CN1060156C

CN1060156C - Production method for calcium acetate

Info

Publication number: CN1060156C
Application number: CN97121852A
Authority: CN
Inventors: 孙素元; 张宪娣
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-12-09
Filing date: 1997-12-09
Publication date: 2001-01-03
Anticipated expiration: 2017-12-09
Also published as: CN1219529A

Abstract

The present invention relates to a method for producing calcium acetate. The present invention comprises the steps that 1. shells are cleaned and dried, and are pulverized to the fineness below 500 mum; 2. the shell powder and 20 to 70 wt% of acetic acid solution are added in the reactor when the weight ratio of the pure acetic acid to shell powder is (1.3 to 2.5): 1, and react for at least 24 hours; 3. the shell powder is dissolved by water with the amount of 2 to 3 times more than shell powder after reaction, and is filtered; 4. the filter liquor is dried. The produced calcium acetate is easily absorbed by human bodies, and the calcium acetate has no harmful effect. The product contains various kinds of beneficial microelements, bone collagens, amino acids, unsaturated fatty acids, etc., and is suitable to serve as a calcium supplementing nutriment for enhancing health.

Description

Production method of calcium acetate

The invention relates to a production method of calcium acetate.

Calcium is one of the most abundant elements in the human body, and is an important component constituting organs such as bones and teeth. Calcium plays an important role in the human body in physiological functions such as blood coagulation, neuromuscular excitation, cell membrane function maintenance, activation of enzyme reaction, and secretion of hormones. Recent clinical medicine has confirmed that calcium deficiency in children can cause growth retardation, dental deformity, bone deformity (rickets), etc.; the middle-aged and the elderly people, especially women, can cause diseases such as bone pain, osteoporosis, hypertension, arteriosclerosis and the like due to calcium deficiency, so that calcium supplement is one of important measures for improving the health level of human bodies. Calcium acetate is easily dissolved in water, and calcium ions are easily absorbed by small intestine and enter relevant parts of human body, thereby playing the role of calcium supplement. Patent applications relating to methods for producing calcium acetate are known from CN1091607A and CN1093573A, but both methods use calcium-containing ores such as limestone, marble, ice river stone, calcite, etc. as raw materials, crush them and react them with acetic acid to produce a calcium acetate solution, and the calcium acetate solution is directly used as a product or spray-dried to obtain a powdery calcium acetate product. However, both of these methods use natural ore as raw material, and it is known that natural ore inevitably contains trace amount of at least heavy metals (such as lead, arsenic, etc.) harmful to human body, and these harmful elements are also easily dissolved in acetic acid and enter into the product together with calcium ions. Therefore, the long-term taking of these calcium acetate products with natural ore as raw material will have very bad influence on human body, so these products are not suitable for use as calcium-supplementing nutriment.

The invention aims to provide a calcium acetate product which is suitable for being used as a calcium supplement nutrient and does not have any adverse effect on human bodies after long-term administration, and a production method thereof.

The inventor of the present invention found that the shell of shellfish such as oyster is similar to pearl, and contains 80-95 wt% of CaCO₃And a small amount of calcium sulfate and calcium phosphate, and also contains various microelements, ossein, amino acids, unsaturated fatty acid, etc. beneficial to human body. The shells of oysters, scallops and other shellfish are used as traditional Chinese medicines for a long time in China. It has been proven in long-term practice that shellfish shells are non-toxic. However, calcium in shellfish shells is not easily dissolved in water, and thus cannot be directly used as a calcium supplement nutritional product. The present inventors tested acetic acid to react with oyster shell powder. As a result, it was found that calcium in oyster shell easily reacts with acetic acid to form calcium acetate and thus easily dissolves in water. In addition, the present inventors also tried to raise mice by mixing the calcium acetate product thus obtained with food, and as a result, found that the calcium content in the bones of the mice was significantly increased, thereby proving that the calcium content was significantly increased from the shellfish shellsThe calcium acetate product extracted from the body is very suitable forCan be used as calcium supplementing nutritional product. The present invention has been accomplished on the basis of this finding.

Accordingly, the present invention provides a process for the production of calcium acetate, characterized in that it comprises the following steps:

(1) washing shell (preferably oyster shell) with water (preferably soaking and washing with 5 wt% HCl aqueous solution), oven drying, and pulverizing to powder of 500 μm (35 mesh) below (preferably 177-149 μm (80-100 mesh));

(2) adding shell powder intoa reaction vessel, adding an acetic acid aqueous solution with the acetic acid concentration of 20-70 wt% (preferably 30-50 wt%) according to the proportion of pure acetic acid to the shell powder (weight ratio) = (1.3-2.5): 1 (preferably = 2: 1), reacting for at least 24 hours (preferably at least 48 hours) under stirring, carrying out liquid-solid separation, and collecting shell powder after reaction (optionally returning part or all of filtrate to be used as water for diluting glacial acetic acid during reaction);

(3) the shell powder after the reaction is dissolved with 2 to 3 times (by weight) of water (preferably, the dissolution is carried out 2 to 3 times). Filtering and collecting filtrate;

(4) and drying (preferably vacuum drying or spray drying) the filtrate by a conventional method (preferably adding 1-2 wt% of ethanol) to obtain a powdery product.

The present invention is explained in detail below.

