阅读说明：本技术 一种基于盐湖矿石与锂辉石的元明粉制备方法 (Preparation method of anhydrous sodium sulphate based on salt lake ore and spodumene ) 是由 何开茂 何东利 伍震洲 汪梨超 许小林 代道和 江莹 王晓洪 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种基于盐湖矿石与锂辉石的元明粉制备方法,属于元明粉制备技术领域,包括以下步骤：将锂辉石依次经过煅烧、冷却、细磨、加酸反应、冷却、调浆、浸出,过滤洗涤,加入盐湖矿石,净化、苛化、冷冻结晶、芒硝溶解、蒸发浓缩、离心分离、干燥后得到元明粉。以盐湖矿石与锂辉石混合,能生产出高品质的元明粉,运用了连续冷冻结晶技术分离出硫酸钠,保证晶核稳定成长以及生产的连续性,能生产出高品质的产品,同时缩短了生产周期,节约了成本。(The invention discloses a glauber salt preparation method based on salt lake ores and spodumene, which belongs to the technical field of glauber salt preparation and comprises the following steps: sequentially calcining spodumene, cooling, finely grinding, adding acid for reaction, cooling, mixing slurry, leaching, filtering and washing, adding salt lake ore, purifying, causticizing, freezing and crystallizing, dissolving mirabilite, evaporating and concentrating, centrifugally separating and drying to obtain anhydrous sodium sulphate. The salt lake ore is mixed with spodumene to produce high-quality anhydrous sodium sulfate, the continuous freezing and crystallizing technology is used for separating sodium sulfate, the stable growth of crystal nucleus and the continuity of production are ensured, the high-quality product can be produced, the production period is shortened, and the cost is saved.)

1. A preparation method of anhydrous sodium sulphate based on salt lake ores and spodumene is characterized by comprising the following steps:

s1, sequentially calcining spodumene, cooling, finely grinding, carrying out acid addition reaction and cooling, cooling a product of the acid addition reaction to be less than or equal to 90 ℃, and then mixing the product with water to obtain slurry, wherein the solid content of the slurry is 10-70%; the granularity of fine grinding is required to be 200 meshes, the calcining temperature is 950-1200 ℃, acid is added for reaction, sulfuric acid with the concentration of 98% is added, and the acid-material ratio is 2-4: 1, adding acid for reaction, and cooling to below 60 ℃;

s2, adding calcium salt into the slurry obtained in the step S1, stirring and leaching, mixing the calcium salt with water to obtain slurry, wherein the solid content of the slurry is 10% -55%, the temperature in a leaching tank is less than or equal to 60 ℃, the pH value is more than or equal to 5, then filtering by using a filter press, rinsing a filter cake by using tap water or process water, purging the filter cake by using compressed air to ensure that the water content of the filter cake is less than or equal to 20%, returning the obtained rinsing water to the step S1 for size mixing, adding salt lake ore into the filtered clear liquid, purifying the mixed liquid by using an alkaline solution, adjusting the pH value to 9-12, and removing impurities of iron, manganese, aluminum and calcium in the filtered clear liquid;

s3, filtering the mixed liquid obtained after purification in the step S2 again to obtain purified liquid and purified filter residues, wherein the purified liquid is subjected to causticization by using a sodium hydroxide solution, the concentration of the sodium hydroxide is 10-50%, the pH value of the solution subjected to causticization is 11-14, and the temperature is normal temperature;

s4, filtering the solution causticized in the step S3 to obtain causticized liquid and causticized filter residues, and filtering the causticized liquid through a precision filter to remove part of calcium ions;

s5, pumping the causticized liquid which is filtered by the precision filter and part of calcium ions are removed in the step S4 into a freezing system, and cooling the causticized liquid by using the forced freezing action of an ice machine, wherein the freezing temperature is-5 to-20 ℃; crystallizing and separating out sodium sulfate in the form of sodium sulfate decahydrate at low temperature, and dissolving the sodium sulfate decahydrate separated from the solution in a crystal melting tank under the centrifugal separation effect;

s6, evaporating, concentrating and purifying sodium sulfate decahydrate, heating, taking out crystal water to obtain anhydrous sodium sulfate, heating at the temperature of 200-800 ℃, centrifugally separating the concentrated anhydrous sodium sulfate slurry, drying an anhydrous sodium sulfate wet product by a flash evaporation dryer to obtain anhydrous sodium sulfate, drying at the temperature of 50-150 ℃, and returning the centrifuged mother liquor to a crystal melting tank or a purification tank;

and S7, carrying out gas-solid separation on anhydrous sodium sulphate obtained after drying by the flash evaporation dryer in the step S6 through a two-stage cyclone separator, and packaging the solid anhydrous sodium sulphate by an automatic packaging machine and then warehousing.

