阅读说明：本技术 一种基于盐湖矿石的元明粉制备方法 (Preparation method of anhydrous sodium sulphate based on salt lake ore ) 是由 何开茂 何东利 伍震洲 汪梨超 杨贤丽 江莹 代道和 谭培渊 黄剑新 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：将水和盐湖矿石混合调浆,经净化除杂、苛化除杂、冷冻结晶、芒硝溶解、蒸发浓缩、离心分离、气流粉碎后得到元明粉。生产出高品质的元明粉。盐湖矿石主要成份为硫酸锂,可以直接净化、苛化,减少浸出环节钙离子的带入,降低了产品中钙离子含量,使产品等级提高。该方法不仅节约了设备成本,还缩短了生产周期,保证了生产的连续性。(The invention discloses a preparation method of anhydrous sodium sulphate based on salt lake ores, which belongs to the technical field of anhydrous sodium sulphate preparation and comprises the following steps: mixing water and salt lake ore, pulping, purifying to remove impurities, causticizing to remove impurities, freezing and crystallizing, dissolving mirabilite, evaporating and concentrating, centrifugally separating, and jet milling to obtain anhydrous sodium sulphate. Producing high-quality anhydrous sodium sulphate. The main component of the salt lake ore is lithium sulfate which can be directly purified and causticized, thereby reducing the introduction of calcium ions in the leaching link, reducing the content of the calcium ions in the product and improving the grade of the product. The method not only saves equipment cost, but also shortens production period and ensures production continuity.)

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

s1, adding salt lake ores into water to prepare slurry, purifying the mixed slurry by using an alkaline solution, and adjusting the pH value to 9-12; then, filtering by using a filter press, rinsing the filter cake by using tap water or process water to ensure that the water content of the filter cake is less than or equal to 20%, returning the obtained rinsing water for size mixing again, and removing impurities of iron, manganese, aluminum and calcium in the filtered clear liquid;

s2, filtering the filtered clear liquid obtained by filtering in the step S1 again to obtain purified liquid and purified filter residues, adding water into the purified filter residues to prepare slurry with the solid content of 10% -70%, returning to the step S1, causticizing the purified liquid by using a sodium hydroxide solution, wherein the concentration of the sodium hydroxide is 10% -50%, the pH value of the causticized solution is 11-14, and the temperature is normal temperature;

s3, filtering the solution causticized in the step S2 to obtain a causticized liquid and causticized filter residues, adding water into the causticized filter residues to prepare slurry with the solid content of 10-70%, returning to the step S2 for purification, and filtering the causticized liquid through a precision filter to remove part of calcium ions;

s4, pumping the causticized liquid which is filtered by the precision filter and part of calcium ions are removed in the step S3 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;

s5, 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;

s6, carrying out gas-solid separation on anhydrous sodium sulfate obtained after drying by the flash evaporation dryer through a two-stage cyclone separator, and packaging the solid anhydrous sodium sulfate by an automatic packaging machine and then warehousing.

2. The method for preparing anhydrous sodium sulfate based on salt lake ore according to claim 1, wherein in step S1, 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 according to claim 1, wherein the clear frozen solution separated from the solution during the centrifugal separation in step S4 is transferred to a buffer tank for the frozen solution, filtered by a fine filter and then fed into a crude product feeding buffer tank.

4. The method for preparing anhydrous sodium sulfate based on salt lake ore according to claim 1, wherein in step S5, 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。

5. The method of claim 1, wherein the water content of the solid anhydrous sodium sulfate obtained by gas-solid separation in step S6 is 5%.

Technical Field

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

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 method for preparing anhydrous sodium sulphate based on salt lake ores, which aims to solve the problem that the anhydrous sodium sulphate with high quality and low cost is difficult to produce by the conventional preparation method.

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 comprises the following steps:

s1, adding salt lake ores into water to prepare slurry, purifying the mixed slurry by using an alkaline solution, and adjusting the pH value to 9-12; then, filtering by using a filter press, rinsing the filter cake by using tap water or process water to ensure that the water content of the filter cake is less than or equal to 20%, returning the obtained rinsing water for size mixing again, and removing impurities of iron, manganese, aluminum and calcium in the filtered clear liquid;

s2, filtering the filtered clear liquid obtained by filtering in the step S1 again to obtain purified liquid and purified filter residues, adding water into the purified filter residues to prepare slurry with the solid content of 10% -70%, returning to the step S1, causticizing the purified liquid by using a sodium hydroxide solution, wherein the concentration of the sodium hydroxide is 10% -50%, the pH value of the causticized solution is 11-14, and the temperature is normal temperature;

