CN100548931C - Phosphoric acid selenium potassium mixture and application thereof - Google Patents

Abstract

Potassium selenium phosphate compound and its application, its chemical molecular formula is K ₃ SeP ₃ O ₁₀ ·XH ₂ O, X=2-4. The potassium selenium phosphate compound can be used as a compound fertilizer that can be applied to crops to increase the selenium content of the crops. The product of the present invention is a quick-acting phosphorus and potassium-based selenium-enriched fertilizer that can comprehensively and thoroughly improve the selenium content of plants. It can be well absorbed by plants, and the application method is also very simple and convenient. Foliar spraying and fertilization can obtain very ideal fertilization effect.

Description

Potassium Selenium Phosphate Complex and Its Application

technical field

The invention relates to a selenium potassium phosphate compound and its application as a compound fertilizer rich in selenium, phosphorus and potassium.

Background technique

Selenium is one of the indispensable important elements in human life and physiological activities. The aging of the human body and the decline of immunity are mainly caused by the excessive presence of oxidative substances in the body. Selenium is an essential component for the synthesis of reducing agents in the human body, so it is beneficial to human health. Selenium deficiency in children can lead to the occurrence of various diseases and the decline of reproductive ability. According to relevant information, selenium can not only prevent and treat endemic diseases such as Keshan disease and Kaschin-Beck disease, but also prevent and treat various diseases such as tumors and cardiovascular and cerebrovascular diseases. Selenium can improve human body immunity and anti-aging ability. Therefore, it enjoys the reputation of "the king of anti-cancer" and "natural antidote". In the United States, selenium is regarded as an equally important life element with vitamins and β-carotene.

After the World Health Organization announced that selenium is an essential trace element for human beings in 1973, the research and application of selenium in biology and medicine have made continuous progress. People have moved from the chemical physics research of selenium to the biology, biochemistry, Molecular biology and other fields of research, and achieved a series of results. China is a country generally deficient in selenium. People have made great breakthroughs in the research of selenium products in recent years, and developed many selenium-enriched products. Such as Peking University's "Fu Se Kang", "Xi Weier" produced by Beijing Lingtai Pharmaceutical Co., Ltd. and so on.

The above products are basically added inorganic selenium and obtained by artificial transformation or artificial synthesis, so they are not biological selenium that is easily absorbed by the human body. In order to obtain biological selenium, people have carried out research work on selenium element soil occurrence and plant transformation in recent years. The units that formed the industry include: Anhui Chaohu Selenium-enriched Fragrant Rice Biological Food Company, Nanjing Yuanwang Selenium-enriched Agricultural Products Group Company, as well as Tanghe County in Henan, Jidong County in Heilongjiang and Halebin, Shaoxing in Zhejiang, Enshi in Hubei, Rongzhou in Guizhou There are products on the market in more than a dozen cities and counties including Jiang County. These selenium-enriched products are all artificially sprayed with selenic acid solution and transformed by these plants except for those that grow naturally in soil containing selenium in very few areas.

It is worth pointing out that simply spraying selenic acid solution on crops is an extensive technology, and the effect cannot be ideal. Due to the growth conditions of different crops, growth time and space, climatic conditions and the choice of absorption function, drug concentration and human factors, etc., it will inevitably lead to the disadvantage that the selenium content cannot be stabilized within a certain index.

As we all know, the growth process of any kind of plant is indispensable to the dependence of phosphorus and potassium elements. We believe that in order to comprehensively improve the amount of selenium in plants, it is the most effective way to develop a quick-acting phosphorus and potassium-based selenium-enriched fertilizer.

Contents of the invention

The purpose of the present invention is to provide a selenium potassium phosphate compound, which can be well applied to crops as a selenium, phosphorus and potassium rich fertilizer.

The purpose of the present invention is achieved in the following manner:

Potassium selenium phosphate complex, its chemical formula is K ₃ SeP ₃ O ₁₀ ·XH ₂ O, X=2-4.

The potassium selenium phosphate complex is 20-25% as SeO ₂ , 26-30% as P ₂ O ₅ , 30-35% as K _{2 O} , and 12-16% as H ₂ O.

The potassium selenium phosphate compound is a white powder; it is easily soluble in water; its melting point is 170-200° C.; when the temperature rises above 350° C., red selenium smoke sublimates.

The reaction principle of the present invention is:

1. Preparation of H ₂ SeO ₃

Se+2HNO ₃ →SeO ₂ +H ₂ O+N ₂ O ₃ ...(1)

2. Preparation of K ₅ P ₃ O ₁₀

6H ₃ PO ₄ +5K ₂ CO ₃ →4K ₂ HPO ₄ +2KH ₂ PO ₃ +5H ₂ O+5CO ₂ ↑

4K ₂ HPO ₄ +2KH ₂ CO ₃ →2K ₅ P ₃ O ₁₀ +4H ₂ O...(2)

3. Preparation of K ₃ SeP ₃ O ₁₀ ·XH ₂ O

2K ₅ P ₃ O ₁₀ +2H ₂ SeO ₃ →2K ₃ SeP ₃ O ₁₀ XH ₂ O+K ₂ O+O ₂ ↑……(3)

The potassium selenium phosphate compound can be used as a compound fertilizer that can be applied to crops to increase the selenium content of the crops.

The preparation process of the present invention is as follows: dissolving potassium carbonate in pure water, then slowly adding phosphoric acid under stirring for neutralization reaction, and dehydrating and drying; generating potassium tripolyphosphate at 380-420°C; dissolving selenium dioxide in water to obtain Selenous acid, then slowly add potassium tripolyphosphate into selenous acid for chemical reaction, dehydration and deacidification at 250-300 ℃ compounded.