2. The method for preparing anhydrous sodium sulphate based on salt lake ore and spodumene as claimed in claim 1, wherein in step S2, the concentration of alkaline substance in the alkaline solution is 10% -50%.

3. The method for preparing anhydrous sodium sulphate based on salt lake ore and spodumene as claimed in claim 1, wherein in step S3, water is added into the purified filter residue to prepare slurry with solid content of 10% -70%, and then the process returns to step S1.

4. The method for preparing anhydrous sodium sulphate based on salt lake ore and spodumene as claimed in claim 1, wherein in step S4, the causticized filter residue is added with water to be made into slurry with solid content of 10% -70%, and then the process returns to the purification process of step S2.

5. The method for preparing anhydrous sodium sulphate based on salt lake ore and spodumene as claimed in claim 1, wherein the clear frozen liquid separated from the solution during the centrifugal separation in step S5 is transferred to a buffer tank of the frozen liquid, filtered by a precise filter and fed into a crude product feeding buffer tank.

6. The method for preparing anhydrous sodium sulphate based on salt lake ore and spodumene as claimed in claim 1, wherein in step S6, the hot air required by the flash dryer is provided by a matched hot blast stove, the fuel of the hot blast stove is natural gas, and the usage amount is 600m³/h。

7. The method for preparing anhydrous sodium sulfate based on salt lake ores and spodumene as claimed in claim 1, wherein the water content of the solid anhydrous sodium sulfate obtained by gas-solid separation in step S7 is 5%.

Technical Field

The invention belongs to the technical field of anhydrous sodium sulphate preparation, and particularly relates to an anhydrous sodium sulphate preparation method based on salt lake ores and spodumene.

Background

Glauber salt refers to sodium sulfate, also called mirabilite. Sodium sulfate, an inorganic compound, sodium sulfate decahydrate, also known as mirabilite, and a high-purity, finely-grained anhydrate called glauber salt. The anhydrous sodium sulphate is mainly used for manufacturing water glass, porcelain glaze, paper pulp, refrigerating mixing agent, detergent, drying agent, dye diluent, analytical chemical reagent, medicinal products, feed and the like. The main methods for producing anhydrous sodium sulphate at present are a beach field method, a mechanical freezing method, a salt lake comprehensive utilization method and the like.

The beach field method is to evaporate water from the material liquid by means of the temperature change in different seasons to crystallize out coarse mirabilite. In summer, the salt water containing sodium chloride, sodium sulfate, magnesium chloride, etc. is poured into beach field, and after sun-drying and evaporation, crude mirabilite is separated out in winter. The method is a main method for extracting mirabilite from natural resources, and has the advantages of simple process, low energy consumption, poor operation conditions and easy mixing of impurities such as sand and the like in the product.

The mechanical freezing method is to utilize mechanical equipment to heat and evaporate the raw material liquid and then freeze the raw material liquid to-5 to-10 ℃ to separate out mirabilite. Compared with the beach field method, the method is not affected by seasons and natural conditions. The product quality is good, but the energy consumption is high.

The comprehensive utilization method of the salt lake is mainly used for sulfate-carbonate type salt water containing various components. The crude mirabilite is separated while extracting various useful components. For example, salt lake water containing sodium carbonate, sodium sulfate, sodium chloride, boride, potassium, bromine and lithium can be processed by firstly carbonizing salt lake brine to convert sodium carbonate into sodium bicarbonate to be crystallized; cooling the mother liquor to 5-15 ℃ to crystallize borax; and (4) freezing the secondary mother liquor after borax separation to 0-5 ℃, and separating out mirabilite.

Therefore, how to prepare anhydrous sodium sulphate with high quality and low cost is a problem to be solved in the field.

Disclosure of Invention

The invention aims to provide a preparation method of anhydrous sodium sulphate based on salt lake ores and spodumene, and aims to solve the problem that the existing preparation method is difficult to produce anhydrous sodium sulphate with high quality and low cost.

