and the stirring time is preferably 0.5 to 3 hours.

The method as described above preferably further comprises the steps of:

s5, calcining the aluminum iron metal salt crystal, adding water into the calcined powder, stirring, filtering and separating to obtain iron oxide and aluminum sulfate solution;

s6, slowly adding alkali into the aluminum sulfate solution, and adjusting the pH value to obtain the aluminum hydroxide colloid flocculating constituent.

In the above method, preferably, in step S5, the calcination temperature is 490 to 520 ℃, and the calcination time is 15 to 30 min.

In the method, preferably, in step S6, the alkali is sodium hydroxide, potassium hydroxide or ammonia water, and the addition of the alkali is stopped when the pH is 5.5 to 7.

(III) advantageous effects

The invention has the beneficial effects that:

according to the method for preparing the water glass and coproducing the metal salt crystals by using the silicon-rich clay, silicon in the silicon-rich clay can be separated and extracted through acid-base combined step-by-step dissolution, the silicon is converted into the water glass product, the aluminum iron is converted into the aluminum iron metal salt crystals, the aluminum iron metal salt crystals can be further calcined and dissolved by adding water according to needs, iron oxide is obtained through filtration, the pH value of the filtrate is adjusted to obtain the flocculating constituent, and the purposes of the iron oxide and the flocculating constituent are multiple, so that the economic benefit is effectively improved.

The method for preparing water glass and coproducing metal salt crystals by using the silicon-rich clay has the advantages of simple process, no special requirements on equipment, low energy consumption, good controllability of process parameters, small residual amount of residues, low cost and the like, and opens up a new way for extracting silicon and improving economic benefits of byproducts from the silicon-rich clay.

Detailed Description

The invention provides a method for preparing water glass and coproducing metal salt crystals by using silicon-rich clay, which comprises the following steps:

s1, crushing and grinding the silicon-rich clay to 100-400 meshes to obtain a silicon-rich clay powdery sample.

And S2, placing the silicon-rich clay powder sample obtained in the step S1 in a sulfuric acid solution with the concentration of 4-12 mol/L according to a certain liquid-solid ratio, stirring for 0.5-6 h under a certain temperature condition, and filtering and separating to obtain acid leaching solution and acid leaching residue.

Through a large amount of experimental researches, in the step, the sulfuric acid solution carries out acid dissolution on alumina or ferric oxide in the silicon-rich clay powder to obtain aluminum sulfate or ferric sulfate which is dissolved in the solution, and silicon dioxide which is not dissolved in acid is remained in acid leaching residues. Preferably, the concentration of the sulfuric acid is 4-12 mol/L, waste is easily caused when the concentration is too high, and aluminum and iron in the silicon-rich clay powder cannot be effectively dissolved when the concentration is too low, for example, the concentration of the sulfuric acid is less than 4 mol/L. The liquid-solid ratio of the sulfuric acid solution to the silicon-rich clay powder sample is preferably 5-10: 1. The stirring and dissolving temperature is preferably 80-200 ℃, the higher the temperature is, the more beneficial the dissolving of metal ions is, but the dissolving efficiency is not obvious when the temperature is higher than 200 ℃, and the most preferable temperature is 80-180 ℃. The stirring time is preferably 0.5-6 h. The stirring time is too short, which is not beneficial to the dissolution of metal ions, and the stirring time is too long, for example, the stirring time exceeds 6 hours, and no ions are dissolved, so that the stirring time is preferably 0.5-6 hours.

And S3, mixing the acid leaching residue obtained in the step S2 with a sodium hydroxide solution with a certain concentration according to a certain liquid-solid ratio, stirring for 0.5-3 h at the temperature of 60-100 ℃, and filtering to obtain the water glass (sodium silicate solution).

In this step, the silica in the acid leaching residue reacts with sodium hydroxide to form sodium silicate. The solid-liquid mass ratio of the acid leaching residue to the sodium hydroxide solution is 1: 3.5-20, and the mass concentration of the sodium hydroxide solution is preferably 10% -40%. Further preferably, the solid-liquid mass ratio of the acid leaching residue to the sodium hydroxide solution is 1: 3.5-14. Filtering to remove water insoluble impurities.

S4, concentrating the pickle liquor obtained in the step S2 to obtain aluminum iron metal salt crystals.

In order to further separate the aluminum and the iron in the aluminum iron metal salt crystal, the following steps can be carried out according to the requirement:

s5, calcining the aluminum iron metal salt crystal, adding water into the calcined powder, stirring, filtering and separating to obtain iron oxide and aluminum sulfate solution.

Research shows that when the calcination temperature is preferably 490-520 ℃, the calcination time is 15-30 min, ferric sulfate can be pyrolyzed into ferric oxide, aluminum sulfate does not decompose at the temperature, the calcined powder is stirred, the ferric oxide is insoluble in water, the ferric oxide is precipitated into ferric oxide after filtration, and the filtrate contains aluminum sulfate to effectively separate aluminum from iron. The obtained iron oxide can be used for analytical reagents, sugar quantitative determination, iron catalysts, mordants, water purifying agent pigment preparation and the like.