s3, filtering the solution causticized in the step S2 to obtain a causticized liquid and causticized filter residues, adding water into the causticized filter residues to prepare slurry with the solid content of 10-70%, returning to the step S2 for purification, and filtering the causticized liquid through a precision filter to remove part of calcium ions;

s4, pumping the causticized liquid which is filtered by the precision filter and part of calcium ions are removed in the step S3 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;

s5, 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;

s6, carrying out gas-solid separation on anhydrous sodium sulfate obtained after drying by the flash evaporation dryer through a two-stage cyclone separator, and packaging the solid anhydrous sodium sulfate by an automatic packaging machine and then warehousing.

As a further alternative, in step S1, the concentration of the alkaline substance in the alkaline solution is 10% to 50%.

As a further alternative, the frozen clear solution separated from the solution during the centrifugal separation in the step S4 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 S5, 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 S6, 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 as raw material to produce anhydrous sodium sulphate, the salt lake ore Li₂SO₄·H₂The content of O reaches 80.1-92.1%, the average content is 85.1%, and high-quality anhydrous sodium sulphate can be produced. The main component of the salt lake ore is lithium sulfate which can be directly purified and causticized, thereby reducing the introduction of calcium ions in the leaching link, reducing the content of the calcium ions in the product and improving the grade of the product. The method not only saves equipment cost, but also shortens production period and ensures production continuity.

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 preparation method of anhydrous sodium sulphate based on salt lake ores, which is provided by the 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 preparation method of anhydrous sodium sulphate based on salt lake ores, which comprises the following steps:

s1, adding salt lake ores into water to prepare slurry, purifying the mixed slurry by using an alkaline solution, and adjusting the pH value to 9-12; then, filtering by using a filter press, rinsing the filter cake by using tap water or process water to ensure that the water content of the filter cake is less than or equal to 20%, returning the obtained rinsing water for size mixing again, and removing impurities of iron, manganese, aluminum and calcium in the filtered clear liquid; the filtered clear liquid can be purified by alkaline solution to remove impurities of iron, manganese, aluminum and calcium, and the concentration of alkaline substances in the alkaline solution is 10-50 percent;

s2, filtering the filtered clear liquid obtained by filtering in the step S1 again to obtain purified liquid and purified filter residues, adding water into the purified filter residues to prepare slurry with the solid content of 10% -70%, returning to the step S1, causticizing the purified liquid by using a sodium hydroxide solution, wherein the concentration of the sodium hydroxide is 10% -50%, the pH value of the causticized solution is 11-14, and the temperature is normal temperature;

s3, filtering the solution causticized in the step S2 to obtain a causticized liquid and causticized filter residues, adding water into the causticized filter residues to prepare slurry with the solid content of 10-70%, returning to the step S2 for purification, and filtering the causticized liquid through a precision filter to remove part of calcium ions;

s4, pumping the causticized liquid which is filtered by the precision filter and part of calcium ions are removed in the step S3 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;

s5, 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;

s6, carrying out gas-solid separation on anhydrous sodium sulfate obtained after drying by the flash evaporation dryer through a two-stage cyclone separator, and packaging the solid anhydrous sodium sulfate by an automatic packaging machine and then warehousing.

Step S1, adding water and salt lake ore into a stirring tank for size mixing, conveying the mixed slurry into a purifying tank by a pump for purification, adding a certain amount of alkaline substances into the purifying tank, conveying the alkaline substances into the purifying tank by a bin pump, adjusting the pH value to 9-12, and removing impurities such as iron, manganese, aluminum and calcium in the filtered clear liquid, wherein the concentration of the alkaline substances in the alkaline solution is 10-50%, and the alkaline substances can be calcium oxide, sodium hydroxide, sodium oxide and the like; then, a purifying filter press is used for filtering, tap water or process water is used for rinsing the filter cake to ensure that the water content of the filter cake is less than or equal to 20%, and the rinsing water is returned for the size mixing.

Then causticizing, freezing and crystallizing, dissolving mirabilite, evaporating and concentrating, centrifugally separating, and carrying out jet milling to obtain anhydrous sodium sulphate.

And S4, 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 S5, 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 S6, the water content of the solid anhydrous sodium sulfate obtained by gas-solid separation is 5%.

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.