Calcium carbonate reacts with acetic acid according to the following formula:

as can be seen from the above formula, 2mol of acetic acid is required for 1mol of calcium carbonate. Due to CaCO₃Has a molecular weight of about 100, and CaCO contained in the shell₃On average about 90% by weight, so that about 9mol CaCO are contained per kg shell₃. In addition, acetic acid has a molecular weight of about 60, and therefore contains about 16.7 mol of acetic acid per kg of glacial acetic acid. That is, for example, 1kg of shell (containing 9mol CaCO) by equivalent reaction₃) 1.08 kg (18mol) of acetic acid are required. However, considering that other materials in the shell also consume a certain amount of acetic acid, and in order to make the reaction reach a certain speed, at least 20% of acetic acid is excessive, so the weight of the acetic acid and the shellThe ratio is at least 1.3: 1, and the use of acetic acid of 2.5: 1 or more is wasteful, so the weight ratio of acetic acid to shell powder is set to 1.3-2.5: 1, preferably 2: 1.

In addition, acetic acid needs to be ionized to accelerate the completion of the chemical reaction, so a proper amount of water needs to be added into the acetic acid during the reaction. Generally, a suitable concentration of acetic acid for reaction with the shell is 20 to 70 wt%, preferably 30 to 50 wt%.

The drying of the calcium acetate-containing leachate is not particularly limited, and may be carried out by a conventional method, but is preferably carried out by vacuum drying or spray drying. In addition, when 1-2 wt% of ethanol is added, the vinegar acidity of the calcium acetate product can be completely removed.

Compared with the similar methods in the prior art, the calcium acetate product produced by the method has the advantages of being easier to be absorbed by human bodies, having no toxicity or adverse effect on the human bodies, and being taken as a calcium supplement nutriment for a long time. Moreover, since the shell is formed by a mucus secreted from the shellfish and contains various trace elements, ossein, amino acids, unsaturated fatty acids, etc. which are beneficial to the human body, it is very suitable for people of various ages (especially children, middle aged and elderly people, especially women) to take as a nutritional product for improving the health level of the human body. In addition, the raw material shells in the method do not contain heavy metal (such as lead, arsenic and the like) impurities like natural ores, so that no toxic gas, waste liquid or waste residue is generated in the production process, and the method is beneficial to the health of operators and environmental protection.

The present invention will be further explained with reference to examples, but the present invention is not limited to these examples.

Example 1

Selecting a batch of thicker Concha Ostreae (containing CaCO)₃About 90 wt%), washed with water to remove silt, then soaked and washed with 5 wt% aqueous HCl solution, the oyster shell was dried and then pulverized to 149 μm (100 mesh) for use.

1kg of oyster shell powder was put into a glass container, 1kg of distilled water was added, then 1kg of glacial acetic acid was added under stirring in a laboratory fume hood, 1kg of glacial acetic acid was added after 24 hours of reaction, and the reaction was further continued for 24 hours. At this time, the reaction solution was viscous, indicating that the reaction was completed. The supernatant (which remained as part of the next reaction) was decanted, the solid was dissolved in 2 more 2 additional 2kg of distilled water with stirring, filtered over activated carbon, and the filtrate was dried under vacuum to obtain 1.36 kg (about 96% yield) of pure white calcium acetate powder, which was very soluble in water. Since the supernatant precipitated after the reaction contains a part of calcium acetate, the recovery rate can be further improved when the supernatant is repeatedly used.

Example 2

A batch of oyster shell powder (100 mesh) was prepared as in example 1. Then 10kg of oyster shell powder is put into a reaction kettle, 10kg of distilled water is added, 10kg of glacial acetic acid is added under stirring, 10kg of glacial acetic acid is added after 24 hours of reaction, and the reaction solution is in a sticky state after 24 hours of reaction. The supernatant (which was left as part of the next reaction solution) was decanted, the solid was dissolved in 20kg of distilled water 2 times withstirring, the solution was filtered through activated carbon, 36kg of distilled water was added to the filtrate, and 560g of anhydrous ethanol was added (at this time, the concentration of calcium acetate in the solution was about 25% by weight). The ethanol-containing calcium acetate solution was then spray-dried (spray-dried conditions: feed concentration 25 wt%, flow rate 25 l/hr, inlet temperature 300 ℃ C., outlet temperature 100 ℃ C. or higher) to obtain 14.0 kg of pure white calcium acetate powder (yield about 98.6%).

The present invention has been explained in detail by the embodiments above, however, many variations can be made to the above embodiments by those skilled in the art according to the basic concept of the present invention, and all variations made based on the inventive concept should be considered to fall within the scope of the present invention.

Claims

1. A method for producing calcium acetate, which is characterized by comprising the following steps:

(1) washing shell with water, oven drying, and pulverizing to powder of below 500 μm;

(2) adding shell powder into a reaction container, adding an acetic acid aqueous solution with the concentration of 20-70 wt% according to the proportion of pure acetic acid to the shell powder (weight ratio) = (1.3-2.5): 1, reacting for at least 24 hours under stirring, carrying out liquid-solid separation, and collecting the shell powder after reaction;

(3) dissolving the shell powder after reaction by using 2-3 times (by weight) of water, filtering, and collecting filtrate;

(4) the filtrate was dried by a conventional method.

2. The method of claim 1, wherein said shellis oyster shell.

3. The method according to claim 1 or 2, wherein in step (1) the shells are rinsed clean with water and then washed with 5 wt% aqueous HCl.

4. The method according to claim 1 or 2, wherein the shell-fish is pulverized to 177 to 149 μm in the step (1) thereof.

5. The process according to claim 1 or 2, characterized in that the pure acetic acid: shell powder (weight ratio) = 2: 1 in step (2) thereof

6. The method of claim 1 or 2, wherein the reaction time in step (2) is at least 48 hours.

7. The method according to claim 1 or 2, wherein the dissolution is performed 2 to 3 times in step (3).

8. The method according to claim 1 or 2, wherein 1 to 2% by weight of ethanol is added to the filtrate in the step (4) thereof, followed by drying.

9. The method of claim 8, wherein said drying is vacuum drying.

10. The method of claim 8, wherein said drying is spray drying.