S6, slowly adding alkali into the aluminum sulfate solution to adjust the pH value, and obtaining the aluminum hydroxide colloid flocculating constituent. Preferably, when the pH value is adjusted to 5.5-7 (preferably 6.0-6.5), the addition of alkali is stopped, and the aluminum hydroxide colloid flocculating constituent is obtained and can be used as a flocculating agent.

For a better understanding of the present invention, reference will now be made in detail to the present invention by way of specific embodiments thereof.

Example 1

SiO in the silicon-rich clay used in this embodiment₂42.85% Fe₂O₃5.38% of Al₂O₃The content is 36.03%.

The method for preparing water glass and coproducing metal salt crystals by using the silicon-rich clay comprises the following specific steps:

s1, crushing and grinding the silicon-rich clay to 100 meshes to obtain a silicon-rich clay powdery sample;

s2, placing the lithium-rich clay mineral powder powdery sample obtained in the step 1 into a sulfuric acid solution with the concentration of 4mol/L according to the liquid-solid ratio of 10, stirring and dissolving for 6 hours at the temperature of 80 ℃, and filtering and separating to obtain acid leaching solution and acid leaching residue;

s3, mixing the acid leaching residue obtained in the step S2 with a sodium hydroxide solution with the mass concentration of 10% according to the mass ratio of 1:14, stirring for 3 hours at the temperature of 60 ℃, filtering to obtain water glass (sodium silicate solution), and measuring and calculating to obtain the utilization rate of silicon dioxide in the acid leaching residue of 98.04%.

S4, concentrating the pickle liquor obtained in the step S2 to obtain aluminum iron metal salt crystals, wherein the average recovery rate is 94.34%.

S5, calcining the aluminum iron metal salt crystal obtained in the step S4 at 500 ℃ for 20min, adding water into the calcined powder for dissolving, stopping adding water when the powder is not dissolved any more, filtering to obtain precipitate and filtrate, washing the precipitate again, filtering, drying, and determining the precipitate as ferric oxide.

S6, slowly adding sodium hydroxide into the filtrate obtained in the step S4, continuously stirring, measuring the pH value, stopping adding sodium hydroxide when the pH value is 6.5, and obtaining the aluminum hydroxide colloid flocculating constituent through determination.

Example 2

SiO in the silicon-rich clay of this embodiment₂42.85% Fe₂O₃5.38% of Al₂O₃The content is 36.03%. The method comprises the following specific steps:

the method for preparing water glass and coproducing metal salt crystals by using the silicon-rich clay comprises the following specific steps:

s1, crushing and grinding the silicon-rich clay to 400 meshes to obtain a silicon-rich clay powdery sample;

s2, placing the lithium-rich clay mineral powder powdery sample obtained in the step 1 into a sulfuric acid solution with the concentration of 10mol/L according to the liquid-solid ratio of 5, stirring and dissolving for 0.5h at the temperature of 180 ℃, and filtering and separating to obtain acid leaching solution and acid leaching residue;

s3, mixing the acid leaching residue obtained in the step S2 with a sodium hydroxide solution with the mass concentration of 40% according to the mass ratio of 1:3.5, stirring for 0.5h at the temperature of 100 ℃, and filtering to obtain water glass (sodium silicate solution), wherein the utilization rate of silicon dioxide in the acid leaching residue is 96.69%.

S4, concentrating the pickle liquor obtained in the step S2 to obtain the metal salt crystals such as aluminum, iron and the like, wherein the average recovery rate is 92.65%.

S5, calcining the aluminum-iron metal salt crystal obtained in the step S4 at 510 ℃ for 15min, adding water into the calcined powder for dissolving, stopping adding water when the powder is not dissolved any more, filtering to obtain precipitate and filtrate, washing the precipitate again, filtering, drying, and determining the precipitate as ferric oxide.

S6, slowly adding potassium hydroxide into the filtrate obtained in the step S4, continuously stirring, measuring the pH value, stopping adding potassium hydroxide when the pH value is 6.0, and obtaining the aluminum hydroxide colloid flocculating constituent through determination.

Compared with the method for preparing the water glass by the quartz sand, the method has the advantages of wide raw material source (the silicon-rich clay is widely distributed), low cost, high comprehensive utilization rate (the method can fully recover silicon components in the silicon-rich clay and can also recover components such as aluminum, iron and the like), and simple process (the water glass prepared by the quartz sand needs to be screened in advance).

Compared with the preparation of sodium silicate by using the silicon micropowder, the technology has the advantages of low cost (the price of the silicon-rich clay is low, the price of the silicon micropowder is high), low energy consumption (the preparation of the sodium silicate by using the silicon micropowder requires high pressure and temperature), high economic benefit (the invention obtains more products, and the products are high value-added products).

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in other forms, and any person skilled in the art can change or modify the technical content disclosed above into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.