CN103508469A

CN103508469A - Purification method of sodium carbonate solution in lithium carbonate production

Info

Publication number: CN103508469A
Application number: CN201310312138.0A
Authority: CN
Inventors: 李有刚; 李增荣; 周晓源; 李健; 周晓军; 刘国旺
Original assignee: Qinghai Li Ye Co Ltd; CINF Engineering Corp Ltd
Current assignee: Qinghai Li Ye Co Ltd; CINF Engineering Corp Ltd
Priority date: 2013-07-24
Filing date: 2013-07-24
Publication date: 2014-01-15

Abstract

The invention discloses a purification method of a sodium carbonate solution in lithium carbonate production. The method comprises the following steps: 1, preparing a sodium carbonate solution with sodium carbonate mass percentage concentration of 25%; 2, adding solid sodium hydroxide, reacting Ca and Mg ions in the sodium carbonate solution with NaOH and precipitating completely to obtain a mixture liquid; 3, carrying out primary filtration on the mixture to obtain a primary filtration liquid; 4, carrying out depth filtration on the primary filtration liquid to realize the content of Ca and Mg no more than 10ppm in a filtrate, so as to obtain a purified sodium carbonate solution finished product; and 5, using the sodium carbonate solution finished product in lithium carbonate production process for reaction with a lithium chloride solution. The method of the invention is characterized in that the deep purification of sodium carbonate solution is added before a traditional lithium carbonate production process, in order to reduce the content of Ca and Mg ions in the industrial grade sodium carbonate product, and can be used for the preparation of lithium carbonate with battery grade standard.

Description

The purifying method of sodium carbonate solution in a kind of Quilonum Retard production

Technical field

The invention belongs to the treatment process of sodium carbonate solution, be specifically related to the purifying method of sodium carbonate solution in a kind of Quilonum Retard production.

Background technology

The LiCl solution of purifying after the LiCl solution of purification or Crude lithium Carbonate dissolving with hydrochloric acid in employing salt lake brine is produced Quilonum Retard technique, and one of key problem in technology is to utilize LiCl and Na ₂cO ₃between precipitin reaction generate the Li be insoluble in water ₂cO ₃, the quality of finished product Quilonum Retard is mainly subject to the impact of Ca in product, Mg content.Traditional Quilonum Retard production technique as shown in Figure 1, is divided into Na ₂cO ₃solution preparation, sinker, separating, washing, the operation such as dry.As the Na that produces one of Quilonum Retard raw material ₂cO _3,on market, be divided into different grades, from economic considerations, Quilonum Retard is produced the general Na that adopts technical grade quality standard ₂cO ₃, but limit by its operational characteristic, technical grade Na ₂cO ₃ca in product, Mg content are higher, fluctuation is larger, in LiCl solution sinker technological process, and will inevitably be by CaCO ₃, MgCO ₃impurity is introduced Li ₂cO ₃product, makes the more difficult control of foreign matter content, and quality product fluctuation rises and falls, and product up-gradation is difficult to break through.

Summary of the invention

The problem that the present invention mainly solves is to provide the purifying method of sodium carbonate solution in a kind of Quilonum Retard production, to reduce technical grade Na ₂cO ₃the content of Ca, Mg ion in product, for the preparation of the Quilonum Retard grade of cell-grade standard.

The purifying method of sodium carbonate solution in Quilonum Retard production provided by the invention, comprises following process:

Step 1, sodium carbonate solution preparation process, add sodium carbonate solution Preparation tank stirring and dissolving by solid sodium carbonate, preparation Na ₂cO ₃mass percent concentration is 25% sodium carbonate solution;

Step 2, purification and impurity removal operation, add sodium carbonate solution Preparation tank by solid sodium hydroxide by reaction aequum excessive 5%, fully stirs, and Ca, Mg ion in sodium carbonate solution being reacted with NaOH and precipitate completely must mixed liquor;

Step 3, primary filter operation, be pumped to pressure filter by the mixed liquor of step 2 and carry out elementary press filtration and obtain primary filtrate;

Step 4, depth type filtration operation, by the primary filtrate of step 3 again pumping filter bag type accurate filter carry out depth type filtration, make Ca in the filtrate after depth type filtration, Mg Han Liang≤10ppm, obtain the sodium carbonate solution finished product after purification;

Step 5, the Quilonum Retard production technique by the sodium carbonate solution finished product of step 3 for reacting with lithium chloride solution.

Solid sodium carbonate in described step 1 is industrial sodium carbonate, initial Ca, Mg mass percent concentration difference 0.005%, 0.02% in sodium carbonate solution.

The quality index of the solid sodium hydroxide in described step 2 is NaOH96%, Ca0.005%, the Mg0.01% of mass percentage content.

Pressure filter in described step 3 is plate and frame or box diaphragm pressing type pressure filter.

In described step 4, the filtering accuracy of filter bag type accurate filter is controlled at below 10ppm.