In order to realize the purpose of the invention, the technical scheme is as follows: a preparation method of anhydrous sodium sulphate based on salt lake ores and spodumene comprises the following steps:

s1, sequentially calcining spodumene, cooling, finely grinding, carrying out acid addition reaction and cooling, cooling a product of the acid addition reaction to be less than or equal to 90 ℃, and then mixing the product with water to obtain slurry, wherein the solid content of the slurry is 10-70%; the granularity of fine grinding is required to be 200 meshes, the calcining temperature is 950-1200 ℃, acid is added for reaction, sulfuric acid with the concentration of 98% is added, and the acid-material ratio is 2-4: 1, adding acid for reaction, and cooling to below 60 ℃;

s2, adding calcium salt into the slurry obtained in the step S1, stirring and leaching, mixing the calcium salt with water to obtain slurry, wherein the solid content of the slurry is 10% -55%, the temperature in a leaching tank is less than or equal to 60 ℃, the pH value is more than or equal to 5, then filtering by using a filter press, rinsing a filter cake by using tap water or process water, purging the filter cake by using compressed air to ensure that the water content of the filter cake is less than or equal to 20%, returning the obtained rinsing water to the step S1 for size mixing, adding salt lake ore into the filtered clear liquid, purifying the mixed liquid by using an alkaline solution, adjusting the pH value to 9-12, and removing impurities of iron, manganese, aluminum and calcium in the filtered clear liquid;

s3, filtering the mixed liquid obtained after purification in the step S2 again to obtain purified liquid and purified filter residues, wherein the purified liquid is subjected to causticization by using a sodium hydroxide solution, the concentration of the sodium hydroxide is 10-50%, the pH value of the solution subjected to causticization is 11-14, and the temperature is normal temperature;

s4, filtering the solution causticized in the step S3 to obtain causticized liquid and causticized filter residues, and filtering the causticized liquid through a precision filter to remove part of calcium ions;

s5, pumping the causticized liquid which is filtered by the precision filter and part of calcium ions are removed in the step S4 into a freezing system, and cooling the causticized liquid by using the forced freezing action of an ice machine, wherein the freezing temperature is-5 to-20 ℃; crystallizing and separating out sodium sulfate in the form of sodium sulfate decahydrate at low temperature, and dissolving the sodium sulfate decahydrate separated from the solution in a crystal melting tank under the centrifugal separation effect;

s6, evaporating, concentrating and purifying sodium sulfate decahydrate, heating, taking out crystal water to obtain anhydrous sodium sulfate, heating at the temperature of 200-800 ℃, centrifugally separating the concentrated anhydrous sodium sulfate slurry, drying an anhydrous sodium sulfate wet product by a flash evaporation dryer to obtain anhydrous sodium sulfate, drying at the temperature of 50-150 ℃, and returning the centrifuged mother liquor to a crystal melting tank or a purification tank;

and S7, carrying out gas-solid separation on anhydrous sodium sulphate obtained after drying by the flash evaporation dryer in the step S6 through a two-stage cyclone separator, and packaging the solid anhydrous sodium sulphate by an automatic packaging machine and then warehousing.

As a further alternative, in step S2, the concentration of the alkaline substance in the alkaline solution is 10% to 50%.

As a further alternative, in step S3, water is added to the purified filter residue to prepare a slurry with a solid content of 10% -70%, and then the process returns to step S1.

As a further alternative, in step S4, after adding water into the causticized filter residue to prepare slurry with the solid content of 10-70%, returning to the step S2 for purification.

As a further alternative, the frozen clear solution separated from the solution during the centrifugal separation in the step S5 is transferred to a frozen post-liquid buffer tank, filtered by a precision filter, and then enters a crude product feeding buffer tank.

As a further alternative, in step S6, the hot air required by the flash evaporation dryer is provided by a matched hot blast stove, the fuel of the hot blast stove is natural gas, and the usage amount is 600m³/h。

Alternatively, in step S7, the water content of the solid anhydrous sodium sulfate obtained by gas-solid separation is 5%.

The invention has the beneficial effects that: the preparation method takes salt lake ore and spodumene as raw materials to produce anhydrous sodium sulphate, wherein the salt lake ore Li₂SO₄·H₂The content of O reaches 80.1-92.1%, the average content is 85.1%, and the sodium sulfate is mixed with spodumene to produce high-quality anhydrous sodium sulfate.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, it should be understood that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a process flow diagram of a method for preparing anhydrous sodium sulphate based on salt lake ores and spodumene according to an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention. It is to be understood that the drawings are provided solely for the purposes of reference and illustration and are not intended as a definition of the limits of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The invention is further described with reference to the following figures and specific embodiments.

