The national standard of fertilizer grade potassium chloride will be officially implemented on March 1, 2020

Recently, the State Administration for Market Regulation (National Standardization Administration) approved the "National Standard for Fertilizer Grade Potassium Chloride GB/T 37918-2019" and announced its formal implementation on March 1, 2020
.
The standard increases the potassium oxide content index from 55%-60% to 57%-62%; the moisture content has been reduced by more than 2 times; the first time limit for the content of "impurities" such as sodium ions and water insolubles has been introduced
.
Compared with the current "Agricultural Potassium Chloride Standard GB 6549-2011", the new standard directly points to indicators that affect the quality, grade and cost of potassium chloride products.
The purpose is to improve grade, squeeze moisture, and reduce "impurities", which will help To improve the quality and fertilizer efficiency of potassium chloride
.
These new standards by the Shanghai Research Institute of Chemical Co.
, Ltd.
, Qinghai Salt Lake Industry Co.
, Legg Mason agricultural (Beijing) Co.
, Ltd.
, Shanghai Institute of Chemical Testing Co.
, Ltd.
drafted
.
? Potassium oxide content increased by 2%-3%.
Extrusion of moisture to reduce fertilizer agglomeration.
The standard implemented on June 1, 2012 divided agricultural potassium chloride into three categories: high-quality products, first-class products, and qualified products
.
The difference is that the newly promulgated standard is not classified according to the above grade names, but divides potassium chloride fertilizers into two types: powder crystalline and granular, corresponding to three types of type I, type II, and type III.
, And the technical indicators have been greatly improved
.
The new standard stipulates that the contents of granular potassium and powder crystal potassium type I, type II, and type III potassium oxide are ≥62%, ≥60%, and ≥57%, respectively.
These three levels of indicators are higher than those of agricultural potassium chloride superior products (≥ 60%), first-class products (≥57%), qualified products (≥55%) 2-3%, which is conducive to improving the grade and quality of potassium chloride, preventing low-grade potassium chloride from flooding the market, and maintaining the stable and healthy development of the industry
.
? In the new standard, the moisture content has the most obvious change, and the index has been reduced exponentially
.
In the agricultural potassium chloride standard, the moisture content indexes of superior products, first-class products, and qualified products are ≤2%, ≤4%, and ≤6% respectively
.
The new standard stipulates that the water content of powder crystal potassium type Ⅰ, type Ⅱ, and type Ⅲ are ≤1%, ≤2%, and ≤3% respectively, and the water content of granular potassium type Ⅰ, Ⅱ and type Ⅲ are ≤0.
3%, ≤ 0.
5%, ≤1%
.
In particular, the moisture content of granular potassium premium products shall not exceed 0.
3%, which is only 15% of the original agricultural potassium chloride standard
.
Strict control of the water content in potassium chloride has production and agricultural considerations
.
Moisture content is the biggest factor in the caking of potassium chloride and other fertilizers during storage, which brings many difficulties to use
.
The higher the moisture content, the easier it is to dissolve the salt in the fertilizer particles, and the easier it is for physical and chemical reactions to occur.
After recrystallization, agglomerations are easily formed.
Repeated dissolution-crystallization processes will cause serious agglomeration
.
In actual agricultural production, chemical fertilizers that are easy to agglomerate are not only troublesome for disassembly and assembly, but also need to be smashed with a hammer and stick to be applied.
At the moment when mechanized fertilization is widely promoted and applied, it is obviously not the first choice of distributors and growers, which affects enterprises.
Brand reputation
.
In addition, the article "The Effect of Potassium Chloride Raw Materials on Compound Fertilizer Agglomeration" published in the "Phosphorus and Compound Fertilizer" magazine in 2015 also pointed out that the use of potassium chloride with excessive moisture content as a raw material to produce compound fertilizers is also the latter stacking An important factor for caking appears within 5-7 days
.
However, the new standard reduces the water content from 6% to 1%, 3% or even 0.
3%, and the nutrient content increases simultaneously.
Although the quality of potassium chloride has been further improved, from a production point of view, it will increase enterprises to a certain extent.
Cost
.
For the first time, the two major indicators issued "impurities" to give a limited amount of sodium chloride (salt) and water insolubles are all "impurities" in potash fertilizer
.
Excessive "impurities" are harmful factors to farmland soil and crops, and it is also a main technical indicator for the quality and grade of potassium chloride fertilizer
.
In agricultural production, too much "salt" content in the soil will lead to soil salinization and compaction
.
Shang Zhaocong, deputy director of the National Fertilizer Quality Supervision and Inspection Center (Shanghai), once stated at the "2014 China Potash Industry Standards Seminar" that excessive sodium ions in the soil cause salt stress damage to plants, and "burning seedlings" in some areas , Which seriously affects the growth and development of crops, so the sodium content in potassium chloride, a bulk fertilizer, should be reasonably limited
.
In the new standard, the sodium chloride content in fertilizer grade potassium chloride is clearly defined for the first time as type I ≤ 1.
0, type II ≤ 3.
0%, and type III ≤ 4.
0%
.
Water-insoluble matter refers to the impurity of potassium chloride fertilizer that is insoluble in water.
The main components are sand, clay, calcium and magnesium carbonates and organic residues, etc.
, which affect the quality of potassium chloride
.
The new standard limits the content of water-insoluble matter to ≤0.
5% (Type Ⅰ, Type Ⅱ) and ≤1.
5% (Type Ⅲ)
.
However, the currently implemented "Agricultural Potassium Chloride National Standard GB6549-2011" does not limit the sodium chloride content in potassium chloride
.
At the same time, the current limit on the potassium oxide content in the qualified agricultural potassium chloride products is low, which will cause some impurities to enter the soil and deteriorate the ecological environment, which is not conducive to the efficient use of resources or even waste
.