Granular Fertilizer Stability via Magnesium Oxide Mediator
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Solution Overview
Problem
Current processes for granulating potassium chloride and magnesium sulphate hydrates fail to produce granulates with adequate mechanical stability and high breaking strength, often resulting in low water availability of magnesium to plants, especially when using synthetically produced magnesium sulphate monohydrate or 5/4-hydrate.
Innovation Solution
A process involving granulation of a mixture consisting mainly of potassium chloride, magnesium sulphate hydrate, and water-insoluble magnesium oxide, such as calcined magnesite, without the need for organic binders, to produce granulates with a potassium content of 35 to 50% and water-soluble magnesium content of 2 to 10%, enhancing mechanical stability and magnesium availability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional granulation processes are used for potassium chloride and magnesium sulphate hydrates, then granular material is produced, but the granulates lack adequate mechanical stability and breaking strength
Solution Approach 1:
Magnesium oxide acts as an intermediary substance that facilitates granulation without requiring organic binders. It promotes particle adhesion and granulate formation through its unique properties, serving as a mediator between the salt particles and the granulation process, thereby achieving adequate mechanical stability without compromising granulate reliability
Solution Approach 2:
The invention changes the physical and chemical parameters of the granulation process by using magnesium oxide instead of conventional organic binders. This parameter change - substituting the binding mechanism - results in granulates with improved mechanical stability and breaking strength while maintaining granulate stability
2Reliability
If organic binders are used for granulation, then granulate stability improves, but cost increases and other properties are negatively affected
Solution Approach 1:
The invention extracts and removes organic binders from the granulation process, replacing them with magnesium oxide. This extraction eliminates the need for costly organic substances while maintaining granulate stability, thereby improving ease of manufacture and avoiding negative effects on other properties
Solution Approach 2:
Magnesium oxide serves as a cost-effective alternative to expensive organic binders. Although magnesium oxide requires specific handling, it provides a economical solution that maintains granulate stability without the high costs and property compromises associated with organic binder systems
3Productivity
If synthetically produced magnesium sulphate monohydrate or 5/4-hydrate is used, then granulates are produced, but magnesium availability to plants is reduced
Solution Approach 1:
The invention creates a composite granulate material containing potassium chloride, magnesium sulphate hydrate, and magnesium oxide. This composite structure combines different magnesium compounds to achieve both adequate water solubility for plant availability and improved granulate stability, resolving the contradiction between productivity and reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting granulates exhibit improved mechanical stability, low abrasion, and high breaking strength, with a significant proportion of magnesium becoming immediately available to plants, surpassing the performance of granulates produced by existing methods.
Implementation Method 1
Granulations are frequently performed in the presence of binders. The latter can be liquid or solid substances whose adhesive strength makes the particles cohere.
Implementation Method 2
A process involving granulation of a mixture consisting mainly of potassium chloride, magnesium sulphate hydrate, and water-insoluble magnesium oxide, such as calcined magnesite
Implementation Method 3
Mixtures of potassium chloride and magnesium sulphate hydrates are widely used in farming as a combined potassium and magnesium fertilizer, especially as both salts are completely water-soluble and hence quickly available to the plants after the fertilizer is spread
Data Source
AI summary
Granulates which mainly consist of potassium chloride, at least one magnesium sulphate hydrate and magnesium oxide, as well as, if applicable, one or more salts chosen from sodium chloride and sodium sulphate, in which the potassium content, calculated as K2O ranges from 35 to 50 % by weight and the content of water-soluble magnesium, calculated as MgO(water-soluble), ranges from 2 to 10 % by weight, in each case referring to the granulates.