阅读说明：本技术 一种钾硅钙缓释复合肥及其制备方法 (Potassium-silicon-calcium slow-release compound fertilizer and preparation method thereof ) 是由 张其武 刘岩矗 胡慧敏 顾纬键 于 2019-09-20 设计创作，主要内容包括：本发明涉及一种钾硅钙缓释复合肥及其制备方法,所述钾硅钙缓释复合肥由云母和氯化钙混合球磨得到,所述云母中钾元素与氯化钙中钙元素摩尔比为1：0.33～2。本发明提供的钾硅钙缓释复合肥具有速溶和缓释硅钾钙元素的效果,能够在植物不同生长期合理地分配供给养分,提升植物对养分的吸收率,并且避免了营养元素的浪费或者不足,该复合粉以工业废弃物云母粉末和氯化钙为原料,原料来源广泛、价格低廉,产品绿色环保无污染,缓解了目前水溶性钾硅资源不足的压力。(The invention relates to a potassium-silicon-calcium slow-release compound fertilizer and a preparation method thereof, wherein the potassium-silicon-calcium slow-release compound fertilizer is obtained by mixing and ball-milling mica and calcium chloride, and the molar ratio of potassium elements in the mica to calcium elements in the calcium chloride is 1: 0.33 to 2. The potassium-silicon-calcium slow-release compound fertilizer provided by the invention has the effects of quickly dissolving and slowly releasing silicon-potassium-calcium elements, can reasonably distribute and supply nutrients in different growth periods of plants, improves the absorption rate of the plants to the nutrients, and avoids the waste or deficiency of the nutrient elements.)

1. The potassium-silicon-calcium slow-release compound fertilizer is characterized by being prepared by mixing mica and calcium chloride and performing ball milling, wherein the molar ratio of potassium elements in the mica to calcium elements in the calcium chloride is 1: 0.33 to 2.

2. the slow-release potassium-silicon-calcium compound fertilizer as claimed in claim 1, wherein the mica comprises muscovite, phlogopite and biotite.

3. The potassium-silicon-calcium slow-release compound fertilizer as claimed in claim 1, wherein the ball milling process conditions are as follows: the ball milling speed is 200-600 rpm, and the ball milling time is 1-4 h.

4. A method for preparing the potassium-silicon-calcium slow-release compound fertilizer as defined in any one of claims 1-3, which comprises the following steps:

1) Carrying out element analysis on mica to determine the content of potassium;

2) according to the molar ratio of potassium element in mica to calcium element in calcium chloride of 1: 0.33-2, mica and calcium chloride are weighed and put into a ball mill for ball milling to obtain the potassium-silicon-calcium slow-release compound fertilizer.

Technical Field

the invention belongs to the field of agricultural compound fertilizer preparation, and relates to a brand-new preparation method of a compound fertilizer with coexistence of multi-element potassium, silicon and calcium instant dissolution and slow release performance.

Background

It is known that NPK is three essential elements for crops, and besides, the medium and trace elements such as silicon and calcium must be in sufficient quantities for crops to absorb. Especially for rice, the sufficient silicon element can improve the disease resistance and the yield of the rice.

At present, the silicon fertilizers applied in China mainly comprise three types, namely slag-dissolving silicon fertilizers (including slag silicon-calcium fertilizers, fly ash silicon-calcium fertilizers and the like), high-efficiency silicon fertilizers (including potassium silicate and sodium silicate) and silicon-containing compound fertilizers. However, the silicon fertilizer is too alkaline, and excessive application of the silicon fertilizer can accelerate mineralization loss of soil nitrogen. The heavy metal content of partial slag silicon fertilizer is higher, the harmful elements are more, and the secondary pollution is large. With the development of green agriculture, the production of green silicon fertilizer products by overcoming the defects is urgently needed.

The mica is a common silicate ore containing potassium, and usually contains 7-10% of K ₂ O and a large amount of silicon elements, and is easy to be excessively crushed in the processing process to generate a large amount of waste mica powder.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art, and provides a potassium-silicon-calcium multi-component slow-release compound fertilizer which is prepared by mixing mica powder, which is an industrial waste, as a raw material and performing ball milling on the mica and calcium chloride, wherein the quick dissolving and slow-release proportion of potassium and silicon elements in the mica is regulated and controlled by controlling the proportion of the calcium chloride and the mica, and the fertilizer can simultaneously release silicon, calcium and other nutrient elements, and has the advantages of good fertilizer effect, simple preparation process, no generation of toxic and harmful substances, economy and environmental protection.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

The potassium-silicon-calcium slow-release compound fertilizer is prepared by mixing mica and calcium chloride and performing ball milling, wherein the molar ratio of potassium elements in the mica to calcium elements in the calcium chloride is 1: 0.33 to 2.

According to the scheme, the ball milling process conditions are as follows: the ball milling speed is 200-600 rpm, and the ball milling time is 1-4 h.

according to the scheme, the mica comprises muscovite, phlogopite and biotite. The mica can be selected from low-grade mica or waste mica generated after industrial processing.

The invention also comprises a preparation method of the potassium-silicon-calcium slow-release compound fertilizer, which comprises the following specific steps:

1) carrying out element analysis on mica to determine the content of potassium;

2) According to the molar ratio of potassium element in mica to calcium element in calcium chloride of 1: 0.33-2, mica and calcium chloride are weighed and put into a ball mill for ball milling to obtain the potassium-silicon-calcium slow-release compound fertilizer.