The feature of the inventive method is, added the operation of deep purifying sodium carbonate solution before traditional Quilonum Retard production technique, can reduce the content of Ca, Mg ion in technical grade sodium carbonate product.After purification and impurity removal operation completes, the liquid-solid separating technology of mixed liquor is combined realization by pressure filter and filter bag type accurate filter.Sodium carbonate solution finished product after deep purifying can be used for traditional Quilonum Retard production technique, carries out sinker react and can generate high-quality Quilonum Retard with lithium chloride solution after deep purifying, through separating, washing, after dry, can reach battery-level lithium carbonate grade.

Accompanying drawing explanation

Fig. 1 is that traditional Quilonum Retard is produced sinker process flow sheet.

Fig. 2 is process flow sheet of the present invention.

Embodiment

Referring to Fig. 2, in Quilonum Retard production provided by the invention, the purifying method of sodium carbonate solution is as follows: according to production requirement, adopt solid industrial sodium carbonate to add deionized water and prepare Na in sodium carbonate solution Preparation tank ₂cO ₃mass percent concentration is 25% sodium carbonate solution, and process for preparation carries out to better dissolve in stirring, initial Ca, Mg mass percent concentration difference 0.005%, 0.02% in sodium carbonate solution; Adopt NaOH96%, the Ca0.005% that quality index is mass percentage content, the solid sodium hydroxide of Mg0.01%, after solid sodium hydroxide is weighed by reaction aequum excessive 5%, be delivered to sodium carbonate solution Preparation tank, fully stir NaOH and Na in this process ₂c0 ₃caC0 in solution ₃, MgC0 ₃react and generate the Ca (OH) that is insoluble in water ₂, Mg (OH) ₂precipitation, obtains mixed liquor after precipitation is complete; After reacting completely, by mixed liquor be pumped to plate and frame or box diaphragm pressing type pressure filter carry out primary filter (press filtration is separated) primary filtrate; Primary filtrate is pumped to filter bag type accurate filter again and carries out depth type filtration (accurate separated), the filtering accuracy of filter bag type accurate filter is controlled at below 10ppm, makes Ca in the filtrate after depth type filtration, Mg Han Liang≤10ppm, obtains the Na after purification ₂cO ₃solution finished product; By Na ₂cO ₃the Quilonum Retard production technique of solution finished product for reacting with LiCl solution, can generate high-quality Li through sinker reaction ₂cO ₃, then can reach battery-level lithium carbonate grade through separating, washing, after dry.

By LiCl sinker process Na ₂cO ₃the application of solution purification technique, Na ₂cO ₃in solution, Ca, Mg content significantly reduce, and in lithium carbonate product, Ca, Mg content are down in 0.005%, efficiently solve the technical problem of lithium carbonate product Control of Impurities, and index reaches cell-grade standard.

Filter residue after primary filter and depth type filtration is Ca (OH) 2 and Mg (OH) 2 throw outs, can be used as to carry magnesium resource and store up stand-by.

Claims

Quilonum Retard produce in the purifying method of sodium carbonate solution, it is characterized in that: comprise following process:

Step 1, sodium carbonate solution preparation process, add sodium carbonate solution Preparation tank stirring and dissolving by solid sodium carbonate, preparation Na ₂cO ₃mass percent concentration is 25% sodium carbonate solution;

Step 2, purification and impurity removal operation, add sodium carbonate solution Preparation tank by solid sodium hydroxide by reaction aequum excessive 5%, fully stirs, and Ca, Mg ion in sodium carbonate solution being reacted with NaOH and precipitate completely must mixed liquor;

Step 3, primary filter operation, be pumped to pressure filter by the mixed liquor of step 2 and carry out elementary press filtration and obtain primary filtrate;

Step 4, depth type filtration operation, by the primary filtrate of step 3 again pumping filter bag type accurate filter carry out depth type filtration, make Ca in the filtrate after depth type filtration, Mg Han Liang≤10ppm, obtain the sodium carbonate solution finished product after purification;

Step 5, the Quilonum Retard production technique by the sodium carbonate solution finished product of step 3 for reacting with lithium chloride solution.
2. the purifying method of sodium carbonate solution in Quilonum Retard production according to claim 1, is characterized in that: the solid sodium carbonate in described step 1 is industrial sodium carbonate, initial Ca, Mg mass percent concentration difference 0.005%, 0.02% in sodium carbonate solution.
3. the purifying method of sodium carbonate solution in Quilonum Retard production according to claim 1 and 2, is characterized in that: the NaOH96% that the quality index of the solid sodium hydroxide in described step 2 is mass percentage content, Ca0.005%, Mg0.01%.
4. the purifying method of sodium carbonate solution in Quilonum Retard production according to claim 3, is characterized in that: the pressure filter in described step 3 is plate and frame or box diaphragm pressing type pressure filter.
5. the purifying method of sodium carbonate solution in Quilonum Retard production according to claim 4, is characterized in that: in described step 4, the filtering accuracy of filter bag type accurate filter is controlled at below 10ppm.