The inventor found through experiments that the molar ratio of K ₂ CO ₃ : H ₃ PO ₄ during the reaction is preferably 0.8-1.5: 1, and 1-1.3: 1 is the best; the molar ratio of SeO ₂ : K ₅ P ₃ O ₁₀ 1.5-2.2:1 is better, and 1.5-2.0:1 is the best.

The product of the present invention is a quick-acting phosphorus and potassium-based selenium-enriched fertilizer that can comprehensively and thoroughly improve the selenium content of plants. It can be well absorbed by plants, and the application method is also very simple and convenient. Foliar spraying and fertilization can obtain very ideal fertilization effects.

Detailed ways

The following examples are intended to illustrate the present invention without further limiting the invention.

Example 1

The raw materials are: _99.999 % selenium powder, nitric acid, potassium carbonate, phosphoric acid (all reagents of analytical grade), purified water. The selenium powder is added into the reactor to react with 30% nitric acid, and the product is concentrated, filtered, dried and thermally decomposed to obtain high-purity selenium dioxide. Then dissolve in water to obtain selenous acid. Potassium carbonate powder and 85% phosphoric acid were weighed according to the mass ratio of 1.667 (ie, the molar ratio was 1.2:1). First dissolve potassium carbonate in pure water at a ratio of 1:2, then slowly add phosphoric acid under stirring to carry out neutralization reaction, and then dehydrate and dry. Potassium tripolyphosphate is produced at 400°C. Then weigh selenium dioxide and potassium tripolyphosphate according to the mass ratio of 5: 13 (that is, the molar ratio is 1.8: 1). First, selenium dioxide is hydrolyzed into selenous acid to obtain a selenous acid concentration of 0.2 g/ml, and then potassium tripolyphosphate is slowly added into the selenous acid to carry out a chemical reaction. The reaction process is completed with stirring in the reactor of the heating device. After dehydration and deacidification, compound at 250-300°C to form the desired product. The product has been tested by the Analysis and Testing Center of Changsha Research Institute of Mining and Metallurgy (Report No.: FX061201-1). The test items are based on the content of SeO ₂ , P ₂ O ₅ , K ₂ O, and H ₂ O. The test basis is: atomic absorption spectrophotometry Determination of potassium content by method (GB6730.49-1986), determination of phosphorus content by phosphomolybdenum yellow spectrophotometry (GB8715-1988), sodium thiosulfate volumetric method (GB2124-1980), determination of combined water content by gravimetric method (GB/T14506.21993 ), the test results are: SeO ₂ 22.39%, P ₂ O ₅ 29.6%, K ₂ O 33.54%, and H ₂ O 14.32%.

Example 2:

Application experiment: 1. Experiment location: Anxi Xianghua Baoye tea production base in Fujian Province.

Subject of the experiment: Tieguanyin tea tree.

Experimental methods and results: 30 grams of selenium potassium phosphate compound was dissolved in organic farmyard manure and used as root fertilizer for winter festivals in 16 mu of tea gardens. The quality of "Gaoshan Tieguanyin" tea produced in 2006 has been significantly improved. The tea taste is more mellow, sweet and fresh, with a clear aroma, which is resistant to brewing and has a strong aftertaste. The price of high-grade tea per catty increased from 400 yuan to 800 yuan.

Test results: In 2006, the selenium content of spring tea samples was 0.43mg/Kg when tested by Changsha Jinduan Technology, and the selenium content of autumn tea samples was 0.44mg/Kg when tested by Hunan Provincial Analysis and Testing Center, both of which reached the national standard (national The standard is 0.3-5mg/Kg).

Example 3:

Application experiment: 1. Experiment location: Danjiahe Village, Quanmin Township, Xiatuopu, Ningxiang County, Hunan Province.

Experimental object: Tyou 210 late indica rice.

Experimental methods and results: 100 grams of selenium potassium phosphate compound, dissolved in 100 liters of water, is used as foliar fertilization for 2 mu of late rice. The rice plants grow upright and lush. The rice ears are golden in color, the grains are plump, the rice quality is white, and the taste is soft and fragrant.

Test results: In 2006, the late rice was sampled at multiple points in the field and sent to the Hunan Provincial Analysis and Testing Center for testing. The result was that the selenium content was 6.5mg/Kg, which fully met the 1992 (GB13105-91) national standard "Hygienic Standards for Selenium Content in Food".

Claims (4)

1. Potassium selenium phosphate compound, characterized in that its chemical molecular formula is K ₃ SeP ₃ O ₁₀ ·XH ₂ O, X=2-4. 2. The potassium selenium phosphate complex according to claim 1, characterized in that: 20-25% as _SeO2 , _26-30 % as _P2O5 , 30-35% as _K2O , and _H2O is calculated as 12-16%. 3. The preparation method of the potassium selenium phosphate complex, which is characterized in that: potassium carbonate is dissolved in water, and then phosphoric acid is slowly added under stirring for neutralization reaction, and dehydrated and dried; potassium tripolyphosphate is generated at 380-420°C; Selenium dioxide is dissolved in water to obtain selenous acid, and then potassium tripolyphosphate is slowly added to selenous acid to carry out a chemical reaction. It is compounded by dehydration and deacidification at 250-300°C; the raw material K ₂ CO ₃ in the reaction process: The molar ratio of H ₃ PO ₄ is 0.8-1.5:1; the molar ratio of SeO ₂ :K ₅ P ₃ O ₁₀ is 1.5-2.2:1. 4. Using the selenium potassium phosphate compound according to claim 1 as a compound fertilizer that can be applied to crops to increase the selenium content of crops.