The applicant discovers through research that calcium chloride and mica are mixed and ball-milled, the calcium chloride and the mica are subjected to Ca/K ion exchange reaction under the action of mechanical force ball milling, so that the dissolution rate of potassium ions in water is enhanced, the calcium chloride plays a role of a conventional instant potassium fertilizer, the calcium ions enter a structure along with the participation of the reaction, are difficult to dissolve in water, and can be completely dissolved in an acid solution, so that the calcium chloride has slow release performance, in addition, the whole structure of the mica is damaged through the mechanical force chemical action in the ball milling process, silicate radicals and potassium ions can be generated under the action of the calcium ions and hydrogen ions, the dissolution rate of potassium and silicon elements in the mica in acid is increased, and the effects of slow release potassium fertilizer and silicon fertilizer are achieved, and the specific reaction principle is shown in equation 1.

Si-O-K+H⁺→Si-O-H+K⁺ (1)

The instant part in the fertilizer is directly dissolved out for plants to absorb in the early stage of plant growth, the slow-release part cannot be dissolved in water, and the fertilizer can be dissolved out to provide nutrients for the plants only in an acidic environment caused by release of acidic substances such as citric acid and the like in the plant growth.

The calcium ²⁺ is a key regulator for plant growth and development, and participates in almost all aspects of plant development, and calcium salt is introduced to the production of fertilizers to greatly help the improvement of fertilizer efficiency, the application regulates the water-soluble proportion of potassium in mica by adjusting the addition amount of calcium chloride, the more the calcium chloride is added, the higher the water-soluble proportion of potassium in mica is, under the condition of less calcium chloride is added, calcium chloride basically completely reacts with mica, as the addition amount is increased, more and more calcium ions cannot participate in the reaction and are dissolved in an aqueous solution for plant absorption, the calcium ions can be added to form silicate with silicate roots, calcium metasilicate is converted into calcium metasilicate to enhance the solubility of silicon elements by increasing the calcium ions, so the solubility of the silicon elements is enhanced by introducing the calcium chloride, the fertilizer efficiency of a silicon fertilizer is further improved, the ingredients are prepared according to the molar ratio of the potassium elements in the mica to the calcium element in the calcium chloride of 1: 0.33-2, nutrients can be reasonably distributed and supplied to improve the absorption rate of the plant to the nutrient elements of the plant to improve the plant to the nutrient consumption of the plant, the calcium salt is continuously reduced, and the calcium salt is added to prevent the calcium salt from being added to the calcium salt, the calcium salt is increased to prevent the calcium salt from being added to the calcium salt, and the calcium salt from being increased to the calcium salt, and the calcium salt is.

The invention has the beneficial effects that: 1. the potassium-silicon-calcium slow-release compound fertilizer provided by the invention has the effects of quickly dissolving and slowly releasing silicon-potassium-calcium elements, can reasonably distribute and supply nutrients in different growth periods of plants, improves the absorption rate of the plants to the nutrients, and avoids the waste or deficiency of the nutrient elements; 2. the invention prepares the potassium-silicon-calcium multi-component compound fertilizer by ball milling in one step, the preparation process is simple, no other additives are needed in the whole reaction process, the obtained product after the reaction is nontoxic and harmless, the potassium-silicon-calcium multi-component compound fertilizer can be directly used as the potassium-silicon-calcium multi-component compound fertilizer, the instant effect of the potassium element in mica can be regulated and controlled by regulating the addition amount of calcium chloride, and the compound fertilizer with the required potassium element instant and slow release proportion is prepared for different crops.

Drawings

FIG. 1 is a graph showing the dissolution rates of potassium element in deionized water and 2% citric acid solution in a sample obtained by ball-milling muscovite as it is in example 1 at different rotation speeds;

FIG. 2 is a graph showing the change in pH of the solution of the muscovite mica of example 1 after being ball-milled at different speeds and dissolved in deionized water;

FIG. 3 is a graph showing the dissolution rates of silicon element in deionized water and 2% citric acid solution in the sample obtained by ball-milling muscovite mica at different rotation speeds as it is in example 1;

FIG. 4 is a graph showing the dissolution rates of potassium in deionized water and 2% citric acid in samples obtained after ball milling of a mixture of calcium chloride and muscovite mica at different Ca/K ratios at 600rpm in example 2;

FIG. 5 is a graph showing changes in pH values of solutions of samples obtained after ball milling of a mixture of calcium chloride and muscovite at 600rpm at different Ca/K ratios in example 2, dissolved in deionized water;

FIG. 6 is a graph showing the residual ratio of calcium in the residue after dissolution in deionized water or a 2% citric acid solution of samples obtained after ball-milling a mixture of calcium chloride and muscovite mica at 600rpm at different Ca/K ratios in example 2;

FIG. 7 is the Ca content of the mixture of calcium chloride and muscovite mica of example 3: k is 0.5: 1, heating supernatant crystal and water-soluble sediment of the ball-milled sample after water dissolving at 1100 ℃ for 2 hours to obtain an XRD (X-ray diffraction) spectrum of a product;

FIG. 8 shows the muscovite as such and the calcium chloride and muscovite ratios as Ca: k is 2: 1 comparative graph of the dissolution rate of silicon measured in deionized water and 2% citric acid solution after ball milling of the samples obtained.

Detailed Description

in order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention is further described in detail with reference to the following examples.