Fig. 1 shows a method for preparing anhydrous sodium sulphate based on salt lake ores and spodumene, which comprises the following steps:

s1, sequentially calcining spodumene, cooling, finely grinding, carrying out acid addition reaction and cooling, cooling a product of the acid addition reaction to be less than or equal to 90 ℃, and then mixing the product with water to obtain slurry, wherein the solid content of the slurry is 10-70%; the granularity of fine grinding is required to be 200 meshes, the calcining temperature is 950-1200 ℃, acid is added for reaction, sulfuric acid with the concentration of 98% is added, and the acid-material ratio is 2-4: 1, adding acid for reaction, and cooling to below 60 ℃;

s2, adding calcium salt into the slurry obtained in the step S1, stirring and leaching, mixing the calcium salt with water to obtain slurry, wherein the solid content of the slurry is 10% -55%, the temperature in a leaching tank is less than or equal to 60 ℃, the pH value is more than or equal to 5, then filtering by using a filter press, rinsing a filter cake by using tap water or process water, purging the filter cake by using compressed air to ensure that the water content of the filter cake is less than or equal to 20%, returning the obtained rinsing water to the step S1 for size mixing, adding salt lake ore into the filtered clear liquid, purifying the mixed liquid by using an alkaline solution, adjusting the pH value to 9-12, and removing impurities of iron, manganese, aluminum and calcium in the filtered clear liquid;

s3, filtering the mixed liquid obtained after purification in the step S2 again to obtain purified liquid and purified filter residues, wherein the purified liquid is subjected to causticization by using a sodium hydroxide solution, the concentration of the sodium hydroxide is 10-50%, the pH value of the solution subjected to causticization is 11-14, and the temperature is normal temperature;

s4, filtering the solution causticized in the step S3 to obtain causticized liquid and causticized filter residues, and filtering the causticized liquid through a precision filter to remove part of calcium ions;

s5, pumping the causticized liquid which is filtered by the precision filter and part of calcium ions are removed in the step S4 into a freezing system, and cooling the causticized liquid by using the forced freezing action of an ice machine, wherein the freezing temperature is-5 to-20 ℃; crystallizing and separating out sodium sulfate in the form of sodium sulfate decahydrate at low temperature, and dissolving the sodium sulfate decahydrate separated from the solution in a crystal melting tank under the centrifugal separation effect;

s6, evaporating, concentrating and purifying sodium sulfate decahydrate, heating, taking out crystal water to obtain anhydrous sodium sulfate, heating at the temperature of 200-800 ℃, centrifugally separating the concentrated anhydrous sodium sulfate slurry, drying an anhydrous sodium sulfate wet product by a flash evaporation dryer to obtain anhydrous sodium sulfate, drying at the temperature of 50-150 ℃, and returning the centrifuged mother liquor to a crystal melting tank or a purification tank;

and S7, carrying out gas-solid separation on anhydrous sodium sulphate obtained after drying by the flash evaporation dryer in the step S6 through a two-stage cyclone separator, and packaging the solid anhydrous sodium sulphate by an automatic packaging machine and then warehousing.

In step S2, the concentration of alkaline substance in the alkaline solution is 10% -50%. The alkaline substance may be calcium oxide, sodium hydroxide, sodium oxide, etc.

In step S3, water is added into the purified filter residue to prepare slurry with the solid content of 10-70%, and then the step S1 is returned.

In step S4, adding water into the causticized filter residue to prepare slurry with the solid content of 10-70%, and then returning to the step S2 for purification.

And S5, transferring the frozen clear liquid separated from the solution during centrifugal separation into a frozen liquid buffer barrel, filtering the frozen clear liquid by a precision filter, and feeding the filtered clear liquid into a crude product feeding buffer barrel.

In step S6, hot air required by the flash evaporation dryer is provided by a matched hot blast stove, the fuel of the hot blast stove is natural gas, and the usage amount is 600m³/h。

In step S7, the water content of the solid anhydrous sodium sulfate obtained by gas-solid separation is 5%.

In step S1, the spodumene is sequentially subjected to high-temperature calcination in a rotary kiln, cooling in a roasting cooling kiln, fine grinding in a ball mill, acid addition reaction in an acidification kiln, and cooling in an acidification cooling kiln. And (3) conveying the calcium salt into a stirring tank by using a screw conveyor in the step S2, preparing slurry by using water, mixing and stirring the slurry with the slurry in the step S1 for leaching, wherein the solid content is 10-55%, the temperature in the leaching tank is less than or equal to 60 ℃, the pH value is more than or equal to 5, and then conveying the leachate to a filter press by using a pump for filtering.

The invention is not limited to the above alternative embodiments, and any other various forms of products can be obtained by anyone in the light of the present invention, but any changes in shape or structure thereof, which fall within the scope of the present invention as defined in the claims, fall within the scope of the present invention.